PROCEEDINGS OF THE

ELEVENTH INTERNATIONAL WORKSHOP ON

AND THEIR APPLICATIONS

and the

SIXTH

INTERNATIONAL SYMPOSIUM ON MAGNETIC

ANISOTROPY AND COERCIVITY IN

RARE EARTH-TRANSITION METAL ALLOYS

PITTSBURGH, PENNSYLVANIA, USA

OCTOBER 1990

Edited by

S. G. Sankar

CARNEGIE MELLON UNIVERSITY

VOLUME I WORKSHOP

TIB/UB Hannover 89

PREFACE:

TABLE OF CONTENTSVOLUME I WORKSHOP PROCEEDINGS

S.G. Sankar

SESSION I. MAGNET PROCESSING I

Page

xvn

Chairmen: J. Prater, U.S. Army Research office.Research Triangle, N.C. and

F. G. Jones, Fred Jones Associates.

Wl.l Current Status of Rapidly Solidified

Nd-Fe-B Permanent Magnets. (INVITED)J. J. Croat

W1.2 Current Situation in the Developmentof Hot-Rolled R-Fe-B Magnets. (INVITED)T. Shimoda, K. Akioka, O. Kobayashi,T. Yamagami and A. Arai

17

SESSION II. MAGNET PROCESSING II

W1.3 Hydrogen: Its Use in the Processingof NdFeB-type Magnets and in the

Characterization of NdFeB-Type Alloysand Magnets. (INVITED)I. R. Harris and P. J. McGuiness

29

W2 .1 Magnetic Properties and Microstructures

of the Nd-Fe-B Magnet Powders Produced bythe Hydrogen Treatment - (III) . (INVITED)T. Takeshita and R. Nakayama

49

W2.2 Fully-Dense Nd-Fe-B Magnets Prepared from

Hot-Rolled Anisotropic Powders.

T. Mukai, Y. Okazaki, H. Sakamoto,M. Fujikura and T. Inaguma

72

W2.3 Rapid Annealing Effect of Metal Baths

on Nd-Fe-B MagnetsT. s. Chin, S.H. Huang, H. J. Bai and

S. K. Chen

85

I

SESSION III. CORROSION AND STABILITY

Chairmen: A.E. Ray, U. of Dayton and

S. Hirosawa, Sumitomo Special Metals, Japan.

W3.1 An Investigation of the Impact of Surface 93

Preparation Techniques Applied to the

Iron-Neodymium-Boron Alloys with Respectto Accelerated Environmental Test Results.

(INVITED) R. W. Ribitch

W3.2 Corrosion Protection of Fe-Nd-B-Magnets 108

by Coating.W. Bloch, K. Grendel and H. Staubach

W3.3 Ugistab Nd-Fe-Co-V-B Magnets: 123

Magnetic Properties, Corrosion Resistance

and Comparison with NdFeB Magnets.P. Tenaud, F. Vial, A. Barzasi,A. Duchene and M. Sagawa

W3.4 Improving Temperature stability and 136

Corrosion Resistance in Nd-Fe-B-TypeSintered Magnets.S. Hirosawa, S. Mino, H. Tomizawa

and K. Tokuhara

W3.5 Improvement of Corrosion Resistance of 148

Nd-Fe-B Sintered Magnets by OrganicElectrodeposition of Ni.

H. Momotani, E. Otsuki and T. Otsuka

W3.6 Superficial Enrichment of Neodymium in 159

Nd-Fe-B Sintered MagnetT. Minowa, M. Yoshikawa, M. Shimao and

M. Honshima

II

SESSION IV INSTRUMENTATION AND STANDARDS

(Jointly Sponsored by IEEE

Technical Committee 15)

Chairmen: J. Cook, CSIRO, Australia andR. Grossinger, u. of Vienna, Austria

W4.1 Review of High Magnetic Field 169

Facilities: Opportunities for

Permanent Magnet Research. (INVITED)S. Foner

W4.2 Permanent Magnet Standards from an 173"

Industry Perspective.Mel Bohlmann

W4.3 How Accurate are Magnetic 182

Measurements?

G. R. Hennig

W4.4 Advances in Computer-Automated 189

Hysteresisgraphs for Hard and Soft

Magnetic Materials

Earle S. Seely and Eric Dennison

SESSION V ELECTROMECHANICAL DEVICES

Chairmen: P. Campbell, Princeton Electro-Technology Inc.

and

D. Lambeth, Carnegie Mellon University.

W5.1 Electromagnetic Motion Devices Using 191

Permanent Magnets With Extremely High

Energy Product. (INVITED)S. Simizu, F. Pourarian and W.E. Wallace

III

W5.2 Future High Energy Magnetic Materials 209for Automotive and Commercial Applications.(INVITED)Daniel Stahura

W5.3 Computer-Aided Design and Analysis of

Permanent Magnet Brushless Drive Systems.(INVITED) Paper not received.D. Howe

W5.4 A New Nd-Fe-B Brushless D.C. Motor for 221a Digital Data Storage Spindle Drive.Peter Campbell

W5.5 Design considerations for Application of 231Permanent Magnets in Aerospace ElectricMotors and Generators.

Jayant G. Vaidya

W5.6 Epoxy Bonded Nd-Fe-B Magnetic Rollers: 241Experimental and Theoretical Analysis.J. K. Lee and T. S. Lewis

SESSION VI ACCELERATOR TECHNOLOGY

Chairman: F. Rothwarf, Center for Innovative

Technology, Virginia.

W6.1 Use of Rare Earth Magnets in Accelerator 256

Technology: Configuration Concepts and

Design Techniques. (INVITED - TUTORIAL)K. Halbach

W6.2 Radiation Damage Mechanisms in NdFeB. 258A. F. Zeller

W6.3 Rare Earth Permanent Magnet Materials for

Particle Accelerator Applications.R. H. Kraus, Jr. (Paper not received)

IV

SESSION VII RAW MATERIALS, RESOURCES

Chairmen: c. Bounds, Rhone-Poulonc,Princeton and

E. Dulis, crucible Materials Research

Center, Pittsburgh

W7.1 Rare Earths: Today and Tomorrow 27 0

In China. (INVITED)Yang Luo

W7.2 The Lanthanide Myths. 286

S. R. Trout

W7.3 Substitution of Nd by Pr in Coreduced 292

NdFeB Alloy Powder.

M. Edeling

SESSION VIII PROCESSING AND MICROSTRUCTURE

WP 1 MQ2 and MQ3 Magnets — Improvements in 2 98

Production Technology and Properties.Yasuaki Kasai, Teruo Watanabe,

Shigeki Shibata, Viswanathan Panchanathan

and John J. Croat.

WP 2 RE-Fe-B Magnets With Improved 313

Temperature Dependence of the Coercive

Field Strength.M. Velicescu

WP 3 The Effect of Oxygen Content on the 3 22

Magnetic Properties and Environmental

Stability of Nd-Fe-B Based Magnets,

c. H. Chen, A. E. Ray and s. Liu

WP 4 Processing and Magnetic Properties of 328

Sintered Nd-Fe-B Magnets.E. Otsuki, T. Otsuka and T. Imai

V

WP 5 Oxidation Mechanism of the Hydrogenated 341Nd-Fe-B Powder.

Jun Nakagawa and Osamu Onitsuka

WP 6 The Effect of Nd Amount on the 351Characteristics of Nd-Fe-B Alloys byReduction-Diffusion Process.C. J. Chen, T. Y. Liu, C. H. Lin,Y. C. Hung, S. H. Chen and C. D. Wu

WP 7 A New Method of Producing Radially 359Anisotropic Rare Earth Magnets.C. H. Lin, C. J. Chen, T. Y. Liu,W. c. Chang and CD. Wu

WP 8 The Effect of Laves Phase on the 367Magnetic Properties of Fe-Co-Nd-B Alloy.C. J. Yang, S. D. Choi and W.Y. Lee

WP 9 The Effect of Carbon on the Magnetic 383

Properties of Ternary NdFeB.F. E. Camp and A. S. Kim

WP 10 Prediction of Temperature Coefficients 389of Magnetization in Rare Earth-TransitionMetal Magnet Alloys.S. Liu, A. E. Ray and H. F. Mildrum

WP 11 High Field Magnetic Behavior of 401

Pr15Fe63Co16GaB5 Sintered Magnet.

F. Pourarian, S. Simizu, R.T. Obermyer,S. G. Sankar and W. E. Wallace

WP 12 A Study of Permanent Magnetic MaterialsBased on Nd-Fe-B With High Thermal Stability.Yang Jun, Ma Deqing and Zhou Shouzeng(This paper was withdrawn.)

VI

WP 13 Magnetic Properties of 408

Nd10+XFe73-XCo8B7.5V1.5 •

N. Tang, Y. L. Liu, J. F. Hu, X. Y. Yin,X. R. Xu, H. Zhao, G. L. Yao

WP 14 Magnetic Properties and Mossbauer 418

Study of NdFeB and

R15_xDyxFeCoAlB Magnets.

S. Y. Jiang, J. X. Yan, F. S. Li,D. S. Xue, S. G. Sankar and W. E. Wallace.

WP 15 Properties and Microstructure of 427

ThMn12-Type Sm-Fe-Ti Alloy Powders

and Sintered Magnets.L. Jiang, J. H. Zhu and D. Li

WP 16 Magnetic Properties and Microstructure 432

of Rapidly Quenched MM Based RFeCoZrB

Magnets.T. Yoneyama, H. Nakamura, K. Annan,T. Nishichi and A. Fukuno

SESSION IX RARE EARTH-COBALT MAGNETS

WP 17 Effects of Processing Parameters on the 443

Properties of Bonded Sm-Co "2:17" MagnetsCold Compacted With Lead.

Meng Li, Karl J. Strnat and

Herbert H. Mildrum

WP 18 Al and Ga Substitution in 2:17 Type 457

Magnets With High Fe Content.

M. Q. Huang, Y. Zheng, J. G. Sohn,J.M. Elbicki, W. E. Wallace and

S. G. Sankar

WP 19 Magnetic Properties of Two Step Aged 466

Sm-Co-Fe-Cu-Zr Permanent Magnets.

H. W. Kwon and I. R. Harris

VII

WP 20 The Precipitation at 500-950 C of 474

Sm(Co,Cu,Fe,Zr)7<4 Magnets and the

Analysis of Coercivity Mechanism.

Pan Shuming, Liu Jinfang and Ma Ruzhang

WP 21 Magnetic Properties of Sintered 481

(PrLa)co5 -Type Magnets.Y. Xu, Bao-Min Ma, W. E. Wallace

and S. G. Sankar

SESSION X Nd-Fe-B MAGNETS, RESOURCES, MICROSTRUCTURE AND

THERMAL STABILITY

WP 22 Developments of NdFeB Magnets in China. 491

Yang Luo

WP 23 Influence of Dy, Al and Ga Addition for 506

Grain Boundary Phase of Nd-Fe-B

Sintered Magnets.M. Endoh, E. B. Boltich, Y. Nozawa and

M. Tokunaga.

WP 24 Magnetic Properties and Microstructure 519

of Tb-Fe-B Sintered Magnets.M. Endoh, E. B. Boltich, K. Nakamura,M. Tokunaga and G. Kido.

WP 25 Effect of Hydrogen-Treatment on 531

Coercivity in Nd-Fe-Co-B Powders.

Y. Xiao, Z. Chang, W. Pan, X. Yu

and Y. Li

WP 26 Relationship Between Properties and 537

Microstructure in NdFeB Magnets.V.K. Chandhok

VIII

WP 27 The Influence of the Microstructure 549

on the Coercivity of Cast

<Ndl-xRx) 2Fe14c [R=Tb,Dy]

Based Permanent Magnet Materials.

Josef Fidler, Claudia Groiss, J. Eisses

and K. H. J. Buschow.

WP 28 Influence of Dy, Al and si Substitutions 560

on Thermal Stabilities of Sintered

Nd-Fe-Co-B Magnets by Reduction Diffusion

Alloy Powders.

W. Pan, D. Li, S. X. Zhou, R. J. Shuai and

J. P. Zhu

WP 29 Influence of Co and Nb Additions on the 571

Magnetic Properties and Microstructure of

Nd-Fe-Co-B Sintered Magnets.

Pan Shuming, Liu Jinfang, Li Dawei and

Ma Ruzhang

WP 30 In-Situ Observation of Nd-Fe-Co-B 577

Permanent Magnet.Pan Shuming, Liu Jinfang and Xu Yingfang

SESSION XI DESIGN OF MOTORS

WP 31 Application of Melt-Spun Nd-Fe-B Bonded 583

Magnet to the Micromotor.

G. X. Huang, W. M. Gao and S. F. Yu

WP 32 Design and Analysis of Axial-Field 59 6

Permanent Magnet Brushless DC Motors.

Z. Q. Zhu and D. Howe.

AUTHOR INDEX TO THIS VOLUME 611

(WORKSHOP PROCEEDINGS)

AUTHOR INDEX TO VOLUME II 613

(SYMPOSIUM PROCEEDINGS)

IX

TABLE OF CONTENTS

VOLUME II SYMPOSIUM PROCEEDINGS

PREFACE: S.G. Sankar XVii

SESSION I MAGNETIC VISCOSITY, ANISOTROPYrCOERCIVITY AND NEW MATERIALS

Chairmen: W. E. Wallace, Carnegie Mellon U.

and

Advanced Materials Corporation,Pittsburgh and

M. Velicescu, Vacuumschmelze,

Hanau, Germany.

Sl.l Angular Dependence of MagneticViscosity Parameters in NdFeB and

PrFeB Magnets. (INVITED)R. Street, L. Folks and S. Hirosawa

SI.2 High-Field Measurements and Crystal- 12

Field Calculations on MagneticProperties of Nd2Fe14B-Type Alloys.(INVITED)Y. Nakagawa, H. Kato, D.W. Lim,G. Kido and M. Yamada

SI.3 A New Family of Rare Earth Iron 36

Nitrides. (INVITED)J. M. D. Coey, H. Sun and Y. Otani

SI.4 Magnetic Properties of the 60

(Co - Fe) Sublattice in the

pseudobinary and the PseudoternaryRare Earth - Transition Metal

Intermetallic Compounds. (INVITED)N. P. Thuy, N.M. Hong, T.D. Hien and

J.J.M. Franse

X

SESSION II MAGNETIC VISCOSITY. ANISOTROPY,

COERCIVITY AND NEW MATERIALS

Chairmen: G. Hadjipanayis, University of Delaware and

D. Laughlin, Carnegie Mellon University.

S2.1 Magnetic Properties of ROo^^M^. 80

(R=rare earth; M=B, Al and Ga) .

(INVITED)H. Ido, K. Konno, S. F. Cheng,

S. G. Sankar and W. E. Wallace

S2.2 The Potential of Sm-Fe-X Alloys for 94

Permanent Magnets.J. Wecker, M. Katter, L. Schultz

and K. Schnitzke

S2.3 Decomposition of the Sm(Fe,Ti)12 101

Compound in Sintered MagnetsDuring Annealing.W. Rodewald and P. Schrey

S2.4 Characterization of Rare Earth 110

Permanent Magnets. (INVITED)A. Hutten and G. Thomas

S2.5 Some Features of Ternary 127

Nd-Fe-50at%B Metastable Phase Diagram.p. P. Pashkov, D. V, Pokrovsky and

G. V. Malakhov

52.6 Magnetic Viscosity and Coercivity 165

Mechanism in Sm2(Co,Fe,Cu,Zr)17Magnets.E. W. Singleton and G. C. Hadj ipanayis

52.7 The Effect of Dopants 176

(Al, Ga, Cu, Mo, V) on Microstructure

and Coercivity of Sintered Nd2Fe14BBased Magnets.Josef Fidler

XI

SESSION III NITRIDES AND CARBIDES

SP 1 Magnetic Properties of R2Fe17Nx 181Compounds.Y. Z. Wang, G. c. Hadjipanayis and

D. J. Sellmyer

SP 2 Spin Reorientation of DyFe10si-Nand DyFen0Si2.Pan Shuming, Liu Jinfang, Li Qingan,Yan Fuming and Zhao Ruwen.

(This paper was withdrawn)

SP 3 Magnetic Properties of Nitrides of 190

the Rare Earth-Iron Intermetallic

Compounds.Ying-chang Yang, Sen-lin Ge,Xiao-dong Zhang, Lin-shu Kong,

Qi Pan, Yong-tian Hou, Shuang Huangand Liu Yang

SP 4 Magnetic Properties and Structure 204

of Nitrogenated R2(Fe,Co)17Intermetallic Compounds.M. Q. Huang, B.M. Ma, W.E. Wallace and

S.G. Sankar

SP 5 Magnetization and PCIs of 219

Nitrogenated R2(CoxFe1_x)17 Systems.L. Y. Zhang, Y. Zheng and W. E. Wallace

SP 6 Magnetic Properties of R2Fe17C.Ying-chang Yang, Lin-shu Kong,Xiao-dong Zhang, Jia-bin Yao,Jiang-chun Han and Jian Lin

(Paper not received)

XII

SESSION IV INTRINSIC PROPERTIES

SP 7 High Field Magnetization Process 230

in the Er2Fe-,7_xMnx Compounds.N. M. Hong, S. P. Thuy and

J. J. M. Franse.

SP 8 Possibility of Using Sm2Co17_xMxAlloys for Recording Media.S. K. Chen, J. G. Duh, H. C. Ku,

Yung-Chen Wang, Kuo-Kwang Wang andChia-Pin Tang(Paper not received)

SP 9 Magnetic Phase Transition in

Pseudoternary Compounds (Yi-xLax) Co4Band (Y1_vLuv)Co4BN. P. Thuy 4nd N. M. Hong(Paper not received)

SP 10 New Generation Permanent Magnets.Y. Bogatin(Paper not received)

SESSION V ANIS0TR0PY. MICROSTRUCTURE AND COERCIVITY

SP 11 Stable and Metastable Ferromagnetic 23 6

Phases in Pr-Fe and Pr-Fe-B.

Augusto C. Neiva, Taeko Yonamine,Fernando J. G. Landgraf and

Frank P. Missell

SP 12 Effect of Carbon, Oxygen and 250

Nitrogen on the Microstructure of

Grain Boundaries in Nd-Fe-B Magnets.Y. J. Zhang, G. C. Hadjipanayis,A. S. Kim and F. E. Camp

SP 13 Anomalous 3d-Anisotropy Behavior 262

in R2Fe13M1B Compounds(R=Y,Gd; M=Fe,Ga,Si,Al) .

X. C. Kou, G. Wiesinger and R. Grossinger

XIII

SP 14 A New Method to Determine the

Onset Temperature of a FOMP

Transition in 3d-4f Compounds.R. Grossinger and X. C. Kou

277

SP 15 Magnetic Hardening in R4Fe77B19 290Ribbons.L. Withanawasam, G. C Hadjipanayis and

K. R. Lawless

SP 16 Magnetization and Anisotropy of 300

J. Q. Xie, C. H. Wu, Y. C. Chuang and

F. M. Yang

SP 17 High Temperature Compressive 308Deformation of Rapidly-QuenchedHot-Pressed Nd-Fe-B Materials.J. Q. Xie and C. D. Graham, Jr.

SP 18 Deformation, Texture Development 322and Domain Observations in Rapidly-Quenched NdFeB Magnets.Lin Li and C. D. Graham, Jr.

SP 19 Transmission Electron Microscopy 331

of Extruded FeNdB Magnets ContainingHfB, Dispersolds.B. G. Demczyk

SP 20 Spin Reorientation and Magneto- 342

optical Kerr Effect in R2Fe14_xMnxB(R=Nd,Er).T. lida, H. Ueki, T. Fukuzawa, T. Saito,K. Shinagawa and T. Tsushima

SP 21 The Magnetocrystalline Anisotropy 351

of R2Fe,4B and RTiFe-^.Sheng-chuan Zhu

XIV

SP 22 On the Relation Between 357Microstructure, Heat Treatment and

Coercivity in Melt-Spun Nd-Fe-B Alloys.M. D. Baro, S. Surinach, J. A. Diego,M. T. Clavaguera-Mora, N. Clavaguera andJ.M. Gonzalez

SP 23 Does a FOMP Exist in Pr2Co14B? 371R. Grossinger and X. C. Kou

SP 24 Intrinsic Magnetic Characteristics 381and Spin Reorientation Behavior of

Rare Earth-Transition Metal Based Alloys.F. Pourarian

SP 25 Phase Analysis and Magnetic 400

Properties of RTiFe11_xCOj,(R=Pr,Nd) (x=0-ll).S. F. Cheng, Y. Xu, S.G. Sankar andW. E. Wallace

SP 26 Spin Reorientation in Rare-Earth- 412Iron-Cobalt Vanadates With

ThMn12 Structure.

M. Jurczyk, G.K. Nicolaides and K. V. Rao

SP 27 Magnetic Behavior of Heavy Rare 425Earth RFe10Cr2 Alloys.Yang Fuming, Li Qingan, Zhao Ruwen,Kuang Jianping, F. R. de Boer and J.P. Liu.

SP 28 Investigation of RTiFeT^.jjCOjj 436

Alloys (R - Tb, Dy, Ho).S. F. Cheng, B. M. Ma, Y. Zheng,V. K. Sinha, S.G. Sankar and W. E. Wallace

SP 29 Microstructure and Magnetic 448

Properties of Nd-B Modified

ThMn12 Type Nd(Fe,M)12 (M=Ti/Cr)Magnet Alloys.T. S. Chin, S. H. Huang, Y. S. Chen,C.H. Lin and S. K. Chen

XV

SP 30 High Coercivity Sm-Fe-Ti-V and 453Sm-Fe-Zr Crystalline Phases.F. J. Cadieu, H. Hegde, N. Kamprath,A. Navarathna and R. Rani

SP 31 Investigation of Zr-Co and 477Hf-Co systems.S. F. Cheng, W. E. Wallace and

B. G. Demczyk

SP 3 2 Spin Reorientation Study in 488

Dy(Fe,Ti)i2 by Neutron Diffraction.

Yang Ji-Lian, Pan Shu-ming,Zhang Bai-Sheng, Jin Lan, Ding Yong-fan andYe Chun-tang

SP 33 Structural and Magnetic Properties 493of RTiFe-,, and Their Hydrides(R = Gd, Tb, Dy, Ho and Er).L. Y. Zhang, S.G. Sankar,W. E. Wallace and S. K. Malik

SP 34 Microstructure and Magnetic 505

Properties of NdFeB- TypeSintered Magnets.Liu Jinfang, Pan Shuming and Luo Helie

SP 35 Observation of The Grain Boundary 514Phase in NdFeB- type Sintered Magnets.Pan Shuming, Liu Jinfang and Luo Helie

SP 36 Magnetic Domains in sintered 520

Nd-Fe-B Magnets Made by Hydrogen-Decrepitation and Conventional Routes.

I. S. Moosa and G. W. Johnson

SP 37 High Coercivity in Melt-Spun 530

R-Fe-B Magnets With Impurity AdditionsG.C. Hadjipanayis and L. Wlthanawasam.

AUTHOR INDEX TO VOLUME II 541(SYMPOSIUM PROCEEDINGS)

AUTHOR INDEX TO VOLUME I 543

(WORKSHOP PROCEEDINGS)

XVI