Seznam účastníků semináře fyz.chemie · 1.3. Poster Instructions The poster session will be...

Welcome to

CALPHAD XXXVIII

May 17 – 22, 2009

Prague, Czech Republic

Organized by

Masaryk University, Brno, Czech Republic

and

Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Brno, Czech Republic

Organizing Committee Jan Vřešťál Masaryk University, Brno Aleš Kroupa Institute of Physics of Materials, ASCR, Brno Mojmír Šob Masaryk University, Brno Pavel Brož Masaryk University, Brno Jiří Sopoušek Masaryk University, Brno Jindřich Leitner University of Chemical Technology, Prague František Chmelík Charles University, Prague Adéla Zemanová Institute of Physics of Materials, ASCR, Brno Jana Pavlů Masaryk University, Brno

It is hard to believe, but Prof. Jan Vřešťál, the chairman of the CALPHAD XXXVIII Organization Committee, is 70 years of age this year. He was born on February 16, 1939 in Brno, Czechoslovakia (as it was known at that time) and managed to become a distinguished scientist and colorful personality despite the difficult times that he has lived through. He studied Analytical Chemistry at the J.E. Purkyne University in Brno from 1956 to 1961 (renamed at that time after the renowned Czech scientist J.E. Purkyne for political reasons; it was originally known as the Masaryk University and has obtained this name again in 1990). He worked at the Institute of Physics of Materials from 1963 to 1991, but for political reasons he wasn’t allowed to defend his PhD. thesis until 1984. He

has been working at the Masaryk University since 1992, became Assoc. Professor there in 1993 and full professor in 1996. He also earned the title D.Sc. in 1994. He has been the Head of the Department of Physical Chemistry and the leading personality behind striving towards the high scientific standards that this Department has enjoyed at this renowned university, successfully removing all remnants of the politically controlled education system of the past. He has been part-time Senior Researcher and Professor since 2004; still very active in research and teaching both at national and international level. His research interests cover the thermodynamics of metals and alloys, the modeling of thermodynamic functions and phase diagrams using the CALPHAD method and ab-initio approach, mass spectrometry and calorimetry. He has published more than 100 papers in internationally recognized journals and has presented more than of 150 contributions at international conferences. He is a member of the Alloy Phase Diagram International Commission (APDIC), a member of the editorial board of The Metallic Materials journal and an important member in many national and international research teams. Jan is a great personality. He remains a very active, hard working scientist of the utmost integrity, an outstanding teacher and organizer, congenial colleague and friend. He was the driving force behind the “Brno thermodynamics group”, persuading the CALPHAD advisory board to entrust him with the organization of this year’s CALPHAD meeting, despite the fact that he and his coworkers were newcomers to the community in 1996. He has devoted his life not only to science; he has been a keen sportsman and coach, spending much of his rare spare time participating in cross-country skiing competitions and successfully introducing new generations of skiers, who are not only excellent in their field but also share Jan’s honesty and fairness in their endeavors. For all of his colleagues and friends, Jan remains valuable source of ideas, enviable activity and indefatigable energy. Despite his “young age”, he pushes his colleagues and friends (mostly significantly younger) into many new activities, making it very difficult for them to accept the embarrassing fact that he is more active than they are. Nevertheless, they know very well that they can always rely on him, and that he will always offer a helping hand when asked. Dear Jan, all your friends and colleagues from the scientific community wish you many happy and active years and look forward to seeing you at many future CALPHAD conferences!

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Table of Contents

1. General Information ............................................................................................... 2 1.1. Conference Location ......................................................................................... 2 1.2. Registration and Information ............................................................................ 2 1.3. Poster Instructions ............................................................................................ 3 1.4. Social Program .................................................................................................. 3 1.5. Currency Exchange ........................................................................................... 5 1.6. Internet Service ................................................................................................. 5 1.7. Taxi Services..................................................................................................... 5

2. Conference Program ............................................................................................... 6 2.1. Sunday, May 17, 2009 ...................................................................................... 6 2.2. Monday, May 18, 2009 ..................................................................................... 7 2.3. Tuesday, May 19, 2009 ..................................................................................... 9 2.4. Wednesday, May 20, 2009 ............................................................................. 11 2.5. Thursday, May 21, 2009 ................................................................................. 12 2.6. Friday, May 22, 2009 ...................................................................................... 15

3. Oral Presentation Abstracts ................................................................................ 17 4. Poster Presentation –List of Authors and Abstracts ......................................... 85

4.1. Poster Session I - List of Authors ................................................................... 86 4.1.1 Poster Session I - Abstracts ......................................................................... 91

4.2. Poster Session II - List of Authors ............................................................... 135 4.2.1. Poster session II - Abstracts ........................................................................ 141

5. List of CALPHAD Scholarship Recipients ....................................................... 187 6. List of participants .............................................................................................. 189 7. Autor index .......................................................................................................... 201

CALPHAD XXXVIII General Information

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1. General Information

1.1. Conference Location The Pyramida Hotel, Prague is within walking distance of Prague Castle in a quiet residential area of Prague. It is 10 km from Prague airport. Prague is well known for its Castle and well-preserved medieval old town, its Jewish quarter, and many museums, galleries and parks. The hotel contact information: OREA Hotel Pyramida Belohorska 24 169 01 Praha 6, Czech Republic tel.: +420 233 102 111 Map 1

The conference sessions will be held in the Conference hall of the hotel

1.2. Registration and Information The registration desk will be open in the hotel lobby on: Sunday, May 17, 15:00-18:00 Monday, May 18, 8:30-18:00


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1.3. Poster Instructions The poster session will be held in the Conference Hall. The ideal dimensions of the poster are 100 cm (width) x 150 cm (height) - portrait orientation. The pins will be available in the poster room. Because of large number of registered contributions, there will be TWO POSTER SESSIONS during the conference. The submission of concrete posters to individual sessions is shown in the Chapters 4.1 and 4.2. The authors, presenting their posters in the Session 1 are kindly requested to exhibit their posters on Monday morning and remove them till Wednesday morning. The authors belonging to the Session 2 are kindly requested to exhibit their posters on Wednesday morning and remove them after the Thursday poster session.

1.4. Social Program Sunday May 17 19:00-22:00 Welcome dinner at Kopernik restaurant ____________________________________________________________________ Monday May 18 10:00 Accompanying person program Prague guided trip (duration 5 hours) ____________________________________________________________________ Tuesday May 19 9:00 Accompanying person program Kutná Hora - UNESCO world heritage

city (duration 8 hours) 19:30-21:30 All participants Evening concert in Aula Carolina of

Charles University in Old Town Prague. Address of the hall is Ovocny Trh 3, Prague 1.

There will be no organized transport to the concert hall. The location of the hall is shown on the map below. It is located directly in the city centre and the simplest way how to get there is to take tram no 22 from the “Malovanka” station (close to the hotel) to the "Národní třída" station (scheduled travel time 21 minutes). From “Národní třída” Station you can go through streets "Na Perštýně, Martinská, Uhelný trh, Rytiřská" to “Ovocný trh” square. The distance is approx. 600 m.


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Map 2

Map 3

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Wednesday May 20 13:30- 22:00 All participants Conference excursion to Karlštejn

Castle, a medieval castle founded by Charles IV, in the afternoon, followed by the Conference Banquet in Strahov Monastery, Prague in the evening. (details will be announced)

_____________________________________________________________________ Thursday May 21 10:00 Accompanying person program Konopište Castle - the castle of Franz

Ferdinand d'Este (duration 5 hours) The swimming pool

The swimming pool (11 by 7 meters, depth of 1.6 m) is located on the ground floor. Water temperature is 28 °C, air has 29 °C. The glass walls of the pool open to Střešovice, Prague’s residential quarter dotted with several architectonical gems. The swimming pool will be reserved free of charge for the CALPHAD participants every morning from 07:30 to 08:00. Otherwise following prices apply: Mo – Fri 2:00 PM – 10:00 PM, Sat, Su. CZK 100,- (60 minutes) Mo – Fri 9:00 AM – 2:00 PM CZK 90,- (60 minutes) ____________________________________________________________________

1.5. Currency Exchange All major credit cards are accepted, the currency can be exchanged in the hotel, in all banks or in street exchange booths. We recommend using the bank services.

1.6. Internet Service Internet connection is available in the hotel premises. Detailed information will be provided at the registration desk.

1.7. Taxi Services We recommend using the hotel service to arrange for the taxi and especially for the airport service.

CALPHAD XXXVIII Conference Program

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2. Conference Program

2.1. Sunday, May 17, 2009 15:00 – 18:00 Registration, Hotel Pyramida, hotel lobby 19:00 – 22:00 Welcome dinner at Kopernik restaurant


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2.2. Monday, May 18, 2009 8:30 – 18:00 Registration, Hotel Pyramida, hotel lobby 9:00 – 9:15 Opening ceremony 9:15 – 10:45 Session I: Ab initio Modelling Chairs: Andre Costa e Silva, Ursula Kattner 9:15 – 9:45 P. E. A. Turchi, A. I. Landa, P. Söderlind, L. Kaufman

Thermodynamics of actinide alloys – results and challenges 18 9:45 - 10:15 M.Y. Lavrentiev, D. Nguyen-Manh, S. L. Dudarev

Modelling the Fe-Cr phase diagram: the first-principles magnetic cluster expansion formalism versus CALPHAD data analysis 19

10:15 – 10:45 T. Mohri

Lattice relaxation effects on the phase equilibria investigated by CVM 20

10:45 – 11.15 Coffee break 11:15 – 12:35 Session II: Ab initio and Atomistic Modelling Chairs: Koretaka Yuge, Claudio Geraldo Schon 11:15 – 11:35 K. Masuda-Jindo, V. Van Hung, P.E.A Turchi

First principles calculations of phase diagrams of solidus and liquidus Mo-Ta-W alloy systems by ´thermodynamic variational principles 21

11:35 – 11:55 Y. Liu, C. Colinet, J-C. Tedenac

Thermodynamic modelling of the Ga-Ti system 22 11:55 – 12:15 G. Shao

An energetic study of transition metal silicides by DFT 23 12:15 – 12:35 K. W. Richter

On the prediction of site preferences in structurally complex metal compounds 24

12:35 – 14:00 Lunch 14:00 – 15:30 Session III: First Principles Magnetic Properties Modelling Chairs: Patrice Turchi, Rafal Kozubski 14:00 – 14:30 Z-K. Liu

Magnetic properties through quantum statistics, and modelling 25


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14:30 – 14:50 J. Pavlů, J. Vřešťál, M. Šob

Energetics and magnetism of Cr-based sigma phases 26 14:50 – 15:10 J. E. Saal, S. Shang, Y. Wang, Z.-K. Liu

Predicting the curie temperature of FCC Co from a statistical/first-principles approach 27

15:10 – 15:30 K. Yuge

Cluster expansion approach for variable lattice systems 28 15:30 – 16:00 Coffee break 16:00 – 17:50 Session IV: Thermodynamic Databases – Hydrogen Containing Systems Chairs: Alan Dinsdale, Andy Watson 16:00 – 16:30 U. R. Kattner

A thermodynamic database for Laves phase - hydrogen systems 29

16:30 - 16:50 K. Bai, P. Wu

Chemical potential phase diagrams and the reversible reactions of hydrogen storage material systems 30

16:50 – 17:10 M. Palumbo, T. Abe, C. Kocer, H. Murakami, H. Onodera

A thermodynamic and first principles revision of the ternary Cr-Ni-Re system 31

17:10 – 17:30 M. Paliwal, I.-H. Jung

Thermodynamic modelling of Mg-Bi and Mg-Sb systems and short-range-ordering behaviour of the liquid solutions 32

17.30 – 17:50 Q. Chen, X. G. Lu, H. Strandlund, A. Engström

Precipitation simulation of Al3(ScxZr1-x) in aluminium alloys 33

17:50 – 19:00 POSTER SESSION I 85 19:00 – 20:30 Dinner 20:30 – 22:00 POSTER SESSION I (cont.) 21:00 – 23:00 Conference of young scientists (Lounge No.3, Organizer:

In-Ho Jung)


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2.3. Tuesday, May 19, 2009 9:00 – 10:40 Session V: Ab initio Computations of Phonons Chairs: Mojmír Šob, Tetsuo Mohri 9:00 – 9:30 X. Gonze

First-principles computation of phonons and thermodynamical properties with ABINIT 34

9:30 - 10:00 K. Parlinski

Ab initio calculations of crystalline materials by Phonon software 35

10:00 – 10:20 D. Belmonte, G. Ottonello, M. Vetuschi Zuccolini

Ab-initio thermal expansion, the mode-gamma analysis in the quasi-harmonic approximation: some examples of application in the Mg-Si-O system 36

10.20 – 10:40 S. R. Nishitani

Vibrational contribution on free energy change in binary system 37

10:40 – 11.10 Coffee break 11:10 – 12:50 Session VI: Ab initio Modelling of Diffusion Phenomena Chairs: Klaus Richter, Jana Pavlů 11:10 – 11:30 R. Kozubski, A. Biborski, V. Pierron-Bohnes

Equilibrium vacancy concentration in B2-ordering AB binary systems: Semi Grand Canonical Monte Carlo (SGCMC) simulations 38

11:30 – 11:50 C. G. Schön

Challenges in the Monte Carlo modeling of vacancies in BCC iron 39

11:50 – 12:10 M. Klähn, A. Seduraman, P. Wu

Molecular simulations of ionic liquids: From the charge distribution in the liquid to a new model for self-diffusion 40

12:10 – 12:30 M. H. F. Sluiter, D. Simonovic

Ab initio prediction of impurity diffusion in aluminum 41 12:30 – 12:50 M. Kajihara, T. Asano

Composition dependence of kinetics for solid-state reactive diffusion between Sn and Ni-Fe alloys 42

12:50– 14:00 Lunch


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14:00 – 15:30 Session VII: First Principles and Thermodynamic Modelling of Systems with Interstitials

Chairs: John Agren, Susan Meschel 14:00 – 14:30 L. Kaufman, G. Cacciamani, M.L. Muolo, F. Valenza and A. Passerone

CALPHAD descriptions and experimental studies of the Ni-HfB2 system 43

14:30 – 14:50 B. Hallstedt

Thermodynamic modeling of ternary phase diagrams containing MAX-phases 44

14:50 – 15:10 A. Costa e Silva, R. Avillez

Precipitation of intermetallics in duplex stainless steels – a kinetic evaluation 45

15:10 – 15:30 U. Hecht, V. Witusiewicz, J. Zollinger, L. V. Artyukh, N. I. Tsyganenko, A. A. Bondar

Thermodynamic description of the Al-B-Nb-Ti system and its application to TiAl-based alloys 46

15:30 – 16:00 Coffee break 16:00 – 17:20 Session VIII: Experimental Thermodynamics Chairs: Zbigniew Moser, Kiyohito Ishida 16:00 – 16:20 H. Flandorfer, C. Schmetterer

Experimental data for CALPHAD 47 16:20 - 16:40 D. Kevorkov, M. Medraj, J. Li, E. Essadiqi, M. Aljarrah, P. Chartrand

Experimental study of the Al-Mg-{Ca,Sr} ternary phase diagrams at 400ºC and comparison with thermodynamic models 48

16:40 – 17:00 M. Medraj, S. W. Rahman, D. Kevorkov, J. Li, E. Essadiqi, Y. Zhang, S. Konica and P. Chartrand

Thermodynamic modelling and experimental investigations of the (Mg, Al)- Ca-Zn system 49

17:00 – 17:20 S. V. Meschel, P. Nash, Q. X. Chen

The standard enthalpies of formation of some binary intermetallic compounds of late 4d and 5d transition metals by high temperature direct synthesis calorimetry 50

17:20 – 18:30 Dinner 19:30 – 21:30 Concert in Aula Carolina (Prague Old Town)


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2.4. Wednesday, May 20, 2009 9:00 – 10:30 Session IX: Thermodynamic Modelling Chairs: Byeong-Joo Lee, Bengt Hallstedt 9:00 – 9:30 J. Gröbner, R. Schmid-Fetzer

Solidification paths and stability of precipitates in Mg-Al-Zn-Mn alloys modified by Ca, Ce, Si, Sr and Sn 51

9:30 – 9:50 N. I. Il'inykh, T. V. Kulikova, P. S. Golubeva

The use of thermodynamic simulation for studying of composition and properties of materials for microelectronics 52

9:50 – 10:10 Ch. Tang, Y. Du, J. Wang, H. Zhou, L. Zhang, J. Lee

Correlation between thermodynamics and glass forming ability in the Al-Ce-Ni system 53

10:10 – 10:30 L. Zhang, Y. Du, J. Wang, R. X. Hu, P. Nash, X.-G. Lu. Reassessment of the Al–Fe–Ni system via a hybrid approach of ab initio calculations, calorimetry and CALPHAD 54

10:30 – 11.00 Coffee break 11:00 – 12:20 Session X: Thermodynamic Modelling of Al-containing Systems Chairs: Rainer Schmid-Fetzer, Gabriele Cacciamani 11:00 - 11:20 A.Ullah Khan, X. Yan, A. Grytsiv, P. Rogl, A. Saccone

On the four-phase reactions in the Ti-Ni-Al system 55

11:20 – 11:40 V. T. Witusiewicz, A. A. Bondar, U. Hecht, J. Zollinger, V. M. Petyukh, V. M. Voblikov, T. Ya. Velikanova

Experimental study and thermodynamic modelling of the ternary Al-Ta-Ti system 56

11:40 – 12:00 T. Abe, M. Ode, C. Kocer, Y.Yamabe-Mitrai, H. Murakami

Thermodynamic assessment of the Al-Ir-Ni ternary system 57 12:00 – 12:20 D. M. Cupid, O. Fabrichnaya, F. Ebrahimi, H. J. Seifert

Phase equilibria in the Ti–Al–Nb–Mo system 58 12:20 – 13:30 Lunch 13:30 – 18:30 Conference excursion 19:00 – 22:00 Conference banquet


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2.5. Thursday, May 21, 2009 9:00 – 10:50 Session XI: Thermodynamics of Lead-free Solder Systems Chairs: Hans Flandorfer, Aleš Kroupa 9:00 – 9:30 Z. Moser, K. Bukat ,W. Gąsior , J. Sitek, M. Kościelski, J. Pstruś

Effect of Bi and Sb additions on wettability of Sn-Zn solders 59

9:30 - 9:50 D. Giuranno, S. Delsante Y. Eichhammer, S. Amore, F. Valenza, R. Novakovic

Thermodynamics and thermophysical properties of liquid Au-Ge alloy 60

9:50 – 10:10 V. Chidambaram, J, Hald, J, Hattel, R. Ambat

Assessment of potential solder candidates for high temperature applications 61

10:10 – 10:30 R. Čička, M. Ožvold, A. Zemanova, A. Kroupa, J. Lokaj, J. Janovec

Study of Ce - Sn binary system 62 10.30 – 10:50 J. Wang, C. Leinenbach, M. Roth

Thermodynamic modeling of the Au-Ge-X (X = Sb, Si, Sn) systems 63

10:50 – 11.20 Coffee break 11:20 – 12:40 Session XII: Challenges in Thermodynamic Modelling Chairs: Zi-Kui Liu, David Sedmidubský 11:20 – 11:40 D. V. Malakhov, M. Hosseinifar

Can a physical unsoundness of a solution model be detected prior to launching a thermodynamic optimization? 64

11:40 – 12:00 G. Kaptay

On a boundary condition for excess Gibbs energy of solution phases at an infinite temperature 65

12:00 – 12:20 V. Lutsyk, V. Vorob’eva

From topology to computer model: ternary systems with polymorphism 66

12:20 – 12:40 M. Jiang, H. X. Li, I. Ohnuma, K. Oikawa, K. Ishida

A thermodynamic description of the order-disorder transitions in a multi-component fcc solid solution 67

12:40 – 14:00 Lunch


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14:00 – 15:30 Session XIII: Ab initio Modelling and Phase Field Simulations Chairs: Andre Schneider, Peter Rogl 14:00 – 14:30 L. Zhang, Y. Du

Phase field simulation of solidification in Al-Ni alloys coupled with thermodynamic and atomic mobility databases 68

14:30 – 14:50 T. Miyazaki, T. Kozakai, C. G. Schön

A mechanism of precipitate-nucleation in the so-called “N-G region” of equilibrium phase diagram 69

14:50 – 15:10 D. H. Kim, H. Y. Kim, J. H. Ryu, H. M. Lee

Phase diagram of the Ag-Pd bimetallic nanoclusters: Practical guideline for nano-material designs 70

15:10 – 15:30 B-J. Lee and E. H. Kim

Molecular statics - Monte Carlo – molecular dynamics hybrid simulation for atomistic structural evolution in interstitial alloys 71

15:30 – 16:00 Coffee break 16:00 – 18:00 Session XIV: Thermodynamics of Non-metallic Systems Chairs: Torsten Markus, George Kaptay 16:00 – 16:20 O. Fabrichnaya, H.J. Seifert

Thermodynamic modelling based on experimental study of the ZrO2-La2O3-Y2O3 system 72

16:20 - 16:40 M. Chen, E. Povoden, J. Østby

Development of the oxide database for the SOFC applications 73 16:40 – 17:00 A. Seko, A. Togo, F. Oba, I. Tanaka

Structure and phase stability of nonstoichiometric compounds of tin oxides 74

17:00 – 17:20 Sh. Tursunbadalov, L. Soliev

Determination of phase equilibria in the Na,K//SO4,CO3, HCO3–H2O system at 0°С 75

17:20 – 17.40 D. Kobertz, I. Dreger, M. Müller

Restudy of the quasi-binary system Na2SO4 – K2SO4 by Differential Thermal Analysis (DTA) and Thermo gravimetry (TG) 76

17:40 – 18.00 J.-M. Joubert, S.-A. Farzadfar Modelling topologically close-packed phases: application to the Mo-Re system 77


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18:00 – 19:00 POSTER SESSION II 135 19:00 – 20:30 Dinner 20:30 – 22:00 POSTER SESSION II (cont.)


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2.6. Friday, May 22, 2009 9:00 – 10:00 Session XV: Thermodynamics of Nuclear Materials Chairs: Olga Fabrichnaya, Jean-Marc Joubert 9:00 – 9:20 D. Sedmidubský, P. Souček, R. J. M. Konings

Ab-initio calculations and phase diagram assessments of An-Al systems, An=U, Np, Pu 78

9:20 – 9:40 V. Tyrpekl, P. Piluso, S. Bakardjiev, J. L. Rehspringer, D. Nižňanský

Nuclear fuel coolant interaction and material effect: thermodynamics at equilibrium and out of equilibrium 79

9:40 – 10:00 S. Chatain, C. Guéneau, J. L. Flèche

Thermodynamic modelling of the uranium-fluoride system 80 10:00 – 10:30 Coffee break 10:30 – 11:50 Session XVI: Miscellaneous Chairs: Marko Hämäläinen, Rada Novakovic 10:30 – 10:50 S. Bhattacharjee, Ch. P. Paolini

An extended state module of TEST web application for property evaluation of gas mixtures 81

10:50 – 11:10 M. Friák, M. Šob

Ab initio analysis of pressure-induced bcc-hcp transformation in iron 82

11:10 – 11:30 J. Pavlů, J. Vřešťál, M. Šob

Stability of Laves phases in the Cr-Ti and Cr-Hf systems 83 11:30 – 11:50 G. Adjanor, M. Athènes

Computing the phase diagram of the FeCr binary alloy by path-sampling techniques 84

11:50 – 12:00 Closing Ceremony 12:00 – 13:00 Lunch


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CALPHAD XXXVIII

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3. Oral Presentation Abstracts

CALPHAD XXXVIII Abstracts - Monday

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Thermodynamics of Actinide Alloys – Results and Challenges P. E. A. Turchi a, A. I. Landa a, P. Söderlind a, Larry Kaufman b a Lawrence Livermore National Laboratory, P. O. Box 808, Livermore CA 94551, USA b 140 Clark Road, Brookline, MA 02445-5848, USA

The prediction of phase stability trends and phase diagrams of multi-component complex alloys is undoubtedly the Holy Grail of alloy physics and materials properties simulation, and this is particularly true for actinide-based materials. On one hand, it was recently shown that first-principles results of alloy energetics and phase diagrams could advantageously supplement phenomenological modeling of alloy thermodynamics although there are limitations in terms of structures and number of alloy components [1]. On the other hand, CALPHAD is successful in modeling complex materials but the accuracy of the output obviously depends on the quality of the thermodynamic database on which this phenomenological approach relies upon [2]. Several classes of applications will be discussed after a brief critical review of the quantum-mechanical-based approaches that are available to interface with CALPHAD modeling, and of the challenges faced by ab initio formalism to describe f-electron systems. First, we show that enough experimental information for U-Zr is available to perform an accurate phase-diagram assessment with a CALPHAD approach, and to test the validity of an ab initio approach to reproduce important features of the phase diagram and gain knowledge on phase stability, especially regarding the co-existence of the bcc (γ) and C32 (δ) phases [3,4]. Second, with limited phase diagram information, we show that the phase diagram of Am-Pu can be assessed with a CALPHAD approach, and identify specific ab initio calculations [5,6] and experimental data that would clearly validate one of the two proposed phase diagrams. Third, with very limited information on the location of the melting line, we show that the phase diagrams of Pu-X (X=Ta,V) can be assessed with a CALPHAD approach, and show that ab initio results on the location of the bcc miscibility gap would confirm the phenomenological results. Finally, for other systems such Am-X (X=U,Np,Cm), no results are available, and since experiments are difficult and costly, an ab initio approach is the only viable route to guide the selection of critical experiments for validation purposes. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

References:

[1] P. E. A. Turchi et al., “Interface between quantum mechanical-based approaches, experiments, and CALPHAD methodology”, CALPHAD, 31 (2007) 4-27. [2] P. E. A. Turchi, L. Kaufman, S. Zhou, and Z.-K. Liu, “Thermostatics and kinetics of transformations in Pu-based alloys”, Journal of Alloys and Compounds, 444-445 (2007) 28-35. [3] A. Landa, P. Söderlind and P. E. A. Turchi, “Density functional study of the U-Zr system”, Journal of Alloys and Compounds (2008), doi:10.1016/j.jallcom.2008.12.052. [4] Alex Landa , Per Söderlind , Patrice E. A. Turchi , L. Vitos , and A. Ruban, “Density-functional study of Zr-based actinide alloys”, Journal of Nuclear Materials (2008), doi:10.1016/j.jnucmat.2008.09.029. [5] A. Landa and P. Söderlind, “Density-functional calculations for Ce, Th, and Pu metals and alloys”, Condensed Matter Physics, 7 (2004) 247-264. [6] A. Landa and P. Söderlind, “First-principles calculations of stability of �-Pu-Am alloys”, Journal of Alloys and Compounds, 376 (2004) 62-67.


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Modelling the Fe-Cr phase diagram: the first-principles magnetic cluster expansion formalism versus CALPHAD data analysis M.Y. Lavrentiev, D. Nguyen-Manh, S.L. Dudarev

EURATOM/UKAEA Fusion Association, Culham Science Centre, United Kingdom Atomic Energy Authority, Oxfordshire, OX14 3DB, UK

Developing predictive models for ferritic/martensitic steels exhibiting higher resistance

to irradiation than other steels represents one of the fundamental challenges for multi-

phase and multi-scale fusion materials modelling. In the case of binary FeCr alloys,

where radiation damage effects are similar to those occurring in ferritic steels, first-

principles spin-polarized electronic structure calculations have recently provided a

fundamental explanation for the negative-mixing-enthalpy anomaly characterizing the

alloy in the 0-10% Cr concentration range, for example the formation of compounds not

predicted by CALPHAD [1]. To understand the thermodynamic and magnetic

properties of FeCr alloys, a new magnetic cluster expansion (MCE) formalism [2] was

proposed and developed as means for ab-initio based modelling the α-γ, and γ-δ phase

transitions in the finite temperature domain of the Fe-Cr phase diagram. Benchmarking

calculations for pure iron show that the predicted Curie temperature Tc as well as Tαγ

and Tγδ transition temperatures agree well with experimental data, a genuinely

significant advance given the exceedingly small Gibbs free energy differences between

the bcc and fcc phases. Extending our MCE-based investigation to the Fe-rich region in

Fe-Cr alloys, we show that the Curie temperature of the alloy is maximum in the range

of small Cr concentrations, resulting from anti-ferromagnetic ordering of moments of

Cr atoms with respect to the ferromagnetically ordered environment of Fe atoms. This

prediction is in agreement with experimental observations and with the CALPHAD data

analysis [3]. We also discuss of the γ-loop formation and the role of vibrational

contribution to the free energy, driving magnetic phase transformations in Fe-Cr alloys.

This work was supported by the UK EPSRC and by EURATOM.

References:

[1] D. Nguyen-Manh, M.Y. Lavrentiev and S.L. Dudarev, C.R. Physique, 9 (2008) 379.

[2] M.Y.Lavrentiev, D. Nguyen-Manh and S.L. Dudarev, J. Nucl. Mater. (2009) doi:10.1016/j.jnucmat.2008.12.052.

[3] S. Hertzman and B. Sundman, CALPHAD, 6 (1982) 67.


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Lattice relaxation effects on the phase equilibria investigated by CVM T. Mohri

Division of Materials Science and Engineering, Graduate School of Engineering, Hokkaido University, Sapporo, 060-8628 Japan

First-principles phase diagram calculations have been attracting broad attentions. One

of the deficiencies of CVM-based first-principles calculations, however, is the fact that

an order-disorder transition temperature is overestimated due to the neglect of local

lattice relaxation effects. In order to circumvent such an inconvenience, two schemes

have been developed. One is to introduce lattice thermal vibration effects into the free

energy formula, and the other is to explicitly consider the local relaxation by an

improved entropy formula termed Continuous Displacement CVM (CDCVM). In the

present study, we compare the results of two kinds of calculations on two dimensional

square lattice. One is to introduce the lattice vibration effects within Debye-Gruneisen

approximation and the other is CDCVM. It has been pointed out that the lattice

vibration effects reduce the transition temperature through the lattice softening at

elevated temperatures which is manifested by the reduction of the curvature of a

binding energy curve. However, we propose that an opposite case may take place when

the Debeye temperature of an ordered phase is lower than that of the constituent pure

phases. CDCVM, on the other hand, always results in the reduction of the transition

temperature.


21

First Principles Calculations of Phase Diagrams of Solidus and Liquidus Mo-Ta-W Alloy Systems by Thermodynamic Variational Principles K. Masuda-Jindo a, Vu Van Hung b, P.E.A Turchi c a Department of Materials Science and Engineering, Tokyo Institute of Technology,

Nagatsuta, Midori-ku, Yokohama 226-8503, Japan. b Department of Physics, Hanoi National Pedagogic University, km8 Hanoi-Sontay

Highway, Hanoi, Vietnam c Lowewnce Livermore National laboratory, PO Box 808, L-353 LLNL, Lovermore CA

94551 U.S.A.

The thermodynamic quantities of solidus alloy phases are studied using the quantum

mechanical statistical moment method (QMSMM), going beyond the traditional quasi-

harmonic approximations. In addition to the thermodynamic quantities like thermal

lattice expansions, specific heats, Grüneisen constants, elastic moduli of solidus phases,

we also calculate the free energies and thermodynamic quantities of liquidus phases by

using the thermodynamic variational theories. For solid portion, the first principles

calculations of alloy phase diagrams by combined statistical moment and cluster

variation methods are presented. Including the power moments of the atomic

displacements up to the fourth order, the free energies of alloy systems are derived

explicitly in closed analytic forms. The configulational entropy term is taken into

account by coupling the moment expansion scheme with the cluster variation method

(CVM). The free energies of liquid phases are evaluated by using the Gibbs-Bogoliubov

variational theory. The internal energies of the alloys are evaluated by using the first

principles TBLMTO-CPA-GPM method. The applications of the present scheme are

given for the high temperature binary Ta-W and Mo-Ta alloys as well as the ternary

Mo-Ta-W alloys. The calculated thermodynamic quantities and equilibrium phase

diagrams, including the liquidus and solidus lines, by the first principles statistical

moment and cluster variation methods are in good agreement with the available

experimental results.


22

Thermodynamic modelling of the Ga-Ti system Y. Liu a,b, C. Colinet c, J.C. Tedenac a

a Equipe Physico-chimie des Matériaux Oranisés Fonctionnels, Université Montpellier II, Institut C. Gerhardt, UMR-CNRS 5253, Montpellier, France

b Key Laboratory of Materials Design and Preparation Technology of Hunan Province, School of Mechanical Engineering, Xiangtan University, Hunan, P.R. China

c Science et Ingénierie des Matériaux et Procédés, UMR 5266, CNRS – INP Grenoble - UJF, BP 75, 38402 Saint Martin d’Hères Cedex, France

Based on the reliable literature data and the calculated enthalpies of formation of Ga-Ti

intermetallic compounds by ab initio approach, a thermodynamic assessment of the

binary Ga-Ti system was performed by means of CALPHAD (CALculation of PHAse

Diagram) method. The solution phase liquid (L), b.c.c (β), h.c.p (α1) and f.c.c (γ1) were

described by a substitutional model with Redlich-Kister polynomials. The intermetallic

compounds Ti2Ga, Ti5Ga3, Ti2Ga3, TiGa2 and TiGa3 were treated as stoichiometric

phases. The compound energy model was employed to describe compounds with

homogeneity ranges of Ti3Ga (α2) Ti5Ga4 (ρ) and TiGa (γ2). A set of self-consistent

thermodynamic parameters is obtained. The thermodynamic quantities, such as the

phase equilibria, invariant reactions, formation enthalpies of the intermetallic phases

and antisite concentration, were calculated using the obtained parameters, and agree

well with experimental data and the results from ab initio calculation.


23

Fig.1 Energy of formation of M5Si3 phases, being consistent with experimental structural

An energetic study of transition metal silicides by DFT Guosheng Shao

Centre for Materials Research and Innovation University of Bolton, Bolton BL3 5AB, UK Transition metal silicide based refractory composite alloys have been extensively studied due to their potential for applications as the next generation turbine airfoil materials, as their operating temperatures are significantly higher than advanced Ni-based superalloys. Most research work has been directed towards studying multi-component alloying in order to develop alloys of a good balance of creep resistance, fracture toughness, oxidation resistance, and room-temperature ductility. Refractory composite alloys based on tranistion metal (M) silicides are mainly made of the M5Si3 and MSi2 compounds, each having various crystal forms. In this work, structural stabilities and energy of sublattice mixing for silicides of the group IVB to VIB transition metal elements are studied using the ab initio density functional theory, aiming to probe alloying/bonding behaviour at the electronic level. The results show that the ground state stability of binary silicies are in excellent agreement with the experimentally built structural map, except for the CrSi2 structures.

Some efforts have been made to understand the latter abnormal stability phenomena [1] from an energetic view on the basis of ground state potential well of the phases [2]. The results are considered to be useful input for extensive thermodynamic assessment using the CALPHAD approach, where lattice stabilities and energy of mixing are often missing due to the difficulty in experimental investigation of refractory materials.

References:

[1] G Shao, “Prediction of structural stabilities of transition-metal disilicide alloys by the density functional theory”, Acta Materialia, 53 (2005) 3729.

[2] G Shao, “Melting of metallic and intermetallic solids: an energetic view from DFT calculated potential wells”, Computational Materials Science, 43 (2008) 1141.


24

On the prediction of site preferences in structurally complex metal compounds Klaus W. Richter

University of Vienna, Dept. of Inorganic Chemistry / Materials Chemistry, Waehringerstrasse 42, A-1090 Vienna, Austria

It is well known that metallic compounds often show considerable homogeneity ranges

based on substitution. The distribution of metals atoms in these solid solution phases is

seldom completely random if the crystal structure of the compound in question allows

site preferences; i.e. if it contains several crystallographically different sites. In a recent

research project we performed an extended study of partial ordering in several ternary

systems combining two early transition metals (M, M’ = V, Nb, Ta, Zr, Hf) with As, Ge

and Ga. Solid solution phases and ternary compounds observed in these systems usually

show extended substitution among the two (chemically closely related) transition metals

M and M’. However, M and M’ are not distributed randomly over all available metal

sites, but show strong site preferences. Preferred site occupation is even found for the

pair Zr / Hf which is considered to be the most closely related pair of homologous

elements in the periodic system. In order to model these site occupations we used

ground state energies of (hypothetical) isostructural ordered compounds (End members)

which were obtained from ab-initio DFT calculations. By implementing these values to

the well known Compound Energy Formalism (CEF), we could predict the

experimentally observed site preferences with good accuracy. In case of closely related

structures it was furthermore possible to predict the relative stability of the compounds

at elevated temperatures without any excess term to the modelled Gibbs energy. Trends

of lattice parameter variation within these solid solution phases could also be

reproduced.


25

Magnetic Properties through Quantum, Statistics, and Modeling Zi-Kui Liu

Department of Materials Science and Engineering The Pennsylvania State University University Park, PA 16802 http://www.phases.psu.edu

In the CALPHAD modeling, the magnetic contribution to the Gibbs energy is described

by the expression )1ln()/( +βCTTRTf with TC being the magnetic transition

temperature, f(T/TC) an empirical polynomial with different expressions above and

below the magnetic transition temperature, and β the Bohr magnetic moment. The

composition dependence of TC and β extends this model to multi-component systems

with β being temperature independent. In the quantum mechanical calculations based on

density functional theory at zero Kelvin, the spin contribution is included in the

exchange-correlation functional approximation and the magnetic spin moments can be

properly predicted as a function of volume. It remains a challenge to predict

quantitatively the magnetic properties as a function of temperature, i.e. the TC and β,

which can be used in the CALPHAD modeling. In this presentation, we explore a

statistic approach based on free energies of competing magnetic states from first-

principles calculations [1].

Reference:

[1] Y. Wang, L. G. Hector, H. Zhang, S. L. Shang, L. Q. Chen and Z. K. Liu, "Thermodynamics of the Ce gamma-alpha transition: Density-functional study," Phys. Rev. B, Vol.78, 2008, 104113.


26

Energetics and magnetism of Cr-based sigma phases J. Pavlů a,b, J. Vřešťál a,b, M. Šob a,b a Masaryk university Brno, Czech Republic b Institute of Physics of Materials, ASCR, Brno, Czech Republic

The overview of ab initio calculated energies of formation of the sigma phases in Cr-Fe

and Cr-Co systems will be given. These energies were evaluated with respect to the

structures of pure constituents which are stable at standard ambient temperature and

pressure (i.e. ferromagnetic hcp Co, antiferromagnetic bcc Cr, ferromagnetic bcc Fe)

and using various methods. [1-5] These total energy differences are compared with

enthalpies of formation of sigma phase measured by calorimetry.

The magnetism of various configurations was also investigated and the stabilizing effect

of magnetic ordering was proved. The magnetic moments per atom and their relation to

the composition and atomic site will be discussed. Acknowledgements: This research was supported by the Grant Agency of the Czech Republic (Project no. 106/07/1078), Ministry of Education of Czech Republic (Project nos. OC164 and MSM0021622410) and Academy of Sciences of the Czech Republic (Project no. AV0Z20410507). The access to the computing facilities of the MetaCenter of the Masaryk University, Brno, provided under the Research Project MSM6383917201, is acknowledged.

References:

[1] G. Krier, O. Jepsen, A. Burkhardt, and O.K. Andersen, computer code TB-LMTO- ASA version 4.6, Max-Planck-Institut für Festkörperforschung, Stuttgart, 1994.

[2] P. Blaha, K. Schwarz, and J. Luitz, computer code WIEN97, Vienna University of Technology, 1997 [improved and updated Unix version of the original copyrighted WIEN code, which was published by P. Blaha, K. Schwarz, P. Sorantin, and S.B. Trickey, Comput. Phys. Commun. 59 (1990) 399].

[3] P. Blaha, K. Schwarz, G.K.H. Madsen, D. Kvasnicka, and J. Luitz, WIEN2k, An Augmented Plane Wave Plus Local Orbitals Program for Calculating Crystal Properties (Karlheinz Schwarz, Technische UniversitätWien, Austria, 2001).

[4] G. Kresse and J. Furthmüller, Comp. Mat. Sci., 6 15 (1996). [5] G. Kresse and J. Furthm¨uller, Phys. Rev. B, 5, 11169 (1996).


27

Predicting the Curie Temperature of FCC Co from a Statistical/First-Principles Approach J.E. Saal, S. Shang, Y. Wang, Zi-Kui Liu

The Pennsylvania State University, Department of Materials Science and Engineering, University Park, PA 16802

Second-order magnetic phase transformations have long been studied experimentally

and theoretically. Previous theoretical attempts to predict such transformations often

involve fitting parameters that define the magnetic properties of the phases in the

transformation. We present an approach where all the relevant magnetic and energetic

properties are determined from first-principles calculations and second-order

transformations are predicted with a statistical partition function. With this method, the

Curie temperature of FCC Co has been predicted as a function of pressure. High-

temperature phases, such as disordered paramagnetic FCC Co, is defined as a mixture of

different states, and the properties of these high-temperature phases can be derived from

the partition function. This approach has been successfully applied to the isostructural

γ-α Ce phase transformation[1] and offers an important step towards realizing the goal

of an accurate prediction of a P-T phase diagram by integrating first-principles and

statistical calculations.

References:

[1] Y. Wang, L. G. Hector, H. Zhang, S. L. Shang, L. Q. Chen, and Z. K. Liu, Phys. Rev. B, 78 (2008) 104113.


28

Cluster expansion approach for variable lattice systems K. Yuge

Department of Materials Science and Engineering, Kyoto University, Japan

Cluster expansion[1] (CE) technique is one of the most promising and well-established approach to predict alloy thermodynamics based on density functional theory (DFT). The CE have been widely applied to a variety of the alloy thermodynamics such as binary and multicomponent bulk phase diagram, surface segregation and ordering, and molecular adsorption on metal surfaces. Furthermore, the CE formalism is modified in various manner for systems which practically require specific treatment in terms of configuration spaces: Mixed space CE,[2] which treats clusters in both real and reciprocal space, is applied to the long-period superlattices. Coupled CE,[3] which treats the distinct sublattices, is applied to the ionic systems and adsorbate-induced surface segregations. In spite of such successful applications of the CE, there still remains an essential limitation for modeling more general alloy configurational thermodynamics. Although the CE formalism certainly allows us to estimate energy of any atomic arrangements on a lattice with desirable accuracy, it is limited to the given lattice; different lattices require different expression of energy. This fact makes it difficult to apply the CE to energetics for specific systems whose lattice points vary with changes in their circumstances such as temperature, atomic arrangements, or composition. One can easily find such systems, e.g., graphite-like layered boron-carbon-nitride, shear structure of titanium oxide, polymorphism in silicon carbide, and close-packed alloy surface between fcc and hcp. In the present work, we propose a cluster expansion technique, variable lattice cluster expansion (VLCE), which can treat a number of lattices in a single formalism. The VLCE first decomposes the given lattices into constituent partial lattices. Then two types of spin variables σ and τ are introduced to uniquely specify atomic arrangements of the lattices: The former specifies atomic arrangements on the partial lattices and the latter specifies arrangements of the partial lattices themselves. Any function of atomic arrangements on the lattices can be rigorously expanded in terms of the complete and orthonormal basis functions constructed from the two types of spin variables. We show an example of the VLCE for one-dimensional lattice with line and zigzag shapes in order to see the concept of the VLCE, and how ECIs in the VLCE are interpreted. Since the VLCE can predict properties of any atomic arrangements on given lattice from those on different lattices, it also have potentials to significantly enhance the number of states that are effectively explored through the cluster expansion technique in configuration space.

References:

[1] J.M. Sanchez, F. Ducastelle, and D. Gratias, Physica 128A, (1984) 334. [2] D. B. Laks, L. G. Ferreira, S. Froyen, and A. Zunger, Phys. Rev. B, 46 (1992)

12587. [3] B. C. Han, A. Van der Ven, G. Ceder, and B. J. Hwang, Phys. Rev. B, 72 (2005)

205409.


29

A Thermodynamic Database for Laves Phase - Hydrogen Systems Ursula R. Kattner

Metallurgy Division, National Institute of Standards and Technology, Gaithersburg, MD, USA

In nickel metal hydride batteries the material in one of the electrodes are either AB5 or

AB2 intermetallic compounds that can store hydrogen. The AB2 compounds are Zr,Ti-

based Laves phases which are attractive because of their larger hydrogen storage

capacity compared to the traditional AB5 compounds. However, the storage capacity by

weight of these alloys is considered to low for automotive applications by the US

Department of Energy even though these alloys have many advantages compared to the

light metal hydride materials currently under investigation. To further improve the

hydrogen storage capacities of these Laves phases the phase equilibria and

thermodynamics of these phases and their hydrides need to be known. The Ni-Cr-Ti-Zr

system was selected as initial system for the construction of a thermodynamic database.

Thermodynamic descriptions are available for three of the four constituent ternary

systems, Ni-Ti-Zr [1], Cr-Ni-Ti [2] and Cr-Ni-Zr [3]. However, the descriptions of two

of the binaries used for Ni-Ti-Zr, Ni-Ti and Ni-Zr, are different from those used for the

ternary systems with Cr and, therefore, a straightforward combination of the

descriptions of these three ternary systems is not possible and a reevaluation of these

descriptions was necessary.

References:

[1] T. Tokunaga et al., Mater. Trans., 48 (2007) 89. [2] N. Dupin, Ph.D. Thesis, LTPCM Grenoble, France, 1995. [3] I. Ansara et al., J. Phase Equilibria, 19 (1998) 6.


30

Chemical potential phase diagrams and the reversible reactions of hydrogen storage material systems Kewu Bai, Ping Wu

Institute of High Performance Computing, 1 Fusionopolis Way #16-16 Connexis, Singapore 138632

The concept of the chemical potential phase diagram in the atomic simulation was

applied to investigate the reversible hydrogen storage reactions of complex hydride

materials. By using the component chemical potential of the system components as

variables, we correlate the points, lines and plane in the chemical potential diagram with

the different metastable phase equilibriums in the system. These can be used to trace the

hydrogen storage reactions and probe the defects energtics of the material systems

combining DFT calculation. As examples, the chemical potential phase diagram of

lithium amides and Ti doped sodium alanate are presented.

References:

[1] Kewu Bai, Pei Shan, Emmeline Yeo and Ping Wu, Chem. Mater., 20 (2008) 7539.


31

A thermodynamic and first principles revision of the ternary Cr-Ni-Re system M. Palumbo a, T. Abe a, C. Kocer b, H. Murakami a, H. Onodera a a National Institute for Materials Science (NIMS,) 1-2-1 Sengen, Tsukuba, Ibaraki, 305-

0047, Japan b School of Physics, University of Sydney, Sydney 2006 Australia

Nowadays, Re-base alloys are used as coating materials for Ni-base superalloys.

However, under service conditions at high temperatures, precipitation of TCP

(Topologically Close-Packed) phases, both in the superalloy and in the interface

between the coating layer and the superalloy, can significantly degrade material

properties, especially creep and oxidation resistance. Knowledge of appropriate phase

diagrams and implementing computer aided design using the CALPHAD approach are

useful approaches to overcome present drawbacks in Re-base coatings.

In this work, the binary and ternary phases of the Cr-Ni-Re system were carefully

reexamined and revised using the CALPHAD approach and the ThermoCalc program.

Using previously unavailable experimental data [1,2] an improved thermodynamic

description of this system was obtained. Results from ab initio calculations, performed

using the VASP code [3] and the ATAT package [4], were used as input parameters in

the modeling of the sigma phase and solution phases in the framework of the CEF

(Compound Energy Formalism). An improved thermodynamic description of the

ternary system has been obtained in good agreement with experimental data.

References:

[1] S. Saito, K. Kurokawa, S. Hayashi, T. Takashima and T. Narita, J. Japan Inst. Metals, 71(8) (2007) 608-614.

[2] S. Saito, K. Kurokawa, S. Hayashi, T. Takashima and T. Narita, J. Japan Inst. Metals, 72(2) (2008) 132-137.

[3] G. Kresse, J. Furthmuller, Phys. Rev. B, 54 (1996) 11169. [4] A. Van de Walle, CALPHAD in press.


32

Thermodynamic modeling of Mg-Bi and Mg-Sb systems and short-range-ordering behaviour of the liquid solutions Manas Paliwal, In-Ho Jung

Dept. of Mining and Materials Engineering, McGill University, Canada

In order to investigate the short range ordering behaviour of liquid Mg-Bi and Mg-Sb

solutions, the thermodynamic modeling of the Mg-Bi and Mg-Sb binary systems has

been performed. All available thermodynamic and phase diagram data of the Mg-Bi and

Mg-Sb binary systems have been critically evaluated and all reliable data have been

simultaneously optimized to obtain one set of model parameters for the Gibbs energies

of the liquid and all solid phases as functions of composition and temperature. In

particular, the Modified Quasichemical Model, which accounts for short-range-ordering

of nearest-neighbor atoms in the liquid, was used for the liquid solutions. A

comparative evaluation of both systems was helpful to resolve inconsistencies of the

experimental data. The thermodynamic modeling shows the strong ordering behaviour

in the liquid Mg-Bi and Mg-Sb solutions at Mg3B2 and Mg3Sb2 compositions,

respectively, and also suggests the metastable liquid miscibility gaps at sub-solidus

temperature. All calculations were performed using the FactSage thermochemical

software. This work is also a part of large thermodynamic database development for

new Mg alloys.


33

Precipitation Simulation of Al3(ScxZr1-x) in Aluminium Alloys Q. Chen, X.G. Lu, H. Strandlund, A. Engström

Thermo-Calc Software AB, Björnnäsvägen 21, 113 47, Stockholm, Sweden

The Al3(ScxZr1-x) precipitates have been previously found to possess a strongly

inhomogeneous structure that contains a Sc-rich core and a Zr-rich external shell, which

exhibits a high resistance to Ostwald ripening in the Al-Sc-Zr system. Atomic

simulations based on first-principles calculations have been reported to give an

explanation of the formation of the structure. In this work, we study the evolution of the

structure by modelling the concurrent process of nucleation, growth, and coarsening of

the Al3(ScxZr1-x) particles on the basis of phenomenological CALPHAD-type

thermodynamics and kinetics. A generalized multi-component KWN approach has been

used. All necessary thermodynamic and kinetic information was calculated directly

from existing thermodynamic and kinetic databases. Non-steady state rate equations

have been applied for modelling nucleation and growth/dissolution. The Gibbs-

Thomson effect and cross diffusion have been treated in a rigorous way. We have

calculated the temporal evolutions of the number density, particle size, and particle size

distribution. The results compare favourably with experimental measurements. By

plotting the variation of composition profiles in the precipitates, we reveal the formation

of the Sc-rich core and Zr-rich shell structure. This validates the capability of our multi-

component interface velocity model where both matrix and precipitate concentrations at

the interface are determined simultaneously together with the moving velocity of the

phase boundary.

CALPHAD XXXVIII Abstracts - Tuesday

34

First-principles computation of phonons and thermodynamical properties with ABINIT X. Gonze

European Theoretical Spectroscopy Facility, Unité PCPM, Université Catholique de Louvain, B-1348 Louvain-la-neuve, Belgium.

The crystal lattice is never rigid. Due to temperature, the nuclei vibrate, the lattice

distorts and expands. The associated changes of energy and entropy can strongly affect

equilibrium between phases. I will first review the basic concepts needed to describe

these changes, in the Born-Oppenheimer approximation, and then I will present the

state-of-the-art method [1] for their parameter-free computation: Density-Functional

Perturbation Theory. Selected examples of computation of free energy, specific heat,

and thermal expansion of different phases will be presented, including the recent

observation of spin-orbit influence on the specific heat of bismuth [2]. They are based

on the ABINIT software, a widely used first-principles software application, that is

available freely on the Web, easy to use, well documented, and specially suited for that

type of calculations [3, 4].

References:

[1] See for example X. Gonze, G.-M. Rignanese, R. Caracas, Z. Kristallogr., 220 (2005) 458.

[2] LE Diaz-Sanchez, A. H. Romero, M. Cardona, R.K. Kremer, and X. Gonze. Phys. Rev. Lett., 99 (2007) 165504.

[3] X. Gonze, et al. Comput. Materials Science, 25 (2002) 478-492. [4] X. Gonze, et al. Z. Kristallogr., 220 (2005) 558-562.


35

Ab initio calculations of crystalline materials by Phonon software K. Parlinski

Institute of Nuclear Physics, Polish Academy of Sciences, ul.Radzikowskiego 152, 31-342 Cracow, Poland

The phonon dispersion curves, and phonon density of states can be calculated with the

standard ab initio program, like VASP, and the code Phonon, which uses the improved

direct method [1]. The procedure can be applied to pure bulk crystals, to study defected

crystals, surfaces, atoms adsorbed on the surface, multilayers, etc. The classical phonon

dispersion curves, phonon density of state, spectroscopic spectra and thermodynamic

functions are now calculated routinely. Since the calculations provide not only the

phonon frequencies, but also the polarization vectors, one can find the intensity of

coherent and incoherent neutron and x-ray scatterings, the infrared active and raman

scattering modes and carry on comparisons with the measurements. Use of phonon data,

such as soft modes, and quasiharmonic approximation allow to provide a scheme for the

phase transition and phase diagram. Phonons can also be used to describe diffusion,

chemical reactions. Crystals build from elements of simple electronic structure are the

easiest units to compute. However, even the strong electron correlation materials

involving transition elements, rare earth and actinides can be successfully considered

within the same scheme, although with larger computational effort.

References:

[1] http://wolf.ifj.edu.pl/phonon/


36

Ab-initio thermal expansion, the mode-gamma analysis in the quasi-harmonic approximation: some examples of application in the Mg-Si-O system D. Belmonte, G. Ottonello, M. Vetuschi Zuccolini Laboratorio di Geochimica at DIPTERIS, Università di Genova, Corso Europa 26, 16132 Genova

Recent improvements in computing capability and the development of accurate computational codes render feasible the investigation of mantle minerals by ab-initio all-electron approaches. Though quite demanding, in some circumstances computational results offer an independent way of assessing the accuracy of the values of various thermo-chemical and thermo-physical properties that are needed to calculate the phase stability limits within the Earth’s mantle. We have shown in various contributions that all-electron calculations performed within the LCAO (Linear Combination of Atomic Orbitals) approach (with the Kohn-Sham formalism and an appropriate choice of basis sets, cut-off limits in the evaluation of Coulomb and exchange series appearing in the SCF equation and an appropriate integration grid) result in thermo-chemical and thermo-physical parameters of sufficient accuracy for polymorphs stable only at high P,T conditions, and, as such, experimentally demanding [1, 2]. In evaluating the extrinsic stability of the various polymorphs a precise assessment of the PV integral of products and reactants is required. This involves at its turn an internally consistent evaluation of thermal expansion (α), molar volume, bulk modulus (K0) and its thermal and baric derivatives [(dK/dP)T , (dK/dT)P, respectively]. While K0 and (dK/dP)T=0 are obtained by the conformation of the static B3LYP energy terms through simmetry-preserving contractions of interionic distances (followed by optimization of internal cohordinates), the evaluation of α and (dK/dT)P may be obtained from the assessment of the gamma-mode of the substance and its choric derivative, in the frame of the quasi-harmonic treatment of normal modes. Two distinct path may be followed: 1) assessment of the αK product with the canonical equation

αTKT = (R/ZV) ∑(i=4,3n) γi e–Xi [Xi/(eXi – 1)]2 where Xi terms are undimensionalised frequencies corresponding to the eigenvectors of the Hessian matrix, with

γi = –(∂lnνi/∂lnV) where νi stands for the i-th vibrational frequency, and (∂K/∂T)P = –αK∞ × [K′ – qht +1] with qht = (∂lnγ/∂lnV)ht 2) adoption of the Born-Huang approximation [3]:

(V – V0)/V0 = (γUvib)/(VK0) = Pthermal/K0 with Uvib= vibrational energy of the substance. Both procedures result in thermal expansions in excellent agreement with experiments within a reasonable range of T. Method (2) apparently overestimates thermal expansion at high T and should be utilized only whenever the characterization of the mode-q is prohibitive for computational reasons or whenever the mode-γ has a complex choric dependence. Application of the two procedures to the α,β,γ polymorphs of Mg2SiO4, stishovite (SiO2), periclase (MgO) and to the high-P phase AnhB (Mg14Si5O24) are presented and discussed.

Reference:

[1] G. Ottonello G., B. Civalleri, J. Ganguly, M. Vetuschi Zuccolini, Y. Noel Y, Phys. Chem. Minerals, 36 (2009) 87-106.

[2] G. Ottonello, B. Civalleri, M. Vetuschi Zuccolini, CALPHAD, (2009) in press. [3] M. Born M., C. Huang, (1954), Dynamical Theory of Crystal Lattices, Clarendon Press, Oxford.


37

Vibrational contribution on free energy change in binary system S. R. Nishitani

Department of Informatics, Kwansei Gakuin Univ., Gakuen 2-1, Sanda, 669-1337 Japan.

For the stability of a single phase at the finite temperatures, quasi-harmonic

approximation is widely used and gives reliable predictions. In the binary systems, it is

noted that the simple approximation on the configuration change for solid solution or

precipitating cluster might lead the unreliable results [1].

When we assume that the free energy of single site is controlled by its vibration

frequency, Taylor expansion of the free energy on the small change of frequency is

expressed as

.

The last equation is valid only when the first Taylor coefficient is independent on the

frequency. As shown in Fig.1, it becomes fairly constant for the materials with the

frequency below 10 THz and the higher temperatures. When we assume that the number

and its quantity of change of softening sites are equal to those of hardening sites, the

vibrational free energy change vanishes. This condition is automatically satisfied when

the spring constant of the unlike-atom pair is comprised by the arithmetic mean of those

of like-atom pairs, kAB=(kAA+kBB)/2. This too simple assumption on the spring constant

is the case using the simple potential of the geometric mean, .

References:

[1] K. Yuge, S. R. Nishitani, I. Tanaka, Calphad, 28 (2004) 167.

Fig.1 First Taylor coefficients as a function of vibration frequency.


38

Equilibrium vacancy concentration in B2-ordering AB binary systems: Semi Grand Canonical Monte Carlo (SGCMC) simulations R. Kozubski a, A. Biborski a, V. Pierron-Bohnes b a Interdisciplinary Centre for Materials Modelling, M. Smoluchowski Institute of

Physics, Jagellonian University, Reymonta 4, 30-059 Krakow, Poland b Institut de Physique et Chimie des Matériaux de Strasbourg, 23 rue du Loess, BP43

67034 Strasbourg, France

Surprisingly slow atomic ordering kinetics in NiAl – a typical triple defect system,

suggests that the process runs via formation/elimination of triple defects trapping

vacancies [1]. In such a case, the system should show a correlation between vacancy

and antisite concentrations: in average 2 vacancies related to 1 antisite defect. Due to

being trapped in triple defects, the numerous vacancies can hardly mediate the process

of chemical ordering, which results slow. The planned Kinetic Monte Carlo (KMC)

simulations of the process definitely require that temperature dependence of vacancy

concentration in the B2-ordering AB binary system is taken into account. The task is

reached by considering a BCC lattice gas built of A and B atoms in 1:1 proportion and

vacancies. The gas decomposes into vacancy-rich and vacancy–poor phases; the latter

one indentified with an AB binary with equilibrium vacancy concentration. The

thermodynamic problem is solved by means of SGCMS implemented with Ising and

EAM-type models of the system. In the case of the energetics yielding different

formation energies of A- and B-antisites a constant 1:2 proportion of antisite and

vacancy concentrations is found within a finite temperature range. This is regarded as a

signature of triple defect formation. The SGCMC simulations not only confirm the

previous Bragg-Williams calculations [2], but their result – i.e. the temperature

dependence of the number of vacancies in the generated B2 supercell, are directly

applicable in the KMC simulations of ordering kinetics.

References:

[1] R. Kozubski, D. Kmieć, E. Partyka, M. Danielewski, Intermetallics, 11 (2003) 897. [2] A. Biborski, R. Kozubski, L.Zosiak, V. Pierron-Bohnes, Intermetallics, 17 (2009)

46.


39

Challenges in the Monte Carlo modeling of vacancies in BCC iron Cláudio Geraldo Schön

Computational Materials Science Laboratory, Department of Metallurgical and Materials Engineering, Escola Politécnica da Universidade de São Paulo, CEP 05508-900 São Paulo, Brazil.

Vacancy modeling in a lattice using the Monte Carlo Method (MCM) in inherently

difficult due to their low concentrations, which requires very large computer crystals for

a reasonable statistical sampling, and hence, long computation times. The use of the

MCM, however, allows the inclusion of arbitrarily long-ranged interactions [1, 2]

between vacancies and the modeling of vacancy kinetics under simulated recovery

"experiments" with the computer crystal. The present work describes two C++ classes

developed for modeling vacancies in lattices and the computational techniques used to

circumvent the previously mentioned difficulties. Both classes are then employed to

build a computer program which is able to work with very large computer crystal

(current tests used up to 2 x 10243 atom blocks) and to model migrating vacancies,

which are allowed to be formed or destroyed only at certain planes in the crystal. This

program is then used to investigate vacancy thermodynamics and recovery kinetics in

BCC Iron, for which, surprisingly enough, only scarce data are available in the

literature[3].

References:

[1] R. N. Nogueira, C. G. Schön, Intermetallics, 13 (2005) 1233. [2] R. N. Nogueira, C. G. Schön, Intermetallics, 13 (2005) 1245. [3] A. Seeger, Phys. Stat. Sol. A, 167 (1998) 289.


40

Molecular Simulations of Ionic Liquids: From the Charge Distribution in the Liquid to a New Model for Self-Diffusion Marco Klähn, Abirami Seduraman, Ping Wu

Institute of High Performance Computing, A*STAR, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632

A new empirical force field for guanidinium-based ionic liquids (GILs) [1] was

developed, based on the charge distribution in the actual liquid, via a combined

quantum mechanical and molecular mechanical (QM/MM) approach [2]. An electron

charge transfer from anions to cations of around 0.1 e and a strong polarization of the

central cation group was found. The resulting force field was validated by comparing

structural, energetic and dynamic properties, including the melting point of a GIL

crystal, with experimental data as well as with ab initio models. The force field was

used to study self-diffusion in several GILs on an atomic level of detail [3]. According

to our simulations, diffusion of ions can be described as a chain of single diffusive

transitions, involving short average displacement distances of around 2 Å and energy

barriers between 32-40 kJ/mol. Diffusion coefficients of ions were mainly determined

by the number and strength of close contacts with their immediate environment rather

than long range interactions. Overall, the observed diffusion resembled the diffusion in

molecular liquids (see Figure 1). Furthermore, the proposed diffusion model for GILs

provides an explanation for the measured differences in cation and complementing

anion diffusion speed, which has been reported for several ionic liquids.

Figure 1. Scheme of proposed self-diffusion mechanism.

References:

[1] Y. Gao, S.W. Arritt, B. Twamley, J.M. Shreeve, Inorg. Chem., 44 (2005) 1704. [2] M. Klähn, A. Seduraman, P. Wu, J. Phys. Chem. B, 112 (2008) 10989. [3] M. Klähn, A. Seduraman, P. Wu, J. Phys. Chem. B, 112 (2008) 13849.


41

Ab initio prediction of Impurity Diffusion in Aluminum M.H.F. Sluiter a, D. Simonovic b a MSE, 3mE, Delft University of Technology, Mekelweg 2, 2628 CD Delft, the

Netherlands b Materials innovation institute M2i, Mekelweg 2, 2628 CD Delft, the Netherlands

Activation energies for vacancy mediated impurity diffusion in face-centered cubic

aluminum have been computed ab initio for all technologically important alloying

elements, as well as for most of the lanthanides [1]. The so-called five-frequency rate

model is used to establish the limiting vacancy interchange process. A strong

correlation between partial molar volume of a solute and its diffusion actiuvation energy

is found for all elements except for the transition metals. Instead, transition metals are

shown to correlate strongly with valence electron per atom ratio.

References:

[1] D. Simonovic and M. Sluiter, Phys. Rev. B (2009) accepted.


42

Composition dependence of kinetics for solid-state reactive diffusion between Sn and Ni-Fe alloys M. Kajihara, T. Asano

Department of Materials Science and Engineering, Tokyo Institute of Technology, Yokohama 226-8502, Japan

In the electronics industry, Cu-base alloys are widely used as conductor materials. However, Cu is not completely corrosion resistant. Hence, the Cu-base alloy is usually plated with a Au layer to improve corrosion resistance. If the Au/Cu conductor material is interconnected using a Sn-base solder, the Au layer may quickly dissolve into the molten Sn-base solder during soldering unless the Au layer is sufficiently thick. When the Au layer dissolves, Cu−Sn compounds are formed at the interconnection due to the reactive diffusion between the Cu-base alloy and the molten Sn-base solder. Since the Cu−Sn compounds are brittle and possess high electrical resistivities, their formation deteriorates the electrical and mechanical properties of the interconnection. To suppress Cu−Sn compounds formation during soldering, the Cu-base alloy is generally plated with a Ni layer prior to Au layer deposition. In such a multilayer Au/Ni/Cu conductor material, the Ni layer actually acts as an effective barrier against the reactive diffusion between the Sn-base solder and the Cu-base alloy. At the interconnection between the Sn-base solder and the Au/Ni/Cu conductor, however, a Ni−Sn compound is formed during soldering, and then grows gradually owing to energization heating at solid-state temperatures. The Ni layer electrolessly deposited onto the Cu-base alloy usually contains 5−20 at% of P. The experimental observation by the present authors indicates that the growth of the Ni−Sn compound is slightly accelerated by P in the Ni layer. Thus, the Ni−P layer may not be a sufficiently effective barrier material. Recently, the solid-sate reactive diffusion between Sn and various Ni−X binary alloys was experimentally examined by the present authors. In this presentation, attention was focused on X = Fe. The experiment was carried out at solid-sate temperatures of 453−473 K for Ni−Fe alloys with Fe concentrations of 26.8−100 at%. During isothermal annealing in this temperature range, compound layers of Ni3Sn4 and FeSn2 are produced at the interconnection between Sn and the Ni−Fe alloy. The overall growth rate of the compound layers takes the maximum value at a certain Fe concentration around 25 at%.


43

CALPHAD DESCRIPTIONS AND EXPERIMENTAL STUDIES OF THE Ni-HfB2 SYSTEM L. Kaufman a, G. Cacciamani b, M.L. Muolo c, F. Valenza c and A. Passerone c a CALPHAD Inc. ,U.S.A. b Dept. Chem. and Ind. Chem., Univ. Genoa, Italy c IENI-CNR, Genoa, Italy

At a recent conference on the ultra high temperature performance of ceramic composites held at Lake Tahoe in California [1] nearly forty papers dealt with the performance of diboride composites [2] and their applications in complex structures. Fabrication of such structures requires the development of joining techniques [3] which in turn requires definition of the wettability of the diborides by various metals over a wide range of composition and temperature [4]. In order to provide a basis for these efforts an attempt has been made to couple CALPHAD methods based on previous studies of ZrB2-SiC and HfB2-SiC composites [5, 6] and the Hf-Ni [7] and Ni-B [8] systems with experimental studies of the HfB2-Ni [9, 10] and experimental characterization of wettability and interfacial characterization of systems based on hot pressed HfB2 ceramics in contact with liquid nickel. The resulting ternary sections defined by the database at temperatures between 800 °C and the melting point of HfB2 at 3392 °C displays the binary phases as well as the ternary liquid as well as the Hf2Ni21B6 tau phase. These sections are compared with the behaviour of the liquid Ni phase in contact with the solid boride at temperatures up to 1500 °C under carefully controlled conditions and by SEM, EDS, WDS analyses of the solidified specimens.

References:

[1] “Ultra- High Temperature Ceramics: Materials for Extreme Environment Applications” Conference Chair-Eric Wuchina-NSWC, August 3-8,2008,Grannlibakken Conference Center, Lake Tahoe, California.

[2] L.Kaufman, “CALPHAD Descriptions of UTHC Equilibrium and Kinetics” IBID paper No.1. [3] A.Passerone, M.L. Muolo, F.Valenza and C.Bottino “High Temperature Interfacial Interactions in

NiX-HfB2 Systems.” IBID paper No.2. [4] Passerone A., Muolo M.L., Valenza F., Monteverde F. and Sobczak N., “Wetting and interfacial

phenomena in Ni-HfB2 systems” Acta Mater., 57 (2009) 356. [5] L.Kaufman, “Boride Composites-A New Generation of Nose Cap and Leading Edge Materials for

Reusable Lifting Re-Entry Systems”AIAA paper No.70-278(1970). AIAA Space Advance Transportation Meeting, Cocoa Beach,Florida (Feb 1970).

[6] L.Kaufman, “Thermodynamic Properties of Transition Metal Diborides” Compounds of Interest in Nuclear Reactor Technology. P.Chiotti, J.T.Waber and N.Miner, eds. AIME N.Y,N.Y. (1964) 193.

[7] L.Kaufman and H.Nesor, “Calculation of the Ni-Al-W, Ni-Al-Hf and Ni-Cr-Hf Systems” Canadian Metals Quarterly 14 (1975) 221.

[8] L.Kaufman et.al, “Transformation, stability and Pourbaix Diagrams of high performance corrosion resistant (HPCRM) alloys” CALPHAD 33 (2009) 123.

[9] H.H.Stadelmaier and C.A. Shoemaker ”Die tau phase in der Sysytem Nickel-Hafnium-Bor”, Metall, Berlin 20(1966) 1056.

[10] E.Lugscheider, H.Reiman and R.Pankert, ”Mit 4a und 5a Metallen stabiliserte tau-Boride des Nickel” Metall-Berlin 36 (1982) 247.


44

Thermodynamic modelling of ternary phase diagrams containing MAX-phases Bengt Hallstedt

Materials Chemistry, RWTH Aachen University, Aachen, Germany

MAX-phases (Mn+1AXn carbides and nitrides) are promising materials for a number of

applications. In particular, MAX-phase thin films are intended for use as coatings or

intermediate layers in high temperature composites, where their properties could

improve toughness and thermal cycling resistance. In such applications it is of critical

importance that undesired reactions at the interfaces do not take place. Such reactions

are generally very difficult to predict and understand, but it has been found that

thermodynamic modelling using the Calphad method can be a very efficient tool in this

context. Modelling results from the Cr-Al-C system containing the Cr2AlC MAX-phase

and the V-Al-C system (with V2AlC) as well as preliminary results from the Ti-Al-C

system (with Ti2AlC and Ti3AlC2) will be shown here. In addition, the chemical

compatibility between Cr2AlC and V2AlC on one hand and Al2O3 and NiAl on the other

hand has been studied using thermodynamic calculation.

Isothermal section of the Al-Cr-C system from [1].

References:

[1] B. Hallstedt, D. Music, Z. Sun, Int. J. Mater. Res., 97 (2006) 539.


45

Precipitation of intermetallics in duplex stainless steels – a kinetic evaluation André Costa e Silva a, Roberto Avillez b a EEIMVR-UFF, 27260-740 Volta Redonda, RJ - Brasil b DCMM-PUC RJ, 22453-900 Rio de Janeiro, RJ - Brasil

Duplex and superduplex stainless steels are becoming the material of choice for several

applications, in special in the oil and gas industry. This is due to their excellent

combination of mechanical properties and corrosion resistance. However, the

precipitation of intermetallic phases may hinder both toughness and corrosion resistance

of these materials. While computational thermodynamics is a proven tool in the

selection of the correct solution heat treatment temperature, the knowledge of the

kinetics of precipitation of intermetallic phases, in special during cooling or exposition

to elevated working temperatures, still depends heavily on experimental determination

of transformation curves.

In this work, the kinetics of intermetallic precipitation is modelled using computational

thermodynamics and diffusion modeling with DICTRA®. The results of these

calculations are compared with experimental data from literature for some commercial

steel compositions, highlighting the agreements and discussing the possible cause of

discrepancies. Furthermore, the technique is applied to steels for which experimental

data for precipitation kinetics is not available in order to derive the best processing

conditions aiming, in special, at the prevention of significant sigma (σ) phase

precipitation.


46

Thermodynamic description of the Al-B-Nb-Ti system and its application to TiAl-based alloys U. Hecht a, V. Witusiewicz a, J. Zollinger a, L.V. Artyukh b, N.I. Tsyganenko b, A.A. Bondar b a Access e.V., Intzestr. 5, 52072 Aachen, Germany b Frantsevych Institute for Problems in Materials Science, Krzhyzhanivsky Str. 3,

02142, Kiev, Ukraine

Boron additions are commonly used for grain refinement of Ti- and TiAl-based alloys.

The process of refinement and the resulting grain size distribution depend on the

amount of added boron, on the corresponding sequence of phase formation and on the

kinetics of phase transformation. Over the past four years the authors jointly

investigated phase equilibria in the Al-B-Nb-Ti system and its ternary constituent

systems, both by experimental methods and thermodynamic modelling. In this

contribution we will present the thermodynamic description of the ternary constituent

systems as well as selected calculations for quaternary alloys. Key experimental results

will be discussed and compared to equilibrium calculations.

Based on this thermodynamic background, distinct scenarios of boride precipitation in

TiAl-based alloys will be outlined and discussed in terms of the resulting grain

refinement.


47

Experimental data for CALPHAD H. Flandorfer, C. Schmetterer

University of Vienna, Department for Inorganic Chemistry / Materials Chemistry, Vienna, Austria

CALPHAD is a well known and widely accepted procedure to present and explore

phase diagrams and to check the consistency of thermodynamic data. Nowadays, further

applications like prediction of micro-structures, diffusion behaviour and the calculation

of physical properties of alloys are available based on the optimized thermodynamic

data sets. Although important progress has been made in the field of first principle and

ab initio calculations, experimental thermodynamic data are still crucial for the

CALPHAD methods. The reliability of the calculations mainly depends on such data.

Unfortunately, during the last 25 years, many groups around the world doing adequate

experiments have dismantled or changed their topics. Thus, for new materials and

alloys, there is a lack of experimental data such as enthalpy of formation, phase

transformation temperatures, and many others. A new project dedicated to the

experimental thermodynamic investigations of alloy systems relevant for HT lead-free

soldering will start at begin of 2009. It is planned to not only provide thermodynamic

data but to combine experimental efforts with CALPHAD methods in a very close and

iterative way. Systems under investigation will be Cu-Ni-Sn and Cu-Ni-(Bi,Ga,Zn). A

new investigation of Ni-Sn [1] and isothermal sections of Cu-Ni-Sn [2] have been

recently published, new results for the binary Ga-Ni system can be presented.

References:

[1] C. Schmetterer, H. Flandorfer, K.W. Richter, U. Saeed, M. Kauffman, P. Roussel, H. Ipser, A new investigation of the system Ni-Sn, Intermetallics, 15 (2007) 869- 884.

[2] C. Schmetterer, H. Flandorfer, C. Luef, A. Kodentsov, H. Ipser, Cu-Ni-Sn: A key system for lead-free soldering, J. Electronic Mat., 38 (2009) 10.


48

Experimental Study of the Al-Mg-{Ca,Sr} Ternary Phase Diagrams at 400ºC and Comparison with Thermodynamic Models D. Kevorkov a, M. Medraj a, J. Li b, E. Essadiqi b, M. Aljarrah a, P. Chartrand c a 1Department of Mechanical Engineering, Concordia University, Montreal, Quebec,

CANADA b Materials Technology Laboratory, CANMET, Ottawa, Ontario, CANADA c Centre for Research in Computational Thermochemistry (CRCT),

Ecole Polytechnique, Montreal, Quebec, CANAD.

The Al-Mg-{Ca,Sr} systems were intensively investigated and thermodynamically

modeled for the last ten years. They are an important part of the Mg-multicomponent

database which is essential for further development of Mg alloys.

The experimental investigations published in the literature reported two ternary phases

in the Al-Mg-Ca systems as well as extensive ternary solubilities of binary

intermetallics in the Al-Mg-{Ca,Sr} systems. Wide ranges of homogeneity were

reported for most of the binary compounds, but the data on their compositions and

solubility ranges is contradictory. Additionally, the phase equilibria among the phases

should be verified. In this work, we present experimental investigation and

thermodynamic calculation of the Al-Mg-{Ca,Sr} ternary phase diagrams compared

with the thermodynamic models reported in literature.

The phase boundaries of the ternary solid solutions were determined using EPMA and

XRD analyses of the diffusion couples and key samples. The experimental investigation

was carried out parallel with thermodynamic calculations. The (Al,Mg)2Ca and

Al2(Mg,Ca) ternary phases with the C36 crystal structures were found at 400ºC. Their

complete solid solubility ranges were determined by the EPMA analysis. The Al2Ca

phase has a complex area of homogeneity. The Mg atoms substitute both Al and Ca

atoms in the ternary solid solution. No ternary phases were found in the Al-Mg-Sr

system, but all binary compounds in the Al-Sr and Mg-Sr systems have extended

ternary solubilities. Our experimental findings and thermodynamic calculations are also

compared with the previous experimental and modeling work reported in the literature.

As a result, we have determined that the thermodynamic datasets reported in literature

should be substantially modified to correctly describe the compositions of the ternary

phases, ternary extensions of the binary solid solutions and phase relations in the Al-

Mg-{Ca,Sr} systems.


49

Thermodynamic Modelling and Experimental Investigations of the (Mg, Al)-Ca-Zn System M. Medraj a, Sk. Wasiur Rahman a, D. Kevorkov a, J. Li b, E. Essadiqi b, Y. Zhang a, S. Konica a, P. Chartrand c a Concordia University, Montreal, Canada b MTL-CANMET, Ottawa, Canada c Ecole Polytechnique, Montreal, Canada

Critical assessment of the experimental data and re-optimization of the binary Mg-Zn,

Ca-Zn, Al-Zn, Al-Ca systems and the Laves phase in the Mg-Ca system have been

performed. In the present assessment, the Modified Quasichemical Model in the pair

approximation is used for the liquid phase to account for the presence of the short-range

ordering properly. The intermediate solid solutions are modeled using the compound

energy formalism. Since the literature included contradicting information regarding the

ternary compounds in both ternary systems, thermodynamic modeling and experimental

investigations are used to determine the most likely description of the two ternary

systems and to exclude the self-contradicting experimental observations. All available

as well as reliable experimental data both for the thermodynamic properties and phase

boundaries are reproduced within experimental error limits.

Diffusion couples experiments were performed to verify the calculated Mg-Ca-Zn and

Al-Ca-Zn systems. This experimental work is still underway and details will be

discussed during this presentation.


50

The Standard Enthalpies of Formation of Some Binary Intermetallic Compounds of Late 4d and 5d Transition Metals by High Temperature Direct Synthesis Calorimetry. S. V. Meschel a, P. Nash a, Q .X. Chen b a Illinois Institute of Technology,Thermal Processing Technology Center, 10 W. 32nd

Street, Chicago, Illinois, 60616 b Oak Ridge national Laboratory, Oak Ridge, Tenn.,

The standard enthalpies of formation of binary intermetallic compounds of some late

4d and 5d transition metals have been measured by high temperature, direct synthesis

calorimetry at 1373± 2K. The following results in kJ/mole of atoms are reported:

NbMn2(-10.4±2.7); NbRu(-0.7 ± 2.8);RhMo(-4.8 ± 1.8); PdMn(-45.2±2.2);

Pd2Mo(-9.2 ± 1.9); TaMn2(-14.5±2.5); IrMn3 (-13.2 ± 2.8); Pt3Cr(-8.8± 3.1);

PtMn(-53.6±1.5); PtMo(-17.9±2.2); Pt3Ta(-21.1±2.4);

The values are compared with predicted values of Miedema and Coworkers and with

new results from ab initio calculations when available. We will present a systematic

picture of how the enthalpies of formation may be related to the atomic number of the

transition metal. We will also compare the thermochemical behavior of the

Fe, Co, Ni group with the late transition metal alloys.

CALPHAD XXXVIII Abstracts – Wednesday

51

Solidification paths and stability of precipitates in Mg-Al-Zn-Mn alloys modified by Ca, Ce, Si, Sr and Sn J. Gröbner, R. Schmid-Fetzer

Institute of Metallurgy, Clausthal University of Technology, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld, Germany

Standard lightweight magnesium alloys, such as AZ91 cast alloy or AZ31 wrought

alloy, are based on the Mg-Al-Zn-Mn system, which also includes the AM alloy series.

Solidification paths and the nature of precipitates are well known in this system [1]. A

key aspect in the microstructure design of advanced Mg alloys is the control of

precipitate formation during solidification and heat treatment or hot forming. This

applies to the initial stages of solidification, relevant for grain refinement, to the

subsequent multiphase precipitation with distinct sequence of phases, to thermally

stable precipitates for improved creep resistance and so on.

A rich variety of precipitates may be formed by modification of AZ and AM alloys with

promising additions like Ca, Ce, Si, Sr and Sn. In attempting, for example, improved

properties at elevated temperature it is not unusual to select "thermally stable

precipitates" simply based on the melting point of intermetallic compounds. It is shown

in the present study that this simplistic approach may lead to drastically wrong choices,

compared to proper multicomponent multiphase thermodynamic calculations from a

coherent thermodynamic database, recently extended to involve all these components.

Relevant information is extracted from these calculations, such as the sequence of

phases formed during solidification and their stability ranges including incipient and

final melting temperatures. The focus is on phases in equilibrium with (Mg) and

corresponding invariant reactions.

This study is supported by the German Research Foundation (DFG) in the Priority Programme “DFG-SPP 1168: InnoMagTec”

References:

[1] M. Ohno, D. Mirkovic, R. Schmid-Fetzer, Acta Materialia, 54 (2006) 3883.


52

The use of thermodynamic simulation for studying of composition and properties of materials for microelectronics N.I. Il'inykh a,b, T.V. Kulikova b, P.S. Golubeva a

a Ural Technical Institute of Communications and Informatics, 15, Repin Str, Ekaterinburg, 620109, e-mail: [email protected]

b Institute of Metallurgy of Urals Branch of Russian Academy of Sciences, 101, Amundsen Str., Ekaterinburg, 620016, Russia, e-mail: kuliko@gmail

Nowadays the roles of material and instrument on its basis are clamped increasingly more closely. Therefore in contemporary electronic engineering it is correctly to speak not about the separate materials, but about the formation of the complex structures. It is difficult to present development and research of the processes of obtaining the semiconductor multifunctional structures of complex composition and structure without the preliminary thermodynamic examination. The importance of thermodynamics is exceptionally great in the solution of the contemporary problems of microelectronics, especially in the creation of the flexible technologies, which determine the general technical progress of electronic engineering. This work is devoted to the investigation of behavior of compounds of Ga-As, Ga-Sb, In-As, In-Sb, Al-As, Al-Sb systems at heating in a wide range of temperatures in the atmosphere of argon and oxygen. Calculations were carried out using the thermodynamic modeling method. As the software the program complexes TERRA and RECTANGLE were used. These programs were created in the Moscow State Technical University named by Bauman. For the realization of thermodynamic simulation the corresponding data base was formed, which contains information about the thermochemical properties of the substances in different states of aggregation (standard enthalpies and entropies of formation, temperature dependences of heat capacities, so on). Values of 0

00298 HH −

were calculated by authors of this work. Information about other properties was undertaken from the literature [1-2]. There were calculated the temperature dependences of content of components of condensed media and gaseous phase. The regions of existing of different phases are determined. The phase diagrams “composition – temperature” were constructed for all investigated systems. So the computer experiment carried out with the use of thermodynamic modeling method has scientific and practical importance. It permits to forecast the optimum conditions to obtaining and formation of product with the specific quality indicators. Thus, it is possible to say that the role of thermodynamics in the solution of the contemporary problems of microelectronics is exceptionally great, especially in the creation of the flexible technologies, which determine the general technical progress of electronic engineering.

This study was supported by RFBR (project No 08-03-00941-a).

References:

[1] H. Yokokawa, Tables of Thermodynamic Properties of Inorganic Compounds, J. Nat. Chem. Laboratory for Industry Japan, 83 (1988) 27.

[2] I. Barin, O. Knacke, O. Kubashewski. Thermochemical properties of inorganic substances. Supplement. 1977. Springer – Verlag. Berlin – Heidelberg – New-York.


53

Correlation between thermodynamics and glass forming ability in the Al–Ce–Ni system Chengying Tang a,b,c, Yong Du b, Jiong Wang b, Huaiying Zhou b, Lijun Zhang b, Joonho Lee c a Department of Materials Science and Engineering, Guilin University of Electronic

Technology, Guilin, Guangxi 541004, China b State Key Laboratory of Powder Metallurgy, Central South University, Changsha,

Hunan 410083, China c Department of Materials Science and Engineering, Korea University, 5-1 Anam-dong,

Seongbuk-gu, Seoul 136-713, Korea

The Al–rich corner of ternary Al–Ce–Ni metallic glass-forming system was investigated

by experiment, thermodynamic modelling and first–principles calculations. A consistent

thermodynamic data set for the Al–Ce–Ni system was obtained. Based on the

correlation between glass forming ability (GFA) and thermodynamics, we found that

the alloy with the eutectic composition demonstrates poor GFA due to its smaller heat

of mixing. Alloys with high GFA appear in off-eutectic area of the Al–Ce–Ni system

with heats of mixing ranging from –15 to –49 kJ/mol of atom. It is revealed that

nucleation driving force is a dominant factor determining the formation of amorphous,

in comparison with the negative heats of mixing for the Al–Ce–Ni alloys in the glass

forming range, and those alloys with minimum driving forces show highest GFA

according to the melt spinning experiment and the calculation for driving force of

crystalline phases in supercooled liquid state. We thus conclude that the negative heats

of mixing and minimum driving forces are the criteria to select the glass forming

compositions in the Al–Ce–Ni system.


54

Reassessment of the Al-Fe-Ni system via a hybrid approach of ab initio calculations, clariometry and CALPHAD Lijun Zhang a, Yong Du a, J. Wang a, R.X. Hu b, P. Nash b, X.-G. Lu c a State Key Laboratory of Powder Metallurgy, Central South University, Changsha,

Hunan, 410083, P. R. China b Thermal Processing Technology Center, Illinois Institute of Technology, 10 West 32nd

St., Chicago, IL 60616 USA c Thermo-Calc Software AB, Björnnäsvägen 21, 113 47 Stockholm, Sweden

The enthalpies of formation of two ternary compounds, �1 (Al9FeNi) and �2

(Al10Fe3Ni), were determined via a combination of ab initio calculations and

calorimetry technique. The ground state structures of the two ternary compounds were

also determined by minimizing their total energies with respect to different atomic

arrangements according their published space group and prototype structure.

Additionally, the total energies of Al2FeNi, AlFe2Ni and AlFeNi2 (at.%) in L12 structure

at ground state were calculated by means of ab initio calculations. Based on the new

data from the literature and the present work, as well as our previous modelling [1], a

thermodynamic reassessment of the Al–Fe–Ni system was performed over the entire

composition and temperature ranges. Comprehensive comparisons show that most of

the reliable data can be well reproduced by the present description. Noticeable

improvements have been made, compared with our previous assessment [1]. It is also

confirmed that the Bcc_B2 miscibility gap exists in the Al–Fe–Ni system by employing

single-equilibrium calculation. This interesting feature has also been experimentally

observed and predicted using ab inito calculations [2, 3].

References:

[1] L.J. Zhang, Y. Du, CALPHAD, 31 (2007) 529. [2] C.T. Liu, S.C. Jeng, C.C. Wu, Metall. Mater. Trans. A, 23 (1992) 1395. [3] F. Lechermann, M. Fähnle, J.M. Sanchez, Intermetallics, 13 (2005) 1096.

Acknowledgement: This research work is supported by Creative Research Group of National Natural Science Foundation of China (Grant No. 50721003).


55

On the four-phase reactions in the Ti-Ni-Al system A.Ullah Khan a, X. Yan a, A. Grytsiv a, P. Rogl a, A. Saccone b a Institute of Physical Chemistry, University of Vienna, Vienna, Austria b Dipartimento di Chimica e Chimica Industriale, Università di Genova, Sezione di

Chimica Inorganica e Metallurgia, Genova, Italy

Although several research teams have investigated the Ti-Ni-Al system, phase

equilibria are still far from beeing complete (for recent reviews see [1,2]). For instance

neither the transition temperature for the reaction among the phases NiAl, TiNiAl(τ3),

TiNiAl2(τ2), TiNi2Al(τ4) nor among the phases TiNiAl, Ti3NiAl8(τ1), TiAl2, TiNiAl2 has

been reported. Furthermore the phase relations around the Ti-rich part of the Laves

phase TiNiAl(τ3) have not been fully elucidated as they are further complicated by a

novel ternary compound, τ5, which has been recently observed by us [3].

In order to solve these problems several four-phase reactions in the Ti-Ni-Al system

were studied on a series of alloys, which were annealed at carefully set temperatures

and quenched. The phase constitution was established by XRD and EMPA analyses.

Due to sluggish reaction kinetics, the transition temperatures were defined by annealing

and quenching techniques as no DTA signals could be received. Reaction temperatures

have been defined for NiAl+TiNiAl ⇔ TiNiAl2+TiNi2Al and for TiNiAl+Ti3NiAl8 ⇔

TiAl2+TiNiAl2. Furthermore we confirmed the three-phase field TiNi2Al+Ti3Al+Laves

(TiNiAl), as reported by Huneau at 900°C [4]. Also the phase relations and phase

reactions in the Ti-rich part involving τ5 and the Laves phase TiNiAl(τ3) have been

elucidated and will be presented in form of a Schulz-Scheil diagram.

References:

[1] V. Raghavan, Journal of Phase Equlibria and Diffusion, 26 (2005) 268-72. [2] J.C. Schuster, Intermetallics, 14(10-11) (2006) 1304-1311. [3] A. Grytsiv, Xing-Qiu Chen, V.T. Witusiewicz, P. Rogl, R. Podloucky, V.

Pomjakushin, D. Maccio, A. Saccone, G. Giester, F. Sommer, Z. Kristallografie, 221 (2006) 334-348.

[4] B. Huneau, P. Rogl, K. Zeng, R. Schmid-Fetzer, M. Bohn, J. Bauer, Intermetallics, 7 (1999) 1337-45.


56

Experimental Study and Thermodynamic Modelling of the Ternary Al-Ta-Ti System V.T. Witusiewicz a, A.A. Bondar b, U. Hecht a, J. Zollinger a, V.M.Petyukh b, V.M. Voblikov b, T.Ya. Velikanova b a Access e.V., Intzestr. 5, 5272 Aachen, Germany b Frantsevich Institute for Problems of Materials Science, Krzhyzhanovsky Str. 3,

03680, Kyiv, Ukraine

Phase relations in the binary Al-Ta system were critically assessed on the basis of

recent experimental data. Alloys of different compositions were prepared and analyzed

by means of DTA, DSC, Pirani-Altertum, SEM/EDS and SEM/EBSD techniques in

order to refine the phase relations in the system. Both, as-cast and annealed samples

were investigated. The thermodynamic description of the entire ternary Al-Ta-Ti system

is obtained by CALPHAD modelling of the Gibbs energy of all individual phases,

taking into account experimental data on phase equilibria published and complemented

by own experiments. The description includes also a re-evaluation of the constituent

binary Al-Ta system. Equilibrium calculations of the phase diagram and of

thermodynamic properties were performed with the Thermo-Calc software using the

proposed description. They are shown to properly reproduce experimental data.


57

Thermodynamic Assessment of the Al-Ir-Ni Ternary System Taichi Abe a, Machiko Ode a, Cenk Kocer a,b, Yoko Yamabe-Mitarai a, Hideyuki Murakami a a National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047,

Japan. b School of Physics, University of Sydney, Sydney 2006 Australia.

Since the late 90’s we have intensively investigated the Ir-based refractory superalloys

[1, 2] because of the potential application as high temperature structural materials. The

results indicated promising mechanical properties in the Al-Ir-Ni alloys, where the fine

dispersion of an intermetallic compound in the fcc-matrix was considered to be the

strengthening mechanism in these alloys. In the present study, the CALPHAD-type

thermodynamic assessment of the Al-Ir-Ni ternary system was performed based on the

previous assessments [3, 4]. The AlIr (B2) phase was described using the two sublattice

model with the formula (Al,Ir,Ni,Va)0.5(Al,Ir,Ni,Va)0.5, and L10/L12 phases was

described by the four sublattice model with the formula

(Al,Ir,Ni)0.25(Al,Ir,Ni)0.25(Al,Ir,Ni)0.25(Al,Ir,Ni)0.25, while other intermetallic phases

were treated as stoichiometric compounds. From ab initio calculations (VASP,

WINE2k) the formation enthalpy of each intermetallic phase was estimated. The

calculated thermodynamic quantities such as the phase equilibria, invariant reactions,

and formation enthalpy of intermetallic phases, agree well with experimental data.

References:

[1] Y.Yamabe-Mitarai, Y.Ro, T.Maruo, H.Harada, Intermetallics, 7 (1999) 49-58. [2] Y.Yamabe-Mitarai, H.Aoki, P.Hill, H.Harada, Scripta Mater., 48 (2003) 565-570. [3] T.Abe, M.Ode, C.Kocer, H.Nurakami, Y.Yamabe-Mitarai, H.Onodera, CALPHAD,

32 (2008) 686-692. [4] N.Dupin, Private communication.


58

Phase Equilibria in the Ti–Al–Nb–Mo System D.M. Cupid a,b , O. Fabrichnaya a, F. Ebrahimi b, H.J. Seifert a

a Institute of Materials Science, Freiberg University of Mining and Technology, Freiberg, Germany

b Department of Materials Science, University of Florida, Gainesville, Florida, USA

Two phase alloys based on a γ–TiAl matrix with disconnected σ–Nb2Al precipitates are

promising for aero-based turbine applications since these alloys are expected to display

high temperature strength, creep resistance, and fracture toughness as well as low

temperature ductility. To improve microstructural control of the alloys, target alloys

should initially solidify as single phase β–bcc and produce the two-phase

microstructures on cooling.

Calculations performed with an existing thermodynamic dataset for the Ti–Al–Nb

system indicate that β–bcc stabilizing elements such as Mo are necessary. Within the

framework of building a thermodynamic description for the Ti–Al–Nb–Mo system, an

existing dataset for the binary Al–Mo system [1] was re-assessed. The re-optimized

dataset calculates the congruent melting of the ζ2–AlMo phase [2] as well as reported

phase equilibria in the Al–Al8Mo3 region indicating peritectic formation of the Al22Mo5

and Al17Mo4 phases and peritectic formation and eutectoid decomposition of the Al3Mo

and Al4Mo phases [3]. The Al3+xMo1-x phase observed in [4] was not modelled in the

present description as the existence of this phase could not be confirmed in [3].

The re-assessed description of the Al–Mo system was used as the constituent binary for

creating a thermodynamic dataset for the Ti–Al–Mo system. The present Ti–Al–Mo

description calculates the experimentally observed single phase β–bcc field at a

composition of Ti–52 at.% Al–3 at.% at 1773 K, as well as the invariant transformation

reaction β + Mo3Al8 → TiAl3 + Mo3Al at 1540 K [5].

References:

[1] N. Saunders in: I. Ansara, A.T. Dinsdale, M.H. Rand (eds.): COST 507, Thermochemical database for light metal alloys, Vol. 2 EUR 18499 (1998) 59.

[2] J. Rexer, Z. Metallkd., 62 (1971) 844. [3] M. Eumann, G. Sauthoff, M. Palm, Int. J. Mater. Res., 97 (2006) 11. [4] J.C. Schuster, H. Ipser, Metall. Trans. A, 22 (1991) 1729. [5] R. Nino, J. Fujinaka, H. Shimamura, S. Miura, T. Mohri, Intermetallics, 11 (2003)

611.

CALPHAD XXXVIII Abstracts – Thursday

59

Effect of Bi and Sb additions on wettability of Sn-Zn Solders Z. Moser a, K. Bukat b,W. Gąsior a, J. Sitek b, M. Kościelski b, J. Pstruś a a Polish Academy of Sciences, Institute of Metallurgy and Materials Science, 30-059

Krakow, Reymonta Str. 25, Poland, [email protected] b Tele and Radio Research Institute, 03-450 Warszawa, Ratuszowa Str. 11, Poland,

[email protected]

The influence of Bi and Sb added to Sn-Zn alloys on their surface and interfacial

tension and the wetting properties on the Cu substrate, expressed by the wetting angle,

were investigated [1-3]. The performed analysis suggest that none of the investigated

compositions of the quaternary Sn-Zn-Bi-Sb alloys, have the optimal composition for

practical application. Therefore, the further studies were directed on the Sn-Zn-Bi alloys

to investigate the influence of Bi additions on surface tension, interfacial tension and

density of Sn-Zn-Bi alloys (Bi =1 and 3 % by mass). The following methods were used:

maximum bubble method for surface tension, Miyazaki method for surface tension and

interfacial tension with density from dilatometric technique. Addition of Bi element in

comparison to the SnZn7 decreases slightly surface tension measured in Ar + H2

atmosphere similarly to Butler’s modeling. There is observed also the similar slight

decrease of the surface tension from Miyazaki method measured in air and in nitrogen

and are on the lower level for interfacial tension using flux in nitrogen. The positive

influence was observed also of Bi additions in SnZn7 alloys on surface tensions and

interfacial tension by wetting angles calculations from interaction with the Cu substrate

on PCBs with different lead-free finishes.

References:

[1] Z. Moser, W. Gąsior, K. Bukat, J. Pstruś, J. Sitek, “Trends in wettability studies of Pb-free solders. Basic and application. Part I. Surface tension and density measurements of Sn-Zn and Sn-Zn-Bi-Sb alloys. Experiment vs. modeling”. Archives Metallurgy and Materials, 53 (2008) 1055.

[2] K. Bukat, Z. Moser, W. Gąsior, J. Sitek, M. Kościelski, J. Pstruś “Trends in wettability studies of Pb-free solders. Basic and application. Part II. Relation between surface tension, interfacial tension and wettability of lead-free Sn-Zn and Sn-Zn-Bi-Sb alloys”. Archives Metallurgy and Materials, 53 (2008) 1064.

[3] K. Bukat, J. Sitek, Z. Moser, W. Gąsior, M. Kościelski, J. Pstruś “Evaluation of the influence of Bi and Sb additions to Sn-Ag-Cu and Sn-Zn alloys on their surface tension and wetting properties using analysis of variance–ANOVA”. Soldering & Surface Mount Technology, 20 (2008) 9.


60

Thermodynamics and thermophysical properties of liquid Au-Ge alloys D. Giuranno a, S. Delsante b, Y. Eichhammer c, S. Amore a, F. Valenza a, R. Novakovic a a National Research Council (CNR) – Institute for Energetics and Interphases (IENI),

Via De Marini, 6 - 16149-Genoa (Italy) b DCCI-University of Genoa, Via Dodecaneso, 31 – 16146 Genoa (Italy) and Genoa

Research Unit of National Consortium of Materials Science & Technology (INSTM) c Department of Metallurgy and Materials Engineering, Faculty of Engineering,

Katholieke Universiteit Leuven, Kasteelpark Arenberg 44, B - 3001 Leuven, Belgium

The mixing behaviour of liquid Au-Ge alloy system has been investigated by the Quasi-

Chemical Approximation (QCA) in the frame of the Quasi-Lattice Theory (QLT)

combined with a statistical mechanical theory. Assuming the order energy parameters as

temperature dependent, various thermodynamic quantities are calculated at different

temperatures using the QCA for regular solution and the subregular solution model.

Thermodynamic properties of this system deviate negatively from the Raoult’s law,

while the thermophysical properties exhibit an opposite trend, typical for compound

forming systems. The energetics of mixing in liquid alloys has been analysed through

the study of surface properties (surface tension and surface composition), transport

properties (diffusion, viscosity, el. resistivity) and microscopic functions (concentration

fluctuations in the long-wavelength limit and chemical short-range order parameter).

Theoretical results are in agreement with the corresponding literature data and support a

compound forming tendency in liquid Au-Ge alloys.


61

Assessment of potential solder candidates for high temperature applications Vivek Chidambaram, John Hald, Jesper Hattel, Rajan Ambat

Department of Mechanical Engineering, Denmark Technical University, Building 425, Produktionstorvet, Lyngby, DK-2800, Denmark.

Multi-Chip module (MCM) technology is a specialized electronic packaging technology

recently gaining momentum due to the miniaturization drive in the microelectronics

industry. The Step soldering approach is being employed in the MCM technology. This

method is used to solder various levels of the package with different solders of different

melting temperatures. High Pb containing alloys where the lead levels can be above

85% by weight, is one of the solders currently being used in this technology. Public

awareness of environmental issues including the use and disposal of potentially toxic

materials has never been greater, with lead being the subject of particular scrutiny.

Thus, in industry there is now an increasing pressure to eliminate lead containing

materials despite the fact that materials for high Pb containing alloys are currently not

affected by any legislations. A tentative assessment was carried out to determine the

potential solder candidates for high temperature applications based on the solidification

criterion, phases predicted in the bulk solder, oxidation resistant and atmospheric

corrosion resistant properties using the CALPHAD approach. These promising solder

candidates were precisely produced using the hot stage microscope and its respective

anodic and cathodic polarization curves were investigated using a micro

electrochemical set up. Focus has also been given to the property of corrosion resistance

since corrosion resistance is a major issue for lead-free solder alloys. Corrosion

products are easily formed and increase current transport resistance in practice. Lower

corrosion resistance is a representative of a lower current conductive effect and reduces

the life time of devices. Although the cost of corrosion in the electronic sector could not

be estimated, it has been suggested that a significant part of all electronic system

failures are caused by corrosion. Thus, the determined potential solder candidates were

also classified based on its property of corrosion resistance.


62

Study of Ce - Sn binary system R. Čička a, M. Ožvold a, A. Zemanová b, A. Kroupa b, J. Lokaj c, J. Janovec a a Institute of Materials, MTF STU, Bottova 25, 917 24 Trnava, Slovakia b Institute of Physics of Materials, AS CR, Žižkova 22, 616 62 Brno, Czech Republic c Institute of Inorganic Chemistry, FCHPT STU, Radlinského 9, 812 37 Bratislava,

Slovakia

Recently much effort was done in the investigation of systems based on Sn-Ag-Cu with

respect to improving their solderability and properties. These systems seem to be

suitable for replacement of lead-containing solders, traditionally used in electronic

industry [1 - 4]. To describe the influence of additional elements in the Sn-Ag-Cu

system, the theoretical modelling of phase diagrams of relevant multicomponent system

is the useful tool. The CALPHAD method can be used for such modelling, using

existing lower order systems and extrapolating them to the higher order systems. Good

assessments of necessary binary systems are crucial for this approach.

This work deals with the binary Ce-Sn system. Three samples with 2.81, 3.22, or 4.23

wt.% Ce were prepared and analysed using XRD, SEM+EDX, and DSC techniques.

The XRD experiments confirmed the presence of Sn and CeSn3 phases. The SEM/EDX

measurements revealed two microstructure constituents; the Sn+CeSn3 eutectic and the

primary solidified CeSn3 particles. However, the eutectic contained more cerium than

reported in the literature varying in dependence on the bulk Ce content. In the next step

therefore, the isothermal annealing of the samples was done to reach nearly equilibrium

conditions. All the available experimental results were used to compile and assess the

binary Ce-Sn system, necessary for the modelling of more complex alloys.

References:

[1] C.M.L. Wu, D.Q.Yu, C.M.T. Law, L. Wang, Mat. Sci. Eng., R 44 (2004) 1. [2] M. Palcut, J. Sopousek, L. Trnková, E. Hodulova, B. Szewczykova, M. Ozvold, M.

Turna, J. Janovec, Kovove Mater. (in press). [3] S. Mhiaoui, F. Sar, J.G. Gasser, J. Non-Cryst. Solids, 353 (2007) 3628. [4] Y.H. Tian, C.Q. Wang, W.F. Zhou, Acts Metall. Sin. (Engl. Lett.), 19 (2006) 301.


63

Thermodynamic modeling of the Au-Ge-X (X = Sb, Si, Sn) systems J. Wang*, C. Leinenbach, M. Roth

EMPA, Swiss Federal Laboratories for Materials Testing and Research, Laboratory for, Joining and Interface Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland

Sn-Pb alloys have been often used as important soldering materials. However, because

Pb is harmful to both the environment and human health, increasing efforts have been

made to search for suitable Pb-free solders to replace the conventional Sn-Pb alloys.

Au-based alloys as high temperature Pb-free alloys, including Au-20wt.%Sn, Au-Si and

Au-Ge eutectic alloys, have been employed extensively during the optoelectronic

packages because of their superior creep resistance, high thermal and electrical

conductivities as well as excellent solder ability. In the present work, thermodynamic

modeling of the Au-Ge-X (X = Sb, Si, Sn) systems have been performed using the

CALPHAD method. Based on the available experimental information, the Au-Ge and

Ge-Sb binary systems have been thermodynamically assessed firstly using the

compatible lattice stability. Then combined with previous assessment of Au-Si, Au-Sn,

Ge-Si, Ge-Sn, Sb-Sn, Sb-Si and Si-Sn binary systems, thermodynamic optimizations of

the Au-Ge-X (X = Sb, Si, Sn) ternary systems have been carried out. Thermodynamic

properties of liquid alloys, liquidus projections and vertical and isothermal sections

have been calculated, which are in reasonable agreement with the reported experimental

data. The available and consistent thermodynamic database of the Au-Ge-X (X = Sb, Si,

Sn) systems has been obtained finally.

*Corresponding author’s e-mail: [email protected]


64

Can a physical unsoundness of a solution model be detected prior to launching a thermodynamic optimization? Dmitri V. Malakhov, Mehdi Hosseinifar

Department of Materials Science and Engineering, McMaster University, Hamilton, Ontario, Canada

Before a procedure tailored for a thermodynamic optimization returns statistically

optimal numerical values of model’s parameters, an appropriateness of the model to

describe the Gibbs energy of the phase is meticulously considered, indeed. While

analyzing the suitability, one usually starts with crystallography of the phase and data

on its homogeneity range [1, 2]. In addition to this bare minimum, one tries to make a

good use of other properties in hope to arrive at a physically feasible phase model [3, 4].

Despite all the efforts, the model may demonstrate an unexpected behavior and result in

artifacts on calculated phase boundaries and concentration and temperature

dependencies of thermodynamic functions [5]. Usually, awkward manners of the model

are discovered after an assessment has been carried out and its outcome has been

published, i.e., when it is too late to undertake corrective actions.

It is extremely difficult and hardly possible to formulate a criterion of correctness,

which, if satisfied, guarantees that a corresponding model is physically sound. Instead

of seeking such a condition of trustworthiness, it was decided to look for a criterion of

erroneousness, which, if fulfilled, warns one against employing a model under

examination. After an exotic yet not insane criterion of wrongness proposed by the

authors is introduced, its applicability to real-life problems will be illustrated on a series

of both thermodynamic examples (a study of models describing the Gibbs energies of

liquid solutions in the Mg–Pb and Sn–Zn systems, and an analysis of Einstein and

Debye models for heat capacity) and an entertaining non-thermodynamic case (a

description of the velocity of a parachutist as a function of time).

References:

[1] K.C.H. Kumar et al., CALPHAD, 22 (1998) 323. [2] J-M. Joubert, Progress in Materials Science, 53 (2008) 528. [3] M. Hillert et al., Metallurgical Transactions A, 16A (1985) 261. [4] A.N. Grudny et al., International Journal of Materials Research, 99 (2008) 1185. [5] R. Schmid-Fetzer et al., CALPHAD, 31 (2007) 38.


65

On a boundary condition for excess Gibbs energy of solution phases at an infinite temperature G. Kaptay

BAY-NANO + University of Miskolc, 3515 Hungary, Miskolc, Egyetemvaros E/7

In the present paper the following boundary condition is suggested: ‘Real solid, liquid

and gaseous solutions of any composition gradually approach the state of an ideal

solution as temperature approaches infinity at any fixed pressure. All excess

thermodynamic properties of real solutions gradually approach zero if the reference

states of all the components are selected as pure components in the same state as that of

the solution and if the concentrations are expressed in mole fractions’. The key

equations for partial and integral excess Gibbs energy and excess volume are given as

follows:

0limlim =Δ=Δ∞→∞→ T

E

T

Ei GG

0limlim =Δ=Δ∞→∞→ T

E

T

Ei VV

Similar equations are valid for the derivatives of the above quantities (such as mixing

enthalpy, excess entropy, excess heat capacity, excess volume expansion coefficient and

excess compressibility). The validity of this boundary condition is checked on the most

recent compilation of excess thermodynamic data by Predel [1]. The logarithmic T-

dependence of the interaction energies suggested by the author earlier [2] is one of the

possible semi-empirical equations obeying the above boundary conditions. However,

this particular equation will not be stressed in this talk, as other alternatives might exist,

as well [3]. Ones accepted by the Calphad community, this boundary condition can be

used to avoid inverted miscibility gaps in Calphad-type calculations and also can be

considered as a 4th law of chemical thermodynamics(-:

References:

[1] B.Predel, Phase Equilibria, Crystallographic and Thermodynamic Data of Binary Alloys, sub-volumes 5a-5g of group IV of Landolt-Börnstein Handbook, Springer-Verlag, Berlin, Germany, 1991-1997.

[2] G.Kaptay, Calphad, 28 (2004) 115. [3] R.Schmid-Fetzer, D.Andersson, PY Chevalier, E.Eleno, O.Fabrichnaya, UR

Kattner, B Sundman, C Wang, A Watson, L Zabdyr, M. Zinkevich, Calphad, 31 (2007) 38.


66

From topology to computer model: ternary systems with polymorphism V. Lutsyk, V. Vorob’eva

Physical Problems Department, Siberian Branch of the RAS, Ulan-Ude, RUSSIA

Investigation results of T-x-y diagrams geometrical constructions of ternary systems

with polymorphism poorly described in literature are represented. The special attention

had been given to phase diagrams with such liquidus which consists of both high- and

low-temperature modifications [1]. To decode the diagrams topology the schemes of

monovariant states (of 3-phase regions) had been elaborated. This sort of schemes with

phase’s routes designations makes possible to calculate the number of phase regions,

surfaces and to know a type of every surface (plane, ruled or unruled surface). Detail

analysis of T-x-y diagrams geometrical constructions had been carried out with their

help and their computer models had been designed. For instance, the T-x-y diagram

with low-temperature modifications A1 and B1 of components A and B has 90 surfaces

(5 liquidus and 5 solidus, 6 solvus, 12 unruled surfaces – borders of 2-phase regions

A+A1 and B+B1, 42 ruled surfaces, 20 horizontal simplexes) and 33 phase regions

(Figure).

Figure. Ternary system with the liquidus surfaces of low-temperature modifications A1 and B1: x-y projection (a), polythermal section I-II (b)

References:

[1] K.A. Khaldoyanidi, Rus. J. of Phys. Chem., 76 (2002) 697.

Supported by the RFBR grant 09-03-00986-a


67

A thermodynamic description of the order-disorder transitions in a multi-component fcc solid solution M. Jiang a, H.X. Li a, I. Ohnuma b, K. Oikawa b, K. Ishida b a Key Laboratory for Anisotropy and Texture of Materials, Northeastern University,

Shenyang 110004, China b Department of Materials Science, Faculty of Engineering, Tohoku University, Sendai

9808579, Japan

Due to the importance of science and technology of the thermal stability of the γ′ phase

in Ni- and Co-base alloys, the γ/γ′ phase equilibrium in the Co-Al-Ni-W system has

been studied by a CALPHAD approach. Comparing with previous theoretical

calculations, an emphasis has been put on the thermal stability of γ′ phase both in stable

and metastable state. The fcc phases including A1, L10 and L12 have been described by

a modified four-sublattice model with short range order (SRO) taken into account.

The binary Co-Al and Ni-Al phase diagrams have been recalculated. The calculation

can not only reproduce the stable phase diagram data and thermodynamic properties

well, but also can reproduce the metastable fcc Ni-Al and Co-Al phase diagrams. The

thermal stability of the metastable L12_Co3W has also been estimated. For the ternary

systems, the stable phase diagrams at higher temperatures were firstly calculated, and

the model parameters for the disordered fcc phase can be optimize separately. The

calculation can reproduce the stability of the ternary γ′ phase in the Co-Al-W, Co-Al-Ni

and Al-Ni-W systems by employing the thermal stabilities of the stable L12_Ni3Al, the

metastable L12_Co3Al and L12_Co3W estimated in the binary systems.

The γ/γ′ phase equilibrium in the Co-Al-Ni-W system can then be calculated. A

systematic experiment had been done in Prof. Ishida’s group where Ni was added to Co-

Al-W alloys from 10 to 60 at.%, and the γ/γ′ phase equilibrium was determined. The

calculation agrees well with the experiments. It should be mentioned that no additional

model parameters were used here in the quaternary system, the calculation was finished

by using the model parameters of the four ternary systems. The calculation shows that

the addition of Ni can increase the thermodynamic stability of the γ′ phase.


68

Phase field simulation of solidification in Al-Ni alloys coupled with thermodynamic and atomic mobility databases Lijun Zhang, Yong Du

State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, 410083, P. R. China

Atomic mobilities of both Al and Ni in liquid and solid phases of the Al-Ni system were

obtained through assessments of all kinds of diffusion coefficients available in the

literature by the DICTRA (DIffusion-Controlled TRAnsformations) simulation

package. Significant improvements have been made, compared with the previous

assessment [1, 2]. With inputs of thermodynamic and mobility databases,

polycrystalline solidification process involving nucleation and subsequent anisotropic

growth in Ni-10 at.% Al alloy was studied by 2D phase field simulation via MICRESS

(MICRostructure Evolution Simulation Software). All the other thermophysical

parameters needed in MICRESS were confirmed by comparing 1D phase filed

simulation results with DICTRA simulation. The transformation kinetics of

polycrystalline solidification obtained by phase field simulation was compared with the

Johnson-Mehl-Avrami-Kologoromov (JMAK) theory through analyzing the growth

kinetics of a single dendrite. The effects of side branches and diffusivities in liquid

phase were also analyzed. Besides, the simulations of microstructure evolution in one

hypoeutectic alloy (Al-4 wt.% Ni) during normal solidification and directional

solidification were performed. The formation of eutectic structure including (Al) and

Al3Ni was observed, which could be of technological interest.

References:

[1] A. Engström, J. Ågren, Z. Metallkd, 87 (1996) 92. [2] C.E. Campbell, Acta Mater., 56 (2008) 4277.

Acknowledgement: This research work is supported by Creative Research Group of National Natural Science Foundation of China (Grant No. 50721003).

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69

A Mechanism of Precipitate-Nucleation in the so-called “N-G Region” of Equilibrium Phase Diagram Toru Miyazaki a, Takao Kozakai a, Claudio G. Schö

n b a Nagoya Institute of Technology, Japan b Sao Paulo University, Brazil

A new characterization method, "Macroscopic Composition Gradient (MCG) Method"

has been recently proposed by us. By using the method, various kinds of phase

transition have successfully been investigated [1, 2]. The critical size of precipitate

nucleus and the nucleation rate near the solubility limit were experimentally obtained

for several binary alloys. The nucleus size shows a steep increase up to several tens of

nm in a very narrow composition range less than 0.3at.% from the phase boundary. The

diameter of nucleus size can reach over 500 nm. The Gibbs-Thomson relation and the

conventional nucleation theory statistically rationalize such composition-dependence of

nucleus size change. However, the nucleus formation is kinetically never rationalized

by the conventional nucleation theories. The kinetic experimental results show

distinctly that the incubation time for nucleation is only controlled by the atom diffusion

and is never affected by the energy barrier for the nucleation. On the basis of

experimental results the application limit of conventional nucleation theory is discussed,

and hence the failure of Boltzmann-Gibbs extensive entropy becomes clear for the early

stage of phase decomposition. A new mechanism of phase decomposition is proposed,

based on the experimental results and the non-extensive entropy. The phase

decomposition of supersaturated solid solution progresses spinodally without energy

barrier for nucleation, even in the so-called Nucleation-Growth region. The N-G region

is caused by an artificial effect arising from the Boltzmann-Gibbs's extensive entropy

and exists only in the equilibrium phase diagram.

Reference:

[1] T.Miyazaki, T.Koyama and S.Kobayashi, Metall.Mater.Trans., 27A (1996) 954. [2] T.Miyazaki, S.Kobayashi and T.Koyama, Metall.Mater.Trans., 30A (1999) 2783.


70

Phase Diagram of the Ag-Pd bimetallic nanoclusters: Practical guideline for nano material designs Da Hye Kim, Hyun You Kim, Ji Hoon Ryu, Hyuck Mo Lee

Department of Materials Science and Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea

The properties of bimetallic nanoclusters are dependent on the composition, the size and

the structures. Firstly, we investigated the solid-to-liquid transition region of

nanoclusters having the different sizes and compositions with molecular dynamics

simulations [1]. Then, to explore the solid state region further, we used the modified

basin hopping Monte Carlo simulations [2] and the density functional theory. The over-

stability of the metastable solid state structures is discussed [3]. The observed results

on the structural stability under given conditions are represented in phase diagrams. Our

phase diagram is supposed to give a brief guidance for practical applications of the Ag-

Pd nanoclusters. As an application, we observed that the Ag-Pd core-shell nanocluster

has more effective catalytic properties for CO oxidation than the pure Ag cluster [4].

The effective structure as a catalyst can be obtained from our nano phase diagram with

respect to composition and temperature.

References:

[1] D. H. Kim, H. Y. Kim, H. G. Kim, J. H. Ryu and H. M. Lee, J. Phys.-Condens. Mat. 20 (2008) 035208; D. H. Kim, H. Y. Kim, J. H. Ryu and H. M. Lee, submitted.

[2] H. G. Kim, S. K. Choi and H. M. Lee, J. Chem. Phys., 128 (2008) 144702. [3] H. Y. Kim, H. G. Kim, D. H. Kim and H. M. Lee, J. Phys. Chem. C, 112 (2008)

17138. [4] H. Y. Kim, D. H. Kim, J. H. Ryu, D. H. Seo and H. M. Lee, submitted.


71

Molecular Statics - Monte Carlo – Molecular Dynamics Hybrid Simulation for Atomistic Structural Evolution in Interstitial Alloys Byeong-Joo Lee, Eun Ha Kim

Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea

Atomistic simulations such as ab-initio calculations, molecular statics (MS), molecular

dynamics (MD) and Monte Carlo (MC) simulations are used to understand the materials

behavior in more fundamental level, e.g. the atomic level. Especially, the MD

simulation has been widely used to investigate the dynamic behavior of materials during

phase transformations or deformations. However, the effect of alloying elements on the

transformation or deformation behavior of materials cannot be examined correctly by

the MD simulation because of not being able to allow the probable diffusion of alloying

elements toward the defects (grain boundaries, crack tip, etc.) during the short

simulation time (order of nano-seconds). Allowing modification of atomic positions by

inserting an MC routine between MD runs can be regarded as a solution to overcome

the above-mentioned limitation of MD simulations. The MC+MD hybrid simulation can

realize the strong interaction between solute atoms and lattice defects, and enable the

investigation of the effects of alloying elements on materials properties. However, in the

case of interstitial alloys, the MC modification of atomic positions is hardly realized

because of the severe local lattice strain around interstitial atoms.

In the present study, we resolve the problem in the MC simulation for interstitial alloys

by introducing a molecular statics (MS) relaxation process that allows lattice relaxation

just after individual MC attempts. This MS+MC hybrid simulation technique is applied

to compute stacking fault energy (SFE) of fcc Fe-N alloys, considering the probable

segragation of nitrogen atoms on the stacking fault region. The MS+MC+MD hybrid

simulation technique is also applied to investigate the effects of interstitial element

atoms, C, N and H on the fracture or deformation behavior of bcc Fe. The non-

monotonic effect of nitrogen content on the SFE of fcc Fe and the similarity or

difference in the effects of interstitial elements on the mechanical behavior of bcc Fe,

which could be investigated only by using the present hybrid simulation, will be

presented.


72

Thermodynamic modelling based on experimental study of the ZrO2-La2O3-Y2O3 system O. Fabrichnaya, H.J. Seifert

Institute of Materials Science, Technical University of Freiberg, Germany

The RE2O3 additives (RE are Rare Earth metals) decrease thermal conductivity of yttria stabilized zirconia (YSZ) thus improving its properties for thermal barrier coating (TBC) application. Two main groups of candidates for new TBC materials are reported, one based on co-doping of YSZ with one or more Rare Earths and the other on pyrochlore type zirconates RE2Zr2O7 (RE = Gd, La). Phase equilibria in the ZrO2-La2O3-Y2O3 were calculated. Initially, two different databases were suggested, because from literature it was not clear, if there was an eutectoid reaction between La2O3(A), LaYO3 and monoclinic phase B in the La2O3-Y2O3 binary system and an invariant reaction B + Pyr = A + LaYO3 in ternary system, respectively. To clarify phase relations in the ZrO2-La2O3-Y2O3 system experimental phase equilibrium study was performed at 1200-1600°C. Samples obtained by the co-precipitation technique were heat treated at temperatures of 1200, 1250, 1400 and 1600°C, respectively. Phase assemblages and compositions were determined by XRD and SEM/EDX. Selected samples with La2O3 rich composition, where the mentioned invariant equilibrium could occur, were heat treated at 1200 and 1250°C and then studied by DTA up to 1700°C. No indication of an invariant reaction was found on heating up to 1500°C. Two endothermic effects were observed at 1500-1600°C. The first effect was attributed to dissolution of Y2O3 in pyrochlore structure and corresponding disordering in cationic sublattices. The second effect was due to transformation of LaYO3 perovskite to monoclinic structure. It was also observed that solubility of Y2O3 increased with temperature and that Y+3 substituted both La+3 and Zr+4. Therefore, it was found that pyrochlore solid solution has a wide homogeneity range along the line with constant ratio Zr/La=1 deviating in both ZrO2 and La2O3 enriched compositions. At 1600°C, pyrochlore dissolves up to 30 mol. % of Y2O3 accompanied by disordering. The obtained results were used to improve the thermodynamic description of the ZrO2-La2O3-Y2O3 system. Modelling of the pyrochlore phase by the compound energy formalism makes it possible to take into account that Y+3 substitutes La+3 and Zr+4 in crystallographic sites preferentially occupied by one of these cations and thus increasing disordering. The formula for the pyrochlore phase can be presented as (La+3,Y+3,Zr+4)2(Zr+4,Y+3,La+3)2(O-2,Va)6(O-2)(Va,O-2) including 36 end-member compounds. The phase diagrams of the ZrO2-La2O3-Y2O3 system are calculated at 1250-1600°C based on new model of pyrochlore.


73

Development of the oxide database for the SOFC applications Ming Chen a, Erwin Povoden b, Jonas Østby a a Fuel Cells and Solid State Chemistry Division, Risø National Laboratory for

Sustainable Energy, DTU, DK-4000 Roskilde, Denmark b Nonmetallic Inorganic Materials, Department of Materials, Swiss Federal Institute of

Technology (Zurich), CH-8093 Zurich, Switzerland

Solid oxide fuel cells are very attractive for power generation systems. The state of the

art SOFC uses yttria stabilized zirconia (YSZ) for electrolyte, Ni-YSZ cermet for anode,

LaMnO3-based perovskite (e.g. La1−xSrxMn1±yO3±δ, LSM) for cathode, and high

temperature oxidation-resistant ferritic steels for interconnects. It is normally operated

at 800−1000 oC. The thermodynamic stability of the component materials and their

mutual compatibility are particularly important for efficient long-term operation of

SOFCs [1].

The oxide database of Co-Cr-Fe-La-Mn-Sr-Y-Zr-O is being developed utilizing the

CALPHAD methodology. All the binary metal-oxygen systems and most of the ternary

metal-metal-oxygen systems have been assessed using experimental thermodynamic

and phase diagram data [1-3]. The descriptions of higher order systems are obtained via

ideal extrapolation. The database is successfully applied to verify the mechanism of the

LSM cathode degradation due to reactions with the YSZ electrolyte or due to the Cr

poisoning and to verify the oxidation mechanism of the interconnect steel.

References: [1] M. Chen, A.N. Grundy, B. Hallstedt, and L. J. Gauckler, Calphad, 30 (2006) 489. [2] E. Povoden, A.N. Grundy, and L. J. Gauckler, Inter. J. Mater. Res., 97 (2006) 1. [3] E. Povoden, A.N. Grundy, and L. J. Gauckler, J. Phase Equili. Diff., 27 (2006) 353.


74

Structure and Phase Stability of Nonstoichiometric Compounds of Tin Oxides Atsuto Seko a, Atsushi Togo b, Fumiyasu Oba b, Isao Tanaka b a Pioneering Research Unit for Next Generation, Kyoto University, Kyoto, Japan b Department of Materials Science and Engineering, Kyoto University, Kyoto, Japan r

The oxides with quadrivalent cations often form a rutile-type structure. Two minerals

with this structure known as rutile (TiO2) and cassiterite (SnO2) have been popular

subjects of fundamental studies for over a century. Both of them often show oxygen

deficiency, which plays a central role in determining their properties and chemical

activities. In the Ti-O system, a series of nonstoichiometric compounds or homologous

compounds are known to exist and are called ‘‘Magnéli phase’’. Many studies have also

been carried out on the nonstoichiometric compounds of SnO2-x. However, the

structures and stabilities are much less understood. To determine the unknown

structures and their stability, a theoretical approach combining first-principles

calculations with a cluster expansion technique can be a powerful tool. In the present

study, a systematic study of the nonstoichiometric compounds in the Sn-O binary

system is carried out by the combined approach [1]. Stable structures for Sn3O4 and

Sn2O3 are found by simulated annealing (SA). In the predicted structures, oxygen

vacancies are aligned along the plane corresponding to (101) of SnO2. They are

composed of SnO2-like and SnO-like local structures. Similar structures for the other

oxygen-deficient compounds using various sizes of supercells were also predicted by

SA. The (101)-layered structures can be expressed as a series of homologous structures

of Snn+1O2n with alternating n layers of SnO2-like bands and a (101) vacancy layer. The

theoretical x-ray diffraction (XRD) patterns for the predicted (101)-layered structure of

Sn3O4 and Sn2O3 are very close to each other, reflecting the similarities of the structures

based on the common SnO and SnO2-like units. The peak positions and relative

intensities of the theoretical XRD patterns are close to those of the experimental XRD

patterns. The agreements of the theoretical and experimental XRD patterns indicate that

the Sn3O4 and Sn2O3 phases observed experimentally in tin oxide systems correspond to

the (101)-layered structures based on the mother rutile structure.

References:

[1] A. Seko et al., Phys. Rev. Lett. 100 (2008) 045702.


75

Determination Phase Equilibria in the Na,K//SO4,CO3,HCO3–H2O System at 00С Sh. Tursunbadalov, L. Soliev

Tajik state pedagogical University, Rudaki 121, Dushanbe, Tajikistan

Phase equilibria in the Na,K//SO4,CO3,HCO3–H2O system at 00С are investigated by

the translation method. It is determined that there are 22 divariant fields, 21

monovariant curves and 7 nonvariant points in the system. The closed phase

diagram(phase complex) of the title system is modeled for the first time on the basis of

the obtained data.

Significant information on phase equilibria in multicomponent systems can be received

by means of modeling by translation method [1, 2] which is based on the topological

properties of geometric images of system and its subsystems and their compatibility in

one diagram [3]. The phase equilibria of the Na,K//SO4,CO3,HCO3–H2O system at 250С

were modeled by the same method [4].

Comparison of geometric images of the system Na,K//SO4,CO3,HCO3–H2O at 0 and

250C determined by translation method is as follows: divariant fields 22 and 32,

monovariant curves 21 and 36, nonvariant points 7 and 13 respectively.

As can be seen from the data provided, the number geometric images for isotherm of

250C are more than for isotherm of 00C, that is linked to a higher number of solid

phases which are in equilibrium at 250C and consistent with the main principles of

Physicochemical Analysis [5].

References:

[1] L.Soliev, Prediction of phase equilibria of multicomponent systems by the translation method. VINITI, Moscow, December, 20 (1987) N8990-B87.

[2] L.Soliev, Prediction of phase equilibria of multicomponent sea water type systems by the translation method (book 1) Dushanbe, TSPU (2000) 247.

[3] Ya.G.Goroshenko, Masscentric method of representation of multicomponent systems. Kiev.: Nauk.Dumka, (1982) 264.

[4] L.Soliev, Sh.Tursunbadalov.// Rus.Journ.Inorg.Chem., 53(5) (2008) 805-811. [5] V.Ya Anosov, М.I.Ozerova, Yu.Ya.Fialkov, Basis of Physicochemical Analysis.

Nauka. М., (1976) 503.


76

Restudy of the quasi-binary system Na2SO4 – K2SO4 by Differential Thermal Analysis (DTA) and Thermo gravimetry (TG) D. Kobertz*, I. Dreger, M. Müller

Institut für Energieforschung, Forschungszentrum Jülich GmbH, GERMANY.

The combustion of solid fuels containing high amounts of sulfur, calcium, potassium and sodium induces the formation of sulfatic depositions (fouling). These depositions diminish the heat conductance and their spalling leads to damages in the power plant. Though different types of experimental work have been done in our lab and in literature, the mechanisms for the formation of these conglomerations are still not yet clear. One can take into consideration that low-melting or adhesive sulfatic phases are able to initiate or will be the assignable cause of this fireside fouling. Multi component (sulfatic) systems can only be really understood after comprehending the basic binary sub-systems. Beside the previous work on Na2SO4-CaSO4 our recent study is focused on the quasi-binary system Na2SO4 – K2SO4 since there are contradictory results and interpretations in the literature (eg. 1. – 11.). Differential Thermal Analysis (DTA) with simultaneous Thermo Gravimetry (TG) as well as X-ray Diffraction (XRD) measurements were done to achieve the transition temperatures and to verify the preparation of the binary compositions. Microstructure analysis was made by Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDX), respectively. DTA experiments in the Na2SO4 – K2SO4 system have been performed under air. Investigations in this system are not yet completed on writing this abstract. So far we found considerable differences to that of the optimized literature data in the range of liquidus – solidus as well as in sub-solidus area. References: [1] J. H. Gladstone, Quart. Journ. of the Chem. Soc., 6 (1854) 106. [2] M. Le Chatelier, Bull. soc. chim., 47 (1887) 300. [3] K. Kubierschky, Hist., (1902) 404-413. [4] J. H. van't Hoff and H. Barschall, Sitzungsber. K. Preuss. Akad. Wiss., 18 (1903)

359-371. [5] E. Jänecke, Z. Phys. Chem. Stoechiom. Verwandschaftsl., 64(3) (1908) 343-356. [6] R. Nacken, Zentralbl. Mineral., Geol. Palaeontol., (1910) 262-271. [7] H. Müller, Neues Jahrb. Mineral., Geol. Palaeontol., Beilageband 30 (1910) 1-54. [8] W. Grahmann, Zeitschrift für Anorganische Chemie, 81 (1913) 257-314. [9] W. Eysel, American Mineralogist, 58(7-8) (1973) 736. [10] J. M. Sangster and A. D. Pelton in "Critical Coupled Evaluation of Phase Diagrams

and Thermodynamic Properties of Binary and Ternary Alkali Salt Systems", Special Report to the Phase Equilibria Program, Part B: Evaluations for 54 common-ion binary systems involving (Li, Na, K) and (F, Cl, OH, NO3, CO3, SO4), American Ceramic Society; Westerville, Ohio; (1987) 4-231.

[11] N. Mofaddel, R. Bouaziz and M. Mayer, Thermochimica Acta, 185(1) (1991) 141-153.

* e-mail: [email protected]


77

Modelling topologically close-packed phases: application to the Mo-Re system J.-M. Joubert, S.-A. Farzadfar

Chimie Métallurgique des Terres Rares, Institut de Chimie et des Matériaux Paris-Est, CNRS, Université de Paris XII, UMR 7182, 2-8 rue Henri Dunant, F-94320 Thiais, France

The modelling of topologically close-packed (tcp) phases is extremely important given

the presence of these phases in many systems of transition metals and therefore in

complex functional alloys such as steels and superalloys. Having models able to

reproduce both their possible compositions and actual configurational entropy is of

primary importance. In this regard, the three most important tcp phases have been

studied: µ, σ and χ [1-3]. In each case, in a quite large number of binary systems, the

atom distribution on the different sites has been studied by crystallographic means. In

particular, the Rietveld refinement method of X-ray powder diffraction data has been

extensively used. Conclusions have been drawn concerning the rules driving the site

occupancies. Consequently, models have been defined in terms of the number and

multiplicity of the sites in which atom mixing can occur in a different manner, as well

as the nature of the atoms occupying these sites.

These models have been used to model the Mo-Re system, an important system for Ni-

based superalloys, in which two tcp phases, σ and χ, are present. An assessment is

presented which reproduces the available experimental data [4].

References:

[1] J.-M. Joubert and N. Dupin, Intermetallics, 12 (2004) 1373-1380. [2] J.-M. Joubert, Prog. Mater. Sci., 53 (2008) 528-583. [3] J.-M. Joubert and M. Phejar, Prog. Mater. Sci., submitted (2009). [4] S.-A. Farzadfar, M. Levesque, M. Phejar and J.-M. Joubert, Computer Coupling of

Phase Diagrams and Thermochemistry, submitted (2009).

CALPHAD XXXVIII Abstracts – Friday

78

Ab-initio Calculations and Phase Diagram Assessments of An-Al Systems, An=U, Np, Pu D. Sedmidubský a,b, P. Souček a, R.J.M. Konings a a Institute of Transuranium Elements, Joint Research Centre, European Commission

P.O.Box 2340, 76125 Karlsruhe, Germany b Institute of Chemical Technology, Technická 5, 166 28 Prague, Czech Republic

Pyrochemical methods for spent nuclear fuel reprocessing are nowadays a subject of

worldwide investigation. Electroseparation techniques in molten LiCl-KCl electrolytes

are developed in ITU to recover all actinides from mixtures containing fission products.

Actinides are during the process selectively electrochemically reduced on a solid

aluminium cathode, forming solid actinide-aluminium alloys. This work is thus focused

on the thermodynamic properties of Np-Al alloys in order to interpret the results of

electrochemical experiments and to optimise the electrodeposition process.

First, the enthalpies of formation of binary intermetallic compounds AlAnn (n = 2, 3, 4,

An = U, Np, Pu) are assessed from first principles calculations of total energies

performed using full potential APW+lo technique within density functional theory

(Wien2k code). The substantial contribution to entropies. S°298, arising from lattice

vibrations is then calculated by direct method within harmonic crystal approximation

(Phonon program + VASP for obtaining Hellmann-Feynman forces). The electronic

heat capacity and the corresponding contribution to entropy are estimated from the

density of states at Fermi level obtained from electronic structure calculations.

Second, the phase diagrams of the relevant systems An-Al are calculated based on the

thermodynamic data assessed from ab-initio calculations, known equilibrium data

(melting behaviour, electrochemical techniques) and, in some cases, measured

thermodynamic data by employing the FactSage program. Whereas the phase equilibria

in U-Al and Pu-Al have been investigated by thermal analytical, X-ray diffraction and

other experimental techniques in the past, there is only little known about the Np-Al

system. The presented phase diagram thus represents only a tentative picture of phase

relations in this system.


79

Nuclear Fuel Coolant Interaction and material effect: thermodynamics at equilibrium and out of equilibrium V. Tyrpekl a,b,c,d, P. Piluso a, S. Bakardjieva b, J.L. Rehspringer c, D. Nižňanský d a CEA Cadarache, DNT/STRI/LMA, bat. 708, 13108 Saint-Paul-lez-Durances, France b UACH AV CR, Husinec-Řež 1001, 250 68 Řež, Czech Republic c Université Louis Pasteur,23 Rue du Loess BP 23,67034 Strasbourg Cedex , France d Charles University Prague, Faculty of Science, Albertov 6., 128 43 Prague 2., Czech

Republic

In the framework of nuclear power plant safety, an important issue in case of severe accident is steam explosion; this event could occur during the interaction between the “corium” (molten mixture of the nuclear power plant components, mainly of UO2 and ZrO2) and the water generating dynamic loading of the surrounding structures. During this very short interaction, phenomena involving thermal-hydraulic and physico-chemistry mechanisms out of thermodynamic equilibrium take place at the millisecond time scale. Nuclear Fuel Coolant Interaction (FCI) belongs to the branches of the nuclear reactor severe accident research and development. Two possible scenarios of FCI could occur in case of an hypothetical severe accident: in-vessel FCI would occur if the primary melted material interacts inside the reactor vessel and gets into the coolant (water for Light Water Reactors), ex-vessel FCI would occur in the case of a reactor vessel leakage failure. In both cases the melt – coolant interaction progresses into a process with or without energetic steam explosion. Until now, the complete understanding of FCI is not well known and therefore the presence or absence of the energetic steam explosion cannot be predicted. It was found that the melt composition could significantly affect the probability of steam explosion. For example, the alumina melt - water interaction gives a spontaneous steam explosion with high energy. On the other hand, non-eutectic corium (UO2 - ZrO2 mixture 80 and 20 mass %, respectively) does not give spontaneous and energetic steam explosions [1]. A recent approach [2] has been developed to explain the so-called “material-effect” in steam explosion. This approach develops a model in which some phases out of thermodynamic equilibrium would exist and would explain the differences of behaviour according to the nature of the material. The presentation will be focused on this thermodynamic approach to describe phenomena involved in Fuel Coolant Interaction.

References:

[1] I. Huhtiniemi, D. Magallon and H. Hohman, Nuclear Engineering and Design, 189 (1999) 379-389.

[2] P. Piluso, G. Trillon, and D. Magallon, International Journal of Thermophysics, Vol. 26 (2005) 1095-1114.


80

Thermodynamic modelling of the uranium-fluoride system S. Chatain a, C. Guéneau b, J.L. Flèche c a,b,c CEA, DEN/DANS/DPC/SCP/LM2T, Point courrier 41, 91191 Gif-sur-Yvette Cedex,

France

The uranium fluorides are key compounds in the nuclear industry. In the present work, a

thermodynamic modelling of the uranium-fluoride system using the CALPHAD method

is presented. The study is focussed on the UF4-UF6 part of the phase diagram.

A review of the phase diagram data and the thermodynamic properties of all the phases

(solid, liquid, gas species and defined compounds) reported in the literature was first

performed. When necessary, a critical analysis helped to select the values used in the

optimisation procedure. Some missing thermodynamic data are obtained using first

principle calculations. An associated model is used to model the liquid phase. The

calculated phase diagram, Agron's diagram [1] and thermodynamic properties of UF4,

UF6 and the intermediate fluorides, UF4,25, UF4,5 and UF5, are compared with the

experimental data of the literature. An overall good agreement between calculated and

experimental data is obtained. Calculations of the composition of the vapour phase in

the UF4-UF6 region are performed at different temperatures.

References:

[1] P. Agron. Chemistry of uranium. (1958). US Atomic Energy Commission, Oak Ridge,Tennessee, USA, p.610-626.


81

An Extended State Module of TEST Web Application for Property Evaluation of Gas Mixtures Subrata Bhattacharjee, Christopher P. Paolini

Mechanical Engineering Department, San Diego State University, San Diego, CA 92014

The TEST (The Expert System for Thermodynamics, www.thermofluids.net) web portal

is comprehensive thermodynamic courseware consisting of multimedia problems and

examples, an online solution manual for educators, traditional thermodynamic charts

and tables, fifteen chapters of animations to illustrate thermodynamic systems and

fundamental concepts, and a suite of thermodynamic calculators called daemons for

analyzing thermodynamic problems and pursuing what-if scenarios. The state module

offers Java applets for evaluation of thermodynamic states of different working

substances grouped into several material models according to underlying assumptions.

Gas mixtures are modeled by the perfect gas or ideal gas mixture models. In this work,

we extend the ideal gas mixture model into an equilibrium mixture model by

incorporating chemical equilibrium calculations as part of the state evaluation. Through

a simple graphical interface, users can set the atomic composition of a gas mixture. In

the state panel, the known thermodynamic properties are entered. For a given pressure

and temperature, the mixture’s Gibbs function is minimized subject to atomic

constraints and the equilibrium composition along with thermodynamic properties of

the mixture are calculated and displayed. What is unique about this approach is that

equilibrium computations are performed in the background, without requiring any major

change in the familiar user interface used in other state daemons. Properties calculated

by this equilibrium state daemon are compared with results from other established

applications such as NASA CEA and STANJAN.


82

Ab initio analysis of pressure-induced bcc-hcp transformation in iron M. Friák a,b,c, M. Šob d,a a Institute of Physics of Materials, Academy of Sciences of the Czech Republic,

Žižkova 22, CZ-616 62 Brno, Czech Republic b Faculty of Science, Institute of Condensed Matter Physics, Masaryk University,

Kotlářská 2, CZ-611 37 Brno, Czech Republic c Max-Planck Institut für Eisenforschung, GmbH, Max-Planck-Strasse 1,

D-40237 Düsseldorf, Germany d Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2,

CZ-611 37 Brno, Czech Republic

We present a first-principles study of four magnetic phases of iron along a

transformation path connecting the bcc and hcp structures at various atomic volumes

using the generalized gradient approximation. The total energies and magnetic moments

are calculated using the full-potential method and are displayed in contour plots as

functions of the parameter of the path and volume; borderlines between various

magnetic phases are shown. A low-symmetry antiferromagnetic state with a total energy

lower than that of the equilibrium nonmagnetic hcp state is found. A comprehensive

picture of the martensitic transition from cubic to orthorhombic iron including both the

magnetic and the structural degrees of freedom is presented, and an alternative three-

stage mechanism is proposed.


83

Stability of Laves phases in the Cr-Ti and Cr-Hf systems J. Pavlů a,b, J. Vřešťál a,b, M. Šob a,b

a Department of Chemistry, Faculty of Science, Masaryk University Brno, Czech Republic

bInstitute of Physics of Materials, Academy of Sciences of the Czech Republic, Brno, Czech Republic

The Cr-Ti and Cr-Hf systems belongs to interesting substances exhibiting all three

polytypes of the Laves phases (C14, C15 and C36) - Cr-Ti, or two of them (C14 and

C15) – Cr-Hf. Comparison of total energies of these structures calculated from first

principles with the total energy of the ideal mixture of elemental constituents reveals the

relative stability of Laves phases in this systems. The effect of magnetic order in the

Laves phases is also discussed.

The calculated total energies of formation of all three polytypes are employed in the

two- and three- sublattice models to revise the thermodynamic description published in

[1,2]. Phase diagrams calculated with the help of re-modelled Gibbs energies of Laves

phases provides an excellent agreement with the experimental phase data found in

literature. Financial support of Czech Science Foundation by grant No.106/07/1078 and of Ministry of Education of Czech Republic by OC164, MSM0021622410 and AV0Z20410507 is gratefully acknowledged.

References:

[1] W. Zhuang, J. Shen, Y. Liu, L. Ling, S. Shang, Y. Du, J.C. Schuster, Thermodynamic Optimization of the Cr-Ti System, Z.Metallkd., 91 (2000) 121.

[2] Y. Yang, J. Schoonover, B.P. Bewlay, D. Lewis, Y.A. Chang, Thermodynamic modeling of the Cr-Hf-Si System, Intermetallics (2009), doi: 10.1016/j.intermet.2008.11.003.


84

Computing the phase diagram of the FeCr binary alloy by path-sampling techniques G. Adjanor a, M. Athènes b a EDF R&D Materials and Mechanics of Components Department, Moret-sur-Loing

France b CEA-Saclay Service de Recherches de Métallurgie Physique

Due to their potential application as structural materials for fusion and Generation IV

reactors, chromium ferritic/martensitic steels have recently received considerable

interest. Ab initio results have shown that due to magnetism the sign of the mixing

enthalpy of the Fe-Cr system changes at low temperature. One of the most challenging

tasks is now to establish how this effect influences the phase diagram of the system. In a

recent study, Monte-Carlo simulations in the semi-grand canonical ensemble and the

thermodynamic integration method were applied, with their respective limitations. We

report on the first attempt to apply a path-sampling method on this system. This method

can be seen as a combination of the former methods in the limiting cases of fast and

slow switching rates respectively. In addition, the analysis of path histograms yields a

built-in criterion for diagnosing the convergence of thermodynamic potential estimates.

CALPHAD XXXVIII

85

4. Poster Presentation - Lists of Authors and Abstracts

CALPHAD XXXVIII

86

4.1. Poster Session I – List of Authors

CALPHAD XXXVIII Poster Session I- List of Authors

87

AB INITIO AND THERMODYNAMIC MODELING AND NON-METALLIC SYSTEMS 1 - Ch. K. Ande, M. H. F. Sluiter Effect of common alloying elements on the structural and electronic properties of cementite (Fe3C), Hagg Carbide(Fe5C2) and Fe3Mo3C 92 2 - M. H. F. Sluiter, A. Pasturel Site occupation in the Cr-Ru and Cr-Os sigma phases from first principles 93 3 - J.-C. Crivello, J.-M. Joubert First principles calculations of the σ and χ phases in the Mo-Re and W-Re systems 94 4 - A. J. Scott, A. Watson, A. M. Ukpong, L. A. Cornish Ab Initio Calculations in the Nb-Pt and Nb-Ru Systems 95 5 - M. Všianská, D. Legut, M. Šob Ab initio Study of Stability of In-Sn Alloys 96 6 - A. Wang, L. Zhou,Y. Kong, Y. Du, Z-K. Liu, J. Wang First-principles study of binary special quasirandom structures for the Al-Cu, Al-Si, Cu-Si, and Mg-Si systems 97 7 - K. Togase, S. Fujii, S. R. Nishitani, T. Kaneko First principles calculations on surface energy of SiC 98 8 - J. Wang, Y. Du, L. Zhang, A. Wang, Y. Ouyang, Y. Kong Thermodynamic properties of Al-based alloys calculated via first-principles method 99 9 - Y. Yamamoto, Y. Takeuchi, S. R. Nishitani, J. Vřešťál Vibration free energy of Cr2Zr Laves phase 100 10 - G. Cacciamani, A. Dinsdale, M. Palumbo, A. Pasturel Fe-Ni system: thermodynamic modelling assisted by atomistic simulations 101 11 - M. Kriegel, D. M. Cupid, O. Fabrichnaya, H. J. Seifert Thermodynamic re–assessment of the Ti–Cr and Ti–Al–Cr systems 102 12 - Y. Liu, E. Gamsjäger, H. Clemens Phase diagrams in ternary Ti-Al based systems 103


88

13 - Ch. Tang, T. Kim, J. Lee, Y-M. Sung The melting of the silica–encapsulated silver nanoparticles 104 14 - R. Novakovic Diffusion bonding in metallic systems 105 15 - H-K. Kim, W-S. Jung and B-J. Lee Atomistic Calculation of Fe/TiC and Fe/TiN Interfacial properties 106 16 - J. Kapała, I. Rutkowska, I. Chojnacka, M. Gaune-Escard Modelling of the thermodynamic properties of the ABr-CeBr3 (A=Li-Cs) systems 107 17 - L. Rycerz, I. Rutkowska, J. Kapała, M. Gaune-Escard, I. Chojnacka , A. Marchewka, J. Klecka, G. Krzyżostaniak Phase diagrams of the AgCl-LnCl3 (Ln=Ce, Nd, Sm, Gd, Dy) systems 108 18 - I-H. Jung, D. Kang, N. J. Kim Thermodynamic modeling and its applications to new Mg-Sn based alloy development 109 19 - S.-K. Seo, M. G. Cho and H. M. Lee Thermodynamic Analysis of the Microstructural Change in Sn-rich Solders affected by their Interfacial Reaction with Cu or Ni(P) UBM 110 20 - A. A. Novakova, A. N. Falkova, T. Yu. Kiseleva , T. F. Grigorieva, A. P. Barinova Mechanoactivated phase transformations in hematite – gallium system 111 21 - T. V. Kulikova, A. V. Mayorova, N. I. Il'inykh, K. Yu. Shunyaev Calculation of thermochemical properties of gaseous and liquid polychlorinated biphenyls (PCBs) 112 22 - A.Costa e Silva, A. Q. Bracarense, E. C. P. Pessoa, M. Monteiro, R. Avillez, F. Rizzo and V. R.Santos Thermodynamics of hydrogen in steel – application to underwater welding 113 23 - J.-M. Joubert A Calphad-type equation of state for hydrogen gas and its application to the assessment of the Rh-H system 114 24 - P. Schmidt How to get ternary phosphide tellurides? A thermodynamic approach 115 25 - K-H. Kang, J-Ch. Lee and B-J. Lee Atomistic analysis of structural evolution in Cu-Zr bulk metallic glasses 116


89

26 - E. Doernberg, R. Schmid-Fetzer, R. Siquieri , H. Emmerich Heterogeneous nucleation and microstructure formation in peritectic alloy systems - Coupling Calphad assessment, directional solidification and phase field modelling 117 27 - P. Brož, J. Sopoušek, J. Vřešťál On the stability of Ag, Cu and Sn nanoparticles 118 28 - T. Markus, S. Fischer, M. Motalov Thermochemistry of the System NaI - CeI3 - CaI2 119 29 - K. Oikawa, K. Anzai, T. Nagasaka, K. Ishida Thermodynamic evaluation of Cu-P binary system 120 30 - K. B. Frederiksen High Temperature Oxidation Modeling of Cr-O 121 31 - J. Leitner, D. Sedmidubský, P. Voňka Thermodynamic database for the oxide system CaO-SrO-Bi2O3-Nb2O5-Ta2O5 122 32 - N. Barbin, S. Alexeev, D. Terentiev, S. Orlov, G. Michurov, M. Mironov Thermodynamic Simulation of Thermal Behavior of Molten Li2CO3-Na2CO3-C System 123 33 - N. Barbin, S. Alexeev, D. Terentiev, S. Orlov, G. Michurov, M. Mironov Modeling of Oxidation of Metal Films 124 34 - E. Yazhenskikh, K. Hack, M. Müller Thermodynamic evaluation and optimization of the systems K2O-Al2O3-SiO2 and Na2O- Al2O3-SiO2 125 35 - J. Jourdan, C. Toffolon-Masclet, J.-M. Joubert Experimental and Thermodynamic Description of the Zr-Er(-O) system 126 36 - C. Corvalan, C. Desgranges, C. Toffolon , J. C. Brachet Calculation of Oxygen profiles evolution during high temperature oxidation of Zr (Zircaloy 4) alloys: coupling of the diffusion code “EKINOX” and the thermodynamics database “ZIRCOBASE” 127 37 - W. Xiong, M. Selleby, Q. Chen, Y. Du An Improved Thermodynamic Description of the Fe-Cr System 128 38 - S.Balanetskyy, M.Feuerbacher, B.Grushko, T.Ya. Velikanova A Comparative Study of the Al-Mn-Ni and the Al-Mn-Pd Alloy Systems in the Al-rich Region 129


90

39 - I. Ohnuma, C. P. Wang, X. J. Liu, K. Ishida Development of Thermodynamic Database for Cu-base Alloy Systems and Microsolders 130 40 - T. Miyamoto, W. Ito, M. Nagasako, R. Y. Umetsu, R. Kainuma, K. Ishida Determination of Ni-Mn-In Ternary Phase Diagrams by Diffusion Triple 131

41 - M. Kopyto, W. Przybyło, B. Onderka, K. Fitzner Thermodynamic Properties of PbO-Sb2O3-SiO2 Liquid Solutions 132

42 - C. Guo, Z. Du Thermodynamic Description of the Ce-La-Mg System 133 43 - A. A. Bukaemskiy, G. Modolo, D. Bosbach Physical Properties of Ceramic in the CeO2 – 8 YSZ and Nd2O3 – 8 YSZ Systems 134

CALPHAD XXXVIII

91

4.1.1 Poster Session I - Abstracts

CALPHAD XXXVIII Poster Session I - Abstracts

92

Effect of common alloying elements on the structural and electronic properties of cementite (Fe3C), Hagg Carbide(Fe5C2) and Fe3Mo3C Chaitanya Krishna Ande a,b, Marcel H. F. Sluiter a a Materials innovation institute, M2i, Mekelweg 2, 2624 CD, Delft, The Netherlands b Delft University of Technology, Mekelweg 2, 2624 CD, Delft, The Netherlands

Precipitate phases play an important role in the strengthening mechanisms of steels.

Understanding the thermodynamics of carbide phases is required for predicting phase

stability in alloyed steel. Alloying elements affect the relative stability of competing

carbide phases such as cementite, Hagg carbide, MC1-x, M23C6, and M13M23C.

Particularly for phases that form as nanoscale precipitates or that are transient or

metastable, experimental information may be difficult to obtain. Such obstacles can be

alleviated by first-principles calculations.

In this study we use first-principles electronic density functional calculations within the

generalized gradient approximation to study the effect of Al, Si, S, P, Ti, V, Cr, Mn, Co,

Ni, Cu, Nb, Mo and W, common alloying elements in steels, on the structural,

electronic and thermodynamic properties of various carbides. We determine the

structural parameters and and ground state thermodynamic properties which are then

used to gain an insight in finite temperature behaviour and properties, such as site

preference and magnetic behaviour.


93

Site occupation in the Cr-Ru and Cr-Os sigma phases from first principles M.H.F. Sluiter a, A. Pasturel b a MSE, 3mE, Delft University of Technology, Mekelweg 2, 2628 CD Delft, the

Netherlands b SIMAP, UMR5266, ENSEEG, INPG, BP 75, 38402 Saint Martin d’Hères Cedex

FRANCE

The site occupation of alloying elements in complex phases, such as the FeCr prototype

sigma phase, is essential for a valid thermodynamic description of its phase stability.

The sigma phase is an ideal case for examining site occupation because the phase

occurs in many alloy systems and its structure features 5 distinct positions with

coordination shells that are typical for the family of Frank-Kasper structures. The

coordination numbers range from 12 to 16 and in the past site occupation were

generally correlated with atomic size, with larger atomic species (typically the early

transition metals) occupying the positions with higher coordination numbers. Later, it

was shown that purely electronic arguments could similarly explain site occupancy [1].

This raised the question whether atomic size or electronic arguments were the main

driver of site preference. Separating the effects of size and of electronic d-band filling is

difficult because larger (transition) elements have a less filled d-band. However, a few

cases exist where atomic size can be contrasted with d-band filling; such is the case for

the sigma phase with approximate composition Cr2Ru and Cr2Os where the early TM Cr

is smaller in size than the late TM so that size and electronic arguments predict different

site occupations.

Experimental data [2] on these systems indicates that the site occupancy in these

systems is confused, with neither size, nor electronic effects dominating. Current ab

initio calculations coupled with cluster expansions support this view and shed light on

this matter.

References:

[1] M. Sluiter, A. Pasturel and Y. Kawazoe, in The Science of Complex Alloy Phases, ed. P.E.A. Turchi and T. Massalski (TMS, Warrendale, PA, USA, 2005) pp. 409 ISBN 0-87339-593-X.

[2] J.-M. Joubert, Progr. Mat. Sci., 53 (2008) 528.


94

First principles calculations of the σ and χ phases in the Mo-Re and W-Re systems J.-C. Crivello, J.-M. Joubert

ICMPE-CMTR, CNRS UMR 7182, 2-8, rue Henri Dunant, 94320 THIAIS, FRANCE

The Frank-Kasper phases appear in many important multi-components systems, like

superalloys. The precipitation of these intermetallic compounds may cause problems

due to their brittleness which affects the mechanical properties of the alloy, motivating

the present study of their stability.

Among them, the moderately complex structures of the σ and χ phases possess 5 and 4

inequivalent sites, respectively, which generate 32 and 16 different ordered

configurations for a binary compound. For two important systems of superalloys (W-Re

and Mo-Re), the total energies of all configurations in relaxed σ and χ structures has

been calculated using first principles methodology.

The Density Functional Theory (DFT) method has been used to perform these

calculations in the Generalized Gradient Approximation (GGA), with Projector

Augmented Wave (PAW) pseudopotentials, as implemented in Vienna ab initio

Simulation Package (VASP).

Considering all the configurations, lattice stabilities and atomic coordinates are

analysed. From the well converged total energies, calculations suggest that the smaller

atom (Re) presents a preferential occupancy for lower coordination number sites, in

agreement with the experimental measurements.

Coupled with the Calphad approach, this work is helpful to investigate the homogeneity

ranges in the binary phases. In both σ and χ phases, the occupancy of the inequivalent

sites has been computed in function of the increasing Re-composition and is compared

to available crystallographic data.


95

Ab Initio Calculations in the Nb-Pt and Nb-Ru Systems A.J. Scott a, A. Watson a, A.M. Ukpong b,c L.A. Cornish b,c a IMR/SPEME, The University of Leeds, UK b DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, Private

Bag 3, Johannesburg 2050, South Africa. c School of Chemical and Materials Engineering, University of the Witwatersrand, Private Bag

3, Johannesburg 2050, South Africa.

A thermodynamic database for Pt-based alloys for high-temperature applications has

been under development for a number of years [1-3]. So far, the database contains

assessed data for binary and ternary systems for Al, Cr, Ru and Pt. The database is

being extended by the addition of Nb, and to this end, it is necessary to produce

assessments of the Nb-Pt and Nb-Ru systems. There are few thermodynamic data for

these systems, encouraging calculation of enthalpies of formation for compounds and

the derivation of end-members for phases in these binary systems via ab-initio methods.

Total energy calculations were performed using the density functional (DFT) plane-

wave pseudopotential code, CASTEP [4] with the exchange-correlation described using

the PBE generalised gradient approximation. The energy was converged with respect to

the kinetic energy cut-off (basis set) and k-point mesh to achieve an energy tolerance

better than 0.5 kJ/mol. All structures were geometry optimised. ‘Heats of formation’

were calculated for the Nb1-xPtx, NbPt2, and NbPt3 phases, which have been treated as

stoichiometric compounds, and starting values for the optimisation of the end-members

of the Nb2Pt (σ-phase), Nb3Pt (A15 phase) and NbRu3 (L12 phase).

References:

[1] A. Watson, L.A. Cornish, and R. Süss, Rare Metals, 25(5) (2006) 1-11. [2] L.A. Cornish, R. Süss, A. Watson and S. N. Prins, Platinum Metals Rev., 51 (2007)

104. [3] A. Watson, R. Süss and L.A. Cornish, Platinum Metals Review, 51 (2007) 189-198. [4] S.J. Clark, M.D. Segall, C.J. Pickard, P.J. Hasnip, M.J. Probert, K. Refson, M.C.

Payne, Zeitschrift für Kristallographie, 220 (2005) 567-570.


96

Ab initio Study of Stability of In-Sn Alloys M. Všianská a, D. Legut b, M. Šob a,b a Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, CZ-

611 37 Brno, Czech Republic b Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova

22, CZ-616 62 Brno, Czech Republic

The In–Sn system contains a phase with a simple hexagonal (sh) structure for

compositions form 72 to 87 at% Sn at 25 °C and from 73 to 85 at% Sn at -150 °C [1, 2].

These alloys are usually referred as γ–Sn. The In–Sn alloys are disordered in the whole

concentration interval. We used the virtual crystal approximation (VCA) to describe

disorder of this system. VCA investigates a solid as composed of "virtual" atoms which

interpolate the behavior of the real atoms from the parent compounds. For the binary

alloys consisting of neighbouring elements (as indium and tin) is possible use sipmler

approximation – to calculate the electronic structure of material which has the atomic

number equal to weighted average atomic number of the alloy. Total energies are

calculated using full potential linearised augmented plane wave method. For exchange–

correlation energy, the local density approximation (LDA) and generalized gradient

approximation (GGA) were employed. All calculations were performed by the WIEN2k

[3]. This connection of highly accurate method for electronic structure calculation of

solids and relatively rough description of disorder gives surprisingly good results. Our

GGA calculation predicted the sh phase in the interval 83–90 at% Sn. In the LDA

calculations, the sh phase exhibits the lowest total energy in the concentration interval

of 54–94 at% Sn.

References:

[1] O.Degtyareva, V. F. Degryareva, F. Porch, W. B. Holzapfel: J. Phys.: Condens. Matter, 14 (2002) 389.

[2] Binary Alloys Phase Diagrams, Second Edition Plus Updates (based on T. B. Massalski, J. L. Murray, L. H. Bennett, H. Baker, editors. Binary Alloy Phase Diagrams, Material Park, OH, ASM, 1990). Materials Park, OH, ASM, 1996.

[3] P.Blaha, K. Schwarz, G. K. H. Madsen, D. Kvasnicka, J. Luitz: WEIN2k, An Augmented Plane Wave + Local Orbitals Program for Calculating Crystal Properties (Karlheinz Schwarz, Techn. Universität Wien, Austria, 2001).


97

First-principles study of binary special quasirandom structures for the Al-Cu, Al-Si, Cu-Si, and Mg-Si systems Aijun Wang a, Liangcai Zhou a, Yi Kong a, Yong Du a, Zi-Kui Liu b, Jiong Wang a a State Key Laboratory of Powder Metallurgy, Central South University Changsha,

Hunan 410083, P.R. China b Department of Materials Science and Engineering, The Pennsylvania State University

Park, Pennsylvania 16802, USA

Based on Special Quasirandom Structure (SQS), enthalpies of mixing for four binary

fcc solid solutions (Al-Cu, Al-Si, Cu-Si, and Mg-Si systems) at nine different

compositions, i.e. x = 1/16, 2/16, 3/16, 4/16, 8/16, 12/16, 13/16, 14/16, 15/16, are

calculated using first-principles method. The calculated results are compared with

previous theoretical results of first-principles and thermodynamic modeling available in

the literature. Besides, the calculated nearest neighbor bond length distributions in the

random fcc solid solutions are presented. Furthermore, the spatial valence charge

distributions among the atoms in these binary solid solutions are calculated, providing

insight into the understanding of mixing behavior for these solid solution phases. The

present calculations indicate that the newly developed SQS model can be readily used

in thermodynamic modeling to overcome scarce or uncertain of experimental data.

Consequently, SQS model can be employed to calculate thermodynamic properties of

fcc solid solution system with narrow solubility range and even the metastable regions

of the phase diagram, which are difficult to study experimentally. Acknowledgement: This research work is supported by Creative Research Group of National Natural Science Foundation of China (Grant No. 50721003).


98

First principles calculations on surface energy of SiC K. Togase a, S. Fujii a, S. R. Nishitani a, T. Kaneko b a Department of Informatics, Kwansei Gakuin Univ., Gakuen 2-1, Sanda, 669-1337

Japan. b Department of Physics, Kwansei Gakuin Univ., Gakuen 2-1, Sanda, 669-1337 Japan.

SiC is a strong candidate for the next generation material of power electronic devices.

For getting cheap SiC wafers, an alternative process to the current expensive one of the

chemical vapor deposition is highly required. The current authors have recently

proposed a quite new method of the SiC crystal growth, which utilizes the solution

method. To understand the growth of crystal in this process, it is necessary to clarify the

orientation dependency of SiC surface energy.

The first principles calculations using VASP, Vienna Simulation Package, are

performed on the surfaces of {0001}, {11-20} and {1-100} in 4H and 6H-SiC. In 3C-

SiC, we performed on the surfaces of {111}, {1-10} and {11-2} which show equivalent

local configurations with those of 4H and 6H-SiC. For describing the chemical potential

dependency of the silicon rich environment, the method proposed by Qian et al. is

applied. The results shown in Fig.1 are summarized as follows; the surface energies are

very close among the equivalent local configuration of different polytypes. The surface

energies of {0001} are lower than those of the other surfaces, that is consistent with the

experimental observation of the initial shapes of 4H-SiC single crystals.

References:

[1] S.R.Nishitani, T.Kaneko, J.Cryst. Growth, 310 (2008) 1815. [2] G.-X. Qian, R. M. Martin, D. J. Chadi, Phys. Rev. B, 38 (1988) 7649.

Fig.1 Surface energies of SiC polytypes.


99

Thermodynamic properties of Al-based alloys calculated via first-principles method Jiong Wang a, Yong Du a, Lijun Zhang a, Aijun Wang a, Y.F.Ouyang b, Yi Kong a a State Key Laboratory of Powder Metallurgy, Central South University, Changsha,

Hunan, 410083, P.R. China b Department of Physics, Guangxi University, Nanning 530004, P.R. China

A first-principles database for thermodynamic properties of 18 binary and 4 ternary

systems in multi-component Al system was constructed by means of first-principles

calculations. These first-principles calculations are compared with the experimental

data for observed ordered compounds in a variety of structure types. It was found that

the enthalpies of formation computed via first-principles method agree with the

experimental data and CALPHAD-type values. The special quasirandom structure

approach is utilized to obtain face centered cubic based mixing energies of disordered

solid solutions over the entire composition range for the investigated binary systems [1].

The ground state structures of the ternary compounds were determined by minimizing

their total energies with respect to the possible atomic arrangements according to their

published space group and prototype structure. The values corresponding to the ground

state structures provide a reliable basis for thermodynamic assessments. The finite

temperature thermodynamic properties of the ternary compounds were calculated by

considering the effects of both lattice thermal vibrational and thermal electronic

contributions to the free energy [2]. Lattice vibration effects were calculated using the

supercell method and the thermal electronic contributions were determined through the

integration of the electronic density of states. With the deduced Helmholtz free energy,

the enthalpy of formation as a function of temperature was calculated, and the computed

values compare with the experimental data available.

References:

[1] A Zunger, S.-H. Wei, L.G. Ferreira, J.E. Bernaed, Phys. Rev. Lett., 65 (1990) 353. [2] R. Arroyave, D. Shin, Z.-K. Liu, Acta Mat. 53 (2005) 1809. Acknowledgement: This research work is supported by Creative Research Group of National Natural Science Foundation of China (Grant No. 50721003).


100

Vibration free energy of Cr2Zr Laves phase Y. Yamamoto a, Y. Takeuchi a, S. R. Nishitani a, J. Vřešťál b a Department of Informatics, Kwansei Gakuin Univ., Gakuen 2-1, Sanda, 669-1337

Japan. b Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2,

CZ-611 37 Brno, Czech Republic.

Laves phases crystallize in cubic (MgCu2, C15) or hexagonal (MgZn2, C14 and MgNi2,

C36) type structures which differ only by a different stacking of the same four layered

structural unit. In the Zr-Cr system, these three Laves phases appear in the phase

diagram. Ab initio analysis of relative stability of Laves phase structures confirms the

sequence of decreasing stability C15–C36–C14 [1].

In the present study, for discussing the finite temperature effect, we applied the quasi-

harmonic approximation with the phonon-DOS calculations. Phonon-DOS calculations

were performed by MedeA, which uses the first principle calculation code of VASP.

Figure 1 shows the temperature dependency of vibration free energy change of ZrCr2

Laves phases. The volumes are fixed at the equilibrium ones of the ground states. The

C15 phase is correctly estimated to be the lowest energy at the low temperatures. The

C14 phase is highly stabilized at the high temperatures, and the phase transition from

C15 to C14 phases is predicted to occur at 1000K. The C36 phase is experimentally

expected to be stable at the middle temperature range, but is not calculated yet.

References:

[1] J. Pavlů, J. Vřešťál, M. Šob, CALPHAD, 33 (2009).

Fig.1 Temperature dependency of vibration free energy change of ZrCr2 Laves phases.


101

Fe-Ni system: thermodynamic modelling assisted by atomistic simulations G. Cacciamani a, A. Dinsdale b, M. Palumbo c, A. Pasturel d a Dipartimento di Chimica e Chimica Industriale, Università di Genova, Italy b Materials Centre, National Physical Laboratory, Teddington, UK c Computational Materials Science Center, National Institute for Materials Science,

Tsukuba, Japan d Laboratoire de Physique et Modélisation des Milieux Condensés (UMR 5493), CNRS,

Grenoble, France

Fe-Ni is a key system for different technologically relevant materials such as invar

alloys, permalloys, inconel alloys, etc. From a fundamental point of view it is

interesting for the peculiar interplay between chemical and magnetic ordering

phenomena. Fe-Ni phase diagram has been studied for more than a century.

Nevertheless some uncertainty still affect low temperature phase relations mainly

because of the difficulty in reaching stable equilibrium at temperatures lower than about

300°C. Atomistic calculations may complement experimental investigation of phase

equilibria and thermodynamics, especially at low temperature. A recent critical

assessment [1] pointed out the need for a complete re-evaluation of the system taking

into account not only stable phase equilibria, but also metastable ordering equilibria,

especially between fcc-based ordered structures. This is in progress and preliminary

results have already been used in the thermodynamic assessment of the Fe-Ni-Ti ternary

system [2]. The present status of the evaluation, also supported by new atomistic

calculations, will be presented and discussed.

References:

[1] G. Cacciamani, J. De Keyzer, R. Ferro, U.E. Klotz, J. Lacaze, P. Wollants, Intermetallics, 14 (2006) 1312-1325.

[2] J. De Keyzer, G. Cacciamani, N. Dupin, P. Wollants, Calphad, 33 (2009) in press http://dx.doi.org/10.1016/j.calphad.2008.10.003.


102

Thermodynamic re–assessment of the Ti–Cr and Ti–Al–Cr systems M. Kriegel, D.M. Cupid, O. Fabrichnaya, H.J. Seifert

Institute of Materials Science, Freiberg University of Mining and Technology, Gustav-Zeuner Straße 5, 09599 Freiberg, Germany

Two-phase γ–TiAl + σ–Nb2Al alloys are promising materials for aero-based turbine

applications because of their high temperature strength, creep, and fracture toughness

properties. The addition of β stabilising elements such as Cr can improve the

processability of these alloys. Within the framework of developing a thermodynamic

description for the quaternary Ti–Al–Nb–Cr system to aid in alloy development,

existing thermodynamic datasets of the Ti–Cr and Ti–Al–Cr systems were re-assessed

to better calculate the available experimental data. All re-optimizations were performed

using the PARROT module of Thermo-Calc software. In the re-assessment of the Ti–Cr

system, a thermodynamic description for the β–TiCr2 phase was added to the dataset of

Saunders [1] and the Gibbs energy and mixing parameters for the three modifications of

the Laves phases were optimized. The calculated binary Ti–Cr phase diagram is

consistent with data accepted in [2]: the congruent formation of γ–TiCr2 from β–bcc

phase at 1632K and the degenerated calculated peritectoid and eutectoid reactions

between γ–TiCr2, β–TiCr2 and β–bcc phases at 1544K and 1542K respectively. In the

Ti–Al–Cr system, the ternary τ1–Ti1Cr0.32Al2.68 phase was modelled as a stoichiometric

phase and the Gibbs energy for this phase was assessed. The ternary mixing parameters

of the β–bcc, β0, α–TiCr2 and β–TiCr2, as well as a single end-member of the α2–Ti3Al

and the end-members and mixing parameters of the τ2–Ti(Al,Cr)2 were optimized. The

calculated liquidus surface and isothermal sections at 1273K and 1073K are now in

better agreement with the critically assessed liquidus surface and respective isothermal

sections [2].

References:

[1] N. Saunders, COST507, I. Ansara, European Commission, (1994). [2] N. Bochvar et al., Al–Cr–Ti, In: Ternary Alloy Systems: Ph. diagrams,

Crystallographic and Thermodynamic Data, Landolt-Boernstein Num. Data and Functional Relationship in Science and Technology (Ed. In Chief W. Martienssen) Vol. IV/11E1, Springer-Verlag Berlin-Heidelberg, (2008) 72-109.


103

Phase diagrams in ternary Ti-Al based systems Y. Liu a, E. Gamsjäger a, H. Clemens b a Institute of Mechanics, Montanuniversität Leoben, Franz-Josef-Straße 18, A-8700 Leoben, Austria b Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, Franz-Josef-Straße 18, A-8700 Leoben, Austria

The phase boundaries of the ternary Ti-Al-Nb system can be calculated by using a

recently published thermodynamic data set [1]. The influence of a small amount of

oxygen (oxygen is always present in industrially produced Ti-Al alloys) has been found

to be almost negligible if one uses the CALPHAD method to calculate phase equilibria

in Ti-Al based alloys [2]. Therefore it is concluded that the thermodynamic assessment

of the Ti-Al-Nb system can make use of experimental data from [3] as done by

Witusiewicz et al. [1]. New experimental results from Rios et al. [4] also support the

new assessment of Witusiewicz et al. [1].

For ternary Ti-Al based alloys containing Mo a thermodynamic description which

correctly reflects all available thermodynamic data is still missing. Interaction

parameters in this ternary system have been calculated based on experimental data from

[5].

References:

[1] V.T. Witusiewicz, A.A. Bondar, U. Hecht, T.Ya. Velikanova, The Al–B–Nb–Ti system IV. Experimental study and thermodynamic re-evaluation of the binary Al–Nb and ternary Al–Nb–Ti systems, J. Alloys Compd., In Press.

[2] N. Saunders, Gamma Titanium Aluminides 1999, eds. YW. Kim, D. M. Dimiduk and M. H. Loretto (Warrendale, PA: TMS, 1999), 183.

[3] H. F. Chladil, H. Clemens, G. A. Zickler, M. Takeyama, E. Kozeschnik, A. Bartels, T. Buslaps, R. Gerling, S. Kremmer, L. Yeoh, K.-D. Liss, Int. J. Mat. Res. 98 (2007) 1.

[4] O. Rios, S. Goyel, M. S. Kesler, D. M. Cupid, H. J. Seifert, F. Ebrahimi, Scripta Mater. 60 (2009) 156.

[5] R. Kainuma, Y. Fujita, H. Mitsui, I. Ohnuma, K. Ishida, Intermetallics 8 (2000) 855.


104

The melting of the silica–encapsulated silver nanoparticles Chengying Tang a,b, Taeyoung Kim a, Joonho Lee a*, Yun-Mo Sung a

a Department of Materials Science and Engineering, Korea University, 5-1 Anam-dong, Seongbuk-gu, Seoul 136-713, Korea

b Department of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin, Guangxi 541004, China e-mail) [email protected]

The size dependence of the melting temperature and the structure transformation of

silica–encapsulated silver nanoparticles (NPs) were investigated by means of

differential thermal analysis (DTA). The silver NPs, with sizes ranging about from 5 to

30 nm, were synthesized by reduction of metal precursor with a reducing agent and then

coated with silica shell to isolate the particles from one another. The melting

temperatures of resulting silica–coated NPs with different sizes were examined by DTA

measurement.


105

Diffusion bonding in metallic systems R. Novakovic

National Research Council (CNR) – Institute for Energetics and Interphases (IENI), Via De Marini, 6 - 16149-Genoa (Italy)

The Diffusion bonding is a solid-state joining process capable to bond all materials

whose chemical and metallurgical properties are compatible. The method is based on

the use of some metal deposited on a metallic substrate inducing by diffusion the local

formation of a low melting point alloy. The coalescence of contacting surfaces is

produced with minimum macroscopic deformation by diffusion controlled processes,

which are induced by applying heat and pressure for a finite interval.

In this work a short presentation of theoretical results on the diffusion bonding in some

metallic systems is given. Dissolution, growth and chemical solid phase diffusion are

kinetic processes involved in the joining of similar materials. The joint formation is

dependent on a number of parameters, in particular, time, bonding temperature, mutual

solubility, diffusion rates of the diffusing components, applied pressure, and method of

heat application. The computed results of simulation of diffusion-controlled, two-phase,

moving interface problems are compared with the results reported in the literature.


106

Atomistic Calculation of Fe/TiC and Fe/TiN Interfacial properties Hyun-Kyu Kim a, Woo-Sang Jung b, Byeong-Joo Lee a* a Department of Materials Science and Engineering, Pohang University of Science and

Technology, Pohang 790-784, Republic of Korea b Materials Science & Technology Research Division, Korea Institute of Science &

Technology, Seoul 136-791, Republic of Korea

Titanium carbides and nitrides are one of the most important precipitates for

strengthening steels. To control mechanical strength of steels, it is necessary to control

the precipitation behavior of carbides or nitrides, and for this one needs to understand

the interfacial property between the matrix and precipitates. In the present study,

interfacial properties between bcc Fe and NaCl-type TiC or TiN have been calculated

using an atomistic approach based on the second nearest-neighbor modified embedded-

atom method (2NN MEAM) interatomic potential. To enable the atomistic calculation,

(2NN) MEAM interatomic potentials for the Fe-Ti-C and Fe-Ti-N ternary systems have

been developed based on the previously developed potentials for sub-unary and binary

systems. Then, the interfacial energy, work of separation and misfit strain energy

between bcc Fe and TiC or TiN were calculated, and were compared with relevant first-

principles calculations. By showing a reasonable agreement between the present

calculation and higher level calculations, the applicability of the present atomistic

approach to investigate nucleation kinetics of TiC or TiN precipitates and their effects

on mechanical properties in steels is demonstrated.

Key words: Atomistic Calculation, MEAM Interatomic Potential, Interfacial Property, Fe-Ti-C, Fe-Ti-N *Corresponding author: B.-J. Lee [email protected] Tel: +82-54-2792157 Fax: +82-54-2792399


107

Modelling of the thermodynamic properties of the ABr-CeBr3 (A=Li-Cs) systems J. Kapała a, I. Rutkowska a, I. Chojnacka b, M. Gaune-Escard c a Faculty of Chemistry, Wrocław University of Technology, Wybrzeże Wyspiańskiego

27, 50-370 Wrocław, Poland b Faculty of Chemistry, Wrocław University of Technology, Wybrzeże Wyspiańskiego

27, 50-370 Wrocław, Poland, master student c Ecole Polytechnique, Mecanique Energetique, Technopole de Chateau-Gombert, 5 rue

Enrico Fermi, 13453 Marseille Cedex 13, France

The thermodynamic functions of mixing of LiBr-CeBr3, NaBr-CeBr3, KBr-CeBr3,

RbBr-CeBr3 and CsBr-CeBr3 systems were calculated directly from respective phase

diagrams by CALPHAD method. The BINGSS program by Leo Lukas was used for

calculations. The liquid phase in the systems studied was described by the associate

model with non stoichiometric associate. Deflection from stoichiometry may suggests

the presence of more than one associate in liquid phase. The phase diagrams, enthalpies

of mixing and entropies of mixing of the ABr-CeBr3 (A=Li-Cs) systems were obtained

from the optimisation procedure. Moreover, the temperature dependences of Gibbs

energies of formation of pseudobinary compounds existing in solid phase were found.

The precision of the results were discussed.


108

Phase diagrams of the AgCl-LnCl3 (Ln=Ce, Nd, Sm, Gd, Dy) systems L. Rycerz a, I. Rutkowska a, J. Kapała a, M. Gaune-Escard b, I. Chojnacka c , A. Marchewka c, J. Klecka c, G. Krzyżostaniak c a Faculty of Chemistry, Wrocław University of Technology, Wybrzeże Wyspiańskiego

27, 50-370 Wrocław, Poland b Ecole Polytechnique, Mecanique Energetique, Technopole de Chateau-Gombert, 5 rue

Enrico Fermi, 13453 Marseille Cedex 13, France c Faculty of Chemistry, Wrocław University of Technology, Wybrzeże Wyspiańskiego

27, 50-370 Wrocław, Poland, master student

The phase diagrams of the AgCl-LnCl3 (Ln=Ce, Nd, Sm, Gd, Dy) systems were

measured by DTA and DSC technique. The phase diagrams change their character from

simple eutectic of AgCl-CeCl3 system to AgCl-DyCl3 system which contains

pseudobinary compounds in solid phase.


109

Thermodynamic modeling and its applications to new Mg-Sn based alloy development In-Ho Jung a, Daehoon Kang a, Nack J. Kim b a Dept. of Mining and Materials Engineering, McGill University, Canada b Center for Advanced Aerospace Materials, POSTECH, Korea

Recently an Mg–Sn based alloy system has been investigated actively in order to

develop new Mg alloys which have a stable structure and good mechanical properties at

high temperatures. In the present study, thermodynamic modeling of the Mg–Sn–Al–

Mn–Sb–Si–Zn system has been performed based on available thermodynamic, phase

equilibria and phase diagram data. With the aid of the optimized database, unexplored

complex phase equilibria/phase diagrams and Scheil cooling solidifications in

multicomponent system can be readily calculated. It shows that the microstructural

evolutions of high-temperature Mg–Sn–Al–Zn alloys with additions of Si and Sb can be

well explained by the thermodynamic calculations. In addition, the database is applied

to predicting potential wrought Mg-Sn based alloys. This shows the applicability of

thermodynamic calculations to new Mg alloy design. All calculations were performed

using the FactSage thermochemical software.


110

Thermodynamic Analysis of the Microstructural Change in Sn-rich Solders affected by their Interfacial Reaction with Cu or Ni(P) UBM Sun-Kyoung Seo, Moon Gi Cho, Hyuck Mo Lee

Department of Materials Science and Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea

Sn-0.7Cu, Sn-3.5Ag and Sn-3.8Ag-0.7Cu (all in wt % unless specified otherwise) are the leading candidates of Pb-free solders in microelectronic packaging. In these Sn-rich solders, their mechanical and physical properties are affected by the Sn crystal orientation. Park et al. reported that the measurements of strain under a thermomechanical loading are changed by the orientation of Sn grains in Sn-Ag-Cu [1]. Lu et al. reported a strong correlation between electromigration degradation mechanisms and Sn-grain orientations [2]. The consumption of an under bump metallurgy (UBM) layer is accelerated near the grains having a [001] of the Sn crystal parallel to the direction of electronic current, which reduces the time to failure (TTF). In order to improve the reliability of solder joints, the understanding of the Sn orientation and intermetallic compounds (IMC) formation in solder joints is needed [3]. In general, when the Sn-rich solders are reacted to UBMs during reflow, their composition is naturally changed. This compositional change during reflow can produce the change of Sn orientation and the formation of more IMCs in the solder matrix. In this study, we investigate the changes of composition and microstructure affected by interfacial reaction with two different UBMs, Cu vs. Ni(P). Sn100, Sn-0.5Cu, Sn-0.5Ag and Sn-1.8Ag alloys are prepared and reflowed with UBM. To obtain the information on Sn grain size and orientation, the electron backscatter diffraction (EBSD) technique was employed. For quantitative composition analyses of solders, the electron probe micro analyzer (EPMA) analysis was conducted. The compositional change of Cu or Ni in solder after reaction with UBM is compared with the thermodynamic calculations of the Cu or Ni solubility in each solder alloy. Consequently, it is discussed whether the Cu or Ni atoms dissolved from UBM into the solder can reach the maximum solubility limit during reflow and whether the solubility of Cu or Ni is changing according to the Cu or Ag composition of solder. References:

[1] S. Park, R. Dhakal, L. Lehman, and E. Cotts, Acta Mater., 55 (2007) 3253. [2] M. Lu, D.-Y. Shih, P. Lauro, C. Goldsmith, and D.W. Henderson, Appl. Phys. Lett.

92 (2008) 211909. [3] S.-K. Seo, S.K. Kang, D.-Y. Shih, and H.M. Lee, J. Electron. Mater., 38 (2009)

257.


111

Mechanoactivated phase transformations in hematite – gallium system A.A. Novakova a, A.N. Falkova a, T.Yu. Kiseleva a , T.F. Grigorieva b, A.P. Barinova b

a Moscow M.V. Lomonosov State University, Department of Physics, 119992, Moscow, Russia

b Institute of Solid State Chemistry and Mechanochemistry, 630128, Novosibirsk, Russia

High energy mechanoactivated (MA) reducing reactions give an opportunity to induce

chemical reactions and phase transformations in ternary system Fe2O3-Ga that could be

achieved only under extremely high temperatures [1]. As it was shown in [2], using

easy-melting agent for high energy MA could provide the necessary conditions for solid

state formation in the grain boundary region even if components are immiscible under

equilibrium thermodynamic conditions. From this point of view it can be assumed that

kinetics of hematite reduction could be changed considerably, when using the liquid

reduction component, such as gallium. MA of stoichiometric powder mixture Fe2O3 +

2Ga was performed in high energy planetary ball-mill AGO-2 in Ar atmosphere. The

structure of the samples, processed during different times (from 40” to 8’) was studied

by means of Mossbauer spectroscopy. This method allows to perform the detailed

quantitative phase analysis of iron containing phases with ~1% accuracy and gives the

unique information about any changes in local solute concentration in the iron phases,

including the boundary areas of the particles. The results of quantitative phase analysis

reveal that the rate of initial hematite reduction decreases heavily because gallium

envelopes all surfaces of oxides particles and prevent them from further reduction: even

after 8’ of attrition about 50% of Fe2O3 still remains in mixture. At the same time the

quantity of intermediate oxides, intermetallics (FeGa3 and Fe3Ga) significantly grows

and the presence of α-Fe is negligible. These results indicate that high energy attrition

leads to formation of intermetallics Fe-Ga even under frugal temperatures. This reaction

takes place mainly at the boundaries of the hematite particles and liquid gallium.

References:

[1] V. Raghavan “Iron-Gallium-Oxygen Ternary Diagram” (1989). [2] A.A. Novakova, T.F. Grigorieva, A.P. Barinova, T.Yu. Kiseleva, N.Z. Lyakhov

J.of All. Comp., 434-435 (2007) 455.


112

Calculation of thermochemical properties of gaseous and liquid polychlorinated biphenyls (PCBs) T.V. Kulikova a, A.V. Mayorova a, N.I. Il'inykh a,b, K.Yu. Shunyaev a a Institute of Metallurgy of Urals Branch of Russian Academy of Sciences, 101,

Amundsen Str., Ekaterinburg, 620016, Russia, e-mail: kuliko@gmail b Ural Technical Institute of Communications and Informatics, 15, Repin Str,

Ekaterinburg, 620219, e-mail: [email protected]

Unique technological and physicochemical properties of polychlorinated biphenyls (PCBs), a huge volume of their production, considerable volatility and solubility, and extreme chemical inertness have led to the world-wide spread of PCB-containing equipment and materials, resulting in the universal contamination with these substances. The most common method used in Russia for destruction of PCBs is their incineration with the formation of polychlorinated dibenzo-n-dioxins (PCDDs) and dibenzofurans (PCDFs), which are among the most hazardous chemical substances known to the mankind. Instrumental investigations of these substances are very expensive and, in this connection, interest is attracted to calculation methods for simulation of processes by the data on their thermochemical properties. Therefore the present study deals with the analysis and systematization of the known and calculation of the unknown thermochemical properties (the standard enthalpy and entropy of formation, the heat capacity, the enthalpy increment, etc.) of gaseous and liquid PCBs. The standard enthalpy and entropy of formation and the heat capacity of liquid and gaseous PCBs were calculated using the group additivity method due to Domalski [1]. But the energy contribution of the group Св-Св (for liquid PCBs) is unavailable for the entropy calculation. However, if one uses known values of o

298S for liquid biphenyl (C12H10) [2] and the data on the contribution of the Св-H and Св-Cl groups for liquid PCBs [1], it is possible to calculate o

298S for the whole series of liquid PCBs: o298S (PCB) = o

298S (BP) - (10-n) o298S (Св-H) + n o

298S ( Св-Cl), where n is the number of chlorine atoms in a PCB molecule.

Missenar's group additivity method [3] was used to calculate temperature dependences of the heat capacity of liquid PCBs. Benson's method [4] was used to calculate temperature dependences of the heat capacity for gaseous PCBs. For gaseous and liquid PCBs the values of

otphH ..Δ at the temperature of evaporation and Нo298-Нo0 were calculated by the equations

respectively: оо

о298 НН − ≈ 0.5Ср

о298⋅298.15 and dTСНH

..Тevор

оо.t.ph ∫Δ+Δ=Δ

298298 .

This study was supported by RFBR (project No 08-03-00362-a).

References: [1] Domalski E. S. and Hearing E. D. J. of Phys. and Chem. Ref. Data, 22 (1993) 805 [2] Richard, Laurent and Helgeson Harold C. Geochimica et Cosmochimica Acta, 62 (1998).

3591. [3] P. Reid, J. Prausnitz, T. Sherwood. 1982, 592 p. (in Russian). [4] S.W. Benson, F.R. Cruickshank, D.M. Golden, G.R. Haugen, H.E. O’Neal, A.S. Rodgers,

R. Shaw, and R. Walsh. Chem. Rev., 69: 279 (1969).


113

Thermodynamics of hydrogen in steel – application to underwater welding A. Costa e Silva a, A. Q. Bracarense b, E. C. P. Pessoa b, M. Monteiro c, R. Avillez c, F. Rizzo c, V. R. Santos c a EEIMVR-UFF, 27260-740 Volta Redonda, RJ – Brasil b UFMG, 31270-901 Belo Horizonte, MG - Brasil c DCMM-PUC RJ, 22453-900 Rio de Janeiro, RJ – Brasil

Hydrogen can cause several problems in steel: embrittlement, cracks (sometimes called

“flakes” in the steel industry), pores and bubbles are some of the defects associated with

hydrogen in steel. The extremely high mobility of hydrogen in iron makes hydrogen

control a complex problem: hydrogen can both enter and exit steel with relative ease –

trapping complicating these aspects; hydrogen seldom is homogeneously distributed in

steel; keeping hydrogen in samples until they are analyzed can be difficult. These all

add to uncertainties related to the observed phenomena. A significant portion of the

knowledge about the thermodynamic of hydrogen both in steels and in the slags used

for its processing are well established; the difficulties mentioned above, however,

sometimes make user skeptical of the use of fundamental knowledge in hydrogen

control both in steelmaking and in welding. In this work, the basic aspects of the

thermodynamics of hydrogen in steel entry in the liquid state are reviewed: the

importance of oxygen activity, iron content in slag as well of physical properties of slag

and the atmosphere above the liquid steel are considered. As an example, the

application of this knowledge to underwater welding is presented: experimental results

of hydrogen absorption in welds using different electrode coatings are compared with

computational thermodynamic calculations for the absorption reactions in question. The

results are discussed and the most promising slags presented. It is also concluded that

the fact that the slag-metal contact time in welding is extremely short when compared to

those experienced in steelmaking does not preclude the effective use of thermodynamics

to guide the development and control of these processes.

Submitted to the XXXVIII CALPHAD, Prague, Czech Republic, May 2009.


114

A Calphad-type equation of state for hydrogen gas and its application to the assessment of the Rh-H system J.-M. Joubert

Chimie Métallurgique des Terres Rares, Institut de Chimie et des Matériaux Paris-Est, CNRS, Université de Paris XII, UMR 7182, 2-8 rue Henri Dunant, F-94320 Thiais, France

Metal-hydrogen systems have received more and more attention due to both their

fundamental properties and applications. Among the many interesting aspects of metal-

hydrogen systems, the behaviour at high pressure has been particularly studied. Indeed,

many metals, particularly transition metals do not form any hydride in normal

conditions, but only at very high pressures up to the Mbar range. Hydrogen is far from

being an ideal gas, in particular at high pressures, and the necessity to investigate the

thermodynamic properties of this gas has yielded the development of numerous

equations of states for hydrogen.

In the present work, a new form of equation of state has been derived that is compatible

with Calphad formalism. In order to check the consistency of the equation, it has been

applied to the assessment of the system Rh-H, this metal forming a hydride only at high

pressures. A complete set of parameters is given allowing to describe the scarce

thermodynamic and phase diagram data on this system.


115

How to get ternary phosphide tellurides? A thermodynamic approach Peer Schmidt

University of Technology Dresden, Inorganic Chemistry, D 01069 Dresden, Germany [email protected], www.peer-schmidt.de,

Although many metal pnictide chalcogenides are known as antimonide selenides,

antimonide tellurides, arsenide selenides, arsenide tellurides and even phosphide

sulfides and phosphide selenides, by now there are only few phosphide tellurides: UPTe

[1], IrPTe [2], OsPTe, RuPTe [3] and BaP4Te2 [4]. This must be due to the fact, that the

synthesis can not be performed straight forward from the elements. The experience in

the synthesis of new ternary phosphide

tellurides is presented by examples of

the systems M/P/Te (M = Ti, Zr, Ce, Fe,

Ru, Ir) [5]. In order to understand the

complex mechanism of formation and

decomposition of compounds and to

optimise the syntheses a detailed

thermodynamic modelling of the particular ternary systems as well as the quaternary

systems M/P/Te/O was realised: differences in oxygen partial pressure between the

metal oxides and the tellurium respectively phosphorus oxides have been used in

thermite type reactions. The adjustment of equilibrium has been estimated using an

electromotive series of solids [6] and different synthesis pathways have been

established dependent on p(O2), fig. 1. The proof of processes succeeded by using

different experimental approaches as total pressure measurements, thermal analysis and

mass spectrometry. The growth of single crystals succeeded by vapour transports.

References: [1] A. Zygmunt, A. Murasik, S. Ligenza, J. Leciejewicz, Phys. Stat. Sol. A22 (1974) 75. [2] G. Kliche, Z. Naturforsch., 41b (1986) 130. [3] H.D. Lutz, Th. Schmidt, G. Wäschenbach, Z. Anorg. Allg. Chem., 562 (1988) 7. [4] S. Jörgens, D. Johrendt, A. Mewis, Chem. Eur. J., 9 (2003) 2405. [5] F. Philipp, P. Schmidt, E. Milke, M. Binnewies, St. Hoffmann, J. Solid State Chem. 181,

2008, 758; F. Philipp, P. Schmidt, M. Ruck, W. Schnelle, A. Isaeva, J. Solid State Chem. 181 (2008) 2859; F. Philipp, P. Schmidt, J. Crystal Growth 310 (2008) 5402; K. Tschulik,; F. Philipp, K. Pinkert, P. Schmidt, Z. Anorg. Allg. Chem. (2009) in press; P. Schmidt, Eur. J. Inorg. Chem. (2009) in prep.

[6] P. Schmidt: http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1200397971615-40549.


116

Atomistic analysis of structural evolution in Cu-Zr bulk metallic glasses Kyung-Han Kang a, Jae-Chul Lee b and Byeong-Joo Lee a* a Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea b Department of Materials Science and Engineering, Korea University, Seoul 136-701, Republic of Korea

Although amorphous has excellent mechanical properties such as yield strength, elastic

limit, it has been known that plasticity is one of the major drawbacks. In order to

examine the mechanism of plastic deformation, extensive researches have been done for

past decades. Many studies suggested that plasticity is affected by free volume, i.e.

atomic packing density, and local atomic structures. In this study, it is shown by a

molecular dynamics simulation that the compositional dependency of plasticity in Cu-

Zr BMGs has a strong correlation with those of atomic packing density and local atomic

structures. The atomistic structural evolution during plastic deformation is analyzed,

which suggest a probable origin of plastic deformation of BMGs. In order to investigate

the effect of Ag on structural evolution in the Cu-Zr bulk metallic glasses, a modified

embedded-atom method (MEAM) interatomic potential for the Cu-Zr-Ag system has

been developed and will also be presented. Key words: BMGs, MEAM potential, atomistic simulation, Cu-Zr, Cu-Zr-Ag

*Corresponding author: B.-J. Lee, [email protected] Tel: +82-54-2792157 Fax: +82-54-2792399


117

Heterogeneous nucleation and microstructure formation in peritectic alloy systems - Coupling Calphad assessment, directional solidification and phase field modeling. E. Doernberg a, R. Schmid-Fetzer a, R. Siquieri b, H. Emmerich b a Institute of Metallurgy, Clausthal University of Technology,Robert-Koch-Str. 42, D-

38678 Clausthal-Zellerfeld, Germany b Center of Computational Engineering Science and Institute of Minerals Engineering,

RWTH Aachen, Mauerstrasse 5, D-52064 Aachen, Germany

In order to gain a better understanding of the nucleation and growth mechanisms in

peritectic solidification a cross-discipline investigation in the Al-Ni alloy system has

been commenced. This joint project is part of a priority programme on „Heterogeneous

Nucleation and Microstructure Formation“.

To achieve this goal, high-precision thermodynamic and constitutional data must first

be generated and utilized in a Calphad type assessment of the system. For the intended

application beyond equilibrium limits, accurate modeling of the Gibbs energy of each

phase and correct prediction of metastable phase boundaries is particularly important.

Previous thermodynamic models of the Al-Ni system which are largely based on stable

phase diagram features must be improved upon. With the Gibbs energy functions of the

individual phases as input, non-equilibrium solidification microstructures can be

simulated using the phase field method. The simulation is then calibrated through

comparison with microstructures generated under controlled conditions in an especially

designed Bridgman furnace. In further investigations these tools will be combined to

investigate the influence of peritectic reaction type as well as processing parameters on

the heterogeneous nucleation of the peritectic phase on the pro-peritectic phase and on

the subsequent growth of peritectic microstructures.

This study is supported by the German Research Foundation (DFG) in the Priority Programme “DFG-SPP 1296” under grant no. Schm 588/31


118

On the stability of Ag, Cu and Sn nanoparticles P. Brož, J. Sopoušek, J. Vřešťál

Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137 Brno, Czech Republic

Metal nanoparticles are considered as potential candidates for use as solder materials

for high temperature applications. It is known that physical, electronic, and

thermodynamic properties of nano-objects are significantly different from those of the

bulk materials because of the effect of decrease of melting point of small particles

below the melting point of the bulk material, e.g. [1]. Exploiting this effect, the

substantial depression of melting temperature of lead-free solders could be reached,

sparing energy, expenses, being friendly to the environment at the same time. One the

other hand the main problem of lead-free solder materials is surface oxidation or

reactions which decrease for example the wettability of the solder.

In order to get new information in this field, stability of Ag, Cu and Sn nanopoparticles

and surface effects as well as potential application for soldering technology were

studied. DSC measurements by means of STA 409 CD/3/5/G apparatus from Netzsch,

X-ray diffraction analysis on PANalytical X´Pert PRO MPD device equipped with

X´Celerator detector and transmission electron microscopy (TEM) in a Philips CM12

STEM apparatus were basic methods used for experimental investigations.

Experimental results were compared with theoretical calculations based on the

CALPHAD approach.

This work has been supported by the Ministry of Education of the Czech Republic under the project MSM0021622410 and OC09010 (COST MP0602).

References:

[1] R. Sambles, Proc. Roy. Soc. London, A 324 (1971) 339.


119

Thermochemistry of the System NaI - CeI3 - CaI2 T. Markus, S. Fischer, M. Motalov

Forschungszentrum Juelich GmbH, IEF-2, D-52425 Juelich, Germany Corresponding author: [email protected]

The studies are part of the systematic investigations of metal halide salt systems, which

are performed in our lab. In the contribution here the assessment for the ternary system

NaI-CeI3-CaI2 will be presented. This includes the experimental determination of

thermodynamic key data like phase transition temperatures, chemical activities,

enthalpies of mixing for the complete composition range of the binary subsystems. The

experimental approach and the facilities will be described.

Calphad type thermodynamic modelling was accomplished using the measured as well

as other thermodynamic data present in the literature. The Phase Diagrams of the binary

and the ternary systems were calculated.

The data have been incorporated into a huge thermodynamic salt database and were

used for model calculations on the corrosion attack of the salts against alumina

observed for metal halide discharge lamps. The relation of our measurements and

calculations towards the industrial application will be illustrated and results will be

discussed.


120

Thermodynamic evaluation of Cu-P binary system K. Oikawa a, K. Anzai, T. Nagasaka, K. Ishida a Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan. b Graduate School of Environmental Studies, Tohoku University, Sendai 980-8579,

Japan

Increasing of municipal waste is becoming a serious social problem in Japan due to lack

of landfill site. A melting process for municipal waste or ash of them (Melting

Treatment Process of domestic waste including incineration residue, MTP) has been

developed to reduce the volume of ash, and recover of metal and slag as valuable

materials. The products or residue of MTP are mainly slag, metal and some secondary

fly ash. Fe-Cu-P-C based alloy including some precious elements such as Ag and Au is

generally the metal products of MTP. Thermodynamic and phase diagram of the Fe-Cu-

P-C system is essential to understand behaviours of the metal products. In this study,

thermodynamic evaluation of the whole range of the Cu-P system has been conducted to

develop the thermodynamic database for Fe-Cu-P-C system. The Cu-P system is

composed of the liquid, Cu-rich fcc, hexagonal Cu3P and hexagonal CuP2 and pure P

phases. A thermodynamic description for the Cu-rich region of this system was

presented by Miettinen.[1] The Gibbs energy for the liquid and fcc phases was

described by the sub-regular solution model and the Cu3P phase was approximated as

the line compound. However, unexpected miscibility gap of the liquid phase in the P-

rich region was calculated by their thermodynamic parameters. The liquid phase was

approximated by the association model to describe the whole range system in this study.

The Gibbs energy of the fcc and Cu3P phases were described by sub-regular solution

model and compound energy model. The CuP2 phase was approximated as the line

compound. A set of thermodynamic parameters was estimated from available

experimental data including recent new data. The whole range of the phase diagram of

the Cu-P system could be calculated by new thermodynamic parameter. The calculated

results were well agreed with the experimental data.

References:

[1] J. Miettinen, CALPHAD, 25 (2001) 67.


121

High Temperature Oxidation Modeling of Cr-O K.B. Frederiksen

Department of Fuel Cells and Solid State Chemistry, Risø National Laboratory for Sustainable Energy, Technical University of Denmark, DK-4000 Roskilde, Denmark

High temperature oxidation is of great importance to Solid Oxide Fuel Cells (SOFC),

specifically to the choice of interconnect material. Accurate prediction of the different

oxide phases forming will allow for an appropriate choice of alloy to reduce the

oxidation kinetics as well as the electrical resistance of the interconnect steel.

Theoretical models for the kinetics of oxide layer growth have been proposed for both

single phase [1], and multi-phase systems [2]. These models make assumptions

regarding reaction kinetics, thermodynamics and mobility in order to arrive at simple

analyzable solutions. These assumptions may not always be satisfied in an actual

system. In this work, a model is described for high temperature oxidation of chromium

as a step towards modeling of complex alloys. The general model takes into account the

simultaneous ionic and electronic transport in the oxide layer. The modeling of the

differential equations describing the oxidation is done utilizing Comsol 3.5. The

modeling is performed by coupling of (1) defect concentration obtained by

thermodynamic calculations on the Cr-O system by ThermoCalc, and (2) varying

diffusion coefficients across the grown oxide scale. The modeling results in parabolic

growth kinetics in accordance with experimental observations [3].

References:

[1] C. Wagner, Corrosion Science, 9(2) (1969) 91-109. [2] T.J. Nijdam, L.P.H. Jeurgens, W.G. Sloof, Acta Materialia, 51(18) (2003) 5295-

5307. [3] K.P. Lillerud, P. Kofstad, J. Electrochemical Society, 127(11) (1980) 2397.


122

Thermodynamic database for the oxide system CaO-SrO-Bi2O3-Nb2O5-Ta2O5 J. Leitner a, D. Sedmidubský b, P. Voňka c a Department of Solid State Engineering, Institute of Chemical Technology Prague,

Technická 5, 166 28 Prague 6, Czech Republic b Department of Inorganic Chemistry, Institute of Chemical Technology Prague,

Technická 5, 166 28 Prague 6, Czech Republic c Department of Physical Chemistry, Institute of Chemical Technology Prague,

Technická 5, 166 28 Prague 6, Czech Republic

Mixed oxides in the system CaO-SrO-Bi2O3-Nb2O5-Ta2O5 possess a lot of extraordinary

electric, magnetic and optical properties for which they are used in fabrication of

various electronic components. For example Sr2(Nb,Ta)2O7 and (Sr,Ca)Bi2(Ta,Nb)2O9

are used for ferroelectric memories, Bi(Nb,Ta)O4 and CaNb2O6 for microwave

dielectric resonators and Ca2Nb2O7 as non-linear optical materials and hosts for rare-

earth ions in solid-state lasers. To assess the thermodynamic stability and reactivity of

these oxides under various conditions during their preparation, processing and

operation, a complete set of consistent thermodynamic data including heat capacity,

entropy and enthalpy or Gibbs energy of formation is necessary. A thermodynamic

database compatible with the FactSage software was developed covering data for binary

oxides CaO, SrO, Bi2O3, Nb2O5, and Ta2O5, thirty eight stoichiometric mixed (ternary

and quaternary) oxides, a number of solid solutions and a liquid oxide melt. Accepted

data were taken from literature or were acquired by calorimetric measurements, ab-

initio calculations or empirical estimations. Entropies at 298 K, Sm(298), were derived

from the low-temperature heat capacity measurements (relaxation time calorimetry) as

well as by an empirical entropy-volume correlation. Temperature dependencies of the

heat capacities above room temperature, Cpm(T), were obtained by Cpm measurements

(DSC) and enthalpy increment measurements (drop calorimetry) or by empirical

Neumann-Kopp’s rule. Enthalpies of formation at 298 K, ΔfH(298), were derived from

solution calorimetry, ab-initio calculations or on the basis of various estimation

methods.

The database capability is demonstrated by calculations of various phase diagrams in

selected binary and ternary systems.


123

Thermodynamic Simulation of Thermal Behavior of Molten Li2CO3-Na2CO3-C System N. Barbin a,b, S. Alexeev a, D. Terentiev a, S. Orlov a, G. Michurov a, M. Mironov a a Ural Institute of State Fire Fighting Service, 22 Mira St., 620062 Ekaterinburg,

Russia b Institute of High-Temperature Electrochemistry, Ural Branch RAS, 22 S.

Kovalevskaya St., 620219 Ekaterinburg, Russia

Molten carbonates are used in a variety of physicochemical and electrochemical processes. They include electrolyte melts for high-temperature fuel cells [1], media for processing of technogenic raw materials and metallurgical processes [2, 3], removal of sulfur from gases and coal gasification [4]. The Li2CO3+Na2CO3+C system can be used as an active ionic medium [4]. However, its thermal behavior is not clearly understood. The method of thermodynamic simulation [5] was used for analysis of the equilibrium behavior of carbonate systems. The equilibrium states of complex heterophase systems were calculated using the ACTPA program package. Thermodynamic functions of individual substances were taken from the IVTANTERMO, ACTPA-OWN and ACTPA-BAS databases. The model of an ideal solution of interaction products was used for description of the molten media. The compositions of the gaseous phase and the condensed solution were determined. In the molten Li2CO3+Na2CO3+C system at temperatures above 1500 K the condensed solution is a Li2O melt, in which the total mass concentration of Na2CO3, Li2CO3 and Na2O impurities is not over 2×10−2. At 1300-1500 K the mass concentration of Na2CO3 decreases sharply in the solution. Thus, it may be thought that addition of carbon leads to an almost complete reduction of Na2CO3 and its removal from the melt, as well as a partial reduction and removal of Li2CO3. In the presence of carbon the remaining lithium carbonate loses its anionic groups by the reaction CO −2

3 + C → 2CO + O2−. The mass concentration of the solution in the carbon-loaded system is higher than in the carbon-free system. At T > 1400 K the mass of the solution is nearly 10 times smaller after addition of the taken amount of carbon. Values of the partial pressure change in the following sequence: CO > Na > Li > CO2 > LiO2 > Na2. The comparison with the carbon-free system shows a dramatic change in the composition of the gaseous phase. The most representative components are CO and metal pairs rather than CO2, Na and O2.

References:

[1] I.R. Selman, H.C. Maru, High Temperature Molten Carbonate Fuel Cell. In: Advances In Molten Salt Chemistry, Vol. 5, Plenum Press, 1982, 290 P.

[2] N.M. Barbin, G.F. Kazantsev, N.A. Vatolin, Processing of Secondary Lead Raw Materials in Ionic Salt Melts, Ekaterinburg, Ural Branch RAS, 2002, 180 P.

[3] N.M. Barbin, G.F. Kazantsev, G.K. Moiseev, N.A. Vatolin, Neorgan. Materialy, 38 (2002) 1436.

[4] Yu.K. Delimarsky, L.P. Barchuk, Applied Chemistry of Ionic Melts, Kiev, Naukova Dumka, 1988, 190 P.

[5] G.K. Moiseev, G.P. Vyatkin, N.M. Barbin, G.F. Kazantsev, The Use of Thermodynamic Simulation for Investigation of Interactions Involving Ionic Melts, Chelyabinsk, South-Ural State University Publishers, 2002, 166 P.


124

Modeling of Oxidation of Metal Films N. Barbin, S. Alexeev, D. Terentiev, S. Orlov, G. Michurov, M. Mironov

Ural Institute of State Fire Fighting Service, 22 Mir St. 620062 Ekaterinburg, Russia

When metal films are exposed to pulsed energy fluxes, they develop various physicochemical processes. In this study we consider the possibility of applying the thermodynamic simulation [1] to the qualitative description of processes in the surface layer of films during their interaction with air. The problem was solved for the metal containing (mass %) 94.66 Fe, 0.48 V, 0.1 Cr, 0.18 Si, 4.4 C, and maximum 0.03 sulfur and phosphorus. The temperature interval (1500-1900 K) included the maximum superheating and crystallization temperatures. The "ACTPA" program package [1] was used for thermodynamic simulation. The calculations demonstrated that all oxygen was consumed for oxidation. The ratio of CO to CO2, which were formed due to decarbonization of the surface layer, was close to four. The surface layer was fully decarbonized and iron was partially oxidized to wustite in this layer. At temperatures of 1800 to 1850 K the thermal effect of the system in the equilibrium state acquired the positive sign. While the CO/CO2 ratio changed little, the decarbonized iron concentration decreased until the FeO phase vanished. The simulation, which was performed considering the formation of solid solutions (the 3rd layer), demonstrated that the iron-based solid solution (99.87% Fe) contained Fe3C, Cr, V, Mn, and C. The iron-oxide-based solid solution (66.5% FeO) included up to 11% V2O3, 6-7% Fe3O4, FeCr2O4 and FeSiO3, and 1.5-2% VO and MnO (T = 1600 K). Once the FeO phase fully vanished, deep layers (the 6th layer) were enriched in Fe3C up to 10% and the concentration of alloying elements V, VC, V2C, Mn, FeSi and Fe3Si increased in the iron-based solid solution in the same layers. The oxide-based solid solution contained up to 30% FeSiO3, 21% V2O3, 13% VO, 10% Cr2O3, 5.50% SiO2, 10% FeCr2O4, 3.7% MnO, 2.5% Mn2SiO4, and 0.98% MnSiO3 (T = 1600 K). As the oxidation front moved further into the film, the chemical composition approached the initial values. The calculation results agreed with the corresponding experimental data: the surface layer of the crystallized films consisted of iron oxides and alloying eelments; the core contained alloying elements in the solid solution based on iron and iron carbide; since calculations revealed the release of CO and CO2 to the gaseous phase, one would expect a porous surface of the film, as was actually observed in experiments; the surface layer of the crystallized films contained a high concentration of alloying elements as compared to their concentration in the bulk.

References:

[1] G.K. Moiseev, G.P. Vyatkin, N.M. Barbin. The Use of Thermodynamic Simulation for Investigation of Interactions Involving Ionic Melts. Chelyabinsk. South-Ural State University Publishers. 2002. 166 P.


125

Thermodynamic evaluation and optimisation of the systems K2O-Al2O3-SiO2 and Na2O-Al2O3-SiO2 E. Yazhenskikh a, K. Hack b, M. Müller a a IEF-2, Jülich Forschungszentrum, Jülich, Germany b GTT-Technologies, Herzogenrath, Germany

Complex oxide systems containing high amounts of silica and alumina and alkali oxides are important in many scientific and industrial fields, e.g. in coal combustion and gasification processes where alkali release and behaviour of slags are among the main problems. Thermodynamic properties of such systems for which the measurements are experimentally difficult can be described and predicted by thermodynamic modelling on the basis of reliable experimental data and appropriate Gibbs energy models for the various phases. The aim of this work is the development of a database for the slag relevant oxide system Na2O-K2O-Al2O3-SiO2 for the modelling of the complete coal ash (slag) and gas system. In the present work, two ternary systems K2O-Al2O3-SiO2 and Na2O-Al2O3-SiO2 are considered. The binary Alk2O-SiO2, Alk2O-Al2O3 (Alk=Na, K), Al2O3-SiO2 and ternary Na2O-K2O-SiO2 systems have already been successfully evaluated. The phase equilibria calculated using the new optimised solution data show good agreement with the experimental data. In contrast to other available databases the new dataset allows the description of the whole composition range including the alkali rich parts of the corresponding subsystems. The associate species model is applied for the description of the liquid and solid phases in the systems under consideration. The available phase diagrams were collected and evaluated for the purpose of improving the solution database. Data on the solution components and interaction parameters are optimised to represent the phase relationships in the systems under consideration. In the system K2O-Al2O3-SiO2, the solution based on KAlO2 is described in the framework of the associated species model. Solid solution components were selected and their thermodynamic data were assessed in order to obtain the best agreement with the experimental data. In the other ternary system, Na2O-Al2O3-SiO2, there are at least two solid solutions based on both modifications of NaAlSiO4, nepheline and carnegieite. Moreover, the phase equilibria in the Na2O-rich part of the ternary diagram need to be optimised using assumptions on a probable solubility in the composition range between NaAlO2 and NaAlSiO4. Further investigations deal with the extension to the quaternary system NaAlSiO4-KAlSiO4-SiO2, where the quaternary solid solutions ((Na,K)AlSiO4, (Na,K)AlSi3O8) have to be taken into account along with the slag phase.


126

Experimental and Thermodynamic Description of the Zr-Er(-O) system Julien Jourdan a,b, Caroline Toffolon-Masclet a, Jean-Marc Joubert b a SAC/DMN/SRMA/LA2M, CEA Saclay 91191 Gif-sur-Yvette, France b CNRS/ICMPE/CMTR UMR 7182, 94320 Thiais, France

This work is a contribution to the development of innovating concepts for fuel cladding

in pressurized water nuclear reactors. Increasing the reactor efficiency implies to use

new materials to control the neutron flux. Burnable poisons, such as erbium or

gadolinium, are added in the heart of the reactor to capture neutrons. They have an

interesting absorption cross section to regulate the fuel life. Recent improvements [1]

have led to the introduction of these poisons directly in the zirconium-alloys cladding.

Because these alloys are subjected to oxygen diffusion throughout their life and in order

to improve the development of complex thermomechanical treatments, it is essential to

have a better knowledge of the Zr-Er(-O) system (solubility limits, phase transformation

temperatures).

The Er-Zr system has been investigated experimentally by means of arc-melted samples

of various compositions equilibrated at different temperatures and characterized using

electron microprobe analysis, scanning electron microscopy, X-Ray diffraction and

differential thermal analysis. Due to the high vapour pressure of erbium, high

temperature measurements (> 1200°C) are very difficult to perform. Thus, liquidus and

solidus have been measured by pyrometric analysis in an induction furnace.

The experimental data has been used to assess the Zr-Er system. Ternary compositions

have also been fabricated in order to investigate the Zr-Er-O phase diagram.

The thermodynamic description of the Er-Zr-O system is being achieved in order to

complement the Zircobase [2], a database dedicated to zirconium-based alloys.

References:

[1] J.C Brachet et al, French patent FR06/09047 (Oct 2006). [2] N. Dupin et al, J. Nucl. Mater., 275 (1999) 287-295.


127

Calculation of Oxygen profiles evolution during high temperature oxidation of Zr (Zircaloy-4) alloys : coupling of the diffusion code “EKINOX” and the thermodynamics database “ZIRCOBASE” C. Corvalan a, C. Desgranges b, C. Toffolon a , JC. Brachet a a CEA, Nuclear Materials Department, SRMA, 91191 Gif-sur-Yvette Cedex, France b CEA, DEN, DPC, SCCME, Laboratoire d’Etude de la Corrosion Non Aqueuse, 91191

Gif-sur-Yvette, France.

The “EKINOX” [1] (Estimation KINetics Oxidation) model has been coupled with the thermodynamic database named “Zircobase” [2] thanks to TQ (Thermo-Calc® program interface) to develop a computational tool to anticipate microstructural evolution of Zr base alloys at high temperature. During some hypothetical Pressurized Water Reactor (PWR) accidental scenario such as Loss Of Coolant Accident (LOCA), the nuclear fuel cladding tubes made of Zr base alloys are subjected to a high temperature oxidation (~1473K) caused by the steam environment. This leads to the growth of a zirconia layer (ZrO2), but also to the growth of αZr(O) from the parent (ductile) βZr phase due to the oxygen diffusion within the suboxide metallic layer. At low temperature, the zirconia and the αZr(O) phase layers are brittle. Then, the residual ductility of the high temperature oxidised cladding tube material depends mainly on the concentration of the dissolved oxygen in the βZr phase inner layer. The kinetics of these phase transformations and the associated modification of the mechanical properties have been already described in [3]. To anticipate the influence of different thermal transients on the cladding tube material microstructural evolution and thus on the resultant mechanical properties, a better quantification of the related diffusion phenomena are needed. Thus, the oxidation model “EKINOX” has been coupled with the thermodynamic “Zircobase” database. The model is based on an original numerical treatment to describe interfaces motion even for non-stationary states. Hence calculations of the oxygen profile evolution during high temperature oxidation can be performed taking into account the finite size of the claddings, and non-isothermal oxidation conditions during the transitory stages of the LOCA scenario. The first simulations performed on Zircaloy-4 alloy are presented and compared with previous experimental data [3] [4].

References:

[1] N. Bertrand, PhD Thesis 2006, INP Toulouse. [2] N. Dupin, I. Ansara, C. Servant, C. Toffolon, C. Lemaignan, J.C. Brachet,

:A thermodynamic database for zirconium alloys“, J. Nucl. Mater., 275 (1999), 287-295. [3] J.-C. Brechet, V. Vanderberghe et al.: “Hydrogen Content, Pre Oxidation and Cooling

Scenario Influences on Post-Quench Mechanical of Zy-4 and M5® Properties in LOCA conditions – Relationship with the Post-Quench Microstructure”, Journal of ASTM International, Vol. 5, No. 5, Paper ID JAI101116, (2008).

[4] X. Ma, C. Toffolon-Masclet, et al, “Oxidation kinetics and oxygen diffusion in low-tin Zircaloy-4 up to 1523 K”, J. Nucl. Mater. 377 (2008) 359–369.


128

An Improved Thermodynamic Description of the Fe-Cr System Wei Xiong a,b, Malin Selleby a, Qing Chen c, Yong Du b a Department of Materials Science and Engineering, Royal Institute of Technology, SE-

100 44 Stockholm, Sweden b State Key Laboratory of Powder Metallurgy, Central South Universtiy, 410083,

Changsha, P.R. China c Thermo-Calc Software AB, Stockholm Technology Park, SE-113 47 Stockholm,

Sweden

The largely accepted thermodynamic description of the Fe-Cr system was carried out by

Andersson and Sundman [1] more than 20 years ago and a sublattice model

Cr4(Fe,Cr)18Fe8 was used for the σ phase. It has been suggested that the sublattice

model should be changed to Cr4(Fe,Cr)16Fe10 [2] or more preferably to

(Fe,Cr)4(Fe,Cr)16(Fe,Cr)10 [3, 4]. In this work, a simplified but almost equally capable

model (Fe,Cr)20(Fe,Cr)10, proposed recently by Joubert [4], is adopted. A new model of

pure Fe accounting for different physical effects has been given by Chen and Sundman

[5]. Significant improvements have been made for the fcc phase at low temperatures

and the magnetic effect in the bcc phase. Therefore, the present work changed the

description of pure Fe accordingly using the newly implanted code within Thermo-Calc

software. It is noteworthy that, since only the Fe-rich part is of interest in the frame of

our investigation, the lattice stability re-evaluation has not been applied for other

elements yet. In view of the above two aspects, the present thermodynamic assessment

is performed considering the available experimental data as well as the ab initio

calculations. The results show a promising way to improve the existing thermodynamic

databases and satisfy the demands for practical applications.

References:

[1] J.-O Andersson, B. Sundman, Calphad, 11 (1987) 83-92. [2] I. Ansara, T. G. Chart, A. Fernández Guillermet, F.H. Hayes, U.R. Kattner, D.G.

Pettifor, N. Saunders, K. Zeng, Calphad, 21 (1997) 171-218. [3] R. Ferro, G. Cacciamani, Calphad, 26 (2002) 439-458. [4] J.-M. Joubert, Prog. Mater. Sci., 53 (2008) 528-583. [5] Q. Chen, B. Sundman, J. Phase Equilib., 22 (2001) 631-644.


129

A comparative study of the Al-Mn-Ni and the Al-Mn-Pd alloy systems in the Al-rich region. *S. Balanetskyy a, b, M. Feuerbacher a, B. Grushko a, T. Velikanova b a Institut für Festkörperforschung, Forschungszentrum Jülich, D-52425 Jülich,

Germany b I.N. Frantsevich Institute for Problems of Materials Science, 03680 Kiev 142, Ukraine

During the last two decades, Al-based alloy systems including transition metals attracted increased attention due to the multitude of binary and ternary intermetallics they often contain. In particular, structurally complex metallic alloys (CMAs) or else structurally complex intermetallics and quasicrystals (QCs) are frequently found. Both these classes of materials constitute modern and very active fields in materials science. Various Al-based CMAs and QCs possess interesting physical and physicochemical properties, which are of high potential for technological application. It is astonishing, but phase equilibria in the Al-Mn-Ni alloy system were very little investigated up to now, although Al, Mn and Ni and their alloys are very widely used in industry. In contrast to Al-Mn-Ni, the Al-Mn-Pd (Ni and Pd belong to the same column of the periodic table) alloy system was very intensively investigated during last 15 years. It worth noting that Al-Mn-Pd was one of the so-called model systems for a study of physicochemical properties of ternary QCs and quasicrystalline-like CMAs. In the present work the liquidus and solidus surfaces of the Al-rich region of Al-Mn-Ni alloy system as well as partial isothermal sections at 1000, 950, 850, 750, 700, 645 and 620 °C were determined. Three ternary thermodynamically stable intermetallics, the ϕ-phase (Al5Co2-type, hP26, P63/mmc: a=0.76632(16) and c=0.78296(15) nm), the κ-phase (κ-Al14.4Cr3.4Nil.1-type, hP227, P63/m: a=1.7625(10) and c=1.2516(10) nm) and the O-phase (Pmmn; oP650; O-Al77Cr14Pd9-type; a=2.3316(16), b=1.2424(15) and c=3.2648(14) nm), as well as three ternary metastable phases, the decagonal D3-phase with periodicity about 1.25 nm; the Al9(Mn,Ni)2-phase (P1121/a, mP22, Al9Co2-type; a=0.8585(16); b=0.6269(9), c=0.6205(11) nm, β=95.34(10)°) and the O1-phase (base-centered orthorhombic, a≈23.8, b≈12.4, c≈32.2 nm) were revealed. In contrast to the Al-Mn-Pd alloy system, the thermodynamically stable QCs were not found in Al-Mn-Ni. Thus, Ni in contrast to Pd does not stabilize the metastable binary Al-Mn decagonal and icosahedral phases. The metastable binary ϕ-Al10Mn3-phase stabilizes by Ni in Al-Mn-Ni. In Al-Mn-Pd stable ϕ was not found. The metastable binary R-Al3Mn-phase (Bbmm; oS156; a=2.36, b=1.24 and c=0.77 nm) stabilizes by Pd in Al-Mn-Pd. The thermodynamically stable R-phase in Al-Mn-Ni was not confirmed in the present study. It worth noting, that the O-, O1- and the R-phase are closely structurally related to each other and with the decagonal quasicrystal D3.


130

Development of Thermodynamic Database for Cu-base Alloy Systems and Micro-Solders I. Ohnuma a, C. P. Wang b, X. J. Liu b, K. Ishida a a Department of Materials Science, Graduate School of Engineering, Tohoku

University, Sendai JAPAN b Department of Materials Science and Engineering, Xiamen University, CHINA

The thermodynamic database for Cu-base alloys and micro-solders have been

constructed by the CALPHAD (Calculation of Phase Diagrams) method. Based on the

thermodynamic assessments on the Cu-X binary and Cu-X-Y ternary systems, the phase

diagrams and thermodynamic properties of Cu-base multi-components systems which

includes eleven elements of Cu, B, C, Cr, Fe, Ni, P, Si, Sn, Ti and Zn can be calculated.

The solder database for eight elements of Ag, Bi, Cu, In, Pb, Sb, Sn and Zn have also

been developed, which can be utilized for all combinations of elements and all

composition ranges. The elements of Al, Au and Ni are also available for the calculation

in the limited composition ranges. The typical examples of the calculations and

applications will be presented.


131

Determination of Ni-Mn-In Ternary Phase Diagrams by Diffusion Triple T. Miyamoto a, W. Ito b, M. Nagasako b, R. Y. Umetsu b, R. Kainuma b, K. Ishida a a Department of Materials Science, Graduate School of Engineering, Tohoku University b Institute of Multidisciplinary Research for Advanced Materials, Tohoku University [Objective]

Recently, Ni-Mn-In system has received much attention as multiferroic materials. In

this system, the magnetization of alloys drastically changes from ferromagnetic to

weak magnetic properties due to martensitic transformation[1]. Therefore, it is

important for alloy design to evaluate the martensitic and magnetic transformation

properties and to determine the phase equilibria in a wide composition range. In the

present study, the alloy phase diagrams of 700 and 850℃ and the martensite and

magnetic properties at room temperature were determined by diffusion triple (DT)

method.

[Experimental procedures]

(1)Ni-Mn binary diffusion couple (DC) was prepared by solid-liquid joining, and the

DC specimens were heat-treated at 1000℃ for 120 h. (2)A cylindrical hole was formed

by drilling near the diffusion zone of Ni/Mn DC and In was inserted into the hole.

Diffusion triple (DT) was finally obtained by diffusion-annealing at 700℃ and 850�.

(3)The obtained DTs were cut in a section vertical to the In cylinder, and were

chemically analyzed using EPMA along some lines parallel to the Ni/Mn interface. (4)

Ferromagnetic zone were determined

by image analysis with magnetic

colloid.

[Results]

Figure 1 shows the isothermal section

diagram at 700℃. It is seen that

NiMn- & NiIn-based B2 and Ni2MnIn

L21 phases continuously exist in the β

phase. A new ternary compound

Mn3Ni2In was found and the crystal

structure was determined by TEM and XRD

to be a cubic structure whose prototype is

Mn3Ni2Si. References: [1] Y.Sutou et al., Appl. Phys. Lett., 85 (2004) 4358.

Fig. 1 Isothermal section diagram in Ni-Mn-In system at 700°C


132

Thermodynamic Properties of PbO-Sb2O3-SiO2 Liquid Solutions M. Kopyto a, W. Przybyło a, B. Onderka b, K. Fitzner b a Institute of Metallurgy and Materials Science, Polish Academy of Sciences,

25 Reymonta Street, 30-059 Krakow b AGH University of Science and Technology, Faculty of Non-Ferrous Metals,

Laboratory of Physical Chemistry and Electrochemistry, 30 Mickiewicza Ave., 30-059 Krakow, Poland

Silver production from post electrorefining anodic sledges is based on so called Kaldo

process in which the solutes in silver are transferred into the oxide slag phase. The

prediction of the distribution of impurities between metal (mainly Ag with traces of Bi,

Pb and Sb) and the slag demands that their thermodynamic properties under fixed T and

the PO2 must be known. Thus, thermodynamic properties of at least four component

oxides solution: SiO2+Bi2O3+Sb2O3+PbO should be known.

The inspection of existing literature on this subject indicates that no such information

exists. Because of difficulties connected with the experimental work it seems that the

only chance to work out a sensible solution of this problem is to gather experimental

information on all binary oxide systems and then to predict (according to a certain

simple thermodynamic model) a behavior of this multicomponent oxide solution.

In the present work the thermodynamic properties of the liquid PbO-SiO2 and Sb2O3-

SiO2 solutions were derived from the results of the electrochemical studies conducted

with the solid oxide galvanic cells with YSZ electrolyte. Activities of PbO in silicate

melts were determined directly in the temperature range from 850 to 1025 K and for

SiO2 mole fractions 0.2, 0.3, 0.4 and 0.5 from measured e.m.f.’s of the cell:

Pb, PbO-SiO2 | YSZ | Ni, NiO

relatively to Gibbs energy change of pure PbO formation.

The thermodynamic properties of Sb2O3-SiO2 liquid solutions were derived indirectly

from the measurements conducted with the cell of the type:

Pb, PbO-Sb2O3-SiO2 | YSZ | Ni, NiO

Measurements were carried out on PbO-Sb2O3-SiO2 liquid solutions in the temperature

range from 1070 to 1280 K. Two pseudobinary phase diagrams, namely, PbO-SiO2 and

PbO-Sb2O3 were optimized, and next, using obtained results the diagram of Sb2O3-SiO2

system, and the liquidus in the pseudoternary PbO-Sb2O3-SiO2 were predicted.


133

Thermodynamic description of the Ce–La–Mg system Cuiping Guo, Zhenmin Du*

Department of Materials Science and Engineering, University of Science and Technology Beijing, Beijing100083, China

The thermodynamic modeling and optimization of the Ce–La and Ce–La–Mg systems

has been carried out using the CALPHAD technique. The solution phases, liquid, body-

centered cubic, face-centered cubic, hexagonal close-packed and double hexagonal

close-packed, were modeled with a substitutional solution model. The isostructural

MgCe in Ce–Mg system and MgLa in La–Mg system with B2 structure form

continuous rafnge of solid solutions in the Ce–La–Mg ternary system. The order–

disorder transition between the solutions with A2 structure and compounds with B2

structure in the system has been taken into account and thermodynamically modeled.

The other isostructural compounds Mg12Ce and Mg12La, Mg17Ce2 and Mg17La2,

Mg41Ce5 and Mg41La5, Mg3Ce and Mg3La, and Mg2Ce and Mg2La were described as

single phases Mg12R, Mg17R2, Mg41R5, Mg3R, Mg2R, respectively. In the present work,

the compounds Mg12R, Mg17R2, Mg41R5, and Mg2R were treated as line compounds

Mgm(Ce, La)n in the Ce−La−Mg system, in which m and n represent different number in

different compounds. The compounds Mg3Ce in Ce–Mg system and Mg3La in La–Mg

system with homogeneity ranges were described by the two-sublattice model in such

formula as Mg3(Ce, Mg) and Mg3(La, Mg). Combining with the model of Mg3Ce and

Mg3La in binary Ce–Mg and La–Mg systems, the compound Mg3R was treated as

Mg3(Ce, La, Mg) in the Ce−La−Mg system. Based on the experimental vertical sections

at 95 wt.% Mg, 90 wt.% Mg, 85 wt.% Mg, 80 wt.% Mg, 75 wt.% Mg and 70 wt.% Mg

in Ce–La–Mg system determined by Rokhlin and Bochvar [12], the Ce–La–Mg system

at Mg-rich corner was optimized. A set of self-consistent thermodynamic description of

the Ce–La–Mg system was obtained.

This work was supported by National Natural Science Foundation of China (NSFC) (Grant Nos. 50731002, 50801004). *Corresponding author. Tel./Fax: +86 10 6233 3772, E-mail address: [email protected] (Z. Du)


134

Physical properties of ceramic in the CeO2 - 8YSZ and Nd2O3 - 8YSZ systems A.A. Bukaemskiy, G. Modolo, D. Bosbach

Institute for Energy Research, Safety Research and Reactor Technology, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany

Yttria fully stabilised zirconia seems to be one of the most promising matrix for the

nuclear waste utilization [1]. In fact, these materials have the ability to form solid

solutions over a wide range of solubility with compounds such as UO2, ThO2, and PuO2

and with rare-earth oxides [2]. Fully stabilised zirconia based ceramic is characterised

by high strength and fracture toughness, structural stability, leaching resistance, high

radiation stability and a small neutron capture cross-section. The fluorite and pyrochlore

crystal structures of the material are preferable for the nuclear applications [1, 3].

In the present work, cerium and neodymium are considered as a simulant for the tetra-

and trivalent actinides, respectively. CeO2 - 8YSZ and Nd2O3 - 8YSZ pellets with the

simulant concentrations from 0 to 100 % were produce. Their mechanical properties,

like microhardness, fracture toughness and brittleness index and microstructure were

investigated in detail. Moreover, the type of crystal structure, and the lattice parameters

depending on the simulant concentration were determined by X-ray diffraction method.

The obtained data on the physical properties of ceramics allow us to define the phase

boundary between pyrochlore and fluorite (for the Nd2O3 - 8YSZ system) and between

fluorite and tetragonal (for the CeO2 - 8YSZ system) crystal modifications more

exactly.

References: [1] V.M. Oversby, C.C. McPheetes, C. Degueldre, J.M. Paratte, J. Nucl. Mater., 245

(1997) 17-26. [2] W.L. Gong, W. Lutze, R.C. Ewing, J. Nucl. Mater., 227 (2000) 239-249. [3] R.C. Ewing, W.J. Weber, J. Lian, J. Appl. Phys., 95, 11 (2004) 5949-5971.

CALPHAD XXXVIII

135

4.2. Poster Session II – List of Authors

CALPHAD XXXVIII Poster Session II – List of Authors

136

EXPERIMENTAL AND THERMODYNAMIC MODELING OF METALLIC SYSTEMS 1 - M. Hosseinifar, D. V. Malakov An experimentally corroborated optimization of the Al–Mg–La system 142 2 - D. Kapush, D. Pavlyuchkov, B. Grushko, T. Ya. Velikanova Phase equilibria in the Al-rich region of Al-Cu-Ir 143 3 - T. V. Kulikova, A. V. Mayorova, N. I. Il'inykh, K. Yu. Shunyaev Investigation of thermodynamic properties of binary intermetallic compounds of Al-Ho system 144 4 - X. Yuan, W. Sun, Y. Du Thermodynamic modeling of the Mg-Si system with Kaptay’s equation for excess Gibbs energy of liquid phase 145 5 - V. Lutsyk, A. Zelenaya, V. Vorob’eva Correction of T-x-y diagrams with immiscibility 146 6 - Z. Hodis, V. Jan, J. Sopoušek, R. Foret Analysis of realistic heterogeneous welds of heat resistant steels by means of experimental and computational techniques 147 7 - C. Corvalan, M. Iribarren, N. Di Lalla, F. Dyment Cr and Co diffusion kinetics along alpha-Zr grain boundaries at power reactors normal temperatures 148 8 - T. Tokunaga, H. Ohtani, M. Hasebe Thermodynamic Analysis of the Cr-Mo-B Ternary System 149

9 - J. Romanowska Experimental study on thermodynamics of Cu-Sn-Sb system in Cu-rich and Sn-rich corners 150 10 - G. Wnuk Thermal analysis of Cu-Ni-Sn-Zn alloys by means of the DCS technique 151 11 - W. Zakulski, W. Gąsior, A. Dębski Thermodynamic Properties of the Ca-Li system, heat of formation of the CaLi2 solid phase 152 12 - Y. Zhang, M. Medraj, D. Kevorkov, J. Li, E. Essadiqi and P. Chartrand Experimental investigation of the Mg-Zn-Ca system using diffusion couples and key experiments 153 13 - M. Mezbahul-Islam, M. Medraj Thermodynamic Analysis of the Mg-Cu-Y-Ni System 154


137

14 - M. Asgar-Khan, M. Medraj Thermodynamic Modelling of the Mg-Mn-(Al, Zn) Systems 155 15 - B. G. Scuracchio, C. G. Schön Influence of alloying elements upon the solidification interval of CA6NM cast martensitic stainless steel 156 16 - A. Kozlov, R. Schmid-Fetzer Phase formation in the Mg-Sn-Ca-Si quaternary system 157

17 - M. H. G. Jacobs, P. Blöchl, R. Schmid-Fetzer Constraining thermodynamic properties of intermetallic phases in the system Fe-Al 158 18 - M. Svobodová, J. Sopoušek Experimental and theoretical studies of bainitic creep-resisting T23 steel 159 19 - D. Pavlyuchkov, B. Grushko, D. Kapush, W. Kowalski, V. Khorujaya, K. Kornienko, T.Ya. Velikanova Constitution of the Al–Cr–Fe phase diagram in the compositional range above 60 at. % Al 160 20 - D. Manasijević, D. Minić, D. Živković, I. Katayama, J. Vřešťál, D. Petković Experimental investigation and thermodynamic calculation of the Bi-Ga-Sn phase equilibria 161 21 - W. Kowalski, B. Grushko, D. Pavlyuchkov, S. Mi, M. Surowiec Phase equilibria in the Al-rich part of Al-Ni-Cr 162 22 - N. David, J. M. Fiorani, G. Hug, J. M. Joubert, M. Vilasi Thermodynamic assessment and modelling of the Mo-Pt system 163 23 - Li Chen, P. H. Mayrhofer, and Y. Du Thermal stability of Ti-Al-Zr-N films 164 24 - R. Ganesan and H. Ipser Thermochemical study on Ni-P and Sn-P systems 165 25 - J. Buršík, P. Brož Intermetallic phases in the Ni-Al-Ti system: analytical electron microscopy and thermodynamic calculations 166 26 - J. Sopoušek, M. Palcut The interpretation of the DSC signals of the lead-free solder alloy systems using the CALPHAD approach 167 27 - J. Gröbner, C.-N. Chiu, A. Kozlov, R. Schmid-Fetzer Mg-rich parts of the ternary Mg-Zn-(Ce, Gd, Y) systems 168


138

28 - M. Hampl, S. Mücklich, B. Wielage, R. Schmid-Fetzer Thermodynamics of magnesium alloy solders 169 29 - V. Homolová, A. Kroupa, A. Výrostková Calculation of isothermal sections of Fe-B-V phase diagram 170 30 - A. M. Ukpong, L. A. Cornish, A. Watson and A. J. Scott Addition of Nb to the Developmental Al-Cr-Pt-Ru Database 171 31 - M. Svoboda, A. Kroupa, J. Buršík Al-Cr-Pd system: analytical electron microscopy and thermodynamic Calculations 172 32 - A. Zemanova, A. Kroupa The Experimental and Theoretical Study of the In-Ni-Sn System 173 33 - B. Smetana, S. Zlá, P. Kozelský, J. Dobrovská Experimental and thermodynamical study of real grades of micro-alloyed steels 174 34 - B. Smetana, J. Drápala, S. Zlá, A. Kroupa Thermodynamical and experimental study of the Al-Sn-Zn system 175 35 - A. A. Bondar, V. T. Witusiewicz, U. Hecht, V. Yu. Pashchenko, L. Sturz, J. Zollinger, O. S. Fomichov, S. Yu. Artyukh, T. Ya. Velikanova Experimental study and thermodynamic re-assessment of the ternary B-Si-Ti system 176 36 - D. Panahi, D. V. Malakhov Formation of stable and metastable intermetallic phases in solidifying Al–Fe–Si alloys 177 37 - A. Ulichová, O. Zobač, J. Sopoušek Study of Sn – Sb – Zn Ternary System 178 38 - W. Gąsior, Z. Moser, A. Dębski Enthalpies of formation of FeNi70, FeNi73,6 and FeNi80 solid alloys from the homogenous region of the FeNi3 phase 179 39 - C. Mekler, G. Kaptay On the thermodynamic optimization of the Si-C and Fe-Si-C systems 180 40 - A. Zemanová, J. Sopoušek, J. Vřeš´tál Experimental determination of phase equilibria and reassessment of Ag-Pd system 181

41 - J. Łapsa, W. Gierlotka , K. Fitzner The thermodynamics of Ag-Pb-Te System 182


139

42 - R. Avillez, A. Costa e Silva Kinetics of carbonitride precipitation in Interstitial Free Steels 183 43 - My. Y. Benarchid, N. David, J. M. Fiorani, M. Vilasi Enthalpies of formation of Mo–Ru and Mo–Ru–Si compounds determined by high-temperature direct reaction synthesis calorimetry 184 44 - My. Y. Benarchid, N. David, J. M. Fiorani, M. Vilasi Enthalpies of formation of Nb-Ru and Nb-Ru-Al alloys determined by direct reaction synthesis in a high-temperature calorimeter 185


140

CALPHAD XXXVIII

141

4.2.1. Poster session II - Abstracts

CALPHAD XXXVIII Poster Session II - Abstracts

142

An experimentally corroborated optimization of the Al–Mg–La system Mehdi Hosseinifar, Dmitri V. Malakhov


LaMg belongs to a family of ductile BCC_B2 intermetallics [1], which raises an

interesting question: Is it possible to fabricate an aluminum alloy containing inclusions

of this compound, i.e., the alloy containing two ductile phases? The alloy may

demonstrate remarkable mechanical properties [2]. Instead of an artless trials and errors

approach to fabricating such an alloy, one can rely upon the CALPHAD method if a

reliable thermodynamic description of the Al–Mg–La system is available. Since an

assessment of this system had not been found in literature, it was decided to optimize it

keeping in mind that some phases seen in this ternary system and corresponding

binaries are also present in other Al–Mg–R systems (R is a rare-earth metal). It was

found that a model for the Al–Mg–La system could not be constructed without

revisiting the descriptions of the LaMg2 (Laves_C15) and LaMg (BCC_B2) phases

suggested in [3]. Although a homogeneity range of LaMg2 is vanishingly small, it is

noticeable in some other RMg2 compounds, which prompts to replace the (La)1(Mg)2

sublattice model accepted in [3] with (La,Mg)1(La,Mg)2 (the major constituent is

bolded). LaMg should be treated as an ordered BCC_A2 structure, which suggests to

use (La,Mg)0.5(La,Mg)0.5(Va)3 instead of (La)1(Mg)1 recommended in [3]. The

assessment with new models was carried out by using PARROT. A good agreement

between the calculated isothermal section at 400°C and that experimentally established

by Odinaev et al. [4] was achieved. However, calculated liquidus temperatures were

dramatically (hundreds of degrees) higher than those measured in [5] (the same problem

with Odinaev’s data was reported for the Al–Ce–Mg system [6]). In order to resolve

this issue, liquidus temperatures for different compositions are being measured.

References:

[1] K.G. Gschneidner, Nature Materials, 2 (2003) 587. [2] C.W.Sinclair, J.D.Embury, G. C.Weatherly, Materials Sci. Eng. A, A272 (1999) 90. [3] C. Guo, Z. Du, J. Alloys and Compounds, 385 (2004) 109. [4] K. Odinaev et al., Izvestiya VUZov, Tsvetnaya Metallurgia, 2 (1988) 81. [5] K. Odinaev, I. Ganiev, Russ. Metallurtgy, 2 (1995) 146. [6] J. Gröbner, D. Kevorkov, R. Schmid-Fetzer, Intermetallics, 10(2002) 415.


143

Phase equilibria in the Al-rich region of Al-Cu-Ir D. Kapush a, D. Pavlyuchkov a,b, B. Grushko b, T.Ya. Velikanova a a I.N. Frantsevich Institute for Problems of Materials Science, 03680 Kiev 142, Ukraine b Institut für Festkörperforschung, Forschungszentrum Jülich GmbH, D-52425 Jülich,

Germany

Phase equilibria were studied in Al-Cu-Ir between 540 to1100 ºC and from 50 to 100 at.

% Al. The results are discussed basing on updated Al-Ir phase diagram [1]. The

solubility of Cu in the binary Al-Ir phases and the solubility of the third element in Al-

Cu phases are established. The decagonal phase of ~Al60Cu24Ir16 composition examined

by electron diffraction exhibited a periodicity of ~4.0 Å in the specific direction, similar

to that in Al-Cu-Rh. Of the periodic ternary phases, one was found to form around

Al70Cu20Ir10 is isostructural to the Al7Cu2Rh ω-phase, also observed at similar

compositions in Al-Cu-Co (Fe, Ru) [2]. The ternary phase of composition in a range

around Al60Cu15Ir25, exhibited a structure type of the C2-phases that are found in Al-Cu-

Rh and a number of other aluminum-transition metal alloy systems [2]. Around the

Al71Cu9Ir20 composition, the ternary phase was revealed, which was also observed in

Al-Rh and Al-Cu-Rh, and is designated ε6. It was also determined by electron

diffraction observations in TEM. While in the binary Al-Rh, the ε6-phase is stable and

can dissolve up to ~15 at. % Cu [3], it does not exist as a stable phase in Al-Ir, but is

stabilized by Cu in a ternary compositional range. Partial 540, 600, 700, 800, 900, 990

and 1100 °C isothermal sections were determined.

References:

[1] D. Pavlyuchkov, B. Grushko, T.Ya. Velikanova, Intermetallics, 16 (2008) 801-806. [2] B. Grushko and T. Velikanova, CALPHAD, 31 (2007) 217-232. [3] B. Grushko, W. Kowalski, B. Przepiórzyński and D. Pavlyuchkov, J. Alloys

Comp., 464 (2008) 227-233.


144

Investigation of thermodynamic properties of binary intermetallic compounds of Al-Ho system T.V. Kulikova a, A.V. Mayorova a, N.I. Il'inykh a,b, K.Yu. Shunyaev a a Institute of Metallurgy of Urals Branch of Russian Academy of Sciences, 101,

Amundsen Str., Ekaterinburg, 620016, Russia, e-mail: kuliko@gmail b Ural Technical Institute of Communications and Informatics, 15, Repin Str,

Ekaterinburg, 620219, e-mail: [email protected]

According to [1] five compounds can be forming in the Al-Ho system: HoAl3, HoAl2,

HoAl, Ho2Al, Ho3Al2. The information about thermochemical properties of these

compounds is limited (see, for example, [2-3]). Therefore purposes of this investigation

were analysis of known and calculation of unknown thermochemical properties of

binary intermetallic compounds of Al-Ho system. The standard enthalpies and entropies

of formation, temperature dependences for heat capacity, heats of phase transformation

and some others were determined using well known and original methods [4] for these

compounds. The obtained results are presented in the Table.

Com- pound

∆Н°298 kJ/mole

[3]

S°298 J/(mole·K)

[2]

∆Н°298-∆Н°298

kJ/mole

Тph.t. К [1]

∆Нph.t., kJ/mole

[2]

Ср =а+bх+сх2+dх3+е105Т-2 , х=Т⋅10-3 Ср at Т>Тph.t.

J/(mole·K) а b с d е

HoAl3 -45.3 160.12 14.939 1360 49.58 107.99 11.317 11.707 -4.35 -11.351 165.12 HoAl2 -52.50 131.77 11.309 1803 38.68 80.263 11.649 2.265 0.435 -7.600 128.31 HoAl -50.50 103.42 7.679 1388 27.78 52.526 11.981 -7.176 5.221 -3.849 91.498 Ho2Al -38.80 178.49 11.727 1291 44.66 77.315 24.295 -23.79 15.23 -3.947 146.18 Ho3Al2 -44.10 281.91 19.405 1267 72.44 129.84 36.276 -30.97 20.45 -7.796 237.68

The work is supported by RFBR (grants NN 07-02-01049 and 07-03-96102 -ural).

References:

[1] State diagrams of binary metallic systems: Handbook. V. 1 / Edited by N.P. Lyakishev. M.: Mashinostroenie, 1996. – 992 p, (in Russian).

[2] V.A. Kireyev. The methods of practical calculations in the thermodynamics of the chemical reactions. - Moscow: Chemistry, 1975.-536 p. (in Russian).

[3] G. Cacciamani, S. De Negri, A. Saccone, R. Ferro. The Al–R–Mg (R=Gd, Dy, Ho) systems. Part II: Thermodynamic modeling of the binary and ternary systems// Intermetallics, 11 (2003) 1135–1151.

[4] G.K. Moiseev, N.A. Vatolin, L.A. Marshuk, N.I. Il'inykh. Temperature Dependences of Reduced Gibbs Energy of Some Inorganic Substances. - Ekaterinburg: Ural Branch of RAS, 1997, 230 p. (in Russian).


145

Thermodynamic modeling of the Mg-Si system with Kaptay’s equation for excess Gibbs energy of liquid phase Xiaoming Yuan, Weihua Sun, Yong Du

State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, 410083, P.R. China

The Mg－Si system was re-modeled using Kaptay’s equation [1], in which the equation

of Li=h0i·exp(－T/τ0i) was introduced to describe the excess Gibbs energy of the liquid

phase. Compared with the previous assessments, in which the Redlich-Kister

polynomial was used for the description of the liquid phase with a linear T-dependence

of the interaction energies [2-4], the artificial inverted miscibility gap at high

temperatures was removed. Moreover, the liquid phase is not re-stabilized at low

temperatures. The calculated phase diagram and thermodynamic properties agree well

with the experimental data.

References:

[1] G. Kaptay, CALPHAD, 28 (2004) 115. [2] H. Feufel, et al., J. Alloys Compd., 247 (1997) 31. [3] Xin-Yan Yan, et al., J. Phase Equilib,. 21 (2000) 379. [4] D. Kevorkov, et al., Journal of Phase Equibria and Difusion, 25 (2004) 140. Acknowledgement: This research work is supported by Creative Research Group of National Natural Science Foundation of China (Grant No. 50721003).


146

Correction of T-x-y diagrams with immiscibility V. Lutsyk, A. Zelenaya, V. Vorob’eva

Physical Problems Department, BSC of RAS (Siberian Branch), Russia

Sometimes inaccuracies of the phase diagrams description create the difficulties in

understanding of their geometrical structure. E. g., these problems are existed for the

diagrams with liquid immiscibility [1, p. 219, 221, 222]. In these systems a typical

solvus surface with 4 points on the contour has shown as a cylindrical one which is

projected vertically in a curve. Solvus surfaces with 5 points on the contour are shown

in such way when the 3-points perimeters of their projections are unclosed. Let’s

discuss it in detail with the solvus surface АСAQAEA0EA0

C (fig. 1a) of a diagram with

monotectic invariant equilibria. As in [1, p. 221] the lines ACA0C and AЕA0

Е are the

vertical segments, they are degenerated at projection in the common pair of points

АС(A0C) and AЕ(A0

Е). In this case a projection of this surface must have contour

АСAQAE, but in [1, p. 221] a line АСAE which joins the points АС and AE is absent. The

same misunderstanding is for the diagrams with two monotectics [1, p. 219] and with

ternary immiscibility surface [1, p. 222]. The surfaces of our diagram with nonvariant

monotectic transformation (fig. 1a) is constructed by a kinematical method [2]. In this

case the surfaces curvatures may be edited by the results of thermodynamic simulation.

It was suggested that the ends of tie-

line Ak1k1 divide the liquidus and

solidus isotherms in proportional ratio

for the solidus quasi-fold Ak1AQ

arrangement (fig.2b).

References:

[1] A. Prince, Alloy Phase Equilibrium, Elsevier Publ. Comp. Amsterdam-London-N.Y. (1966) 219-222.

[2] V.I. Lutsyk, A.M. Zyryanov, MRS Proceedings, 349 (2004) 804.

Supported by RFBR grant 09-03-00986-a and Russian Science Support Foundation.


147

Analysis of realistic heterogeneous welds of heat resistant steels by means of experimental and computational techniques Z. Hodis a, V. Jan a, J. Sopoušek b, R. Foret a a Brno University of Technology, Brno, Czech Republic b Masaryk University Brno, Czech Republic

Two alternative composite welds were manufactured by GTAW technology according to standard technological procedures. The welds connected two base materials with different chromium content using high chromium intermediate layer and low alloyed main weld consumable material. Experimental analysis was carried out on weld samples after PWHT and on samples annealed up to 1000 hours at 650ºC. Microhardness and chemical profiles of interstitial and substitutional elements across all weld interfaces in the samples were measured. Phase diagrams, activity values for diffusing elements for all materials used in the welds were calculated by ThermoCalc using Steel16 database. Phase and chemical profiles for all interfaces in the welds after heat treatment and annealing were also calculated using DICTRA and Steel16 and Dif databases. Non-linear starting chemical profiles were used for the kinetic simulations to model the mixing during realistic welding. The results of the simulations agree well with all experimental results. C Mn Si Cr Ni Mo V W Nb N

Base material 1 (P91) 0,10

0,50

0,30

8,45

0,23 1,1 0,2

1 - 0,08

0,06

Intermediate layer 1 (9Cr4Ni) 0,03 - 0,7

0 9,50

4,60

0,95 - - - -

Intermediate layer 2 (P23) 0,07

0,60

0,50

2,50 - 0,3

0 0,30

1,65

0,05

0,03

Main weld consumable (OK13.43) 0,10

1,39

0,56

0,70

2,60

0,71

0,20 - - -

Base material 2 (ŠN16 537) 0,25

0,36

0,19

2,54

3,46

0,58

0,09 - - -

Chemical composition of the materials used in experiments

Microstructure of Intermediate1/ Weld consumable interface after 1000 hours at 650ºC.


148

Cr and Co diffusion kinetics along alpha-Zr grain boundaries at power reactors normal temperatures C. Corvalan a,b, M. Iribarren a,c, N. Di Lalla b, F. Dyment b a Atomic Energy National Comission (CNEA) Buenos Aires, República Argentina. b Argentine Republic National Council of Investigations (CONICET)

Buenos Aires, Argentina. c General San Martin University (UNSAM) San Martin, Buenos Aires

República Argentina

Atomic transport along grain boundaries, being several orders of magnitude faster than

in the crystal, plays a key role in a large number of metallurgical processes as phase

transformations, corrosion, surface treatments, sintering, etc. The study of auto and

heterodiffusion a matrix give us information that can be used in theoretical calculation

and in experimental predictions. At low temperatures, diffusion processes are often not

properly considered. In fact, even when bulk diffusion can be neglected the atomic

displacement along grain boundaries is important and the whole diffusion processes

becomes relevant. Different models concerning bulk and grain boundary diffusion have

been developed and a direct application to the study of policrystals is also possible.

Zirconium, the base material for nuclear devices exhibit singular behaviour in both auto

and heterodiffusion of Fe, Ni, Co and Cr. Autodiffusion shows a non Arrhenius-like

behaviour, while the other elements present extremely high difusion coefficients. They

are called ultra fast diffusors, several orders of magnitude faster than self-diffusion.

Recent experiments concernig Co and Cr fast diffusion along alpha-Zr grain boundaries

as well as the well known bulk ultra fast characteristics of them in Zr based alloys give

us the necessary information to study the different kinetics of diffusion for Cr and Co in

alpha-Zr. On these basis, the effective diffusion coefficients and mean-square

displacement (involving those concerned to GB diffusion in type C kinetics) were

calculated. Extrapolations to [373-573] K temperature range becomes suitable from the

basis of measured data: [380-449] K for Cr and [430-487] K for Co. An analysis is

made on the basis of the validity of the different regimes in the Harrison´s

classification.


149

Thermodynamic Analysis of the Cr-Mo-B Ternary System T. Tokunaga a, H. Ohtani b, M. Hasebe b a Department of Applied Science for Integrated System Engineering, Kyushu Institute of

Technology, Kitakyushu 804-8550, Japan b Department of Materials Science and Engineering, Kyushu Institute of Technology,

Kitakyushu 804-8550, Japan

Nickel-based self-fluxing alloys are widely used in thermal sprayed coatings for boiler

tubes, rolling mill rolls, and heat exchangers, where good wear and corrosion resistance

are required. These alloys contain mainly nickel, chromium, boron, carbon, and silicon,

and various carbides and borides with high hardness values are known to form in the

sprayed coatings. The Cr-Mo-B ternary system is one of the basic constituent ternary

systems relevant to sprayed coatings, and thus, it is important to obtain information on

the phase equilibria involving hard precipitates in this ternary system to improve the

wear resistance of the coatings.

In this study, a thermodynamic analysis of the Cr-Mo-B ternary system has been carried

out using the CALPHAD method. Among the three binary systems present in this

ternary phase diagram, the thermodynamic description of the Cr-Mo system was taken

from a previous study [1]. For the Cr-B and Mo-B binary systems, the thermodynamic

parameters assessed by the authors’ group [2,3] using a combined first-principles and

CALPHAD approach were adopted. In this analysis, the ternary thermodynamic

parameters were optimized using the experimental information on the phase relationship

and the solubility of the third element in the binary borides. In addition, the energies of

formation of the ternary boride, (Cr,Mo)3B2, obtained from our first-principles

calculations, were utilized together with the experimental data. The calculated results

have nicely reproduced the experimental Cr-Mo-B ternary phase diagrams.

References:

[1] K. Frisk, Report D 60, KTH, (1984). [2] K. Yamada, H. Ohtani, M. Hasebe, J. Jpn. Inst. Met. 73(2009), No.3, in press, (in

Japanese). [3] K. Yamada, H. Ohtani, M. Hasebe, High Temperature Materials and Process,

28(2009), in press.


150

Experimental study on thermodynamics of Cu-Sn-Sb system in Cu – rich and Sn-rich corners Jolanta Romanowska

Rzeszów University of Technology, Poland

Interaction of lead-free solders with a cooper substrate is an essential issue for the

reliability of solder joints. In order to understand this interaction, the knowledge of the

ternary system Cu-Sn-Sb is necessary. This paper presents the results of the Sb activity

measurements in the Cu-Sn-Sb system for xCu>0.8 and Sn-Cu-Sb systems for xSn>0.8

for the temperature 1173 and 1373 K. The measurements were carried on by the

equilibrium saturation method [1, 2]. As this method is a comparetive one, the Sn-Sb

alloy was accepted as a reference alloy, where a formula for Sb activity proposed by

Jonsson [3] and verified by Vassiliev [4] was accepted.

The interaction parameters and were determined by the least squares method

and the experimental values were determined with the values calculated on the basis of

the central atom theory [5].

References:

[1] G. Wnuk, J. Romanowska, Arch. of Met. and Mat., 51(4) (2006) 1. [2] G. P. Vassilev, J. Romanowska, G. Wnuk, Int. Mat. Res., 98 (2007) 6. [3] B. Jonsson, J. Agren, Mat. Sci. Techn., 2 (1986) 913. [4] G. P. Vassilev, Y. Feutelais, M. Sghaier, B. Legendre, J. of Alloys and Compounds,

314 (2001) 198. [5] C. H. Lupis, J. F. Elliot, Acta Metallurgica, 15 (1967) 265.


151

Thermal analysis of Cu-Ni-Sn-Zn alloys by means of the DCS technique Grzegorz Wnuk

Rzeszów University of Technology, Poland

The urgent need to find new, non toxic, high temperature solders caused the abundance

of research of multicomponent systems, as to find new materials that could substitute

lead-containing solders. In this work Cu-Ni-Sn-Zn alloys a were studied by differential

scanning calorymetry (DSC). Thermal effects during melting and solidifying were

experimentally studied by the DSC technique [1] in the argon atmosphere using the

heating rate 10K/min and the cooling rate 15K/min. There were calculated heat effects

and the temperature of the beginning and ending of phase transitions. Each sample was

heated and cooled twice, at the second run the Zn concentration was smaller (as Zn is a

volatile component). This way. There has been established the Zn influence on phase

transformations. For the second run, when the Zn activity is smaller, heats and

temperatures of transformations are higher.

These experimental results, combined with other thermodynamic properties of the

studied alloy [2] enable phase diagram calculation in the frame of the COST action

MP0602. This work was sponsored by the Polish Ministry of Science and Education, Grant nr N N507 44 3834

References:

[1] W. Zielenkiewicz, Calorymetry, (2008) Institute of Physical Chemistry of the Polish Academy of Sciences.

[2] J. Romanowska, G. Wnuk, Arch of Met and Materials, 53(4) (2008) 1107.


152

Thermodynamic Properties of the Ca-Li System, Heat of Formation of the CaLi2 Solid Phase W. Zakulski, W. Gąsior, A. Dębski

Institute of Metallurgy and Materials Science, Polish Academy of Sciences 30-059 Krakow, Reymonta Street 25

The Ca-Li system is one of those binaries which have no thermodynamic data in the

literature. Also, the phase diagram of that system is not completely defined. It is related

to the high reactivity of Ca and Li with O2, H2, N2 and the moisture. This situation has

not changed for many years, even though those alloys play a very important role in the

aluminum and magnesium industries. In the future, the importance of these alloys is

going to be even higher when we take into account the fact that they can be a candidate

for safe and ecological hydrogen storage as an energy source for the application in the

automobile industry.

The goal of the project supported by the Polish Ministry of Science and Higher

Education is to fill up this serious gap in the word data. At present, as a first step, the

calorimetrically measured heat of formation ΔH(f) of the CaLi2 solid phase was

determined.

In the subsequent future steps, the calorimetrically measured heats of mixing H(m) of

the liquid phase, and the phase equilibrium data by the DSC/DTA method will be

studied. Finally, the experimental own data and the literature information will be used

for the phase diagram calculation of the whole Ca-Li phase diagram.


153

Experimental investigation of the Mg-Zn-Ca system using diffusion couples and key experiments Yinan Zhang a, Mamoun Medraj a, Dmytro Kevorkov a, Jian Li b, Elhachmi Essadiqi b and Patrice Chartrand c a Concordia University, Montreal, Canada; b MTL-CANMET, Ottawa, Canada; c Ecole Polytechnique, Montreal, Canada

In this work, Mg-rich corner of the Mg-Zn-Ca system has been investigated using

diffusion couples and key experiments. Binary Mg-Ca and ternary Mg-Ca-Zn diffusion

couples have been prepared and studied extensively using optical microscopy, XRD,

SEM, EPMA. The SEM and optical microscopy have been used for microstructure

analysis and measurement of layer thickness. The XRD and EPMA results were used

for the phase analysis and determination of the phase compositions and solid solubility.

Due to the very reactive nature of Ca and brittleness of the Mg2Ca, only the solid-liquid

binary diffusion couples in the Mg-Ca system have been studied successfully. Mg2Ca

was found to be a stoichiometric compound with no homogeneity range. The EPMA

study of the Zn-Mg2Ca, Mg64.2Zn35.8-Zn58.85Ca41.15 and Mg-Zn58.8Ca41.2 ternary diffusion

couples allowed us to determine a ternary compound with a wide homogeneity range.

Its composition is close to the Mg5Ca5Zn2 ternary compound which was reported by

Paris in 1960. Ca18Mg44.5Zn37.5, Ca18Mg37.5Zn44.5, Ca18Mg41Zn41, and Ca18Mg55Zn27

alloys have been prepared and studied using XRD to verify the formation of the

Ca2Mg6Zn3 and Mg5Ca5Zn2 ternary compounds. Also Ca5Zn95, Ca5Mg10Zn85 and

Ca5Mg18Zn77 alloys have been prepared to verify the formation of the Ca2Mg5Zn13

ternary compound in the Zn rich corner. Only one ternary compound with the

composition Mg5Ca5Zn2 was found in this study. The Ca2Mg5Zn13 compound reported

in literature could be associated with the CaZn13 phase that has a ternary solid solubility

up to 10 at.% Mg.


154

Thermodynamic Analysis of the Mg-Cu-Y-Ni System M. Mezbahul-Islam, M. Medraj

Dept. Mechanical and Industrial Engineering, Concordia University 1455 de Maisonneuve Blvd. West, Montreal, Quebec, H3G 1M8, CANADA

Mg based alloys especially Mg-Cu-Y have shown a lot of promise as metallic glass

since they have a large super cooling liquid region. Introducing Ni to partially substitute

Cu improves the glass-forming ability of the alloys. To find a suitable glass forming

composition of this system a reliable thermodynamic database based on a suitable

model is required because unguided experimental investigation will consume a lot of

time and effort. Hence the main objective of this work is to provide a better insight on

the Mg-Cu-Y-Ni system by thermodynamic modeling. A self consistent thermodynamic

database of the Mg-Cu-Y-Ni system has been developed by combining the

thermodynamic descriptions of the constituent binaries Mg-Cu, Mg-Y, Mg-Ni, Cu-Y,

Cu-Ni and Ni-Y and the ternaries Mg-Cu-Y, Mg-Cu-Ni, Mg-Y-Ni and Cu-Y-Ni. Most

of these systems, especially those contain Cu and Y, show strong tendency for short

range ordering in the liquid which is actually one of the requirements for an alloy to

have glass forming ability. Because of this tendency of short range ordering in some of

the systems it is necessary to use a model that accounts for this phenomenon such as the

modified Quasichemical model. Besides, The sublattice model within the compound-

energy formalism is used for the intermediate solid solutions with long range order.The

model parameters are optimized based on the experimental phase equilibrium and

thermodynamic data available in the literature. The pure element data is taken from

Dinsdale pure element database [1]. The constructed database has been used to calculate

liquidus projection, isothermal and vertical sections of the ternary systems which are

compared with the available experimental information on these systems. The current

calculations are in a good agreement with the experimental data reported in the

literature.

References:

[1] A. Dinsdale, CALPHAD, 15 (1991) 317-325.


155

Thermodynamic Modeling of the Mg-Mn-(Al, Zn) Systems M. Asgar-Khan, M. Medraj

Department of Mechanical Engineering, Concordia University, Montreal, Quebec, Canada

A self-consistent thermodynamic model of the Mg-Mn, Al-Mn, Mn-Zn binary systems

as well as the Mg-Mn-Al and Mg-Mn-Zn ternary systems has been developed in the

current work. The major difference with the previous works on these systems is the

application of the modified quasichemical model for the liquid phase for which most of

the existing descriptions use random mixing model. In the absence of key data for the

Mg-Mn system, the calculated thermodynamic quantities from this model have been

found comparable to other similar systems. A comparison between the current work and

the most recent work on the Al-Mn system that uses the same model for the liquid phase

reveals that better agreement with the experimental data with less number of model

parameters has been achieved in the current work. The Mn-Zn system has been modeled

for the entire compositon range and wide temperature range starting from room

temperature. The accepted experimental data are well reproduced with the current

description of the Mn-Zn system. Kohler extrapolation model has been used to calculate

both Mg-Mn-Al and Mg-Mn-Zn systems. The thermodynamic description of the Mg-

Al-Mn system has been verified by extensive comparison with the available

experimental data from numerous independent experiments. The calculated Mg-Mn-Zn

system could not be thoroughly verified due to the absence of reliable experimental

data. The model can satisfactorily reproduce all the invariant points and the key phase

diagram and thermodynamic features of the Mg-Mn-Al, Mg-Mn-Zn ternaries and the

constituent binaries.


156

Influence of alloying elements upon the solidification interval of CA6NM cast martensitic stainless steel B. G. Scuracchio a,b, C. G. Schön b a Mangels Com. Ind. Ltda. - Steel Division, Rua Max Magnels Senior, 777 – CEP

09895-900 São Bernardo do Campo-SP, Brazil b Computational Materials Science Laboratory, Department of Metallurgical and

Materials Engineering, Escola Politécnica da Universidade de São Paulo, CEP 05508-900 São Paulo-SP, Brazil

The influence of different contents of the alloying elements Cr and C upon the

solidification interval of ASTM A352M-06 Grade CA6NM cast martensitic stainless

steels has been investigated using computational thermodynamics and checked against

DTA measurements in samples taken from 13 large cast parts, in order to identify

potential sources for improvement of the part castability. Calculation results suggest,

indeed, that this would be the case for C: when its content increases from 0.018wt%C to

0.044wt%C (within the range allowed by the alloy standard), the solification intervals

increases from 25oC to 43oC, which indicates improved castability with lower C

contents. DTA results, however, do not support this prediction, showing a fairly

constant solidification interval around 23oC for all investigated samples. The results

(Figure 1) are discussed both with respect to the impact for alloy processing and to the

fitness of the existing databases to reproduce experimental results in these limit cases.

(a) (b)

Figure 1- Calculated and experimental solidus and liquidus temperatures for different

runs of the CA6NM steel as a function of (a) Cr and (b) C content.


157

Phase formation in the Mg-Sn-Ca-Si quaternary system A. Kozlov, R. Schmid-Fetzer

Institute of Metallurgy, Clausthal University of Technology, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld, Germany

Aluminum-free Mg-alloys are currently attracting attention as a next generation of

commercial alloys which offer potential to improve the property profile and to extend

the range of applications for magnesium alloys.

Three ternary subsystems, namely Mg-Sn-Ca [1, 2], Mg-Si-Ca [3] and Mg-Sn-Si were

investigated in our group in entire concentration range. These datasets were applied for

an initial, extrapolative calculation of quaternary Mg-Sn-Ca-Si equilibria in the Mg

corner. In the frame of this investigation the solidification paths and possible

precipitations of exemplary alloy compositions were calculated, using both equilibrium

and Scheil conditions. Key experiments were selected and performed to check these

predictions. First results of this study are presented.

This study is supported by the German Research Foundation (DFG) in the Priority Programme “DFG-SPP 1168: InnoMagTec” under grant no. Schm 588/26.

References:

[1] A. Kozlov, M. Ohno, R. Arroyave, Z.K. Liu, R. Schmid-Fetzer, Intermetallics, 16 (2008) 299-315.

[2] A. Kozlov, M. Ohno, T. Abu Leil, N. Hort, K.U. Kainer, R. Schmid-Fetzer, Intermetallics, 16 (2008) 316-321.

[3] J. Gröbner, I. Chumak, R. Schmid-Fetzer, Intermetallics, 11 (2003) 1065-1074.


158

Constraining thermodynamic properties of intermetallic phases in the system Fe-Al M.H.G. Jacobs a, P. Blöchl b, R. Schmid-Fetzer a a Institute of Metallurgy, Clausthal University of Technology,

Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld, Germany b Institute of Theoretical Physics, Clausthal University of Technology

Leibnitz-Str. 10, D38678 Clausthal-Zellerfeld, Germany

Our goal is to develop an accurate thermodynamic model description of the system Fe-

Al. In Jacobs and Schmid-Fetzer [1] we have demonstrated that no accurate

thermodynamic descriptions are available for thermophysical properties of the

intermetallic phases FeAl2, Fe2Al5 and FeAl3. The thermodynamic description of these

phases is hampered by the lack of experimental data for heat capacity, thermal

expansivity and bulk modulus. Presently the heat capacity in our thermodynamic

formulation for the intermetallic phases is described in terms of Neumann-Kopp’s rule

resulting in a physically anomalous behavior of this property. However, there is no

physical reason for the applicability of this rule to phases having different

crystallographic structures relative to the elements. The rule does not necessarily lead to

the correct heat capacity as has been demonstrated by Jacobs and Spencer [2] for

intermetallic phases in the system Mg-Ni. Consequently, the present inadequate

thermodynamic description for the intermetallic phases also hampers the achievement

of a proper thermodynamic description of the phases bcc, fcc, and liquid. Because

constraining heat capacity and heat of formation for FeAl2, Fe2Al5 and FeAl3 is one of

the preliminary steps to constrain thermodynamic mixing properties of bcc, fcc and

liquid, we performed ab initio calculations of these properties. This paper reports on

first results of ab initio calculations of thermodynamic properties of intermetallic phases

in the system Fe-Al.

This study is supported by the German Research Foundation (DFG) under grant no. Schm 588/28.

References:

[1] Jacobs M.H.G. and Schmid-Fetzer R. Phase behaviour and thermodynamic properties in the system Fe-Al. Calphad, (2009) in press.

[2] Jacobs M.H.G. and Spencer P.J. Calphad, 22 (1998) 513-525.


159

Experimental and theoretical studies of bainitic creep-resisting T23 steel M. Svobodová a, J. Sopoušek b a UJP PRAHA a.s., Prague, Czech Republic b Department of Chemistry, Faculty of Science, Masaryk University, Brno, Czech

Republic

CALPHAD approach is a progressive tool of material engineering helping in a

development of new advanced materials. Based on this approach, we can make phase

diagram calculations and predictions, and simulate diffusion-controlled phase

transformation, too. In a view of the application, these phase diagrams calculations play

a significant role in a, i.e., prediction of thermal-induced structure changes in new

materials supposed to be used for power industry. Furthermore, perhaps all structural

parts of power plants are welded, so, if the operation temperature is achieving values

above 500 °C, the simulations of diffusion-controlled phase transformations occurring

in so thermal loaded weld joints enable to predict their structure stability and then a

service lifetime of all the structural part. One of those new materials supposed to be

used for power industry is bainitic creep-resisting T23 steel, a modification of low-

alloyed 2.25Cr-1Mo steel, containing Cr (2.25 wt.%), Mo (0.1 wt.%), C, V, Mn (each

0.2 wt.%), and B, N (each 0.006 wt.%). Moreover, T23 steel is alloyed with 1.6 wt.% of

W and 0.04 wt.% of Nb. Due to addings, as-treated steel has an improved creep

resistance, high elastic-plastic properties, and a good weldability. Therefore, T23 steel

is said to be use for power components at operating conditions up to 600 °C. Because

of, considering a service lifetime of components, a necessary prediction of long-term

structure, corrosion, and strength behaviour of the material, our research was focused on

study of structure behaviour of T23 steel at long-term isothermal exposure at 650 °C. In

opposite to 100 000 hrs exposure at 600 °C (maximum service temperature), the

increased temperature allows to get same degraded structure of steel after already

10 000 hrs. The thermal-induced phase transformations of as-received, as-welded, and

as-exposed T23 steel were predicted by using Thermo-Calc and DICTRA. At the same

time, XRD analysis, light and electron microscopy, and Vickers hardness measurement

were used.


160

Constitution of the Al–Cr–Fe phase diagram in the compositional range above 60 at. % Al D. Pavlyuchkov a,b, B. Grushko b, D. Kapush a, W.Kowalski c, V. Khorujaya a, K. Kornienko a, T.Ya. Velikanova a a I.N. Frantsevich Institute for Problems of Materials Science, 03680 Kiev 142, Ukraine b Institut für Festkörperforschung, Forschungszentrum Jülich GmbH, D-52425 Jülich,

Germany c Institute of Material Science, University of Silesia, 40007 Katowice, Poland

The Al–Cr–Fe alloy system was investigated at 700 to 1100ºC in the compositional

range above 60 at.% Al. Binary Al13Fe4, Al5Fe2 were found to extend up to 7 at.% Cr

and Al2Fe up to 4 at.% Cr. The dissolution of Cr in these binaries only slightly

influences their Al concentrations. The Al-Fe є and Al-Cr γ1 probably form a

continuous range of solid solutions. The solubility of Fe in the Al–Cr μ-phase is about

2.5 at.%, the Al–Cr η-phase dissolves up to 5 at.% Fe, which results in a sharp decrease

of its Al concentration and increase of melting temperatures. The binary θ-phase was

found to dissolve about 2 at.% Fe. For the first time the stable decagonal

quasicrystalline phase was found around the Al72Fe12Cr16 composition. It exhibits

periodicity of ~1.2 nm along the 10-fold symmetry axis (D3 structure). Also three

ternary periodic phases were observed: a complex orthorhombic O1-phase with a≈3.27,

b≈1.24 and c≈2.34 nm, a hexagonal H-phase with a≈1.74 and c≈4.14 nm and an

orthorhombic ε-Al4(Cr,Fe) with a≈1.27, b≈3.46 and c≈2.04 nm. Partial isothermal

sections at 1100, 1075, 1042, 1000, 900, 800 and 700°C were determined.

The reaction scheme, liquidus and solidus surfaces of Al–Cr–Fe were determined.

Fifteen ternary reactions involving the liquid phase were revealed: two peritectic and

thirteen transition reactions. The D3, O1 and ε-Al4(Cr,Fe) phases are formed by

reactions between the liquid and the Al–Cr γ1-phase at about 1090, 1070, 1045 °C

respectively, while the H-phase is formed by peritectic reaction: L + O1 + Al13Fe4 ↔ H

at ≤ 1000°C. The lowest temperature of the liquid phase 655°C corresponds to the

binary eutectic between (Al) and Al13Fe4.


161

Experimental investigation and thermodynamic calculation of the Bi-Ga-Sn phase equilibria

D. Manasijević a, D. Minić b, D. Živković a, I. Katayama c, J. Vřešťál d, D. Petković b a University of Belgrade, Technical Faculty, VJ 12, 19210 Bor, Serbia b University of Pristina, Faculty of Technical Sciences, 38220 Kosovska Mitrovica,

Serbia c Research Inst. for Ubiquitous Energy Devices, Advanced Industrial Science and

Technology, Ikeda, Osaka, Japan d Department of Chemistry, Faculty of Science, Masaryk University, 611 37 Brno,

Czech Republic

Binary thermodynamic data, successfully used for phase diagram calculations of binary

systems Bi–Ga, Bi–Sn, and Ga–Sn, were used for prediction of phase equilibria in

ternary Bi–Ga–Sn system. The thermodynamic functions, such as enthalpy of formation

and activity, were calculated using the Redlich–Kister–Muggianu model and compared

with experimental data reported in the literature. The liquidus surface, invariant

equilibria and three vertical sections with molar ratio Ga:Sn=1, Bi:Sn=1 and Bi:Ga=1 of

the Bi-Ga-Sn ternary system were calculated by the CALPHAD method. Alloys,

situated along three calculated vertical sections, were investigated by Differential

Scanning Calorimetry (DSC). The experimentally determined phase transition

temperatures were compared with calculation results and good mutual agreement was

noticed.


162

Phase equilibria in the Al-rich part of Al-Ni-Cr W. Kowalski a, B. Grushko b, D. Pavlyuchkov b,c, S. Mi b, M. Surowiec a a Institute of Materials Science, University of Silesia, 40-007 Katowice, Poland b Institute of Solid State Research, Research Centre Jülich,52428 Jülich, Germany c I.N. Frantsevich Institute for Problems in Materials Science, 03680 Kiev 142, Ukraine

Following our previous study [1] the Al-Ni-Cr constitutional diagram was specified at

700 and 800°C in the compositional range above 50% of Al using SEM/EDX, TEM,

powder XRD and DTA. In total, the ternary extensions of the binary Al-Cr phases were

found to be: the θ-phase and η-phase up to 2 at.% of Ni, the μ-phase and ν-phase up to

1 at.% of Ni and the γ-phase(s) up to 3 at.% of Ni. The binary Al3Ni phase dissolve

around 1 at.% of Cr and the Al-Ni δ-phase up to 4 at.% of Cr. In addition to the ternary

ζ-phase and ε-phase reported in [1] two ternary phases designated ζ1 and φ were

localized. The ζ-phase (hexagonal, a≈1.78, c≈1.23nm) is formed between Al82Ni2Cr16,

Al75Ni4Cr21 and Al71Ni11Cr18 below ~1030°C. Similar structure was observed in the Al-

Cu-Cr system [2,3]. The ε-phase (orthorhombic, a≈1.27nm, b≈3.46nm, c≈2.04nm) was

found to be formed around Al76Ni2Cr22 in a small temperature range around 1000°C.

The ζ1-phase phase stable in a compositional range Al82Ni3Cr15 at 700 and 800°C. Its

structure is closely related to the structure of the ζ-phase. A rhombohedral lattice with

a=1.77 and c=8.04 nm was associated with this phase, although also other electron

diffraction patterns were observed, which could belong to a hexagonal structure with

a≈3.07nm, c≈1.23nm. The φ-phase (monoclinic, a≈1.33nm, b≈1.25nm, c≈1.25nm,

β=100°) was found to be stable below 860°C around Al79Ni9Cr12. Partial isothermal

sections at 700, 800, 900, 1000, 1025 and 1150ºC will be presented.

References:

[1] B. Grushko, W. Kowalski, D. Pavlyuchkov, B. Przepiórzyński, M. Surowiec, J. Alloys Comp., 460 (2008) 299-304.

[2] B. Grushko, E. Kowalska-Strzęciwilk, B. Przepiórzyński, M. Surowiec, J. Alloys Comp., 417 (2006) 121.

[3] B. Grushko, B. Przepiórzyński, D. Pavlyuchkov, S. Mi, E. Kowalska-Strzęciwilk, M. Surowiec, J. Alloys Comp., 442 (2007) 114-116.


163

Thermodynamic assessment and modelling of the Mo-Pt system N. David a, J.M. Fiorani a, G. Hug b, J.M. Joubert c, M. Vilasi a a Institut Jean Lamour Département Chimie et Physique des Solides et des Surfaces, UMR 7198 CNRS -

Université Henri Poincaré Nancy 1, Boulevard des aiguillettes, BP 70239, 54506 Vandœuvre-lès-Nancy, France

b Laboratoire d’Etude des Microstructures, ONERA-CNRS-UMR 104, BP 72, 29. avenue de la Division Leclerc, 92322 Châtillon, France

c Chimie Métallurgique des Terres Rares, Institut de Chimie et des Matériaux Paris-Est, CNRS UMR 7182, 2-8 rue Henri Dunant 94320 Thiais, France

The accepted diagram of the Mo-Pt system is that proposed by Brewer and. Lamoreaux

[1] which is based mainly on works due to Flükiger et al [2] and to Ocken and Van

Vucht [3]. In the literature, there is no experimental data about the thermodynamic

quantities. In order to verify and complete the knowledge of this system, we have

performed several studies:

- phase diagram investigations showing new phase equilibria;

- calorimetric study providing enthalpies of formation of intermetallic compounds (A15,

DO19, B19 and MoPt2) and A1 solid solution;

- crystallographic study providing site occupancies at different temperatures and

compositions of the DO19, B19 and MoPt2 phases;

- first-principal calculations were performed to give the enthalpies at low temperatures

for the B19 and MoPt2 compounds

All these results have been used to build a CALPHAD optimization of the system

taking into account the following ordered–disordered transitions A3/DO19, A3/B19 and

A1/MoPt2. A very good consistency was obtained between all available data.

References:

[1] L. Brewer, R.H. Lamoreaux, Bull. Alloy. Phase Diagrams, 1 (1980) 89. [2] R. Flükiger , K. Yvon, C. Susz, R. Roggen, A. Paoli, J. Muller, J. Less-Common

Met., 32 (1973) 207. [3] H. Ocken, J.H.N. Van Vucht, J. Less-Common Met., 15 (1968) 193.


164

Thermal stability of Ti-Al-Zr-N films Li Chen a,b, P.H. Mayrhofer b, Yong Du a a State Key Laboratory of Powder Metallurgy, Central South University, Changsha,

Hunan, 410083, P. R. China b Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben,

8700, Austria

Ti-Al-N films, which combine high temperature oxidation resistance and age-hardening

abilities, are widely applied in the cutting tools. TiAlN films are subjected to high

temperatures with cutting temperatures exceeding 900oC in dry cutting, giving rise to

structural transformation of metastable c-TiAlN into stable h-AlN affecting application-

oriented properties. Here, we study the effect of Zr addition on the thermal stability of

Ti-Al-N films. Results obtained by thermal analyses as well as X-ray diffraction

investigations on as-deposited and annealed film powders show that Zr effectively

retards the decomposition of the c-TiAlZrN into h-AlN. The transformation temperature

from c-AlN to h-AlN is shifted from ~950oC for (Ti0.5Al0.5)N to ~1200oC for

(Ti0.4Al0.55Zr0.05)N and (Ti0.4Al0.5Zr0.1)N. Compared with (Ti0.4Al0.5Zr0.1)N film,

(Ti0.4Al0.55Zr0.05)N film with low Zr content behaves better thermal stability.

Key words: TiAlN film, Zr, thermal stability, phase transformation Acknowledgement: This research work is supported by Creative Research Group of National Natural Science Foundation of China (Grant No. 50721003).


165

Thermochemical study on Ni-P and Sn-P systems Rajesh Ganesan, Herbert Ipser

Institut fuer Anorganische Chemie / Materialchemie, Universitaet Wien,Waehringerstr. 42, A-1090 Wien,Austria

In electronics industries Ni is used as protective layer on the Cu metallization of PCB

boards. This is usually carried out by electroless or electroplating in phosphorus

containing baths. During this process Ni-P layers are formed which results in

phosphorus composition as high as 16 at%. During the soldering process, this Ni-P

layer interacts with Sn based solder alloy. In order to understand the behaviour of these

components, a thermochemical study of the systems Ni-P, Sn-P and Ni-Sn-P is needed.

In the present work, a detailed study on thermochemical behaviour of Ni-P and Sn-P

systems was carried out by an isopiestic method. The Ni and Sn samples were

equilibrated in the temperature ranges 600-1000 K and 950-1350 K, respectively, at

various known phosphorus vapour pressures. The equilibrium phases were characterised

and their phosphorus activity was determined. The thermochemical behaviour of Ni-P

and Sn-P was derived. The derived data may be used as inputs in the optimisation of the

Ni-P and Sn-P phase diagrams by the CALPHAD approach.


166

Intermetallic phases in the Ni−Al−Ti system: analytical electron microscopy and thermodynamic calculations J. Buršík a, P. Brož b a Institute of Physics of Materials, Academy of Sciences of the Czech Republic, v.v.i.,

Žižkova 22, CZ-61662 Brno, Czech Republic b Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, CZ-

61137 Brno, Czech Republic

The Ni−Al−Ti system is one of the key model systems for technically important

materials based on nickel and titanium aluminides. A recent critical literature review by

Schuster [1] stated a lack of experimental data apart from corners of the composition

triangle. To improve this situation, Schuster et al [2] delivered a thorough experimental

study of the system. Regarding thermodynamic calculations, the work by Dupin and

Sundman [3] and papers by Huneau et al [4] and Zeng et al [5] present the state of the

art.

This work is focused on several alloys of Ni−Al−Ti system from the central part of the

composition triangle, where numerous intermetallic phases coexist. The microstructure

of alloys was studied and quantified after long term annealing at 1050 °C, mostly by

means of scanning electron microscopy with an energy dispersive X-ray analysis and

electron backscatter diffraction. Experimental results were compared with existing

literature data. In order to compare experimental knowledge on phase equilibria with

results of thermodynamic modelling, phase diagram was calculated using the software

package ThermoCalc and two different thermodynamic databases.

The work has been supported by the Institute Research Plan (AV0Z20410507) and by the Ministry of Education of the Czech Republic (projects MSM0021622410 and OC098 - COST action 535 “THALU”)

References:

[1] J.C. Schuster, Intermetallics, 14 (2006) 1304. [2] J.C. Schuster, Z. Pan, S. Liu, F. Weitzer, Y. Du, Intermetallics, 15 (2007) 1257. [3] N. Dupin, B. Sundman, Scand. J. Metall., 30 (2001) 184. [4] B. Huneau, P. Rogl, K. Zeng, R. Schmid-Fetzer, M. Bohn, J. Bauer, Intermetallics,

7 (1999) 1337. [5] K. Zeng, R. Schmid-Fetzer, B. Huneau, P. Rogl, J. Bauer, Intermetallics, 7 (1999)

1347.


167

The interpretation of the DSC signals of the lead-free solder alloy systems using the CALPHAD approach Jiří Sopoušek a, Marián Palcut b,c a Institute of Chemistry, Faculty of Science, Masaryk Univ., Brno, Czech Rep. b Institute of Materials Science, Slovak University of Technology, Trnava, Slovakia c Divison of Fuel Cells and Solid State Chemistry, Risø National Laboratory for

Sustainable Energy, Technical University of Denmark, Roskilde, Denmark

The knowledge of the phase diagrams and the predictions of the respective liquidus and

solidus temperatures are of a great importance. In the present study, the heat flow

differential scanning calorimetry (DSC) was used to describe the phase transformations

in the lead-free solder systems Sn-Ag-Cu and Sn-Ag-Cu-X (X=Bi, In). We used the

Neztsch STA CD/3/403/5/G instrument that enables for the detection of the DSC signal

using the heating and cooling rates of down to 0.1 K/min. At these conditions, the

samples could be considered to be in the state close to the thermodynamic equilibrium.

The DSC heating signal of the materials consisted of two or more different overlapping

peaks resulting from the precipitation of secondary phases. The equilibrium state

calculations were performed using the CALPHAD approach. The individual phases and

their molar Gibbs energies were described by the parameters taken from the COST531

Thermodynamic Database of Lead-free Solders [1]. Since the CALPHAD approach

allows for the calculation of thermodynamic functions, the experimental DSC curves

could be simulated using the calculated molar enthalpies of the solders (ΔH). The

standard molar enthalpies were calculated for different temperatures and for the various

lead-free alloys. The respective temperature derivatives were directly and successfully

compared with the experimental DSC curves.

Acknowledgement: The authors acknowledge the project support through grants VEGA 1/3032/06, VEGA 1/3191/06, MSM0021622410 and OC09010 (COST MP0602).

References:

[1] Dinsdale, A. T.; Watson, A.; Kroupa, A.; Vřešťál, J.; Zemanová, A. Vízdal, J.: COST Action 531 - Atlas of Lead-free Soldering. COST Office 2008, ISBN 978-80-86292-28-1.

[2] Boettinger, W. J.; Kattner, U. R.; Moon, K.-W.; Perepezko, J. H.: DTA and Heat-flux DSC Measurements of Alloy Melting and Freezing, 2006, Washington, National Institute of Standards and Technology.


168

Mg-rich parts of the ternary Mg-Zn-(Ce, Gd, Y) systems J. Gröbner a, C.-N. Chiu a,b, A. Kozlov a, R. Schmid-Fetzer a a Institute of Metallurgy, Clausthal University of Technology, Robert-Koch-Str. 42,

D-38678 Clausthal-Zellerfeld, Germany b Department of Chemical Engineering, National Tsing Hua University, 101, Section 2

Kuang Fu Rd. Hsin-Chu 300, Taiwan, ROC

Magnesium based Mg-Zn alloys are considered to have great potential as lightweight

alloys in automotive and aerospace industry, since they provide a better creep resistance

than Mg-Al alloys [1]. In order to improve the creep resistance and strength at elevated

temperatures, new alloys are being developed by adding rare earth (RE) elements (Ce,

Gd, and also Y). Stable and metastable precipitations are formed in these alloys by age

hardening. For the Mg-Zn-Y system a first thermodynamic dataset is available [2]. Five

ternary phases characterize this system. However, the experimental basis for this system

is quite limited. The presumably related Mg-Zn-Ce system, by contrast, shows large

ternary solubilities of the binary Ce-Mg phases. In commercial alloys misch-metal is

used instead of pure elemental RE additions. An understanding of the impact of various

misch-metal compositions requires the knowledge of different Mg-Zn-RE systems.

In this presentation the Mg-rich parts of the ternary systems Mg-Zn-Ce, Mg-Zn-Gd and

Mg-Zn-Y will be compared. Liquidus surfaces, isothermal sections and vertical sections

of these systems are calculated and compared with experimental data from own

investigations and from the literature.

This study is supported by the German Research Foundation (DFG) in the Priority Programme “DFG-SPP 1168: InnoMagTec” under grant no. Schm 588/29.

References:

[1] M. Bamberger, Mater. Sci. Technol., 17 (2001) 15. [2] G. Shao, V. Varsani, Z. Fan, Calphad 30 (2006) 286.


169

Thermodynamics of magnesium alloy solders M. Hampl a, S. Mücklichb, B. Wielageb, R. Schmid-Fetzer a a Institute of Metallurgy, Clausthal University of Technology, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld

b Chemnitz University of Technology, Erfenschlager Str. 73, D-09125 Chemnitz

Magnesium alloys of the most important commercial system AZ are essentially based

on the Mg-Al-Zn ternary system. Extended applications of these lightweight alloys

require an appropriate joining technology for both similar and dissimilar materials. The

common techniques of joining magnesium alloys such as welding are not applicable in

the case of high alloyed magnesium parts or dissimilar materials such as magnesium

and aluminum. Therefore the presented work focuses on the thermodynamic aspects of

phase formation during soldering processes in magnesium alloys. The currently most

promising filler material used in our research is based on the Mg-Zn-(Al) system,

enabling the soldering processes to be carried out at reasonable temperatures around

350°C. The thermodynamic modeling of soldering connected with experimental results

will be used to identify/suggest the appropriate filler composition corresponding to the

desired microstructure in the joint. First binary Mg-Zn filler materials with different

composition are used for experimental examination and modeling the proper conditions

by joining commercial alloys AZ31 and AZ91. The research will later be extended to

joints of dissimilar materials such as and aluminum alloys. First results are presented in

this work. This study is supported by the German Research Foundation (DFG) under grant no. Schm 588/32 and Mu 1773/2-1.


170

Calculation of isothermal sections of Fe-B-V phase diagram V. Homolová a, A. Kroupa b, A. Výrostková a

a Institute of Materials Research, Slovak Academy of Sciences, Watsonova 47 Košice 040 01 Slovakia,

b Institute of Physics of Materials, Academy of Sciences of Czech Republic, Žižkova 22 Brno, Czech Republic

The work describes results of experimental and theoretical investigation of the phase

equilibria of the Fe-B-V ternary system. Phase diagram of the system was modelled by

CALPHAD method. Boron is modelled as an interstitial element in the FCC and BCC

solid solution phases and all borides are modelled as stoichiometric phases with respect

to boron. Twenty model Fe-B-V alloys were prepared in the experimental part of the

work. After long term annealing at 903 K and 1353 K the present phases were analysed

by means of the scanning electron microscopy (EDX) and X-ray diffraction. The

calculated isothermal sections of the phase diagram were compared with experimental

results at 903 and 1353 K and with available experimental literature data [1]. Good

agreement between experimental results and calculations were found. At 1353 K a

ternary phase “T “ with chemical compositions approximately 26 Fe-37V-38B in at. %

was found in more alloys.

The work has been supported by Slovak Grant Agency (VEGA) under grant No. 2/0042/09.

References:

[1] J. B. Kuzma, P.K. Starodub, Neorganiceskije Materialy, 3 (1973) 376.


171

Addition of Nb to the Developmental Al-Cr-Pt-Ru Database A.M. Ukpong a,b, L.A. Cornish a,b, A. Watson c, A.J. Scott c a DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand,

Private Bag 3, Johannesburg 2050, South Africa. b School of Chemical and Materials Engineering, University of the Witwatersrand,

Private Bag 3, Johannesburg 2050, South Africa c Institute for Materials Research, University of Leeds, Leeds LS2 9JT, U.K.

A thermodynamic database for Pt-based alloys for high temperature applications has

been the focus of development in South Africa for a number of years [1]. Extension of

the database is now underway through the inclusion of niobium, which has been

identified as a useful addition to alloys of up to about 12 at.% [2]. Most of the four

binary phase diagrams that are needed for the addition of Nb to the current database are

well established [3], although the Nb-Ru diagram would seem to be uncertain. The Al-

Nb [4] and Cr-Nb [5] systems have been assessed recently and have been implemented

into the new database. Assessment work has been undertaken on the Pt-Nb and Nb-Ru

systems. The terminal solid solutions were modelled as substitutional solutions and the

ordered L12 phase, the σ-phase (Nb2Pt) and the A15 phase (Nb3Pt) were modelled using

the compound energy model. Phases with a narrow range of homogeneity were

modelled as line compounds. Ab Initio calculations were performed to provide

enthalpies of formation of the stoichiometric phases and starting values for optimisation

of the end-members of the L12, A15 and σ-phase.

References:

[1] L.A. Cornish, R. Süss, L.H. Chown, A. Douglas and L. Glaner, Plat. Met. Rev., 53 (2009) 2.

[2] G. F. Ndlovu, Microstructural Investigation of the Pt-Al-Nb System, M.Sc. Dissertation, University of the Western Cape, December 2006.

[3] T.B. Massalski (Ed.), Binary Phase Diagrams, ASM International, Ohio, USA, 1990.

[4] V.T.Witusiewicz, A.A. Bondar, U. Hecht, T.Ya. Velikanova, J. Alloys and Compd, (2008) doi:10.1016/j.jalcom.2008.05.008.

[5] P. Franke, D. Neuschütz,and Scientific Group Thermodata Europe (SGTE), Elements and Binary Systems from B – C to Cr – Zr, Landolt-Börnstein - Group IV Physical Chemistry, Springer, Berlin , Vol. 19B2 (2004) 1.


172

Al−Cr−Pd system: analytical electron microscopy and thermodynamic calculations M. Svoboda, A. Kroupa, J. Buršík

Institute of Physics of Materials, Academy of Sciences of the Czech Republic, v.v.i., Žižkova 22, CZ-61662 Brno, Czech Republic

In the last decades, special alloys based on binary, ternary, or quaternary systems,

referred to as complex metallic alloys (CMA) became the subject of considerable

interest. So far, a very small group of these CMAs has been investigated and developed

for use from a huge variety of possible metallic systems. In these multicomponent

alloys, phases form crystal structures based on giant unit cells where the atoms arranged

in clusters of icosahedral coordination play a prominent role. As a consequence, the

structures of CMAs often show duality; they are periodic crystals on the scale of several

nanometers, whereas they resemble quasicrystals on the atomic scale.

In this work we focus on several ternary alloys of Al−Cr−Pd system from the Al-rich

part of the compositional triangle, where the occurrence of CMAs may be expected. The

microstructure of alloys was studied and quantified after long term annealing at 750 °C

by means of scanning and transmission electron microscopy and energy dispersive X-

ray analysis. Experimental results were compared with existing literature data. In order

to compare experimental knowledge on phase equilibria with the results of

thermodynamic modelling, phase diagram was calculated using the software package

ThermoCalc.

The work was supported by the Czech Science Foundation (Project No. 106/07/1259).


173

The Experimental and Theoretical Study of the In-Ni-Sn System A. Zemanová, A. Kroupa

Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Zizkova 22, 616 62 Brno, Czech Republic

The ternary In-Ni-Sn system was experimentally and theoretically studied in the scope

of this work. The phase equilibria of the system In-Ni-Sn were investigated at 700 °C

using X-ray diffraction (XRD), scanning electron microscopy (SEM) and the

differential thermal analysis (DTA). This temperature was chosen because it allows

obtaining reliable results in reasonable time that can be used as a starting point for

CALPHAD modelling.

No theoretical assessment of the In-Ni-Sn system has existed up to now; hence this

study is also focused on its thermodynamic assessment, using own experimental data

and experimental data from [1]. The unary data were taken from new version of SGTE

(4.4) database [2]. The thermodynamic data for In-Ni, Ni-Sn and In-Sn binary systems

used in this assessment are taken from the COST 531 thermodynamic database [3].

References:

[1] H. Flandorfer, C. Schmetterer, H. Ipser, J. Favier, publication in preparation. [2] Version 4.4 of the SGTE Unary Database. [3] Version 3.0 of the COST 531 Database for Lead-free Solders.

Acknowledgement: The authors are grateful to the Ministry of Education of the Czech Republic (projects No. OC08053), and to the Academy of Sciences of the CR (project No. KJB200410601) for financial support.


174

Experimental and thermodynamical study of real grades of micro-alloyed steels B. Smetana a, S. Zlá a, P. Kozelský b, J. Dobrovská a a VSB-TU Ostrava, Faculty of Metallurgy and materials engineering, Department of

physical chemistry and theory of technological processes, Ostrava b VSB-TU Ostrava, Faculty of Metallurgy and materials engineering, Department of

foundry engineering, Ostrava

Paper deals with phase transformations investigation of selected real grades of micro-

alloyed steels (poly-component systems). Temperatures and latent heats of

characteristic phase transitions were obtained with use of Setaram SETSYS 18TM

experimental laboratory system for thermal analysis. The technique of Differential

Thermal Analysis (DTA) was selected for the study of micro-alloyed steels.

Temperatures of phase transformations (liquidus, solidus, etc.) were obtained. Latent

heats of melting and solidifying were obtained. Small samples of selected real grades of

steels were analysed at linear heating/cooling rate of 7°C/min in high pure dynamical

atmosphere of argon (>6N). Influence of admixed and alloyed elements on shift of

temperatures and latent heats amount was investigated. Resulting data were compared

with data of Fe-C binary system and with data calculated according relations published

in available literature also. The thermodynamic-kinetic solidification model IDS

(Solidification analysis package for steels-software) was used to calculate characteristic

temperatures and latent heats of investigated systems. Comparison of data shows good

agreement between calculated and experimental obtained temperatures of liquidus.

Major difference was observed for solidus temperature. Latent heats show difference

also. It follows from the obtained results that differences, still exist between

experimental and theoretical data, which implies necessity of further systematic

research in this area.

Acknowledgements: This work was compiled in the framework of project of Czech Science Foundation, No. 106/08/0606.


175

Thermodynamical and experimental study of the Al-Sn-Zn system B. Smetana a, J. Drápala b, S. Zlá a, A. Kroupa c a VSB-TU Ostrava, Faculty of Metallurgy and Materials Engineering, Department of

physical chemistry and theory of technological processes, Ostrava, Czech Republic b VSB-TU Ostrava, Faculty of Metallurgy and materials engineering, Department of

non-ferrous metals, refining and recycling, Ostrava, Czech Republic c Institute of Physics of Materials, Academy of Sciences, Brno, Czech Republic

Twenty binary Sn-Zn and ternary Al-Sn-Zn alloys were prepared experimentally. The

alloys were studied metallographically after long-time homogenizing annealing. The

micro-hardness and X-ray micro-analysis (EDAX, WDX) of the phases was measured.

Temperatures and latent heats of characteristic phase transitions were obtained with use

of the DTA method (differential thermal analysis). Experiments were performed with

Setaram SETSYS 18TM experimental laboratory system for thermal analysis. Small

samples of selected alloys were analysed at linear heating/cooling rate of 4°C/min in

high pure dynamical atmosphere of argon (>6N). Temperatures and latent heats of

corresponding phase transformations (liquidus, solidus, invariant reactions etc.) were

obtained. Aluminium influence on shift of phase transformations temperatures and

amount of latent heats was investigated. Resulting experimental data were compared

with data of known Sn-Zn binary system and Al-Sn-Zn ternary system. For the

modelling of phase equilibria from critically assessed data different software packages

were used: MTDATA, and Thermo-Calc.

Acknowledgements: This research was done under the project realized in the framework of European Concerted Action on COST MP0602 „Advanced Solder Materials for High-Temperature Application – HISOLD” and financed by the Ministry of Education, Youth and Sports of the Czech Republic (Projects No. OC 08032, OC 08053 and 6198910013).


176

Experimental study and thermodynamic re-assessment of the ternary B-Si-Ti system A. A. Bondar a, V. T. Witusiewicz b, U. Hecht b, V. Yu. Pashchenko c, L. Sturz b, J. Zollinger b, O. S. Fomichov a, S. Yu. Artyukh a, T. Ya. Velikanova a a Frantsevych Institute for Problems in Materials Science, 02142, Kiev, Ukraine b Access e.V., Intzestr. 5, 52072 Aachen, Germany c Ivan Franko Zhytomyr State University, 10008, Zhytomyr, Ukraine

In literature there are experimental data for the Ti-corner of the B-Si-Ti system, up to

the homogeneity range of ternary Ti6Si2B phase [1], and for the region of terminal solid

solution of B in Ti5Si3 [2]. The thermodynamic description of entire system was early

elaborated in [3] basing on experimental data for the Ti-corner and without

experimental background in other fields.

In the present work alloys from pure components were arc melted in all three-phase

fields formed by titanium silicides and TiB2. Samples as-cast and annealed at subsolidus

temperatures were studied by SEM/EDX, XDR analysis, DTA, and pyrometry. The

thermodynamic description of the entire B-Si-Ti system was obtained by CALPHAD

modelling of the Gibbs energy of all individual phases with the Thermo-Calc software

basing on the experimental data.

The phase diagram was calculated as projections of solidus and liquidus surfaces,

isothermal and vertical sections. The main differences of the present work results from

the phase diagram of [3] are as follows:

- more extended homogeneity ranges of titanium silicide phases, containing some

atomic percents of B,

- more fields of primary solidification of all the titanium silicides and B-Si phases for

the expanse of that for TiB2.

As found, the Si solubility in titanium borides TiB and TiB2 is about 0.3 at.%.

References:

[1] A.S. Ramos, C.A. Nunes, G. Rodrigues, P.A. Suzuki, G.C. Coelho, A. Grytsiv, P. Rogl, Intermetallics, 12 (2004) 487.

[2] J.J. Williams, Y.Y. Ye, M.J. Kramer, K.M. Ho, L. Hong, C.L. Fu, S.K. Malik, Intermetallics, 8 (2000) 937.

[3] Y. Yang, Y.A. Chang, L. Tan, Intermetallics, 13 (2005) 1110.


177

Formation of stable and metastable intermetallic phases in solidifying Al–Fe–Si alloys Damon Panahi, Dmitri V. Malakhov


A slow solidification of Al alloys results in stable intermetallic phases embedded in FCC grains and/or residing along grain boundaries. This changes pronouncedly if a rate of heat extraction is increased. In the case of direct-chill casting, an interior of an ingot contains mainly intermetallics seen on the equilibrium phase diagram, but a near-surface region has a significant fraction of metastable phases. If heat fluxes are further intensified by employing, for instance, strip casting or sputtering, then metastable phases dominate. We experimentally examined precipitation of intermetallics from Al–Fe–Si melts solidifying with various rates. It was proven by various characterization techniques that morphological differences seen in the figures below reflected dissimilarities of phase portraits, i.e., that the cooling rate governed the nature of precipitating particles.

Freezing in a graphite crucible

Solidification in a copper mold

Sputtering

One may try to apply the concept of the driving forces for the onset of precipitation to explain this phenomenon by assuming that greater rates of heat extraction lead to greater supersaturations and then computing the driving forces for all solid phases for various casting conditions. Such attempt will fail, because it was firmly established experimentally that if a composition of alloy corresponds to the primary FCC field (the case for wrought Al alloys), the supercooling never exceeds a couple of degrees whatever the cooling rate (an explanation of that undisputable observation will be given in the presentation). It is proposed to take this firmly established fact into account by allowing the primary FCC phase to solidify in the Gulliver-Scheil mode. By utilizing the driving forces for the beginning of formation of intermetallics from a remaining solute-rich liquid one can explain microstructural particularities much better than by using the quantities corresponding to a globally supercooled melt.


178

Study of Sn – Sb – Zn Ternary System A. Ulichová, O. Zobač, J. Sopoušek

Department of Chemistry, Faculty of Sciences, Masaryk University, Brno, Czech Republic

The CALPHAD method [1] was used for preliminary phase diagram calculations using

thermodynamic database COST 531 [2] optimized for lead-free solders. The

preliminary phase diagram cross-sections were respected in alloy preparation so that the

compositions of the alloys were in different phase fields. The zinc composition varied

approximately from 2 to 20 wt % and antimony from 6 to 75wt%. The alloys were

annealed and after that investigated by light microscopy. The compositions of the

equilibrated phases were obtained by means of EDX microanalysis. Thermal effects

during melting and solidifying were experimentally studied by the DSC technique in the

inert atmosphere using the different heating and cooling rates 1-10K/min. The liquidus

and solidus were determined. The DSC signal was also simulated by method similar to

approach given in literature [3]. The experimental DSC signal of each alloy was

compared with a simulated curve. The experimental temperatures of phase

transformations were found.

The authors acknowledge the project support through MSM0021622410 and OC09010 (COST MP0602). The authors are also indebt to Dr. Adéla Zemanová from the Institute of Physics of Materials, Czech Academy of Sciences Brno for his assistance with the EDX measurements.

References:

[1] N. Saunders - A.P. Miodovnik: CALPHAD (calculation of phase diagram) – A Comprehensive Guide; 1998, Amsterdam, Elsevier Science.

[2] Database SOLDER at http://www.slihot.co.uk/COST531/td_database.htm. [3] W. J. Boettinger - U. R. Kattner - K.-W. Moon - J. H. Perepezko, “DTA and Heat-

flux DSC Measurements of Alloy Melting and Freezing”, 2006, Washington, National Institute of Standards and Technology.


179

Enthalpies of formation of FeNi70, FeNi73,6 and FeNi80 solid alloys from the homogenous region of the FeNi3 phase W. Gąsior, Z. Moser, A. Dębski

Institute of Metallurgy and Materials Science, Polish Academy of Sciences, 30-059 Kraków, 25 Reymonta Street, POLAND

Solution calorimetric with liquid Al bath, have been used for the determination of

enthalpies of formation of alloys from the homogenous region of FeNi3 phase. Metals of

high purity (minimum 99.99 mass %) were used for the synthesis of samples as well for

Al bath for calibration. Samples of alloys with compositions FeNi70, FeNi73,5 and FeNi80

were obtained by melting metals in glove-box filed with high purity argon with amounts

of impurities of nitrogen, oxygen and moisture lower than 1ppm. The obtained alloys

were next annealed at 673 K (400oC) over 2 month. The X-ray phase analysis confirmed

the high ordering and lack of another phases. Calculated lattice parameters were almost

identical with those obtained in earlier work by Wakelin and Yates [1]. Obtained

enthalpies of solution of Ni and Fe in liquid Al amount -150 ±0.4 (kJ/g.atom) and -120

±0.7 (kJ/g.atom) for Ni and Fe, respectively and the measured values of enthalpies of

formation are: -7,5 ± 1,5 kJ/mol of atoms for FeNi70, -7,2 ± 1.2 kJ/mol of atoms for

FeNi73,5 and –6,9 ± 1.9 kJ/mol of atoms for FeNi80. The obtained values are slightly

higher then those calculated by [2] (ΔfH = -9.75 kJ/mol of atoms) and [3] (ΔfH = -9.2

kJ/mol of atoms) for FeNi3 phase.

References:

[1] R. J. Wakelin and E. L. Yates, A Study of the Order–Disorder Transformation in Iron–Nickiel Alloys in the Region FeNi3, Proc. Phys. Soc., London, Sect. B, B66, 221-240.

[2] T. Horiuchi, M. Igarashi, F. Abe and T. Mohri, Phenomenological Calculation of Phase Equilibria In the Fe-Ni System, Calphad, 26(4) (2002) 591-597.

[3] Pasturel, C. Colinet, Ab initio determination of enthalpies of formation in Al, Fe, Ni, and Ti based systems, TOFA 2004.


180

On the thermodynamic optimization of the Si-C and Fe-Si-C systems C. Meklera, G. Kaptaya,b aBAY-NANO + bUniversity of Miskolc, 3515 Hungary, Miskolc, Egyetemvaros E/7

The Si-C system is of high importance for both Al-based and Fe-based alloys.

Nevertheless, the so-called optimized thermodynamic properties of the Si-C system are

different for the Al-Si-C [1] and for the Fe-Si-C [2-3] systems. In the present work the

re-optimization of the binary Si-C and the ternary Fe-Si-C system is undertaken. A

fragment of the results is shown in the figure below.

References

[1] J. Gröbner, H.L. Lukas, F. Aldinger - Thermodynamic calculation of the ternary system AI - Si - C - Calphad, 1996, vol. 20, pp. 247-254.

[2] L. Lacaze, B. Sundman - An assessment of the Fe-C-Si system - Metal. Trans. A, 1991, vol. 22A, pp. 2211 - 2223.

[3] J. Miettinen - Reassessed thermodynamic solution phase data for ternary Fe-Si-C system - Calphad, 1998, vol. 22, pp. 231-256.


181

Experimental determination of phase equilibria and reassessment of Ag-Pd system A. Zemanová a, J. Sopoušek b, J. Vřešťál b a Institute of Physics of Materials, ASCR, Brno, Czech Republic b Masaryk university Brno, Czech Republic

In lead-free soldering, the silver is usually used as solder component and palladium

often as component of substrate. Therefore, Ag-Pd system is of interest for possible

interference of components in solder joints. The system Ag-Pd reveals simple liquidus-

solidus two phase region [1]. An enthalpy of mixing of liquid Ag-Pd solution was

evaluated recently [2].

In this work an additional DSC determination of solidus and liquidus temperatures at

chosen compositions was performed. Existing assessment [1] of thermodynamic and

phase equilibrium data in the Ag-Pd system was revised on the base of calorimetric data

for liquid Ag-Pd alloys [2] and DSC measurement. New determination of liquidus and

solidus temperatures using DSC method in this work confirmed substantially narrower

liquid/fcc two-phase field in phase diagram, in agreement with the reassessment. The authors acknowledge the project support through MSM0021622410, OC09010 (COST MP0602), and AV0Z20410507.

References:

[1] Ghosh, G., Kantner, C., Olson, G.B.: J. Phase Equilib., 1999 20(3) 295-308. [2] Luef, Ch., Paul, A., Flandorfer, H., Kodentsov, A., Ipser, H.: J. Alloys Comp., 2005

391(1-2) 67-76.


182

The thermodynamics of Ag-Pb-Te System J. Łapsa, W. Gierlotka, K. Fitzner

AGH University of Science and Technology, Faculty of Non-Ferrous Metals, 30 Mickiewicza Ave., 30-059 Krakow, Poland

Pure silver and its alloys are very important materials for various technological

applications. Tellurium and lead are unwanted admixtures in silver and have to be

removed during metallurgical refining processes. The knowledge of the phase diagram

and thermodynamic properties of Ag-Te-Pb alloys are essential for optimization of this

refining process.

The critical assessment of three binary Pb-Te [1], Ag-Te [2] and Ag-Pb [3] systems has

been already done using literature information. Good agreement between experimental

data reported in the literature and calculated values has been found. In this work,

calculations were extended upon the ternary system. Phase equilibria were calculated

and from the properties of the liquid solutions vapor pressure of Pb and Te over liquid

phase was derived.

References:

[1] W.Gierlotka, J.Łapsa, D.Jendrzejczyk-Handzlik, J.Alloys Comp., (2009) in print. [2] W.Gierlotka, (in preparation for publication). [3] J.Łapsa, D.Jendrzejczyk-Handzlik, W.Gierlotka, (in preparation for publication).


183

Kinetics of carbonitride precipitation in Interstitial Free Steels Roberto Avillez a, André Costa e Silva b a DCMM-PUC RJ, 22453-900 Rio de Janeiro, RJ – Brasil b EEIMVR-UFF, 27260-740 Volta Redonda, RJ - Brasil

The IF-interstitial free steels have been developed to increase the formability properties

after continuous annealing. The residual carbon and nitrogen solutes are gettered using

strong carbide and nitride formers, such as Nb and Ti. The precipitation of the

carbonitrides starts at very high temperature, almost together with the solidification

process. Even though equilibrium calculation shows that very low values of interstitial

solutes are possible to be attained by microalloying with Ti, or Nb, the precipitation is a

diffusion controlled process and, therefore, depends on the rate of cooling of the steel

during continuous casting, or afterwards, during reheating and hot rolling.

The present research employs a simple model with DICTRA® to explore the growth of

carbonitride in two typical IF-steels microalloyed with titanium and niobium as a

function of the cooling rate and the size of diffusional field. It is shown that the carbide

growth can be far from equilibrium conditions for normal cooling rates that might be

used from solidification until the complete austenite transformation to ferrite. The

implications of the results of the present kinetic model to the processing of these steels

is discussed.


184

Enthalpies of formation of Mo–Ru and Mo–Ru–Si compounds determined by high-temperature direct reaction synthesis calorimetry My.Y. Benarchid , N. David , J.M. Fiorani , M. Vilasi

Institut Jean Lamour Département Chimie et Physique des Solides et des Surfaces UMR 7198 CNRS - Université Henri Poincaré Nancy 1 Boulevard des aiguillettes, BP 70239 54506 Vandœuvre-lès-Nancy, France

The enthalpies of formation of (Ru) hcp solid solution and Mo5Ru3 (� phase) in the

Mo–Ru system and ternary extension in the Mo–Ru–Si system at Mo56Ru37Si7

composition, have been determined by high-temperature direct reaction synthesis

calorimetry at 1760 K.

The following values are reported: 5.06.10)(1760 ±−=Δ RuKHf kJ/mol at.;

4.04.7)35(1760 ±−=Δ RuMoKHf kJ/mol at; 3.31.13)73756(1760 ±−=Δ SiRuMoKHf

kJ/mol at. The results are compared with the previous values derived from e.m.f

measurements. They are also compared with the predicted values obtained by Calphad,

by ab initio method combined to Calphad modelling, and derived from TM16.TDB

database [1].

References:

[1] F. Aldinger, A.F. Guillermet, V.S. Iorich, L. Kaufman, W.A. Oates, H. Ohtani, M. Rand, M. Schalin, Calphad, 19 (1995) 555-571.


185

Enthalpies of formation of Nb-Ru and Nb-Ru-Al alloys determined by direct reaction synthesis in a high-temperature calorimeter My.Y. Benarchid , N. David , J.M. Fiorani , M. Vilasi

Institut Jean Lamour Département Chimie et Physique des Solides et des Surfaces UMR 7198 CNRS - Université Henri Poincaré Nancy 1 Boulevard des aiguillettes, BP 70239 54506 Vandœuvre-lès-Nancy, France

In the present work we measure by high-temperature direct reaction synthesis

calorimetry at 1775 K the enthalpies of formation of primary binary solid solutions

which exhibits a large solubility range, NbRu (B2 phase), NbRu2 compound in the Nb-

Ru binary system, and two compositions Nb(Ru,Al)2 and NbRu2Al identified by Cerba

[1] in the Nb-Ru-Al ternary system. The as-synthesised alloys are analysed by means of

X-ray diffraction and scanning electron microscopy with electron-probe microanalysis.

For some binary alloys the experiment cannot provide results because the direct reaction

synthesis is not completed contrarily to ternary alloys experiments. The results are

compared with predicted ab initio data.

References:

[1] P. Cerba, M. Vilasi, B. Malaman, J. Steinmetz, Journal of Alloys and Compounds, 201 (1993) 57-60.

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5. List of CALPHAD Scholarship Recipients

CALPHAD XXXVIII Scolarship Recipients

188

Mr. Asgar Khan Mohammad Concordia University Montreal, Canada [email protected]

Mr. Chidambaram Vivek Denmark Technical University, Department of Mechanical Engineering Kgs. Lyngby, Denmark [email protected] Mr. Frederiksen Kristian Bødker Risø National Laboratory for Sustainable Energy, Technical University of Denmark Roskilde, Denmark [email protected] Mr. Kapush Denys I.N. Frantsevich Institute for Problems of Materials Science Kiew, Ukraine [email protected] Mr. Khan Atta Ullah Institute for Physical Chemistry of the University of Vienna Vienna, Austria [email protected] Mr. Saal James The Pennsylvania State University University Park, USA [email protected] Mrs. Všianská Monika Masaryk University, Faculty of Science, Department of Chemistry Brno, Czech Republic [email protected] Mr. Wang Jiong State Key Lab of Powder Metallurgy, Central South University Changsha, China [email protected] Mr. Xiong Wei Department of Materials Science and Engineering, Royal Institute of Technology Stockholm, Sweden [email protected]

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6. List of participants

CALPHAD XXXVIII List of Participants

190

Mr. Abe Taichi National Institute for Materials Science (NIMS) Tsukuba, Japan [email protected] Dr. Adjanor Gilles EDF R&D, Materials and Mechanics of Components Moret sur Loing, France [email protected] Prof. Ågren John KTH, Materials Science and Engineering Stockholm, Sweden [email protected] Dr. Alexeev Sergey Ural Institute of State Fire Fighting Service Ekaterinburg, Russia [email protected] Mr. Askar Khan Mohammad Concordia University Montreal, Canada [email protected] Dr. Balanetskyy Sergiy Frantsevich Institute for Problems of Materials Science (IPMS), NASU Kiew, Ukraine [email protected] Prof. Barbin Nikolay Ural Institute of State Fire Fighting Service Ekaterinburg, Russia [email protected] Mr. Belmonte Donato Laboratorio di Geochimica at DIPTERIS, Università di Genova Genova, Italy [email protected]

Prof. Bhattacharjee Subrata (Sooby) San Diego State University San Diego, USA [email protected] Mr. Biborski Andrzej Institute of Physics, Jagellonian University Cracow, Poland [email protected] Dr. Bondar Anatolii I.N. Frantsevich Institute for Problems of Materials Science Kiew, Ukraine [email protected] Prof. Brož Pavel Masaryk University, Faculty of Science, Department of Chemistry Brno, Czech Republic [email protected] Dr. Bukaemskiy Andrey Jülich Forschungszentrum, Institute for Energy Research, Safety Research and Reactor Technology, IEF-6 Jülich, Germany [email protected] Dr. Buršík Jiří Institute of Physics of Materials, Academy of Sciences of the Czech Republic, v.v.i. Brno, Czech Republic [email protected] Prof. Cacciamani Gabriele Dipartimento di Chimica e Chimica Industriale, Università di Genova Genova, Italy [email protected] Dr. Chatain Sylvie Commissariat à l'energie atomique-Saclay (CEA - Saclay) Gif-sur-Yvette, France [email protected]


191

Dr. Chen Ming Risø National Laboratory for Sustainable Energy, Technical University of Denmark Roskilde, Denmark [email protected] Dr. Chen Qing Thermo-Calc Software AB Stockholm, Sweden [email protected] Mr. Chidambaram Vivek Denmark Technical University, Department of Mechanical Engineering Kgs. Lyngby, Denmark [email protected] Dr. Čička Roman Institute of Materials Science, MTF STU in Trnava Trnava, Slovakia [email protected] Dr. Coelho Gilberto Institut Jean Lamour, Département Chimie et Physique des Solides et des Surfaces Nancy, France [email protected] Prof. Colinet Catherine SIMAP-INPG Saint Martin d'Hères, France [email protected] Prof. Cornish Lesley DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand Johannesburg, South Africa [email protected] Dr. Corvolan Moya Carolina Commissariat à l'energie atomique-Saclay (CEA - Saclay) Gif-Sur-Yvette, France [email protected]

Prof. Costa e Silva Andre UFF/ IBQN Rio de Janeiro, Brazil [email protected] Dr. Crivello Jean Claude Chimie Métallurgique des Terres Rares, Institut de Chimie et des Matériaux Paris-Est, CNRS-Université Paris XII (ICMPE - CNRS) Thiais, France [email protected] Mr. Cupid Damian Institute of Material Science, Freiberg University of Mining and Technology Freiberg, Germany [email protected] Dr. David Nicolas Institut Jean Lamour, Département Chimie et Physique des Solides et des Surfaces Nancy, France [email protected] Prof. de Avillez Roberto Pontifícia Universidade Católica Rio de Janeiro, Brazil [email protected] Dr. Dinsdale Alan National Physical Laboratory Teddington, UK [email protected] Ms. Doernberg Evelyn Clausthal University of Technology, Institute of Metallurgy Clausthal-Zellerfeld, Germany [email protected] Prof. Du Yong State Key Lab of Powder Metallurgy, Central South University Changsha, China [email protected]


192

Prof. Du Zhenmin University of Science and Technology Beijing Beijing , China [email protected] Dr. Fabrichnaya Olga Institute of Material Science, Freiberg University of Mining and Technology Freiberg, Germany [email protected] Mrs. Falkova Alexandra M.V. Lomonosov Moscow State University Moscow, Russia [email protected] Prof. Flandorfer Hans Institute for Inorganic Chemistry and Materials Chemistry of the University of Vienna Vienna, Austria [email protected] Mr. Frederiksen Kristian Bødker Risø National Laboratory for Sustainable Energy, Technical University of Denmark Roskilde, Denmark [email protected] Dr. Frisk Karin Swerea KIMAB Stockholm, Sweden [email protected] Dr. Ganesan Rajesh Institute for Inorganic Chemistry and Materials Chemistry of the University of Vienna Vienna, Austria [email protected] Dr. Gąsior Władysław Institute of Metallugy and Materials Science, Polish Academy of Sciences Cracow, Poland [email protected]

Prof. Gonze Xavier Université Catholique de Louvain / Unité PCPM Louvain, Belgium [email protected] Dr. Gröbner Joachim Clausthal University of Technology, Institute of Metallurgy Clausthal-Zellerfeld, Germany [email protected] Dr. Hallstedt Bengt Materials Chemistry, RWTH Aachen University Aachen, Germany [email protected] Dr. Hämäläinen Marko Helsinki University of Technology, Department of Materials Science and Engineering Espo, Finland [email protected] Ing. Hampl Milan Clausthal University of Technology, Institute of Metallurgy Clausthal-Zellerfeld, Germany [email protected] Dr. Hecht Ulrike Access e.V. Aachen, Germany [email protected] Dr. Homolová Viera Institute of Material Research, Slovak Academy of Sciences Košice, Slovakia [email protected]; [email protected]


193

Dr. Ilinykh Nina Ural Technical Institute of Communication and Informatics; Institute of Metallurgy of Ural Branch of Russian Academy of Sciences Ekaterinburg, Russia [email protected] Prof. Ishida Kiyohito Tohoku University Sendai, Japan [email protected] Dr. Jacobs Michael Clausthal University of Technology, Institute of Metallurgy Clausthal-Zellerfeld, Germany [email protected] Dr. Jan Vít Brno University of Technology, Faculty of Mechanical Engineering Brno, Czech Republic [email protected] Prof. Jiang Min Key laboratory for anisotropy and texture of materials, School of Materials and Metallurgy, Northeastern University Shenyang, China [email protected] Dr. Joubert Jean Marc Chimie Métallurgique des Terres Rares, Institut de Chimie et des Matériaux Paris-Est, CNRS-Université Paris XII (ICMPE - CNRS) Thiais, France [email protected] Mr. Jourdan Julien Commissariat à l'energie atomique-Saclay (CEA - Saclay) Gif-sur-Yvette, France [email protected]

Prof. Jung In-Ho Dept. of Mining and Materials Engineering, McGill University, Canada Montreal, Canada [email protected] Prof. Kajihara Masanori Department of Materials Science and Engineering Tokyo Institute of Technology Yokohama Yokohama, Japan [email protected] Mr. Kang Kyunghan Pohang University of Science and Technology Pohang, Republic of Korea [email protected] Dr. Kapała Jan Faculty of Chemistry, Wrocław University of Technology Wrocław, Poland [email protected] Prof. Kaptay George Bay Zoltán Foundation for Applied Research, Institute for Nanotechnology (BAY-NANO) Miskolc, Hungary [email protected] Mr. Kapush Denys I.N. Frantsevich Institute for Problems of Materials Science Kiew, Ukraine [email protected] Dr. Kaskiala Makku Helsinki University of Technology, Department of Materials Science and Engineering Espo, Finland [email protected]


194

Dr. Kattner Ursula National Institute of Standards and Technology Gaithersburg, USA [email protected] Dr. Kaufman Larry CALPHAD Inc.,U.S.A. Brookline, USA [email protected] Mr. Kensuke Togase Department of Informatics, Kwansei Gakuin University Sanda, Japan [email protected] Dr. Kevorkov Dmytro Concordia University Montreal, Canada [email protected] Dr. Kewu Bai Institute of High Performance Computing (IHPC) Singapore, Republic of Singapore [email protected] Mr. Khan Atta Ullah Institute for Physical Chemistry of the University of Vienna Vienna, Austria [email protected] Mr. Kim Hyunkyu Pohang University of Science and Technology Pohang, Republic of Korea [email protected] Dr. Klahn Marco Institute of High Performance Computing (IHPC) Singapore, Republic of Singapore [email protected]

Mr. Kobertz Dietmar Forschungszentrum Jülich Jülich, Germany [email protected] Dr. Koepsel Detlef Schott AG Mainz, Germany [email protected] Dr. Konrad Joachim Salzgitter Mannesmann Forschung GmbH Duisburg, Germany [email protected] Dr. Kozlov Artem Clausthal University of Technology, Institute of Metallurgy Clausthal-Zellerfeld, Germany [email protected] Prof. Kozubski Rafal Institute of Physics, Jagellonian University Cracow, Poland [email protected] Mr. Kriegel Mario Institute of Material Science, Freiberg University of Mining and Technology Freiberg, Germany [email protected] Dr. Kroupa Aleš Institute of Physics of Materials, Academy of Sciences of the Czech Republic, v.v.i. Brno, Czech Republic [email protected] Dr. Kulikova Tatjana Institute of Metallurgy of Ural Branch of Russian Academy of Sciences Ekaterinburg, Russia [email protected]


195

M.S. Łapsa Joanna AGH University of Science and Technology Cracow, Poland [email protected] Prof. Lee Hyuck Mo Dept. of Materials Science and Engineering / KAIST Daejeon, Korea [email protected] Prof. Lee Byeong-Joo Pohang University of Science and Technology Pohang, Korea [email protected] Prof. Leitner Jindřich Department of Solid State Engineering, Institute of Chemical Technology Prague, Czech Republic [email protected] Dr. Liu Yuhong Institute of Mechanics, Montanuniversität Leoben Leoben, Austria [email protected] Dr. Liu Yu Equipe Physico-chimie des Matériaux Oranisés Fonctionnels, Université Montpellier Montpellier, France [email protected] Prof. Liu Zi-Kui The Pennsylvania State University University Park, USA [email protected] Prof. Malakhov Dmitri McMaster University Hamilton, Canada [email protected]

Dr. Markus Torsten Jülich Forschungszentrum, Institute of Energy research, Microstructure and properties of material, IEF-2 Jülich, Germany [email protected] Prof. Medraj Mamoun Concordia University Montreal Canada [email protected] Dr. Meschel Susan V. Illinois Institute of Technology Chicago, USA [email protected] Mr. Mezbahul-Islam Mohammad Dept. Mechanical and Industrial Engineering, Concordia University Montreal, Canada [email protected] Prof. Miodownik Peter THERMOTECH/SENTE LTD Guildford, UK [email protected] Mr. Miyamoto Takashi Kainuma Laboratory, IMRAM, Tohoku University Sendai, Japan [email protected] Prof. Miyazaki Toru Nagoya Institute of Technology Nisshin, Japan [email protected] Prof. Mohri Tetsuo Hokkaido University Sapporo, Japan [email protected] Prof. Moser Zbigniew Institute of Metallurgy and Materials Science, Polish Academy of Sciences Cracow, Poland [email protected]


196

Dr. Nguyen-Manh Duc UKAEA, Culham Science Centre Abingdon, UK [email protected] Prof. Nishitani Shigeto Department of Informatics, Kwansei Gakuin University Sanda, Japan [email protected] Dr. Novakovic Rada National Research Council (CNR), Institute for Energetics and Interphases (IENI) Genova, Italy [email protected] Dr. Ohnuma Ikuo Department of Materials Science, Tohoku University Sendai, Japan [email protected] Prof. Oikawa Katsunari Department of Metallurgy, Graduate School of Engineering, Tohoku University Sendai, Japan [email protected] Prof. Onderka Bogusław AGH University of Science and Technology Cracow, Poland [email protected] Dr. Palumbo Mauro National Institute for Materials Science (NIMS) Tsukuba, Japan [email protected] Prof. Parlinski Krzysztof Institute of Nuclear Physics, Polish Academy of Sciences Cracow, Poland [email protected]

Dr. Pavlů Jana Masaryk University, Faculty of Science, Department of Chemistry Brno, Czech Republic [email protected] Mr. Pavlyuchkov Dmytro Institute of Material Science, Freiberg University of Mining and Technology Freiberg, Germany [email protected] Prof. Richter Klaus Institute for Inorganic Chemistry and Materials Chemistry of the University of Vienna Vienna, Austria [email protected] Prof. Rizzo Assuncao Fernando PUC-Rio Rio de Janeiro, Brasil [email protected] Prof. Rogl Peter Institute for Physical Chemistry of the University of Vienna Vienna, Austria [email protected] Dr. Romanowska Jolanta Rzeszów University of Technology, Department of Materials Science Rzeszów, Poland [email protected] Dr. Rutkowska Iwona Faculty of Chemistry, Wrocław University of Technology Wrocław, Poland [email protected] Mr. Saal James The Pennsylvania State University University Park, USA [email protected]


197

Dipl. Ing. Sarriegi Etxeberria Haritz MGEP/ Mondragon Unibertsitatea Arrasate - Mondragon, Spain [email protected] Prof. Schmid-Fetzer Rainer Clausthal University of Technology, Institute of Metallurgy Clausthal-Zellerfeld, Germany [email protected] Dr. Schmidt Peer Institution University of Technology Dresden, Institute for Inorganic Chemistry Dresden, Germany [email protected] Dr. Schneider Andre Benteler Stahl/Rohr GmbH Paderborn, Germany [email protected] Prof. Schön Cláudio Geraldo Dept. of Metallurgical and Materials Engineering Escola Politecnica da Universidade de Săo Paulo São Paulo, Brazil [email protected] Mr. Scuracchio Bruno Dept. of Metallurgical and Materials Engineering Escola Politecnica da Universidade de Săo Paulo São Paulo, Brazil [email protected] Prof. Sedmidubský David Institute of Transuranium Elements, Joint Research Centre, European Commission Karlsruhe, Germany [email protected] Dr. Seko Atsuto Kyoto University Kyoto, Japan [email protected]

Prof. Shao Guosheng Centre for Materials Research & Innovation, University of Bolton Bolton, UK [email protected] Prof. Sluiter Marcel MSE, 3mE, Delft University of Technology Delft, Netherlands [email protected] Dr. Smetana Bedřich Vysoká škola báňská - Technická univerzita Ostrava Ostrava, Czech Republic [email protected] Prof. Šob Mojmír Masaryk University, Faculty of Science, Department of Chemistry Brno, Czech Republic [email protected] Prof. Sopoušek Jiří Masaryk University, Faculty of Science, Department of Chemistry Brno, Czech Republic [email protected] Dr. Svoboda Milan Institute of Physics of Materials, Academy of Sciences of the Czech Republic, v.v.i. Brno, Czech Republic [email protected] Ing. Svobodová Marie UJP PRAHA a.s. Prague, Czech Republic [email protected] Prof. Tang Chengying Department of Informational Materials Science and Engineering, Guilin University of Electronic Technology Guilin, Guangxi, China [email protected]; [email protected]


198

Prof. Tedenac Jean Claude Equipe Physico-chimie des Matériaux Oranisés Fonctionnels, Université Montpellier Montpellier, France [email protected] Dr. Tokunaga Tatsuya Kyushu Institute of Technology Kitakyushu, Japan [email protected] Dr. Turchi Patrice Lawrence Livermore National Laboratory Livermore, USA [email protected] Mr. Tursunbadalov Sherali Tajik State Pedagogical University Dushanbe, Tajikistan [email protected] Dr. Tyrpekl Vaclav CEA Cadarache, DNT/STRI/LMA St Paul lez Durances, France [email protected] Dr. Ukpong Aniekan Magnus DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand Johannesburg, South Africa [email protected] Dr. Vorob'eva Vera Physical Problems Department, Siberian Branch of the Russian Academy of Sciences Ulan-Ude, Russia [email protected] Prof. Vřešťál Jan Masaryk University, Faculty of Science, Department of Chemistry Brno, Czech Republic [email protected]

Dipl. Ing. Všianská Monika Masaryk University, Faculty of Science, Department of Chemistry Brno, Czech Republic [email protected] Mr. Wang Aijun State Key Lab of Powder Metallurgy, Central South University Changsha, China [email protected] Dr. Wang Jiang Laboratory for Joining and Interface Technology EMPA Dübendorf, Switzerland [email protected] Mr. Wang Jiong State Key Lab of Powder Metallurgy, Central South University Changsha, China [email protected] Dr. Watson Andy SPEME/IMR, University of Leeds Leeds, UK [email protected] Dr. Witusiewicz Victor Access e.V. Aachen, Germany [email protected] Dr. Wnuk Grzegorz Rzeszów University of Technology, Department of Materials Science Rzeszów, Poland [email protected] Mr. Xiong Wei Department of Materials Science and Engineering, Royal Institute of Technology Stockholm, Sweden [email protected]


199

Dr. Yazhenskikh Elena Jülich Forschungszentrum, Institute of Energy research, Microstructure and properties of material, IEF-2 Jülich, Germany [email protected] Mr. Yosuke Yamamoto Department of Informatics, Kwansei Gakuin University Sanda, Japan [email protected] Dr. Yuge Koretaka Dept. Mater. Sci. and Eng., Kyoto University Kyoto, Japan [email protected] Dr. Zakulski Wojciech Institute of Metallurgy and Materials Science, Polish Academy of Sciences Cracow, Poland [email protected] Dr. Zemanová Adéla Institute of Physics of Materials, Academy of Sciences of the Czech Republic, v.v.i. Brno, Czech Republic [email protected] Mr. Zhang Yinan Concordia University Montreal, Canada [email protected] Dr. Zlá Simona Vysoká škola báňská - Technická univerzita Ostrava Ostrava, Czech Republic [email protected]

CALPHAD XXXVIII

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CALPHAD XXXVIII

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7. Autor index

CALPHAD XXXVIII Authors Index

202

—A— Abe T. ........................................... 31, 57 Adjanor G. .......................................... 84 Alexeev S. ................................ 123, 124 Aljarrah M. ......................................... 48 Ambat R. ............................................ 61 Amore S. ............................................. 60 Ande C. K. .......................................... 92 Anzai K. ........................................... 120 Artyukh L. V. ..................................... 46 Artyukh S. Yu. ................................. 176 Asano T. ............................................. 42 Asgar-Khan M. ................................. 155 Athènes M. ......................................... 84 Avillez R. ........................... 45, 113, 183 —B—

Bai Kewu ............................................ 30 Bakardjieva S. .................................... 79 Balanetskyy S. .................................. 129 Barbin N. .................................. 123, 124 Barinova A. P. .................................. 111 Belmonte D. ....................................... 36 Benarchid My. Y. ..................... 184, 185 Bhattacharjee S. .................................. 81 Biborski A. ......................................... 38 Blöchl P. ........................................... 158 Bondar A. A. ........................ 46, 56, 176 Bosbach D. ....................................... 134 Bracarense A. Q. .............................. 113 Brachet J. C. ..................................... 127 Brož P. ...................................... 118, 166 Bukaemskiy A. A. ............................ 134 Bukat K. ............................................. 59 Buršík J. .................................... 166, 172 —C—

Cacciamani G. ............................ 43, 101 Chartrand P. .......................... 48, 49, 153 Chatain S. ........................................... 80 Chen Li ............................................. 164 Chen Ming .......................................... 73 Chen Q. ....................................... 33, 128 Chen Q. X. .......................................... 50 Chidambaram V. ................................ 61 Chiu C.-N. ........................................ 168 Cho Moon Gi .................................... 110 Chojnacka I. ............................. 107, 108 Čička R. .............................................. 62

Clemens H. ....................................... 103 Colinet C. ............................................ 22 Cornish L. A. .............................. 95, 171 Corvalan C. ............................... 127, 148 Costa e Silva A. .................. 45, 113, 183 Crivello J.-C. ...................................... 94 Cupid D. M. ................................ 58, 102 —D—

David N. ........................... 163, 184, 185 Dębski A. .................................. 152, 179 Delsante S. .......................................... 60 Desgranges C. ................................... 127 Dinsdale A. ....................................... 101 Dobrovská J. ..................................... 174 Doernberg E. ..................................... 117 Drápala J. .......................................... 175 Dreger I. .............................................. 76 Du Yong ................................................. ........ 53, 54, 68, 97, 99, 128, 145, 164 Du Zhenmin ...................................... 133 Dudarev S. L. ...................................... 19 Dyment F. ......................................... 148 —E—

Ebrahimi F. ......................................... 58 Eichhammer Y. ................................... 60 Emmerich H. ..................................... 117 Engström A. ........................................ 33 Essadiqi E. ............................ 48, 49, 153 —F—

Fabrichnaya O. ..................... 58, 72, 102 Falkova A. N. ................................... 111 Farzadfar S.-A. ................................... 77 Feuerbacher M. ................................. 129 Fiorani J. M. ..................... 163, 184, 185 Fischer S. .......................................... 119 Fitzner K. .................................. 132, 182 Flandorfer H. ...................................... 47 Flèche J. L. ......................................... 80 Fomichov O. S. ................................. 176 Foret R. ............................................. 147 Frederiksen K. B. .............................. 121 Friák M. .............................................. 82 Fujii S. ................................................ 98 —G—

Gamsjäger E. .................................... 103 Ganesan R. ........................................ 165 Gąsior W. ............................ 59, 152, 179


203

Gaune-Escard M. ..................... 107, 108 Gierlotka W. ..................................... 182 Giuranno D. ....................................... 60 Golubeva P. S. .................................. 52 Gonze X. ............................................ 34 Grigorieva T. F. ............................... 111 Gröbner J. ................................... 51, 168 Grushko B. ............... 129, 143, 160, 162 Grytsiv A. ........................................... 55 Guéneau C. ......................................... 80 Guo Cuiping ..................................... 133 —H—

Hack K. ............................................ 125 Hald J. ................................................ 61 Hallstedt B. ........................................ 44 Hampl M. ......................................... 169 Hasebe M. ........................................ 149 Hattel J. .............................................. 61 Hecht U. ............................... 46, 56, 176 Hodis Z. ........................................... 147 Homolová V. .................................... 170 Hosseinifar M. ........................... 64, 142 Hu R. X. ............................................. 54 Hug G. .............................................. 163 Hung Vu Van ..................................... 21 —I—

Il'inykh N. I. ....................... 52, 112, 144 Ipser H. ............................................. 165 Iribarren M. ...................................... 148 Ishida K. ..................... 67, 120, 130, 131 Ito W. ............................................... 131 —J—

Jacobs M. H. G. ............................... 158 Jan V. ............................................... 147 Janovec J. ........................................... 62 Jiang M. ............................................. 67 Joubert J.-M. ........ 77, 94, 114, 126, 163 Jourdan J. ......................................... 126 Jung In-Ho ................................. 32, 109 Jung Woo-Sang ................................ 106 —K—

Kainuma R. ...................................... 131 Kajihara M. ........................................ 42 Kaneko T. ........................................... 98 Kang Daehoon ................................. 109 Kang Kyung-Han ............................. 116 Kapała J. ................................... 107, 108 Kaptay G. ................................... 65, 180 Kapush D. ................................ 143, 160 Katayama I. ...................................... 161

Kattner U. R. ...................................... 29 Kaufman L. .................................. 18, 43 Kevorkov D. ......................... 48, 49, 153 Khan Ullah A. .................................... 55 Khorujaya V. .................................... 160 Kim Da Hye ....................................... 70 Kim Eun Ha ....................................... 71 Kim Hyun-Kyu ................................ 106 Kim Nack J. ...................................... 109 Kim Taeyoung .................................. 104 Kiseleva T. Yu. ................................ 111 Klähn M. ............................................ 40 Klecka J. ........................................... 108 Kobertz D. .......................................... 76 Kocer C. ....................................... 31, 57 Kong Yi ........................................ 97, 99 Konica S. ............................................ 49 Konings R. J. M. ................................ 78 Kopyto M. ........................................ 132 Kornienko K. .................................... 160 Kościelski M. ..................................... 59 Kowalski W. ............................. 160, 162 Kozakai T. .......................................... 69 Kozelský P. ...................................... 174 Kozlov A. ................................. 157, 168 Kozubski R. ........................................ 38 Kriegel M. ........................................ 102 Kroupa A. ........... 62, 170, 172, 173, 175 Krzyżostaniak G. .............................. 108 Kulikova T. V. ................... 52, 112, 144 —L—

Lalla Di N. ........................................ 148 Landa A. I. ......................................... 18 Łapsa J. ............................................. 182 Lavrentiev M. Y. ................................ 19 Lee Byeong-Joo ................. 71, 106, 116 Lee Hyuck Mo ........................... 70, 110 Lee Jae-Chul .................................... 116 Lee Joonho ................................. 53, 104 Legut D. ............................................. 96 Leinenbach C. .................................... 63 Leitner J. ........................................... 122 Li H. X. .............................................. 67 Li J. ............................................... 48, 49 Li Jian ............................................... 153 Liu X. J. ............................................ 130 Liu Y. ......................................... 22, 103 Liu Zi-Kui .............................. 25, 27, 97 Lokaj J. ............................................... 62 Lu X. G. ....................................... 33, 54


204

Lutsyk V. .................................... 66, 146 —M—

Malakhov D. V. .................. 64, 142, 177 Manasijević D. ................................. 161 Marchewka A. .................................. 108 Markus T. ......................................... 119 Masuda-Jindo K. ................................ 21 Mayorova A. V. ........................ 112, 144 Mayrhofer P. H. ................................ 164 Medraj M. ............. 48, 49, 153, 154, 155 Mekler C. .......................................... 180 Meschel S. V. ..................................... 50 Mezbahul-Islam M. .......................... 154 Mi S. ................................................. 162 Michurov G. ............................. 123, 124 Minić D. ........................................... 161 Mironov M. .............................. 123, 124 Miyamoto T. ..................................... 131 Miyazaki T. ........................................ 69 Modolo G. ........................................ 134 Mohri T. ............................................. 20 Monteiro M. ..................................... 113 Moser Z. ..................................... 59, 179 Motalov M. ....................................... 119 Mücklich S. ...................................... 169 Müller M. ................................... 76, 125 Muolo M. L. ....................................... 43 Murakami H. ................................ 31, 57 —N—

Nagasaka T. ...................................... 120 Nagasako M. ..................................... 131 Nash P. ......................................... 50, 54 Nguyen-Manh D. ................................ 19 Nishitani S. R. ...................... 37, 98, 100 Nižňanský D. ...................................... 79 Novakova A. A. ................................ 111 Novakovic R. .............................. 60, 105 —O—

Oba F. ................................................. 74 Ode M. ................................................ 57 Ohnuma I. ................................... 67, 130 Ohtani H. .......................................... 149 Oikawa K. ................................... 67, 120 Onderka B. ....................................... 132 Onodera H. ......................................... 31 Orlov S. .................................... 123, 124 —Ø—

Østby J. ............................................... 73 —O—

Ottonello G. ........................................ 36

Ouyang Y.F. ....................................... 99 Ožvold M. ........................................... 62 —P—

Palcut M. ........................................... 167 Paliwal M. ........................................... 32 Palumbo M. ................................ 31, 101 Panahi D. .......................................... 177 Paolini C. P. ........................................ 81 Parlinski K. ......................................... 35 Pashchenko V. Yu. ........................... 176 Passerone A. ....................................... 43 Pasturel A. .................................. 93, 101 Pavlů J. ......................................... 26, 83 Pavlyuchkov D. ................ 143, 160, 162 Pessoa E. C. P. .................................. 113 Petković D. ....................................... 161 Petyukh V. M. ..................................... 56 Pierron-Bohnes V. .............................. 38 Piluso P. .............................................. 79 Povoden E. .......................................... 73 Przybyło W. ...................................... 132 Pstruś J. ............................................... 59 —R—

Rahman S. W. ..................................... 49 Rehspringer J. L. ................................. 79 Richter K. W. ...................................... 24 Rizzo F. ............................................. 113 Rogl P. ................................................ 55 Romanowska J. ................................. 150 Roth M. ............................................... 63 Rutkowska I. ............................. 107, 108 Rycerz L. .......................................... 108 Ryu Ji Hoon ........................................ 70 —S—

Saal J. E. ............................................. 27 Saccone A. .......................................... 55 Santos V. R. ...................................... 113 Schmetterer C. .................................... 47 Schmid-Fetzer R. .................................... ................ 51, 117, 157, 158, 168, 169 Schmidt P. ......................................... 115 Schön C. G. ........................... 39, 69, 156 Scott A. J. ................................... 95, 171 Scuracchio B. G. ............................... 156 Sedmidubský D. ......................... 78, 122 Seduraman A. ..................................... 40 Seifert H. J. ........................... 58, 72, 102 Seko A. ............................................... 74 Selleby M. ......................................... 128 Seo Sun-Kyoung ............................... 110


205

Shang S. ............................................. 27 Shao Guosheng .................................. 23 Shunyaev K. Yu. ...................... 112, 144 Simonovic D. ..................................... 41 Siquieri R. ........................................ 117 Sitek J. ................................................ 59 Sluiter M. H. F. ...................... 41, 92, 93 Smetana B. ............................... 174, 175 Šob M. .............................. 26, 82, 83, 96 Söderlind P. ........................................ 18 Soliev L. ............................................. 75 Sopoušek J. ............. 118, 147, 159, 167, 178, 181 Souček P. ........................................... 78 Strandlund H. ..................................... 33 Sturz L. ............................................. 176 Sun Weihua ...................................... 145 Sung Yun-Mo .................................. 104 Surowiec M. ..................................... 162 Svoboda M. ...................................... 172 Svobodová M. .................................. 159 —T—

Takeuchi Y. ...................................... 100 Tanaka I. ............................................ 74 Tang Chengying ......................... 53, 104 Tedenac J. C. ...................................... 22 Terentiev D. ............................. 123, 124 Toffolon-Masclet C. ................. 126, 127 Togase K. ........................................... 98 Togo A. .............................................. 74 Tokunaga T. ..................................... 149 Tsyganenko N. I. ................................ 46 Turchi P. E. A. ............................. 18, 21 Tursunbadalov Sh. ............................. 75 Tyrpekl V. .......................................... 79 —U—

Ukpong A. M. ............................ 95, 171 Ulichová A. ...................................... 178 Umetsu R.Y. .................................... 131 —V—

Valenza F. .................................... 43, 60 Velikanova T. Ya.

........................ 56, 129, 143, 160, 176 Vetuschi Zuccolini M......................... 36 Vilasi M. ........................... 163, 184, 185 Voblikov V. M. .................................. 56 Voňka P. ........................................... 122 Vorob’eva V. .............................. 66, 146 Vřešťál J. ...... 26, 83, 100, 118, 161, 181 Všianská M. ....................................... 96 Výrostková A. .................................. 170 —W—

Wang Aijun .................................. 97, 99 Wang C. P. ....................................... 130 Wang Jiang ......................................... 63 Wang Jiong ............................ 53, 54, 97 Wang Y. ............................................. 27 Watson A. ................................... 95, 171 Wielage B. ........................................ 169 Witusiewicz V. T. ................ 46, 56, 176 Wnuk G. ........................................... 151 Wu Ping ........................................ 30, 40 —X—

Xiong Wei ........................................ 128 —Y—

Yamabe-Mitarai Y. ............................ 57 Yamamoto Y. ................................... 100 Yan X. ................................................ 55 Yazhenskikh E. ................................ 125 Yuan Xiaoming ................................ 145 Yuge K. .............................................. 28 —Z—

Zakulski W. ...................................... 152 Zelenaya A. ...................................... 146 Zemanová A. ...................... 62, 173, 181 Zhang Lijun ...................... 53, 54, 68, 99 Zhang Yinan ............................... 49, 153 Zhou Huaiying ................................... 53 Zhou Liangcai .................................... 97 Živković D. ...................................... 161 Zlá S. ........................................ 174, 175 Zobač O. ........................................... 178 Zollinger J. ........................... 46, 56, 176

Seznam účastníků semináře fyz.chemie · 1.3. Poster Instructions The poster session will be...

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