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G. Amorphous and High-entropy Alloys

Organizers: Ke-Fu Yao, Shian-Ching Jang, Zhao-Ping Lu, Xun-Li Wang, Eun Soo Park

G-01 Cluster connectivity in metallic glass Xiaoya Wei, Si Lan, and Xun-Li Wang Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Ave., Kowloon, Hong Kong SAR Bulk metallic glasses were discovered more than 30 years ago. It has been established that, for multicomponent metallic glass alloys, the short-range order or the fundamental building block is characterized by solute-centered clusters [1]. Over longer length scales, the clusters are packed on a fractal network forming the medium-range order [2]. Still, there remain a lot of questions on the structure of metallic glasses, particularly with regard to the development of short- and medium-range orders during structure evolution induced by temperature or mechanical deformation. The experimental results seem to show that during crystallization [3], mechanical deformation [4], and liquid-to-liquid phase transformation [5], the short-range order is enhanced but there are no substantial changes in the structure order. Rather, it is the connectivity between clusters at medium-range scale, that drives the dynamic response. In this paper, we explore the meaning of cluster connectivity and apply the concept to explain our experimental observations. References. 1. D. B. Miracle, Nature Mater. 3, 697-702 (2004). 2. D. Ma, A. D. Stoica, and X.-L. Wang, Nature Materials, 8, 30-34 (2009) 3. X.-L. Wang et al., Phys. Rev. Lett., 91, 265501 (2003). 4. D. Ma et al., Phys. Rev. Lett., 108, 085501 (2012) 5. S. Lan et al., Appl. Phys. Lett., 108, 211907 (2016) G-02 The cyclic oxidation of FeCoNiCr-based quinary high-entropy alloys from 25 to 900oC Wu Kai1, Chia-Chin Lee1, Fu-Ben Cheng1, Leu-Wen Tsay1, Rong-Tan Huang1, Ji-Jung Kai2,3 1. Institute of Materials Engineering, National Taiwan Ocean University, Keelung, 20224, Taiwan, Republic of China 2. Department of Mechanical and Biomedical Engineering, The City University of Hong Kong, Kowloon, Hong Kong 3. Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30050, Taiwan, Republic of China The cyclic oxidation behavior of three FeCoNiCr-based quinary high-entropy alloys containing FeCoNiCrAl (H5A), FeCoNiCrMn (H5M), and FeCoNiCrSi (H5S) was studied from 25 to 900oC in dry air under a cyclic period of 5 h up to 20 cycles. The results showed that the cyclic-oxidation kinetics of the HEAs followed by the fast to slow rank of H5M > H5A > H5S. The scales formed on H5A consisted mostly of α-Al2O3 and θ-Al2O3, and a minor amount of FeAl2O4 which was observed beneath the spalled alumina scales, while both Cr2O3 and SiO2 (a-quartz) were detected on the H5S

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alloy. In addition, triplex scales formed on the H5M alloy, consisted of an exclusive outer-layer of Mn3O4 and an intermediate-layer of (Mn,Cr)3O4 and Cr2O3, and an exclusive inner-layer of Cr2O3 Keywords: FeCoNiCr-based, cyclic oxidation G-03 Towards dilation in deformation and fracture of metallic glasses Lanhong Dai State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences Dilation is the common and intrinsic feature of metallic glasses (MGs) as it is sheared because sheared portion of these materials do not find such a perfect fit and must leave some holes. It is well recognized that volume change generating structural disordering is the main origin of inhomogeneous plastic flow and fracture of MGs. The shear-dilatation coupling leads to the pressure (or normal stress) sensitivity of macroscopic failure (flow and fracture) of metallic glasses, which essentially differs from that of their crystalline counterparts. In this talk, we attempt to provide a up-to-date review on this aspect, but from a viewpoint of the dilatation. We first review the representative flow modes for metallic glasses, where the shear-dilatation correlation is highlighted. We further present the atomic-level mechanism for local shear and dilatation events, respectively. Based on the inherent shear-dilatation competition, a united failure criterion is constructed, and dilatation induced ductile-brittle shear banding transition is discussed as well. Keywords: Metallic glass; dilation; flow; fracture; shear band G-04 MD simulation of the mechanical behaviour of BMGs under triaxial stress state Yi Li Institute of Metal Research Many previous simulations of deformation in metallic glasses showed that shear banding is the dominant plastic deformation mode accompanied by Voronoi volume increase. In this simulation, we report a contrary phenomenon of Voronoi volume annihilation process during the plastic deformation in CuZr metallic glasses. By creating a notched geometry, the deformation mode of notched samples transits from shear banding to necking.With the suppressing of shear banding, a notch strengthening and structure ordering phenomenon accompanied by the recovery of Cu-center full-icosahedra fraction and decrease in local temperature are also observed. Our result is contrary to previous results which suggest that Voronoi volume generation and structural disordering dominate deformation of metallic glasses, but it is well consistent with new experimental results. The present work reveals a better understanding of the plastic deformation of MGs. Keywords: Metallic glasses, mechanical behaviour G-05 Strengthening mechanisms in high-entropy alloys with different solid-solution structures Z. P. Lu State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing, 100083, P. R. China

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High-entropy alloys (HEAs) are an emerging research area for metallic materials, and have attracted extensive attention recently due to their interesting mechanical, physical and structureal properties. Unlike in conventional metallic materials, the traditional “solutes and solvents” lose their original meaning in these equal molar or near equal molar HEAs. Therefore, the strengthening behavior and underlying mechanisms in these highly concentrated matrices became important both scientifically and technologically. In this talk, our representative progresses regarding employment of different methodologies to strengthen HEAs will be presented: Precipitation hardening in the fcc FeCoNiCrMn HEA matrix; effects of alloying additions and thermomechanical treatment on precipitation behavior and tensile properties will be discussed. Solid-solution hardening in the bcc TaNbHfZrTi HEA matrix; effects of interstitial atoms on deformation behavior and damping properties will be discussed, and Transformation mediated strengthening in a hcp matrix with an equal molar atomic ratio; effects of transformation-induced-plasticity and deformation behavior will be analyzed. Keywords: High entropy alloys; strengthening mechanisms; solid-solution hardening; precipitation hardening; Transformation mediated hardening G-06 Fracture and strength of bulk metallic glasses Z. F. Zhang, R. T. Qu and Z. Q. Liu Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016, P.R. China Based on the analysis of substantial experimental observations of fracture behaviors of metallic glasses and other high-strength materials, here we developed a new fracture criterion and proved it effective in predicting the critical fracture conditions under complex stress states. The new criterion is not only a unified criterion which unifies the three classic fracture criteria, i.e., the maximum normal stress criterion, the Tresca criterion and the Mohr-Coulomb criterion, but also a universal criterion which has the ability to describe the fracture mechanisms of a variety of different high-strength materials under various external loading conditions. Furthermore, in terms of the universal fracture criterion above, we show that the fracture of metallic glasses originates from the thermodynamic destabilization of the amorphous structure driven by imposed mechanical energy. The fracture behaviors and properties of metallic glasses can be predicted precisely and comprehensively just according to their elastic constants. This endows deep insights on the fracture nature of materials and makes it possible to compute fracture non-destructively without destroying the materials and free from a computer. Keywords: Bulk metallic glasses; Fracture; Strength; Shear band; Elastic constant. G-07 The Effect of Ni Addition on Soft-magnetic Properties of FeCoZrBCu Nanocrystalline Alloys Baolong Shen Southeast University Influence of Ni element on microstructure ， soft-magnetic properties and Curie temperature of (Fe1-xCox-yNiy)88Zr7B4Cu1 nanocrystalline alloys was investigated by substituting Co by Ni. It was found that the addition of Ni element promotes the precipitation of the single-phase α-(Fe,Co,Ni) nanocrystalline grain. The DSC curve of the alloy moves toward the low temperature region, and the Curie temperature of amorphous and nanocrystalline phases decreases slightly. Addition of Ni element promoted the refinement of grain size of

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nanocrystals and the decrease of coercivity, core loss and especially high frequency core loss. (Fe0.7Co0.2Ni0.1)88Zr7B4Cu1 nanocrystalline alloy exhibits optimum magnetic properties after annealing at 540 oC for 1 h, i.e., high Bs of 1.66T, low Hc of 19 A/m and low core loss (P) of 0.93 W/kg at 1 T and 50 Hz, and 600W/kg at 0.2 T and 100 kHz, which shows more excellent soft magnetic properties and energy saving effect compared with HITPERM alloy. Keywords: Fe-based nanocrystalline alloys, soft-magnetic properties, high Curie temperature G-08 Designing nanogranular metallic glasses with tunable properties Na Chen, Wenjian Liu, Kefu Yao Tsinghua University Research purpose We aim to design and development of a new type of non-crystalline solids termed as nanogranular metallic glasses (NGMGs). The produced NGMG alloys show tunable ferromagnetic, electric and mechanical properties. Materials and experiments Different metal-based NGMGs were produced by magnetron sputter deposition. The structure of the thin films was investigated using high-resolution transmission electron microscopy (HRTEM) and aberration-corrected scanning transmission electron microscopy (STEM). The optical, electrical and magnetic properties were measured by using a UV/VIS/NIR spectrophotometer (Lambda 950), a Physical Property Measurement System (PPMS-9T) and a scanning superconducting quantum interference device (SQUID-VSM) magnetometer, respectively. Results The Au-based NGMG shows high catalytic activity while the Ti-based NGMG exhibits superior biocompatibility. Furthermore, the individual NGMGs can be nanoalloyed together to form non-crystalline “solid solutions” – NGMG alloys. Based upon this bottom-up approach, immiscible FeSc and CuSc NGMGs are intermixed at the nanoscale. The produced NGMG alloys show tunable ferromagnetic properties with changing the nanoglass component of FeSc. Conclusions We synthesized different NGMGs in a variety of glass-forming alloy systems to obtain specific functionalities. Owing to the combination of the glassy nature and nanostructure, they show very unique and tunable properties. Our experimental testing of these NGMG alloys provides a novel material design concept to create new structures for modifying the properties. Keywords: nanogranular metallic glass, ferromagnetism, nanostructure G-09 Study of Zr52Cu35Al8Co2Nb3 bulk metallic glass composites with peculiar B2 CuZr phases H.Y. Lu, Z.W. Zhu, Z.K. Li, H.M. Fu, H. Li, A.M. Wang, H.W. Zhang, H.F. Zhang* Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China Limited glass forming ability (GFA) and unstable B2 CuZr phases in (Cu0.5Zr0.5)100-xAlx system restrict the sample size of the bulk metallic glass composites (BMGCs). In this work, a newly developed metallic glass composite with the composition of Zr52Cu35Co2Nb3Al8 (denotes as Z35238) with high GFA and peculiar B2 CuZr phases is

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investigated systematically. The microstructure and distribution of B2 CuZr are characterized by scanning electron microscope and optical microscope. Particularly, a conic as-cast sample is prepared to explore the correlation between the precipitation of the CuZr phases and cooling rate by observing its longitudinal section. Compressive tests indicate that B2 CuZr shows higher strength than the glassy matrix, which accounts for the result that the BMGC exhibits higher strength than BMG. In addition, the B2 CuZr phases precipitate steadily over a large range of cooling rates without martensitic transformation or decomposition. As a result, such peculiar B2 CuZr phases are helpful in synthesizing larger size of BMGCs without deterioration in mechanical properties. Keywords: Bulk metallic glass composite, B2 CuZr phase, Microstructure, Mechanical properties, Conic cast sample. G-10 Improving the thermal stability, glass forming ability and ferromagnetism of bulk ferromagnetic metallic glasses by metalloids Tongde Shen, Baoru Sun, Shengwei Xin Yanshan University In most previous studies, the thermal stability and glass forming ability (GFA) of bulk ferromagnetic metallic glasses (BFMG) are often improved by modifying the content of alloying metal elements, which usually degrades the fundamental magnetic properties of BFMG. We prepared Fe-Mo-P-C, Fe-Mo-Ga-P-B-C, and Fe-(Co, Sb, Cr, Mo, Ga)-P-B-C BFMG and studied the influence of both alloying metals and metalloids on the thermal stability, GFA and fundamental magnetic properties of BFMG. We have found that tuning the thermal stability of supercooled liquid by modifying the content of alloying metalloids is more effective than by modifying the content of alloying metals. Adding 1 at% alloying metalloids and metals can increase Tx - Tg by ~ 20 K and 4 K, respectively. We have found that upon increasing the content of alloying metalloids, Tx - Tg increases and reaches a maximum where the GFA is highest. Bulk ferromagnetic glasses can only be formed by modifying the content of metalloids within a narrow range, ~ 2 to 6 at%, in our alloy systems. These phenomena can be explained by the effect of metalloids on the density of atomic packing. We have also studied the effects of alloying metals (Cr, Mo, and Ga) and metalloids (P, B, and C) on the saturation moment and Curie temperature of bulk Fe-(Cr, Mo, Ga)-(P, B, C) glasses. We have found the saturation moment and Curie temperature of our BMFG are largely degraded by alloying metals rather alloying metalloids. The degraded saturation moment can be well explained by the well-known charge-transfer model. Our experimental results suggest that optimizing the content of metalloids is a powerful tool for effectively improving the GFA and thermal stability of BFMG without degrading their fundamental magnetic properties. Keywords: bulk metallic glasses; glass forming ability; thermal stability; magnetic properties; metalloids G. Amorphous and High-entropy Alloys G-11 Stress-induced relaxation and hardening in a Zr-based bulk metallic glass under elastostatic compression Yi-Mei Wang, Meng Zhang, Lin Liu School of Materials Science and Engineering and State Key Lab for Materials Processing and Die & Mold Technology, Huazhong University of Science and Technology, 430074 Wuhan, China When a constant load is applied to a crystalline metallic material at room temperature, no permanent plastic deformation or structure change could take place if the load is below the yield strength. However, metallic glasses

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does not follow this role, in which static load, even below the yield strength, could cause significant change in structure and mechanical properties. To clarify this issue, in the present study, elastostatic compression test on Zr60.14Cu22.31Fe4.85Al9.7Ag3 bulk metallic glass (BMG) was performed at stress level of 90% of the yield strength for different holding times (24-120 hs). The structural evolution of the BMG and mechanical properties at different loading stages was then systematically examined by differential scanning calorimetry, density measurement and, instrumental nanoindentation and quasi-static compressive tests. It was found that homogeneous deformation with 0.48% plastic strain and without shear banding was achieved after holding for 120 hs. The pre-loaded BMG shows decreased relaxation enthalpy and increased hardness and density with increasing the loading times, indicating stress-induced relaxation and hardening. The phenomena are interpreted in terms of atomic level stress theory and the coalescence of negative and positive free volume in BMGs. Keywords: Bulk metallic glass; Relaxation; Elastostatic loading G-12 Fe-based Bulk Metallic Glasses: Brittle or Ductile ? Shengfeng Guo Southwest University Fe-based bulk metallic glasses (BMGs) typically exhibit ultrahigh strength but a poor ductility at room temperature. To overcome the negligible plasticity we have developed a series of Fe-based BMGs from structural and compositional design rules. I will describe our efforts in the development of Fe-based BMG composite reinforced with ductile α-Fe dendrites and monolithic Fe-based BMGs which exhibit a super large compressive plasticity. Such a discovery is guided by understanding a composition-strength-ductility map, in which most of Fe-based BMGs are classified into three types: FeC-based, FeB-based, and FeP-based. Among these, the FeP-based BMGs often possess a lower glass transition temperature, a lower shear modulus, and a higher Poisson's ratio, resulting in a lower shear flow barrier and a higher plasticity. Our findings will provide a new insight into how to prevent the brittle failure and develop the high performance of Fe-based BMGs. Keywords: Fe-based bulk metallic glass; Brittle; Ductile G-13 The multiple shear bands and plasticity in metallic glasses: an origin from stress inhomogeneity Guannan Yang1,2, yang Shao1,2, kefu Yao1,2 1. School of Material Science and Engineering, Tsinghua University, Beijing 100084, P. R. China 2. Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, P.R. China What is the origin of plasticity and multiple shear bands in the shear-softened metallic glasses? Here we present a finite element method simulation to explore this question under a conventional loading situation of uniaxial compression. The simulation successfully reproduces the multiple shear bands formation, shear-offset size and shear band intersections, and also consists with experiments. It shows that the after the former shear bands formation, the stress field would redistribute and become inhomogeneous, and thereby could trigger the formation of new shear bands. These findings indicate that the multiple shear bands in metallic glasses could originate from stress field redistribution, but not from the conventional mechanism of work-hardening induced plasticity. Such results might improve the understanding to the origin of plasticity in these shear-softened materials, and could reasonably explain that the plasticity of metallic glasses depends on both the material and loading condition.

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Keywords: metallic glass, shear band, plasticity, finite element simulation G-14 Inverse notch effect in bulk metallic glasses Jie Pan1, Haofei Zhou2, Yi Li1, Huajian Gao2 1. Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China 2. School of Engineering, Brown University, Providence, Rhode Island 02912, USA Understanding notch-related failure is crucial for the design of reliable engineering structures. However, substantial controversies exist in the literature on the notch effect in bulk metallic glasses (BMGs), and the underlying physical mechanism responsible for the apparent confusion is still poorly understood. Here we investigate the physical origin of an inverse notch effect in a Zr-based metallic glass, where the tensile strength of the material is dramatically enhanced, rather than decreased (as expected from the stress concentration point of view), by introduction of a notch. Our experiments and molecular dynamics simulations show that the seemingly anomalous inverse notch effect is in fact caused by a transition in failure mechanism from shear banding at the notch tip to cavitation and void coalescence. Based on our theoretical analysis, the transition occurs as the stress triaxiality in the notched sample exceeds a material-dependent threshold value. Our results fill the gap in the current understanding of BMG strength and failure mechanism by resolving the conflicts on notch effects and may inspire re-interpretation of previous reports on BMG fracture toughness where pre-existing notches were routinely adopted. Keywords: Bulk metallic glasses, Notch, Strength, Shear band, Cavitation G-15 Casting of Zr-based bulk metallic glass mingzhen ma, xinyu zhang, riping liu Yanshan University In the present research, Zr-based bulk metallic glass (BMG) is used to study its application on the casting and forming. Medium frequency induction melting furnace and two different molds, e.g. high purity graphite and copper molds are used to cast Zr-based metallic glass rods, triangle and ringlike casting to discuss the influence of the casting temperatures on the fluidity and mold filling capacity of the Zr-based bulk metallic glass. After then, X-ray diffraction analysis and differential scanning calorimetry are used to analyze the effect on the glass forming ability of the Zr-based BMG. The results show that the fluidity and mold filling capacity increase with the temperature and the glass forming ability is influenced by temperature Keywords: Zr-based bulk metallic glass, Cast forming, Fluidity, Casting temperature G-16 The Hardening Mechanism of BMGs upon Laser Shock Peening Kun Zhang1, G Y Xu1, Y P Wei2, K Zhang1, B C Wei1 1. Key Laboratory of Microgravity (National Microgravity Laboratory), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China 2. Key Laboratory for Mechanics in Fluid Solid Coupling Systems, Instituteof Mechanics, Chinese Academy of Sciences, Beijing 100190, China

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Bulk metallic glasses (BMGs) have drawn much attention due to their unique properties such as high strength, hardness and large elastic deformation capability. However, the applications of BMGs in structural materials are impeded by the catastrophic brittle fracture at room temperature. More recently, therefore, much work has been devoted to understanding the plastic deformation mechanism and the finding of the ductilizing techniques. Laser shock peening (LSP) has been gradually recognized as an advanced surface treatment technology with regard to several conventional methods, i.e. shot peening, and has been used for improving fatigues life, wear and corrosion resistance of commercial alloys. In this paper, Laser shock peening (LSP) is promising surface treatment technique to improve the mechanical properties of metals material through introducing a deep compressive residual stresses region. In this work, the surface feature and mechanical properties of Vit1 bulk metallic glasses (BMGs) after LSP treatment is studied. Special arc-shaped localized plastic deformation structures, with the size of 5~20 μm, are observed on the shock treated surface, which is not found in the crystalline alloys. X-ray diffraction shows that the BMGs preserve their amorphous structures. However, the surface hardness and modulus is found to increase to 17% and 21% respectively, in contrast to the superficial softening upon shot peening. The origin of the hardening of the BMGs upon LSP is discussed, which is believed to depending on the free volume concentration. Keywords: BMGs, Laser Shock Peening, free volume G-17 Tensile plasticity in monolithic bulk metallic glass with sandwiched structure Yangyang Cheng, Tao Zhang Beihang University In this work, for the first time, tensile plasticity is achieved in a millimeter-scale thick smooth specimen of Cu-Zr-Al-Co bulk metallic glass (BMG). This is derived from the sandwiched structure introduced by the laser surface melting which can lead to the evaporation of element Cu in the near-surface zone with micro-scale depth. It is found that the near-surface and the nether zones are still amorphous structures but possess different elastic moduli and mechanical properties. The present work demonstrates that the micro-scale structural heterogeneities in the monolithic BMG can effectively stabilize the shear banding behavior even under tensile loading, and may shed light on the structural application of BMGs. Keywords: Metallic glasses Laser processing Rapid-solidification Mechanical properties G-18 Concentrration Heterogeneity of Fe50Cu50 Melts and Plastic Deformation of Metallic Glass Li Wang, Yun Cheng, Zhenting Zhang, Kaikai Song, Shengzhong Yuan School of Mechanical & Electrical Information Engineering, Shandong University at Weihai, 264209, China The bulk metallic glass has aroused extensive attention due to its excellent mechanical properties, but its fragility at room temperature limits its application as structure materials. Recently, Nano-sized droplet is introduced to the glass by controlling the solidification process to fabricate phase separation bulk glass with high strength and toughness. It is due to the fact that the uniformly distributed atomic-scale heterogeneous structure obtained by phase separation can successfully enhance the overall plastic deformability through the formation of multiple branched shear band. Therefore, it is of significance to control the size, shape as well as distribution of droplet for the mechanical properties of glass. However, the characterization of LLPS and its formation mechanism have been not understood fully and verified, yet. In this paper, Molecular dynamics simulation has been performed to

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characterize the liquid-liquid phase separation (LLPS) of Fe50Cu50 melts. It separates into Fe-rich and Cu-rich liquid upon relaxation through the gap controlled by spinodal decomposition mechanism. The LLPS undergoes the formation of interconnected structure and its coarsening; the formation of droplet and its migration and coagulation by potential energy minimization. During the LLPS process, the Fe (Cu) content in Fe (Cu) -rich region increases quickly, the lower temperature implies the higher diffusion rate because of the larger potential energy difference between Cu-rich region and Fe-rich region. Fe atom is more active to move to the Fe-rich region due to energy minimization, therefore, Cu atom around Fe atoms are pushed out to the Cu-rich region. The concentration almost does not vary after up-hill diffusion. Compared to the up-hill diffusion, longer time will be spent on migration of droplet. The composition difference in Fe-rich region and Cu-rich region becomes larger and larger with decreasing temperature. The driving force of LLPS comes from the decreasing of potential energy, although it is inhomogeneous in the separated liquid. The studies above characterize concentration and energy heterogeneity of phase separated liquid on the atomic scale. Unlike crystalline metals, the plastic deformation of metallic glasses (MGs) involves a competition between disordering and structural relaxation ordering, which is not well understood, yet. Molecular dynamics (MD) simulations were performed to investigate the evolutions of strain localizations, the free volume in the glass during compressive deformation of Fe50Cu50 MGs with different degrees of phase separation. Our findings indicate that the free volume in the phase separating MGs decreases while the shear strain localizations increase with increasing degree of phase separation. Cu atoms show higher potential energies and Voronoi volumes, and bear larger local shear strains. The present study could provide a better understanding of the relationship between the structural inhomogeneity and the deformation of MGs. Keywords: Undercooled Fe50Cu50 melts; Concentration fluctuation; Up-hill diffusion; Plastic deformation; Voronoi volume; Molecular dynamics G-19 Toughening Fe-based Amorphous Coatings by amorphous carbon Wei Wang, Cheng Zhang, Peng Xu, Yasir Mohammed, Lin Liu Huazhong University of Science and Technology Owing to poor toughness, the Fe-based amorphous coatings are limited for practical applications. To overcome this drawback, we designed an amorphous composite coating reinforced with 10 vol % nylon-11 powders by high velocity oxy-fuel (HVOF) thermal spray. The nylon-11 powders could be carbonized to be amorphous carbon during thermal spray, which homogeneously distributed in the amorphous matrix and could enhance the toughness of the coating. The microstructure of the composite coating was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The mechanical properties, such as hardness, impact resistance, bending and fatigue behavior, were studied by micro-indentation, drop-weight impacting and static/dynamic three-point bending tests. The results revealed that the composite coating exhibits better impact resistance and higher fatigue strength due to that the amorphous carbon phase, as a second soft phase, can restrain the crack propagation and enhance the toughness of the coating. Keywords: HVOF; Fe-based amorphous coating; impact resistance; toughness; fatigue G-20 Structure- and temperature-dependent mechanical properties of monolayer CuTa alloys and CuTa/Cu nanolaminates Chao Gu1, Fei Wang2, Ping Huang1, Kewei Xu1, Tianjian Lu2,3

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1. State-Key Laboratory for Mechanical Behavior of Material, Xi’an Jiaotong University, Xi’an, 710049, China 2. State Key Laboratory for Strength and Vibration of Mechanical Structures Xi'an Jiaotong University, Xi’an, 710049, China 3. MOE Key Laboratory for Multifunctional Materials and Structures Xi’an Jiaotong University, Xi’an 710049, China In previous studies, the amorphous/nanocrystalline nanolaminate structures were designed to improve the mechanical properties of amorphous metal alloys. While tremendous efforts had been focused on the size effect of these nanolaminate structures, the structure- and temperature-dependent mechanical properties had received little attention. In the present study, monolayer CuTa alloys with different Ta contents, i.e., 11 at%, 27 at%, 34 at%, 37 at% and 42 at%, were prepared by means of magnetron sputtering technique. In addition, for all Cu1-xTax alloys, by alternately depositing a 138 nm Cu1-xTax and a 12 nm Cu layers, Cu1-xTax/Cu nanolaminates with the same total thickness as monolayer CuTa were also prepared. All samples were then annealed at 100℃, 200℃ and 300℃ for an hour in vacuum annealing furnace. The transmission electron microscope (TEM) results showed that the microstructures of CuTa alloys transformed from nanocrystalline to amorphous phase while increasing the Ta content. The structure-dependent, including crystalline structure and interface structure, and temperature-dependent mechanical properties of monolayer CuTa and CuTa/Cu nanolaminates were systematically studied. Nanoindentation tests were performed to study the hardness of all samples. The results indicated that for as-deposited monolayer CuTa and CuTa/Cu nanolaminates, the hardness was increased with increasing Ta content, till to 37 at%, and then decreased with further increasing the Ta content. The cross-sectional HRTEM images indicated that the mechanical properties of CuTa/Cu nanolaminates were strongly affected by the interface structure. After annealing treatment at 100℃, for monolayer CuTa, the hardness of all samples was decreased compared with their as-deposited counterparts except for CuTa37at.%. The structure of amorphous phase with nanoparticles was considered to be the major reason for the annealing strengthening effect for CuTa37at.%. For CuTa/Cu nanolaminates, the strengthening effect occurred when the Ta content was lower than 27 at%, while the softening effect occurred when the Ta content was higher than 27 at%. The different variation trends of annealing hardness for monolayer CuTa and CuTa/Cu nanolaminates indicated that the Cu layers could strongly affect the thermo stability of CuTa alloys with either crystalline or amorphous phase. In order to further study the effect of Cu layer on the thermo stability and deformation behavior of CuTa alloys at higher temperatures, the surface morphologies and fracture appearance after bending test under three-point loading of monolayer CuTa and CuTa/Cu nanolaminates after annealing at 200℃ and 300℃ were further investigated through scanning electron microscope (SEM). Precipitates were observed on all samples and the density of the precipitates was found to be increased with increasing Ta content, which indicated that the amorphous CuTa had the much worse thermo stability. While the annealing temperature was 200℃, the density of precipitates for monolayer CuTa and CuTa nanolaminates was nearly the same. However, the density of precipitates for CuTa nanolaminates became larger than that for monolayer CuTa when the annealing temperature was increased to 300℃. The fracture appearance showed that the ductile fracture surface was replaced by brittle fracture surface when the temperature increased from 200℃ to 300℃. The results indicated that Cu atoms would diffuse into CuTa layer in a higher temperature and the integrity of the nanolaminte structure would be destroyed. As a result, the effect of Cu layer on the deformation behavior and mechanical properties of CuTa alloys would be minimized. By combining the hardness and TEM results, the underlying deformation mechanisms were discussed. Keywords: CuTa alloy; amorphous; nanolaminate; annealing; interface G-21

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Tribological behaviors of Zr-based bulk metallic glass sliding on different counterparts under relatively heavy loads Hua Zhong, Yun Yue, Mingzhen Ma, Xinyu Zhang, Riping Liu State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, P.R. China As a novel engineering material, Zr-based bulk metallic glasses (BMGs), especially Zr41Ti14Cu12.5Ni10Be22.5, are widely used as mechanical components due to their simple preparation process and excellent combined properties. In the present study, Zr41Ti14Cu12.5Ni10Be22.5 pins and discs are prepared by copper-mold suction casting. X-ray diffractometer, differential scanning calorimeter are respectively used to analyze the structure and thermal stability of the Zr-based BMG. The tribological properties of Zr-based BMG pins and different counterpart materials (AISI 5120 steel, AISI 52100 steel and Zr41Ti14Cu12.5Ni10Be22.5 amorphous discs) are investigated using a pin-on-disc tribological configuration in the ambient under relatively heavy loads varied from 100 to 150 N. Coefficient of friction is in the range from 0.15 to 0.30 and is found to depend significantly on the counterpart material. Wear weight loss of crystalline material disc is lower than that of the pins, whereas the opposite result is obtained when the Zr-based BMG is used as the counterpart material. Scanning electron microscopy is used to observe the wear track of the worn surface to determine the wear mechanism after sliding on different counterparts. The results show that Zr-based BMG pins included grooves, micro-cracks, peeling-off and vicious flow when it slid against crystallization material. However, rough detached damages and wave-like patterns were found on the BMG pins when amorphous discs were used as the counterpart. Meanwhile, there also existed differences of wear mechanisms between the crystallization material and amorphous discs. Keywords: Zr-based bulk metallic glass; Different counterpart materials; Wear Loss; Wear mechanisms G-22 Structural signatures evidenced in dynamic crossover phenomena in metallic glass-forming liquids Maozhi Li Department of Physics, Renmin University of China, Beijing 100872, China Molecular dynamics simulations were performed to investigate dynamic evolution in metallic glass-forming liquids during quenching from high temperature above melting point down to supercooled region. Two crossover temperatures TA and TS (TA>TS) are identified and their physical meanings are clarified. TA and TS are found to be not only the sign of dynamic crossover phenomena, but also the manifestation of two key structure correlation lengths. As temperature decreases below TA, structure correlation length goes beyond the nearest-neighbor distance, resulting in the Arrhenius-to-non-Arrhenius transition of structural relaxation time and the failure of Stokes-Einstein (SE) relation. As TS is traversed, the increase rate of the structure correlation length reaches the maximum, leading to the simultaneous appearance of dynamical heterogeneity and fractional SE relation. It is further found that structure correlation increases much faster than dynamic correlation, playing a role of structural precursor for dynamic evolution in liquids. Thus, a universal structural link is established for deeper understanding dynamic crossover phenomena. Keywords: metallic glass-forming liquids, dynamic crossover, structure correlation length, molecular dynamics simulation G-23

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A sliding cell technique for diffusion measurements in liquid metals and its first applications in Al- and Ce-based liquids Bo Zhang Hefei University of Technology Atomic diffusion is fundamentally involved with the mass transport process in phase transitions. Particularly, in liquid metals, diffusion data is basically required for modeling and describing the solidification process thus scientifically and technically important for research and applications. In the past about 50 years, long capillary and shear cell method have been the most widely used methods for diffusion measurements in liquid metals. For the conventional long capillary method, it has obvious disadvantages. In the heating processes, the long capillary method cannot avoid the additional diffusion happened there. Also, in the cooling process, this method cannot remove the additional diffusion and subsequent solidification effect either. The shear cell method has better accuracies but with higher cost and difficulties of manufacturing and handling. In this work, we report a new "sliding cell" technique for diffusion measurements for liquid metals [1-3]. The present method has combined merits of the conventional long capillary and shear cell methods. By using the sliding movement and design, it can easily control the starting point of the isothermal diffusion process thus has ruled out the heating effect as existed in the conventional long capillary method. We also demonstrated that by using diffusion time dependent experiments the present sliding cell method in principle can provide reliable diffusion data if the measuring conditions like temperature gradients and other disturbances are well controlled. By using this technique, first results in Al-Cu [1, 4] and Ce-Cu [5] binary liquids are measured. For the Al-Cu liquids, the measured diffusion data shows good agreement with previous data measured by in-situ X-ray radiography method [6], which indicating the success of the sliding cell method. In the measured Al-based and Ce-based binary liquids, the measured data are also compared with self-diffusion data measured by quasi-elastic neutron scattering and the relation between the present interdiffusion data and the self-diffusion data is also discussed within the frame of the famous Darken equation [4-5]. These results indicate that the newly developed sliding cell method has obvious merit for diffusion measurements in liquid metals, which shows potentials for further uses in other alloys like multicomponent metallic glasses and high entropy alloys. [1] Yongliang Geng, Chunao Zhu, and Bo Zhang, A sliding cell method for diffusion measurements in liquid metals, AIP advances 4, 037102, 2014. [2] Bo Zhang, Yongliang Geng, and Chunao Zhu,An instrument for diffusion measurements in liquid metals, China Patent, ZL201210105060.0. [3] Bo Zhang, Yongliang Geng, and Chunao Zhu, A method for preparing samples of diffusion measurements in liquid metals, China Patent, ZL201210105224.X. [4] Yongliang Geng, Chunao Zhu, and Bo Zhang, A new sliding cell technique for diffusion coefficient measurements in liquid Al-Cu alloys, SCIENTIA SINICA Physica, Mechanica & Astronomica 44, 728-736, 2014. [5] Wan Bo, Hu JinLiang, Zhong LangXiang, and Zhang Bo, The self-diffusion and inter-diffusion in liquid Ce80Cu20, SCIENTIA SINICA Physica, Mechanica & Astronomica 45, 056101, 2015. [6] Zhang B, Griesche A, Meyer A. Diffusion in Al-Cu melts studied by Time-Resolved X-Ray Radiography. Phys.Rev.Lett., 104, 035902, 2010. Keywords: diffusion measurements, liquid metals, sliding cell technique G-24 Unique thermal-driven glass-glass transitions in metallic glasses

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Xiongjun Liu1, Qing Du1, Qiaoshi Zeng2, Huiyang Fan1, Hui Wang1, Yuan Wu1, Zhaoping Lu1 1. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China 2. Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China Analogous to the well-known polymorphism in crystalline materials, the polyamorphic transition in glassy matters is also a ubiquitous and intriguing phenomenon in the natural world, such as the glassy water (amorphous ice) can exit in two distinct forms: low- and high-density amorphous ices, under different pressures. Recently, pressure-induced glass-glass transitions (GGTs) have also been observed in some lanthanide-based and Ca-Al metallic glasses, where the GGT seems impossible due to their densely-packed atomic structures. In this talk, we will report a non-pressure-induced GGT in a metallic glass. In particular, the following information will be delivered: (1) a unique thermal-induced GGT under ambient pressure condition is discovered in a Pd-based metallic glass, which has never been reported in the literature; (2) the in-situ synchrotron X-ray scattering observation reveals that the observed GGT is attributed to an abnormal atomic ordering process at the medium-range scale occurred within its suprcooled liquid region; (3) atomistic simulations are performed to reveal the atomic-structure origin of this unprecedented phenomenon; and (4) the composition dependence of this unique thermal-induced GGT will be discussed in detail. Keywords: Metallic Glass; Glass-Glass Transition; Synchrotron X-ray Scattering; Rerse Montel Carlo G-25 Unraveling the Crystallization Kinetics of Supercooled Liquid GeTe by Ultrafast Calorimetry Yimin Chen1,2, Junqiang Wang1, Lijian Song1, Xiang Shen2, Tiefeng Xu2 1. Ningbo Institute of Material Technology and Engineering, Chinese Academy of Science 2. Laboratory of Infrared Material and Devices, Advanced Technology Research Institute, Ningbo University A study of crystallization kinetics in supercooled liquid state for phase change materials (PCMs) would help us understand the materials’ behavior and performance, e.g., crystallization speed and data retention. Traditional calorimetry with low heating rate only cover the kinetics temperature closed to the glass-transition temperature (Tg), lacking the most important information in a high temperature range, where the kinetic coefficient for crystal growth exhibits a strongly non-Arrhenius temperature dependence. Ultrafast differential scanning calorimetry (DSC) offers a new capability to explore previously inaccessible high temperature region for crystallization kinetics due to the expanded heating rates to more than 4×104 Ks-1. Here, we first employed the ultrafast DSC to unravel the crystallization kinetics of a typical PCM, GeTe. Meanwhile, we obtained three crystal growth kinetics coefficient (Ukin) expressions that from different viscosity models. For estimating the absolute value of Ukin, we considered a constant when viscosity expressions transfer to crystallization kinetics. The results show that the MYEGA model is more suitable to describe the relationship between the viscosity and temperature for supercooled liquid GeTe, and its glass transition temperature and fragility m was calculated for 410 K and 105, respectively. The temperature dependence crystal growth rates, which are extrapolated by MYEGA model, are in good agreement with the real crystal growth rates that are estimated by TEM and SEM at given temperature. The maximum crystal growth rate was calculated for 8×10-3 ms-1 at ~840 K. These results based on ultrafast DSC with the MYEGA model not only offer an interpretation for the typical PCM GeTe, but strongly support the design for phase change memory applications. Keywords: Amorphous films, Crystallization kinetics, Ultrafast calorimetry, Supercooled liquid

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G-26 Effect of Cu doping on La0.7Sr0.3MnO3 perovskite materials using Non-destructive evaluation Thamilmaran Pandian1, Arunachalam Manikavasagam1, Sundara Venkatesh Perumalsamy1, Sankarrajan S2, Sakthipandi K3 1. Sri S. Ramasamy Naidu Memorial College 2. Department of Physics, Unnamalai Institute of Technology, Kovilpatti- 628 503, Tamil Nadu, India 3. Department of Physics, Sethu Institute of Technology, Kariapatti 626 115, Tamil Nadu, India The effect of Cu doping on the structural and magnetic transition properties of La0.7Sr0.3MnO3 was studied. The Perovskite samples of La0.7Sr0.3CuxMn-xO3 (x=0.05, 0.10 and 0.15) was prepared employing solid state reaction method. The XRD patterns have confirmed the crystalline nature and belong to rhombohedral structure. The XRD and SEM characterization reveal that the crystalline and particle size decreases as the level of Cu in the sample increases. In-situ ultrasonic measurements indicate the Te values shift towards the lower temperature region as the Cu content in the samples increases. The substitution of Cu in Mn site affects Mn3+ and Mn4+ ratio and the electron density of charge carriers. The substitution causes on additional disorder by weakening the Double Exchange Interaction and reduce the ferromagnetic phase transition temperature (Tc) 358, 341 and 328 K for the samples respectively. The increase in acoustical activation energy into increase in Cu content of the sample in confirmed by the observed decrease in ultrasonic velocity an increase in attenuation. Keywords: Perovskite, Ultrasonic velocity and attenuation, Phase Transition. G-27 Composition design procedures of Ti-based bulk metallic glasses using the cluster-plus-glue-atom model Chuang Dong, Zengrui Wang Key Laboratory of Materials Modification (Ministry of Education), Dalian University of Technology, China It is known that bulk metallic glasses are interpreted by simple composition formulas [cluster](glue atom)1 or 3, with the valence electron number per unit formula (e/u) being universally 24. In the present work, this cluster-plus-glue-atom approach was explored in great details for the objective of establishing the standard procedures towards designing bulk metallic glasses, via example of Ti-Cu-based alloys. The cluster selection from devitrification phases and the e/u calculation methods were first clarified. Then, step-by-step procedures toward developing alloys with high glass forming abilities were proposed. The cluster formula [Ti-Cu6Ti8]Cu3, with e/u ≈ 23.6, was taken as the basic composition formula. Upon properly alloying with Zr and Sn, large glass forming abilities up to 5mm in diameter were experimentally reached at Ti40Zr10Cu56.94Sn3.06 via copper mould suction casting. Another alloy Ti45.71Zr11.43Cu39.29Sn3.57 showed a slightly inferior glass forming ability of 4 mm but contained the highest Ti content of all the Ti-based BMGs, Ni-, Pd- and Be-free. The thus-obtained bulk metallic glasses generally exhibited high compressive strengths of about 1.8 GPa and nearly zero ductilities, except a Co-alloyed one, [Ti-Cu5.3Sn0.5Co0.2Ti6.2Zr1.8]Cu3, whose compressive ductility exceeded 6%. Keywords: Metallic glasses, cluster-plus-glue-atom approach, Ti-based alloys; glass forming abilities. G-28 Lightweight Ti-based bulk metallic glasses with superior thermoplastic formability Pan Gong1,2, Xinyun Wang1, Lei Deng1, Junsong Jin1, Sibo Wang1, Kefu Yao2 1. State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, Hubei, China

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2. School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China In order to extend the application scope of bulk metallic glasses (BMGs), much attention has been paid to the processing of BMGs in recent years. Taking advantage of the superplasticity in supercooled liquid region, thermoplastic forming is a particularly well adapted technique for processing BMGs as near-net-shape products on length scales ranging from nanometer-order to several centimeters. Ti-based BMGs are very attractive for engineering applications because of their outstanding properties such as high specific strength, good corrosion resistance, etc. However, the relatively poor thermoplastic formability greatly restrain the wide application of Ti-based BMGs. In this study, a series of novel lightweight Ti-based BMGs with enhanced thermoplastic formability have been developed by alloying method based on a Ti41Zr25Be34 alloy. The improvement mechanisms of thermoplastic formability induced by different alloying elements have also been systematically studied. The representative Ti41Zr25Be28Fe6 alloy exhibits a wide supercooled liquid region of ~123 K and low viscosity of ~106 Pa s in its supercooled liquid region, resulting in the best thermoplastic formability among all the developed Ti-based BMGs. Moreover, the good GFA and excellent mechanical properties of Ti41Zr25Be28Fe6 alloy also make it applicable as engineering materials. This work will greatly promote the development and application of Ti-based BMGs. Keywords: Bulk metallic glass, Titanium alloys, Thermoplastic forming, Formability G-29 Alloying effects on the viscosity of ternary glass-forming Zr-(Co,Ni)-M melts Chenchen Yuan1,2, F. Yang2, F. Kargl2, D. Holland-Moritz2, G. G. Simeoni3, A. Meyer2, B. L. Shen1 1. School of Material Science & Engineering, Southeast University, Nanjing 211189, P. R. China 2. Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 51170 Köln, Germany 3. Heinz Maier-Leibnitz Zentrum (MLZ) and Physics Department, Technische Universität München, 85748 Garching, Germany Addition of a third component to a binary metallic glass forming melt can significantly improves its glass forming ability. In some cases only a very small amount of such elements is necessarily. The underlying mechanism is so far not very well understood. Particularly, very little attention has been paid to the change of melt properties in this respect. We thus studied the microscopic mass transport and the macroscopic flow behavior of the Zr-(Co,Ni)-(Al,Pd,Ti) melt with a systematic variation of the third component. Utilizing the containerless processing technique of electrostatic levitation allows us to obtain precise data on diffusion coefficient and melt viscosity over a wide temperature range, without artifacts caused by container-melt reactions. We shows that the addition of the of Al to the binary Zr-(Co,Ni) melt leads to an increase of the melt viscosity of system accompanied by a remarkable decrease of the Co, Ni self-diffusion coefficient [1]. In contrast, upon alloying of Ti and Pd the effect of slowing-down of the liquid dynamics is much weaker. However, the average packing fraction of the Al contained melt derived from the measured macroscopic density is smaller than that of the corresponding binary alloys. This indicates that apparently such slowing down of the liquid dynamics cannot be explained a hard-sphere like model of packing, although metallic glass-forming melts in which is absent are often considered to be most closed to a hard-sphere like system [2]. Instead, the chemical interactions of Al with transition metal atoms should play an important role here, which also contribute to their improved glass-forming ability. References:

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[1] C. C. Yuan, F. Yang, F. Kargl, D. Holland-Moritz, G. G. Simeoni, and A. Meyer, Phys. Rev. B 91, 214203 (2015). [2] S. M. Chathoth, A. Meyer, M. M. Koza, and F. Juranyi, Appl. Phys. Lett., 85, 4881 (2004). Keywords: metallic glasses, liquid dynamics, packing fraction G-30 Die-imprinting of Metallic Glasses for Precise Optical Devices in Large-area Xue Liu1,2, Ke-Fu Yao1 1. School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People’s Republic of China 2. Institute of Materials, China Academy of Engineering Physics, Mianyang 621900, People’s Republic of China Metallic glasses (MGs) exhibit excellent comprehensive performance as well as outstanding thermoplastic forming ability, making them very suitable for preparing precise optical devices. However, due to the nonuniform structure of the commonly used free-imprinting, the prepared MG optical devices are limited in small area and simple structures, which severely limit their applications.In the present work, by employing the die-imprinting method, large-area Pd40.5Ni40.5Si4.5P14.5 photonic crystals (PCs) and Ni62Pd19Si2P17 complex gratings are successfully prepared. The Pd40.5Ni40.5Si4.5P14.5 PCs are consisting of uniform rods with diameter of ~ 350 nm and height of ~ 100 nm, and exhibits a periodicity of 1.580 ± 0.002 μm. The Ni62Pd19Si2P17 gratings are consisting of units that varying from ~10 μm-50 μm. Both the Pd40.5Ni40.5Si4.5P14.5 PCs and the Ni62Pd19Si2P17 gratings exhibit excellent optical performances, and have been successfully applied as mold inserts for hot-embossing of polymethylMethacrylate (PMMA) optical devices. The die-imprinting of MGs offers an inexpensive, effective and one-step approach for producing large-area and high-quality metallic optical devices and may shed new insights on both scientific fundamentals and technological innovations in optical device area. Keywords: Metallic glasses (MGs); Die-imprinting; Optical devices; Large-area G-31 Tune the mechanical properties of Ti-based metallic glass composites by additions of nitrogen Liyuan Li, Jun Wang, Hongchao Kou, Jinshan Li State Key Laboratory of Solidification Processing, Northwestern Polytechnical University Different amounts of nitrogen from 1000 to 14000 wt. ppm were added into the Ti48Zr20Nb12Cu5Be15 bulk metallic glass composite using TiN powder. The results calculated by XRD refinement demonstrated that a significant lattice distortion occurs in the precipitated β-Ti phase caused by the addtion of nitrogen. The crystal lattice parameters of β-Ti phase dendrite which is increased with increasing the content of nitrogen (0 ppm: 0.33145 nm and 14000 ppm: 0.33290 nm). Some former searchers found that the β-Ti →α-Ti phase transformation can be easily induced by adding oxygen into the alloy. However the results of SEM and TEM can make sure that the addition of nitrogen neither induce the β-Ti →α-Ti phase transformation, nor change the microstructure of the Ti-BMG composites even the nitrogen level achieve 14000ppm. The DSC curves give the evidence that the glass transition temperatures (Tg) and the corresponding crystallization onset temperatures (Tx) were determined to be negative changes with the increase of the nitrogen contents. So the GFA of matrix does not decrease with the nitrogen levels. The compressive yield strength of Ti48Zr20Nb12Cu5Be15 bulk metallic glass composite should be significantly increased after solid solution strengthening caused by nitrogen, whereas ductility should be decreased. However the Ti48Zr20Nb12Cu5Be15 metallic glass composite still have about 10%

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ductility when the composite containing 14000 ppm nitrogen. The higher shear modulus and hardness of β-Zr phase because of the excessive solid-solution hardening effect of nitrogen may decrease the ability of β-Zr phase to arrest the shear in the glass matrix, which will decrease the ductility of Ti48Zr20Nb12Cu5Be15 metallic glass composite. But deteriorating the mechanical properties of composite attribute to the brittle tiny α-Ti crystals exist in the interface between the dendrite and matrix. Keywords: Ti-based metallic glass composites; mechanical properties; nitrogen G-32 Synthesis of TiZr-based amorphous brazing filler metals for high-strength joining of titanium alloy Lulu Sun, Shujie Pang, Ying Liu, Tao Zhang Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing, China Amorphous alloys have attracted great attentions due to their outstanding mechanical, physical and chemical properties. As an attractive application of amorphous alloys, amorphous brazing filler metals (BFMs) have been applied to the brazing of various materials. In comparison to crystalline BFMs, amorphous BFMs exhibit some significant advantages including easy fabrication into flexible ribbons which can be used in a preplaced preform with a minimal and accurate amount in the joint clearances, high purity and homogeneity in composition and structure, leading to higher joint mechanical properties. For brazing titanium alloys, BFMs should possess suitable melting and liquidus temperatures in order to avoid the mechanical property impairment of the base materials caused by phase transformation and grain coarsening. Ti-Cu-Ni and Ti-Zr-Cu-Ni system BFMs are considered to be the best choice for the brazing of titanium alloys, and these BFMs in both crystalline and amorphous states usually contain high contents of Cu and Ni （≥20 at.%） as the melting point depressants. Meanwhile, Cu and Ni are also important constituent elements for the formation of Ti-based amorphous alloys. However, high contents of Cu and Ni in BFMs lead to the formation of brittle intermetallic compounds, which is detrimental to the mechanical properties of the brazed joints. Therefore, development of novel TiZr-based amorphous BFMs with low contents of Cu and Ni for acquiring high-strength joining of titanium alloys is of great importance. In this work, a multicomponent TiZr-based amorphous BFM with low total content of Cu and Ni (12 at.%) and suitable liquidus temperature was designed and synthesized by melt spinning. The mechanism for the formation and crystallization behavior of the multicomponent amorphous BFM was investigated. By using the present TiZr-based amorphous BFM, the Ti-6Al-4V joint brazed with this amorphous BFM exhibited a Widmansttten structure consisting mainly of alpha-Ti, beta-Ti and Ti-Zr-rich phase whereas a small amount of brittle intermetallics, thus considerably improved joint shear strength up to 460±7 MPa was achieved. It was also confirmed that the titanium alloy joint strength can be enhanced by decreasing the Cu and Ni contents of in amorphous BFMs that lead to reducing brittle intermetallics in the joint. It is suggested that multicomponent composition design of amorphous alloys would be an effective approach for tailoring novel BFMs satisfying various composition and property requirements. Keywords: Amorphous material, Brazing, Titanium alloy, Microstructure, Mechanical property G-33 Cluster plus glue atom model and Fe-based multi-component transition metal metalloid bulk metallic glasses Gul Jabeen Naz, Cuang Dong Key Laboratory of Materials Modification (Ministry of Education),

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Dalian University of Technology, Dalian 116024, China It is known that bulk metallic glasses follow simple composition formulas [cluster](glue atoms) within the framework of the cluster-plus-glue-atom model. In this model, an amorphous structure of high stability (or high glass forming ability) is dissociated into a characteristic first-neighbor polyhedron cluster plus one or three glue atoms located between the clusters, and the total number of valence electrons per unit cluster formula (e/u) is close to 24. The present work is devoted to understanding the composition rule of Fe-Based multi-component transition metal-metalloid bulk metallic glasses using the cluster formula approach. After a comprehensive survey of typical bulk metallic glasses based on binary systems Fe-(B,P,C), only three devitrification phases are identified, from which three principal clusters are obtained, respectively octahedral antiprism [B-B2Fe8] from devitrification phase BFe2, capped trigonal prism [P-Fe9] from Fe3P, and capped trigonal prism [C-Fe9] from CFe3. Then these cluster formulas matched with one or three glue atoms, so that the total number of valence electrons per unit cluster is close to 24. So the relevant eutectic points FeB FeP, and FeC are interpreted using the cluster formula i.e. [B-B2Fe8]Fe, [P-Fe9] P2Fe and [C-Fe9]C2Fe. G-34 Strengthening Mechanism of TiZrNbHfX High Entropy Alloys Xidong Hui, Yidong Wu, Ziyuan Rao, Yandong Wang University of Science and Technology Beijing TiZrNbHfX high-entropy alloys (HEAs) with body centered cubic structure were designed and prepared by copper mold casting technology. The phase composition and stability of these HEAs were characterized by using X-ray diffraction, scanning electron microscopy and transmission electron microscopy, etc. The mechanical properties of the as-cast and homogenized HEAs were measured and evaluated comprehensively at room and elevated temperature. Based on atomic size difference, mixing enthalpy and valence electron parameters, the phase selection and the solid solution hardening effect of these HEAs were investigated. The solid solution and precipitation strengthening mechanism for these HEAs was discussed in detail by using TEM and 3D atomic prober technology. Keywords: TiZrNbHfX, High-entropy alloys, Phase, Mechanical Properties, Strengthening mechanism G-35 Design of Refractory High-Entropy Alloys J.W. Qiao1a Laboratory of Applied Physics and Mechanics of Advanced Materials, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China Refractory high-entropy alloys hold the potential for high-temperature applications beyond the capability of the-state-of-the-art Ni-based superalloys, and thus it is important to study their solid solution formation and mechanical properties. In this work, designed by CALPHAD method, a series of refractory HEAs with single body-centered cubic structure were prepared via arc-melting. They have high hardness and strength. The mechanical properties of the alloys are estimated using a simple model of solid solution strengthening, and reasonable agreement between modeling prediction and experiments is obtained.

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Keywords: high-entropy alloy; mechanical properties; solid solution strengthening; CALPHAD; refractory; single-phase; body-centered cubic G-36 Designing of BCC high-entropy alloys strengthened by cuboidal B2 nanoprecipitates via a cluster structural model Qing Wang1, Yue Ma1, Xiaona Li1, Chuang Dong1, Peter K. Liaw2 1. Dalian University of Technology 2. University Of Tennessee High-entropy alloys (HEAs), also called multi-principal-element solid solution alloys, generally exhibit high-temperature structural stabilities and excellent properties. Similar to the traditional solid solutions, the stabilities and properties of HEAs were also determined largely by chemical short-range interactions between elements. In recent years, we have developed a structural model, i.e., the cluster-plus-glue-atom model, for the description of chemical short-range orders in solid solution alloys. Thereof, the composition and structure characteristics of HEAs in Al-TM (TM: transition metals) systems were investigated using this new alloy design approach, where Al is regarded as the main solute that interacts with the TM multiple elements as a whole element M. The relevant cluster-based local structural units and composition formulas were then extracted, from which one of the cluster formula of [Al-M14]Al1 is issued for BCC HEAs. Here, the [Al-M14] cluster is centered by Al, surrounded by fourteen average atoms M = Co1/5Cr1/5Fe2/5Ni1/5, and glued with one Al atom. The excellent mechanical properties of this HEA are attributed to a superalloy-like microstructure, characterized by cuboidal B2 nanoprecipitates coherently embedded in the BCC matrix. Keywords:high-entropy alloys; alloy design; cluster structrual model; coherent precipitation; mechanical properties G-37 Improving ductile properties of high entropy alloys by optimizing GB mechanical properties through element alloying zhidong han, kefu yao Tsinghua University High entropy alloys (HEAs) which containing five or more components in equimolar or near-equimolar ratios, have been considered as a new class of advanced materials in recent years. Due to a combination of high entropy, lattice distortion, sluggish diffusion and Cocktail effects, HEAs hold promises for a variety of applications, such as high strength alloys, corrosion resistant alloys, wear resistant alloys, and diffusion barriers. However, most of the high entropy alloys are brittle, which limited their applications. For instance, NbMoTaW and VNbMoTaW alloys show superior mechanical properties at elevated temperatures, but they are brittle at room temperature with very limited compressive plasticity (~ 2%). Alloying is proved to be an effective method to improve mechanical properties of alloys, and it can be used to enhance the ductile of NbMoTaW and VNbMoTaW alloys. By evaluate the mixture enthalpy, melt temperature, atomic radius and other physical properties, it was expected that alloying with Ti element would improve the grain boundary mechanical properties of the NbMoTaW and VNbMoTaW alloys. The TiNbMoTaW and TiVNbMoTaW alloys were produced in present work and the effect of Ti additions on their structural stability and mechanical properties were investigated at both room temperature and elevated temperature.

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Both of them exhibit single body-centered cubic (BCC) crystal structures, which remain stable even after annealing at 1000 oC for 10 h. In comparison with the mechanical properties of the NbMoTaW and VNbMoTaW alloys, Ti additions are beneficial in enhancing both the strength and the compressive ductility at room-temperature. The room-temperature yield strength values of the TiNbMoTaW and TiVNbMoTaW alloys are as high as ~1343 and ~1515 MPa, respectively. In addition, their compressive plasticities are significantly enhanced to be larger than 10% at room temperature compared with the limited compressive plasticity of ~2% for the NbMoTaW and VNbMoTaW alloys. In particular, they also show very promising high temperature mechanical performance. During deformation at 1200 oC, their yield strength values are as high as ~586 and ~659 MPa, respectively. The combination of high strength and good ductility at elevated temperatures enables the present refractory high entropy alloys to be used as high temperature structure materials for engineering applications. Keywords:high entropy alloy; microstructure; phase stability; mechanical property G-38 Microstructure, mechanical properties and corrosion resistance of CuZrY/Al, Ti, Hf series high-entropy alloys Zitang Zhang, Yan Wang University of Jinan A series of high-entropy alloys (HEAs) CuYZrTiHf (Z1), CuYZrAlHf (Z2) and CuYZrAlTi (Z3) were prepared. The research objectives of these HEAs are pursued: (1) to investigate the microstructural features for HEA consisting of elements traditionally used in the metallic glass; (2) to study whether the main elements with hcp structure are beneficial to form hcp solid solution phase. All the tested HEAs were prepared by arc melting. All these HEAs mainly consist of hexagonal close-packed (hcp) dendrites and CuY-type body-centered cubic (bcc) interdendrite phases. The result affirmed that principal elements with hcp structure and suitable atomic size are beneficial to the formation of hcp dendrites. Specially, small content of amorphous phase appears in Z3 HEA, which is related to the increased melt viscosity and principal elements used for preparing bulk metallic glasses. The compressive strength and plastic strain of Z1 are 1340 MPa and 13.2%, indicating a plastic fracture. Z2 and Z3 HEAs have higher Vickers hardness and compressive strength but the plasticity is severely depressed. The electrochemical corrosion measurements in the seawater solution were carried on. Z1 and Z2 HEAs possess better corrosion resistance and Z3 has a higher pitting resistance. According to the observation of corrosion morphologies, the interdendritic region containing CuY-type phase is feasible to preferential corrosion. Keywords:High-entropy alloys; Hexagonal close-packed phase; Amorphous phase; Mechanical properties; Corrosion resistance. G-39 Microstructure characterization and excellent properties of CoCrFiNiM(M= Cu, W, W0.5Mo0.5, WC) high-entropy alloy coatings prepared by mechanical alloying and vacuum hot consolidation Yan Wang, Caiyun Shang, Wenjuan Ge Jinan University In the present study, the several high entropy alloy coatings (HEACs) with excellent mechanical properties and corrosion resistance in the seawater solution have been prepared by mechanical alloying (MA) and vacuum hot pressing sintering (VHPS) technique. We studied the microstructural evolution of the as-milled CoCrFeNi and

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CoCrFeNiM (M= Cu, W, W0.5Mo0.5, WC) HEACs HEA powders. It presents that the milling products of W and W0.5Mo0.5 additions induce the formation of FCC and BCC solid solutions, however, only single FCC phases appear for the other tested specimens. The bounding between coating and Q235 steel substrate is of a good combination and presents a uniform distribution of principle elements after VHPS technique. The VHPS-ed HEACs are about 800 μm in thickness, and consist of a single FCC phase (CoCrFeNi and CoCrFeNi), two FCC phases with a few CoCr and NiW intermetallics (CoCrFeNiW and CoCrFeNiW0.5Mo0.5), and FCC phase with WC (CoCrFeNi+WC). The microhardness values of CoCrFeNi HEACs with W and W0.5Mo0.5 additions reach more than 650 and 700 HV, which are about 44 and 56% higher than that free additions, respectively. Compared with Q235 substrate, it even displays good wear resistance for all the tested HEACs under the same conditions, and CoCrFeNiW HEAC possesses the best wear resistance. However, the CoCrFeNi HEAC shows the enhanced corrosion resistance greatly in the seawater solution, indicated by the lower corrosion current and wider passive region. Keywords:High entropy alloy coating; Mechanical alloying; Vacuum hot pressing sintering; Microhardness; Wear resistance; Corrosion resistance G-40 Aging behavior of AlCrMoTiZr high-entropy alloy prepared by powder metallurgy Bo Ren1,2, Ruifeng Zhao1 1. Henan Institute of Engineering 2. Zhengzhou University A high-entropy alloy, AlCrMoTiZr, was synthesized using a well-developed powder metallurgy process. The alloy ingot was heat treated for 12 h at 700–1000 °C to investigate the effects of aging treatment on the microstructure and hardness of the high-entropy alloy. The as-cast alloy exhibited a mixture of the dendrite (Cr, Mo)-rich with a body-centered cubic (BCC) phase and the inter-dendrite (Al, Zr)-rich with a hexagonal close-packed phase. The aged alloy showed a peak hardness of 656 HV at 800 °C and then softened after annealing at 900 °C. Age hardening of the alloy was mainly attributed to precipitation strengthening at 800 °C. Formation of ZrO2 and decomposed BCC phase were the main reasons for the softening. Keywords:High entropy alloy; Microstructure; Age hardening; Powder metallurgy process G-41 Effect of thermomechanical processing on microstructure and mechanical properties of CoCrFeNiMn high entropy alloy Jianxin Fu, liangming peng CAS Key Laboratory for Mechanical Behavior and Design of Materials, Department of Modern Mechanics, School of Engineering Science, University of Science and Technology of China, Hefei 230026, PR China Objective: The thermomechanical processing including homogenization, cold-rolling and subsequent recrystallization on CoCrFeNiMn high entropy alloy was carried out to investigate its microstructural evolution and mechanical properties. Methods: The equiatomic CoCrFeNiMn alloy was produced by vacuum induction melting in argon atmosphere and cast into a rectangular steel mold with a dimension of 120 ×65 ×10 mm3. The drop cast ingots were homogenized at 1100 ℃ for 24 h in vacuum followed by furnace cooling, and then cold rolled with different reduction in thickness as 20 %, 30 % and 40 %. The rolled sheets were recrystallized at 900 ℃ and 1000 ℃ for

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1 h, respectively. Flat dog bone specimens with a gauge length of 25 mm and a cross section of 5.6 ×1.5 mm2 were machined from the recrystallized sheets and then mechanically ground to remove surface asperities. Tensile tests were conducted on a CSS-3905 multi-functional testing machine between room temperature (RT) and 800 ℃ at a strain rate of 3 ×10-4 s-1. The microstructural observation was performed using optical microscope (OM) and the phase constitution was identied by X-ray diffraction (XRD) with Cu-Ka radiation. Results: The cast alloy exhibited typical dendrite and interdendrite microstructures. The dense shear band structures in the cold rolled alloy were changed into homogeneous equiaxed grain with several annealing twins after recrystallized treatment. All of the alloys in different states showed a single face-centered cubic (fcc) crystal structure. Both the rolling ratio and recrystallization temperature exerted prominent effects on the average grain size, varying in a wide range between 25 and 100 μm. For the alloys recrystallized at 900 ℃, higher rolling ratio yielded much more refined grain, resulting in higher ultimate strength and yield strength. The alloy with the rolling ratio of 40% (grain size～25μm) showed the highest ductility at elevated temperature. Unexpectedly, for the coarse-grained alloys, both the ductility and work hardening effect were gradually deteriorated with increasing temperature. The deterioration may be related to the serrations observed in the engineering stress-strain curves. Conclusion: Adequate thermomechanical treatment including rolling and recrystallization can produce refined microstructure in CoCrFeNiMn alloy, and thus improved the ultimate strength and yield strength. The alloy showed an abnormal ductility－temperature variation as its ductility decreased with increasing temperature, which might be attributed to the serrated flow behavior as observed in the intermediate temperature. Keywords:high entropy alloy, thermomechanical processing, microstructure, mechanical properties G-42 Strong grain-size effect on deformation twinning of an Al0.1CoCrFeNi high-entropy alloy S. W. Wu, G. Wang Shanghai University An Al0.1CoCrFeNi high-entropy alloy (HEA) is produced by arc melting, mold casting, cold rolling, and homogenization. A homogeneous face-cater-cubic single structure solid solution in the as-cast and the recrystallized states are investigated. The as-cast and the recrystallized HEAs with mean grain sizes of ~ 114.9 ± 26.2 μm and ~ 7.9 ± 0.2 μm, respectively, are tension tested. The strain-hardening behaviors of these two HEAs are studied. It finds that both the as-cast and recrystallized HEAs exhibit high ductility and strong strain-hardening behavior. The fractured substructures reveal that deformation twinning is the main mechanism dominating the plastic deformation of two HEAs, which contributes much to of the outstanding mechanical performances. However, the as-cast HEA shows a higher ductility for increasing the strain-hardening rate with increasing strain in the range from 0.06 to 0.14. The recrystallized HEA reduces the decreasing rate of the strain-hardening rate. With decreasing the grain size, twin spacing increases, and twin thickness decreases, which, thus, results in a low twinning activity. The twinning activity of the recrystallized HEA is strongly inhibited by grain refinement, which, hence, degrades the promotion of twinning on the strain-hardening ability and the tensile ductility. Keywords:High-entropy alloys; Mechanical properties; Deformation twinning; Strain hardening; Grain refinement G-43 Liquid-Phase Separation in Undercooled CoCrCuFeNi High Entropy Alloy Tong Guo, Jinshan Li, Jun Wang, Yi Wang, Hongchao Kou, Sizhe Niu

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State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an, Shaanxi, 710072, P. R. China Liquid-phase separation in a CoCrCuFeNi high entropy alloy is evidenced by supercooling method. The CoCrCuFeNi high entropy alloy is supercooled by glass fluxing method with a sample mass about 100 g which allows tensile test at different undercoolings. The microstructure evolution of CoCrCuFeNi high entropy alloy solidified at different undercoolings are investigated. The variation of interdenritic Cu-rich phase and the hardness of the dendrites are described in detail and liquid-phase separation is confirmed to have taken place when undercooling is equal or greater than 100 K. The plastisity and elastic modulus during tensile tests are strongly affected by liquid- phase separation. The samples solidified after liquid-phase sepration exhibit much higher plasticity and lower elastic modulus. Keywords: High entropy alloy; Liquid-phase separation; Microstructure evolution; Critical undercooling G-44 Phase transform kinetics and the evolution of microstructure in Al0.5CoCrFeNi high entropy alloy Sizhe Niu Northwestern Polytechnical University The phase transformation of Al0.5CoCrFeNi high entropy alloy was investigated by non-isothermal dilatometry, which demonstrated that three phase transitions occurred in the process of heating. The phase transition temperature is 384 oC, 533 oC and 769 oC under the heating rate of 3 oC /min, respectively. The kinetics of FCC→BCC transformation at 769 oC of Al0.5CoCrFeNi high entropy alloy has been analyzed and the mechanism of nucleation and growth has been studied by the non-isothermal local Avrami exponent. Both the local Avrami exponent and the local activation energy during the phase transformation process change significantly with the transformed volume fraction, indicating that the phase transformation mechanism in this alloy varies at different stages. The local Avrami exponent lies between 2 and 3 in transformed volume fraction range of 0.03–0.37, indicating that the mechanism of BCC phase transformation in this stage is two-dimensional growth with the decrease of nucleation. When the local Avrami exponent lies between 1 and 2, the corresponding transformed volume fraction is in the range of 0.37-0.77 which suggests that the mechanism of BCC phase transformation in this stage is one-dimensional growth with a near-zero nucleation rate. The evolution of microstructure during phase transformation is observed using high temperature laser confocal microscope. The type of phase transformation at 384 oC and 533 oC will be determined which involves the production of nano-scale phases and the microstructure will be characterized in detail. Keywords: high entropy alloy; thermal dilation; kinetics of phase transformation G-45 Development of High Entropy Alloys using CALPHAD approach Hai-Lin Chen, Huahai Mao, Shan Jin, Qing Chen, Johan Bratberg Thermo-Calc Software AB Objective: High entropy alloys (HEA) offer an interesting combination of high strength, good structural stability, low thermal conductivity, excellent oxidation resistance, and thus attract increasing interest in both research and structural applications. The CALPHAD (CALculation of PHAse Diagram) approach, which has been widely employed in alloy development and research, is the most promising method for exploring potential high entropy

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alloys. However, high entropy alloys are different from conventional alloys in that they do not have a base element and also tend to form relatively simple phase constitution. Hence, the development of a reliable multicomponent thermodynamic database for high entropy alloys faces new challenges that do not exist in conventional alloy databases. We rise to the challenges and aim to develop a reliable thermodynamic database for high entropy alloys. Methods: The CALPHAD methodology where Gibbs free energy of each phase in a multicomponent system is modeled hierarchically from lower-order systems and the model parameters are optimized by considering both ab-initio and various experimental data is adopted for the development of the database. A hybrid approach of experiments, first-principal calculations and CALPHAD modelling has been used to obtain reliable thermodynamic descriptions of the BCC_A2 and FCC_A1 solid solutions. Results: The thermodynamic database, TCHEA1, has been developed within a framework of 15-element. It consists of 105 binaries and 200 ternaries and contains nearly all the stable solutions and intermetallic compounds in each of the assessed systems. The developed TCHEA1 database can be used to guide the search for new high entropy alloys, i.e., identify additional principal elements or specific combinations of elements that are most likely to form a single solid solution, evaluate the stability competition among phases, and predict phase fractions and phase compositions. It can also be used to calculate oxide formation for alloy corrosion resistance, study equilibrium and non-equilibrium solidification, segregation during solidification, and more. Conclusions: Selected application examples of using the TCHEA1 database for high entropy alloys design and development are demonstrated. Good agreement between experiments and calculations is obtained. Keywords: High entropy alloys, Thermodynamic, CALPHAD G-46 A research on the glass-forming ability of Fe-based bulk amorphous alloys with high-iron content Ke-Fu Yao, Shuang-Qin Chen, Jing-Feng Li, Yang Shao Tsinghua University Iron based amorphous alloys (AAs) or metallic glasses (MGs) possess not only superior mechanical and anti-corrosion properties but also excellent soft magnetic property, which have attracted lots of attentions both from researchers and engineers. But it is very difficult to prepare Fe-based AAs with large glass-forming ability, especially for those with high iron conten t, despite of that high Fe content is very important for the alloy possessing high saturation magnetization. As a result only few Fe-based bulk amorphous alloys (BAAs) with Fe content close to 80 at% have been reported up to date. Then developing Fe-based BAAs with high Fe content and good soft magnetic property is meaningful. Recently, the effects of alloying elements and processing techniques on the glass-forming ability and the magnetic property of the high Fe content alloys have been studied in our group. It shows suitable alloying and/or melt purification could significantly enhance the glass-forming ability of the high Fe content alloys. The Fe-based bulk amorphous alloys with the Fe content (or total magnetic elements content) of 80-82 at% have been successively developed. The present results indicate that it is possible to enhance the glass-forming ability of high Fe content alloys and develop high performance Fe-based BAAs. Keywords: Fe-based alloys, bulk amorphous alloys, glass-forming ability, magnetic property. G-47 Novel Fe-based nanocrystalline alloy powder cores with excellent magnetic properties produced from gas-atomized powders by cold compacting Chuntao Chang1, Yaqiang Dong1, Qiang Li2

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1. Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Science 2. School of Physics Science and Technology, Xinjiang University Magnetic powder cores are components made of ferromagnetic powder particles that initially are insulated electrically from each other by an organic and/or inorganic insulation layer at the powder surface before powder compaction process. It is widely used in a range of various choke coils, reactors in electromagnetic devices. But with the development of electromagnetic devices towards the direction of high frequency, miniaturization and light weight, the properties of traditional magnetic powder cores cannot meet the requirements of advanced applications. So, it is absolutely necessary and urgent to develop a new kind of magnetic core material with excellent soft magnetic properties. FeSiBPNbCu nanocrystalline alloy powder cores with excellent magnetic properties produced from gas-atomized powders have beensynthesized. The obtained nanocrystalline powder cores (NPCs) at optimum annealing conditions exhibit excellent magnetic properties, which including stable permeability of 90 up to 103 kHz , low core loss of 265mW/cm3 at 100 kHz for Bm=0.05 T (Pcv (0.05/100) = 265 mW/cm3) and highly DC-bias permeability (μ (H)/μ (0) = 60%) at a bias field of 100 Oe. It is considered that the excellent magnetic properties of NPCs are due to the ultrafine α-Fe (Si) obtained in amorphous matrix and the gas-atomized powders were coated uniform insulating layer in cold compaction. Keywords: Nanocrystalline powder cores; Gas atomization; Excellent magnetic properties G-48 Synthesis and properties of new soft magnetic FeCoNi(P, C, B) high-entropy bulk metallic glasses Yanhui Li, Wei Zhang, Tianlong Qi School of Materials Science and Engineering, Dalian University of Technology High entropy bulk metallic glasses (HE-BMGs), which provide a new strategy to design and synthesis BMGs, are becoming the new research frontier in materials filed. The HE-BMGs possess excellent mechanical and physical properties inherited from the advantages of both HEAs and BMGs, and show great potential for practical applications. Some of developed HE-BMGs exhibit comparable glass forming ability (GFA) and thermal stability of supercooled liquid to the traditional Zr-based BMGs. By taking the advantages of viscous flow workability in the supercooled liquid region together with the unique mechanical and physical properties, the HE-BMGs are hopeful to be utilized for making micro- and nanodevices in MEMS/NEMS. However, the developed HE-BMGs with large critical diameter for glass formation (dc) and wide supercooled liquid region (ΔTx = Tx - Tg, Tx: crystallization temperature, Tg: glass transition temperature) always contain toxic element Be or noble element Pt/Pb, which would bring difficulty to the production or consumption. Recently, we reported pseudo-quaternary FeCoNi(B, Si) HE-BMGs with good soft magnetic and mechanical properties. These soft magnetic HE-BMGs exhibit a high strength of over 3200 MPa, which is superior to other HE-BMGs. While the high Tg and small ΔTx of the HE-BMGs make it difficult to be used for thermoplastic forming. To overcome the disadvantage of the pre-developed HE-BMGs, we here developed new FeCoNi(P, C, B) HE-BMGs possessing low Tg, large ΔTx, combined with excellent mechanical and soft magnetic properties. Alloy ingots were prepared by induction melting of Fe, Co, Ni, C, B, and Fe3P precursor with a purity of over 99 mass% under Ti-gettered argon atmosphere. The alloy samples were produced by injection copper mold casting method for bulk cylindrical rods, and by a single-roller melt spinner for the ribbons. The melt-spun alloy were isothermally annealed for 600 s at different temperatures to examine the crystallization products. The structure of

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the samples was examined by XRD. The thermal stability of the samples was examined by DSC at a heating rate of 0.67 K/s. The saturation magnetization (Is) of ribbon samples was measured by VSM under an applied field of 800 kA/m, and the coercive force (Hc) was measured with a B-H loop tracer. The mechanical properties were measured using an Instron mechanical testing machine. Fully FeCoNi(P, C, B) HE-BMG rods with dc of over 1 mm were successfully prepared. The developed HE-BMGs possess low Tg of 672-702 K, and large ΔTx of 47-56 K. The alloys also exhibit also exhibit good soft magnetic and mechanical properties, i.e., low coercive force of 1.2-3.4 A/m, high saturation magnetization of 0.80-0.86 T, high yield strength of 2817-3210 MPa, and distinct plastic strain of 0.3-1.2%. The primary crystallization product of (Fe, Co, Ni)23(C, B)6 phase with a complex fcc structure may explain the mechanism for the enhancement of the stability of supercooled liquid and GFA for the present HE-BMGs. The developed HE-BMGs with good thermal stability and soft magnetic and mechanical properties give excellent promise for making MEMS/NEMS devices by thermoplastic processing. Keywords: High-entropy alloys; Bulk Metallic glasses; Supercooled liquid region; Magnetic properties; Mechanical properties. G-49 Linking structure and soft magnetic properties in Fe-Si-B metallic glasses: investigations of low-temperature annealing at atomic-scale Jian Dai, Li Zhu, Yingang Wang, Liang Yang Nanjing University Of Aeronautics And Astronautics Recently, accelerating demands of Fe-based amorphous alloys have motivated researchers to concern more about structural essence behind the macroscopic properties. Heat treatment as well as composition design is widely adopted to optimize the properties of Fe-based metallic glasses. Lately, atomic-level stress theory has been successfully applied to characterize the local structure and interpret the modifications of these physical properties. In this work, amorphous Fe-Si-B ribbons were annealed at various temperatures below the crystallization temperature. Annealing-induced structural evolution at atomic-scale in Fe-based metallic glasses was investigated by synchrotron X-ray diffraction. It was found that the thermal oscillations of the atoms lead to the relief of residual stress. Heating up to a temperature higher than 523K reconstructs the distribution of internal stress and gives compressive stress an advantage. The variation of the distribution of atomic-scale hydrostatic stress upon annealing is responsible for the modification of the coercivity. However, the underlying structural mechanisms for magnetic softening remain elusive. Combining synchrotron radiation X-ray diffraction with M"> alternates with increasing distance from an average atom and almost reaches to constant value finally. The volumetric thermal strain monotonically increases with annealing temperature, which implies the occurrence of stress relief in Fe-Si-B amorphous ribbons upon annealing. The inhomogeneous thermal strains upon thermal loading contribute to the rotation of easy axis. Keywords: Metallic glasses; Annealing; Atomic-scale structure; Soft magnetic properties. G-50 Composition design and manufacturability of high Bs nanocrystalline soft magnetic alloys Anding Wang1,2, Chuntao Chang1, Tao Liu1, Xinmin Wang1 1. Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences

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2. Center for Advanced Structural Materials, Department of Mechanical and Biomedical Engineering, College of Science and Engineering, City University of Hong Kong Soft-magnetic materials play important functional role in electronic and magnetic products which greatly affect the human production and living ways. In the 21st century, stronger, lighter, higher energy efficient and more silent are the long-term targets and key challenges of device development. This requires constant enhancement of magnetic performance containing higher effective permeability (μe) and saturation flux density (Bs), lower coercivity (Hc) and core loss. Fe-based amorphous and nanocrystalline soft-magnetic alloys have attracted great interests because of their excellent soft-magnetic properties. The representative amorphous FeSiB (Metglas) and nanocrystalline FeCuNbSiB (Finemet) soft-magnetic alloys have been widely used for industrial application. Nevertheless, the comparatively lower saturation magnetic flux density (Bs) and much larger magnetostriction (λs) of amorphous FeSiB alloys hinder the realization of miniaturization, higher efficiency and quietness of electrical machinery and apparatus. In turn, the much lower Bs of nanocrystalline FeCuNbSiB alloy which has near zero λs and high effective permeability makes it unsuitable for distribution transformers and electric motors. Accordingly, increasing efforts from both academic/research and the industrial communities have been devoted to further improve their soft-magnetic properties and expand commercial applications. In this study, the composition design rules for high Bs nanocrystalline alloys are introduced from the binary phase diagram, atomic size and mixing entropy. A series of high Fe content Fe83SiBPCCu nanocrystalline soft-magnetic alloys were design and prepared. The effects of adding elements on magnetic performance, ribbon manufacturability, crystallization behavior and annealing process were explored. The non-homogeneity of crystallization behavior and magnetic properties of high Bs FeSiBCu nanocrystalline alloys were studied systematically. It is found that three layers with different microstructure were formed along the cross-section direction during the solidification process. These results will provide a theoretical basis for the design of composition and heat treatment process. Keywords: Nanocrystalline alloys; soft-magnetic properties; amorphous forming ability; Crystallization behavior; G-51 Tuning of Cu clusters and its effect on nanocrystallization of FeBCCu(Mo) metal glasses Gongting Xia, Yang Li, Yingang Wang, Yaodong Dai College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People’s Republic of China In recent years, Cu clusters were applied as heterogeneous nucleation sites of a-Fe to tailor soft magnetic properties of Fe-based alloys. However not all Cu clusters can serve as heterogeneous nucleation sites for nanocrystallization of Fe-based amorphous alloys. Therefore It becomes attractive to make the most use of limited Cu (about 1 at% in most alloy systems) and exhaust its potential to form Cu clusters as heterogeneous nucleation sites. In this study, tuning of Cu clusters in FeBCCu(Mo) alloy by pre-annealed or Mo doping are studied through Mssbauer spectroscopy. FWHM and area of low-field humps in magnetic hyperfine field distributions of FeBCCu(Mo) metal glasses are strongly dependent on the size distribution and density of Cu clusters, respectively. It is found that Fe83B10C6Cu1 alloy pre-annealed at 588 K for 10 min and Fe82.25B10C6Cu1Mo0.75 pre-annealed at 593 K for 10 min have the most uniform size distribution and largest density of Cu clusters, respectively. After optimizing of Cu clusters in FeBCCu(Mo) metal glasses, an increment of heterogeneous nucleation sites are

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obtained, which contributes to a good nanocrystallization of a-Fe (refined grains and an increased crystal volume fraction) and thus optimal soft magnetic properties. Keywords: Cu cluster, heterogeneous nucleation sites, Mössbauer spectroscopy G-52 Fabrication of FePBSiNbCr amorphous powder cores with excellent soft magnetic properties by cold pressing Yaqiang Dong, Min Liu, Chuntao Chang, Xin-Min Wang, Run-Wei Li Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences. Ningbo, Zhejiang 315201, China Amorphous soft magnetic composites based on nearly spherical FePBSiNbCr amorphous powders are investigated in details. The amorphous powders were synthesized using raw materials in the particle size range below 100 μm by water atomization with a pressure of 60 MPa. Amorphous magnetic powder cores were produced from a mixture of the amorphous alloy powders and different volume of insulation and bonding materials by mold compacting with a compact pressure of 1800 MPa at room temperature. As a result, the toroidal samples with the outer diameter of 20.3 mm, the inner diameter of 12.7 mm, and the thickness of 5 mm were produced. Then the compacted cores were annealed at 673 K for 1 h in vacuum to reduce the internal stress caused by pressing. The results show that the corresponding amorphous magnetic cores exhibit excellent soft magnetic properties. For example, the sample with 2% epoxy resin exhibits high permeability of 70 up to 10 MHz and a low core loss of 1140 mW/cm3 (Bm = 0.1 T, f = 100 kHz). In addition, it also exhibits superior DC-Bias properties of 63% under the external field of 100 Oe. The Fe-based amorphous magnetic powder cores with excellent soft magnetic properties are a potential candidate for a variety of industrial applications. Keywords: Amorphous powder; Amorphous soft magnetic composites; Soft magnetic properties; DC-bias properties G-53 Effect of metalloid elements on magnetic properties of Fe-based bulk metallic glasses Mingqing Zuo1, Shangyong Meng1, Qiang Li1, Chuntao Chang2, Hongxiang Li3, Yanfei Sun1 1. School of Physics Science and Technology, Xinjiang University 2. Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences 3. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing In this work, we successfully prepare Fe-metalloid bulk metallic glasses (BMGs) with the compositions of Fe80P13C7, Fe80P10C7B3, Fe80P8C7B5, Fe80P13C4B3 and Fe80P8C9B3 by combining fluxing treatment and J-quenching technique, and the effects of the metalloid elements (P, C, B) on the thermal stability and magnetic properties of the present Fe80(P, C, B)20 BMGs are investigated systematically. It is indicated that the replacements of B or P by C and B by P lead to the increase of the Tg and Tx, i.e. thermal stability, of Fe-metalloid BMGs. The substitutions of B for C or P and C for P enhance the saturation magnetization of Fe-metalloid BMGs, which can be well explained by using charge transfer model. Additionally, the compositional dependence of saturation magnetization for the Fe-metalloid BMGs can also be well explained in quantitative by magnetic valence theory. The replacements of P by B or C and C by B lead to the increase of the Curie temperature of Fe-metalloid BMGs, which can be accounted for based on mean field theory.

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Keywords: Fe-P-C-B bulk metallic glasses; thermal stability; magnetic properties G-54 A novel method of fabrication Fe-based metallic glassy composite coatings with high wear and corrosion resistance Zhenhua Chu, yong Yang, Xueguang Chen, Dianran Yan School of Materials Science and Engineering, Hebei University of Technology, Tianjin, 300132, China In order to obtain bulk metallic glassy composite coatings with high wear and corrosion resistance, a novel of gas multiple-tunnel plasma spraying technology was adopted to fabricate composite coatings with various content of Fe-based metallic glass and ZrO2 in the present study. By this way the glassy formation ability of the Fe-based metallic glass is not affected, and proportion of the two phases in the composite coatings can be regulated according to design. The tribological test results indicate that the addition of ZrO2 improves the wear resistance and corrosion resistance. However, the wear rate and the property of the corrosion of the composite coating is nonlinear related to the fraction of ZrO2. There is a transformation from toughness to brittleness with the increase of ZrO2 in the composite coating. Therefore, the wear failure mechanism of the composite coating is changed from abrasive wear to fatigue wear. The highest corrosion resistance is obtained in the composite coating with 50% ZrO2. Keywords: Plasma spraying; Metallic glass; Composite coating; Wear property; Corrosion resistance G-55 Fe-based multi-component amorphous alloys with excellent soft-magnetic properties ran wei, Juan Tao, Shileii Liu, Guowen Sun, Leipeng Lu, Chen Chen, Fushan Li School of Materials Science and Engineering, zhengzhou University, zhengzhou 450001, China (FeM)80(PCSiB)20 (M=Cr, Ni ,Co, Mn, Cu and Mo) amorphous alloys with excellent soft magnetic properties were developed. The amorphous alloy synthesized by only adding B and Si in a commercial medium alloy steel has high saturation magnetization (1.45 T), high initial permeability (22847 at 1 kHz) and high frequency stability as well as good corrosion resistance. In order to widen the application of the medium alloy steel, seven kinds of amorphous alloys were created by tuning their composition by removing Cr, Ni or Co elements. Interestingly, these amorphous alloys also possess good soft magnetic properties, among which the maximum value of Bs

reaches 1.67 T while the permeability value at frequency of 1 kHz is over 8300. The integration of excellent soft-magnetic properties and low cost makes the Fe-based amorphous alloys promising soft-magnetic materials for industrial applications. Keywords: Fe-based amorphous alloy; High permeability; Soft-magnetic properties; Multi-component G-56 Effects of Mo and Cr additions on the glass-forming ability and corrosion resistance of Fe-based Fe-P-C-B metallic glasses Siwen Wang, xuewei Wang, xingjie Jia, Yanhui Li, wei Zhang School of Materials Science and Engineering, Dalian University of Technology Fe-based bulk metallic glasses (BMGs) have attracted considerable attentions due to their high strength, high wear resistance, and good soft magnetic properties. By taking the advantage of good mechanical properties and low

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cost, Fe-based BMGs are expected to serve as coating materials for bipolar plate separator in PEMFC, earth-excavating, and tunnel-boring machines, etc. However, the pre-developed Fe-based BMGs do not simultaneously possess low glass transition temperature (Tg), wide supercooled liquid region (ΔTx), high glass-forming ability (GFA), and excellent corrosion resistance, which are essential requirements for metallic glasses as coating materials. In this work, with the aim of developing Fe-based BMGs with high stability of supercooled liquid, GFA and good corrosion resistance, we selected a Fe-based Fe-P-C-B metallic glass with low Tg as base alloy, and investigated the effects of Mo and Cr additions on the thermal stability, GFA and corrosion resistance. Alloy ingots were prepared by induction melting of Fe, C, B, Mo, Cr, and Fe3P precursor with a purity of over 99 mass% under a highly purified argon atmosphere. The glassy alloys were produced by injection copper mold-casting for bulk cylindrical rods and by melt spinning for ribbons. The melt-spun alloys were isothermally annealed for 600 s at different temperatures to examine the crystallization behaviors. The structure of the samples was examined by XRD and the thermal properties were measured by DSC and DTA. Corrosion behaviors of the metallic glasses were evaluated by electrochemical measurement in 1 N HCl and H2SO4 solutions open to air at room temperature. Proper Mo or/and Cr additions significantly enhance the stabilization of supercooled liquids and GFA of the Fe-P-C-B metallic glasses whereas without excess increase of Tg. Combined addition of Mo and Cr increases the ΔTx of the base alloy from 29 K to 42 K, and Fe-Cr-Mo-P-C-B BMG rods with a diameter up to 1.5 mm were successfully obtained. Additions of Mo and/or Cr also improve the corrosion resistance of the base alloy in the H2SO4 and HCl solutions. The corrosion resistance of the Fe-Cr-Mo-P-C-B alloys is better than those of SUS316L. In addition, the BMGs also possess high fracture strength of over 2900 MPa. The developed Fe-Cr-Mo-P-C-B BMGs with large ΔTx, high GFA, and superior corrosion resistance is promising for the future applications as new coating materials. Keywords: Fe-based metallic glasses; Alloying; Glass-forming ability; Supercooled liquid region; Corrosion resistance. G-57 Corrosion, wear and magnetic properties of novel Fe-based amorphous coatings Jiawei Li1, Haoran Ma1,3, Chuntao Chang1, Jun Shen2, Xinmin Wang1, Runwei Li1 1. Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China 2. School of Materials Science and Engineering, Tongji University, 4800 Caoan Road, Shanghai 201084, PR China 3. Laboratory for Microstructures, Shanghai University, Shanghai 200444, China Fe-based amorphous alloys have attracted worldwide attention because of their excellent soft magnetic properties, high fracture strength, and good corrosion resistance. However, the application is largely restricted due to their poor glass-forming ability (GFA) and low plasiticity at room temperature. Preparation of amorphous coating using high velocity oxygen/air fuel (HVOF and HVAF) is one of the effective methods to solve the above application bottlenecks. In this paper, based on the shortage of well-known SAM series alloys (SAM2X5 Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 and SAM1651 Fe48Mo14Cr15Y2C15B6), we developed a series of novel Fe-based bulk amorphous alloys with low cost, high glass-formation ability, high corrosion and wear resistance, and then investigated its corrosion mechanism by X-ray photoelectron spectroscopy (XPS). Besides, we prepared high quality HVOF and AC-HVAF amorphous coatings by optimizing the preparation technology. Finally, the

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microstructure, corrosion resistance, wear resistance, soft magnetic properties of the coatings were studied using X-ray diffractometer (XRD), scanning electron microscope (SEM), friction and wear testing machine, electrochemical workstation and vibrating sample magnetometer etc.. The main results can be summarized as follows: First of all, the Fe71Mo3.5Ni5P10C4B4Si2.5 alloy was chosen as the base alloy, and a series of large-sized Fe-based amorphous rods were obtained through micro-alloying Cr and optimizing composition ratio. The electrochemical measurements performed in 3.5 wt.% NaCl solution showed that the corrosion resistance was significantly improved by alloying a small amount of Cr, while for more than 8 at.% Cr the alloys exhibited similar corrosion behavior to each other. Secondly, the Fe71Mo3.5Ni5P10C4B4Si2.5 alloy with comparable corrosion resistance with the amorphous steel SAM1651 was chosen as the thermal spraying material due to its high GFA, good mechanical and corrosion properties. The HVOF and AC-HVAF coatings exhibited high amorphous content, low porosity and oxygen content, and high binding strength with the matrix. However, AC-HVAF coatings showed higher amorphous content and lower porosity than those of HVOF coatings, indicating that AC-HVAF is more suitable for the preparation of high-quality Fe-based amorphous coatings compared with HVOF. Finally, the corrosion resistance, friction and wear properties, and soft magnetic properties of Fe68Cr8Mo3.5Ni5P10C4B4Si2.5 amorphous coatings were investigated in detail. The HVOF and AC-HVAF coatings exhibited similar corrosion current density and corrosion potential. However, the AC-HVAF coatings displayed an order lower passivation current density compared with the HVOF coatings, which mainly resulted from the formation of a thick and dense passive film with higher pitting resistance and stability as well as stronger re-passivity on the surface of the AC-HAVF coating. It should be noted that these coatings showed comparable corrosion and wear resistance compared with the well-known SAM2X5 and SAM1651 amorphous coatings, despite the absence of W and low Mo and Cr content. In addition, the soft magnetic properties of the coating was obviously better than those of FeSi, FeSiB, FeSiBNbCu nanocrystalline coatings, which is good for further expanding the application field of Fe-based amorphous coatings. Keywords: Fe-based amorphous coating; Thermal spraying; Glass-forming ability; Corrosion resistance; Wear resistance; Soft magnetic properties G-58 Elastic evidence of Metal-Insulator phase transition in LCMO perovskites using Non-destructive evaluation Arunachalam Manikavasagam1, Thamilmaran Pandian1, Sankarrajan S2, Sakthipandi K3 1. Department of Physics, Sri S. Ramasamy Naidu Memorial College, Sattur - 626 203, Tamilnadu, India. 2. Department of Physics, Unnamalai Institute of Technology, Kovilpatti- 628 503, Tamil Nadu, India 3. Department of Physics, Sethu Institute of Technology,Kariapatti 626 115, Tamil Nadu, India La1-xCaxMnO3 perovskite samples with the composition of x= 0.70, 0.75 and0.90 were prepared using the solid state reaction technique. The XRD patterns of the prepared samples confirmed the crystalline nature and the orthorhombic structure of the samples. No secondary phases are found in the samples. The elastic constants such as longitudinal and shear modulus at various temperatures (from 300 to 700 K) of the samples have been determined by subjecting them into non-destructive in-situ ultrasonic measurement of longitudinal and shear velocities using through transmission technique at the fundamental frequency of 5 MHz. The observations revealed anomalous behaviour at the transition temperatures. The anomalies observed at the temperatures 640, 560 and 370 K for the samples for the composition x=0.70, 0.75 and 0.9 respectively were used to explain the high

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temperature metal-insulator phase transition existing in the prepared samples. Further, the investigation reveals that the magnetic entropy increases with a decrease in the doping concentration of calcium in the samples. Keywords: Perovskites, Phase transition, Ultrasonic measurements, Elastic constants, Non-destructive evaluation G-59 On the microstructural evolution in FeCoNiAl0.5CrMox high entropy alloys Yan Xin Zhuang, Xiu Lan Zhang, Zi Min Wang Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, 110819, P.R. China FeCoNiAl0.5CrMox multi-component alloys have been designed to improve strength and thermal stability of FCC-based Al0.5CoCrFeNi high entropy alloys. The possible phases existing in the FeCoNiAl0.5CrMox multi-component alloys have been evaluated using the Thermo-Calc program with TTNI7 database. The microstructure and phase constituents of FeCoNiAl0.5CrMox high entropy alloys have been investigated using scanning electron microscopy, X-ray diffraction and transmission electron microscopy. Thermodynamic calculation shows that three equilibrium phases, FCC, (Ni, Al)-rich NiAl phase and (Cr ,Mo)-rich sigma phase, exist in the alloys at various equilibrium temperature and compositions. The as-cast FeCoNiAl0.5CrMox (x=0-0.5 in mole ratio) alloys has a typical dendrite microstructure, which consists of FCC phase in dendrite region and different morphology in the interdendrite region. The Mo element enhances the formation of the (Ni,Al)-rich BCC phase and (Cr, Mo)-rich sigma phase. The annealing processes between 600-1100oC induce the precipitation of (Ni,Al)-rich phase and (Cr,Mo)-rich phase, and thereby modify the mechanical properties of FeCoNiAl0.5CrMox alloys. Keywords: high entropy alloys; thermodynamic calculation; microstructure; mechanical properties; annealing G-60 Microstructure, mechanical and tribological properties of Al0.2CoCrFeNi high entropy alloy matrix self-lubricating composite fabricated by spark plasma sintering Aijun Zhang1,2, Junhu Meng1 1. State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences 2. University of Chinese Academy of Sciences 1. Objective The tribological properties of sliding parts determine the efficiency, reliability, stability and durability of the mechanical equipment that served in extreme conditions such as high temperature, vacuum, cryogenic, high-speed and heavy-load, especially in the high temperature conditions. It is difficult to use conventional oil and grease lubricating systems in high temperature environments. Therefore, it is urgent to develop materials with excellent self-lubricating property from room temperature to high temperatures. The metal matrix self-lubricating composites are highly desirable for high temperature tribological applications to increase the life time and performance of mechanical systems. Ni-based alloys have been widely used as matrix materials of high-temperature self-lubricating composites due to their good mechanical properties and thermal stability at high temperatures. However, the addition of solid lubricants will inevitably detrimental to the mechanical properties of the metal matrix self-lubricating composites, and which may cause severe deformation, fracture or collapse in

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their applications. Therefore, it is still a challenge to achieve good balance between mechanical properties and tribological properties in the metal matrix self-lubricating composites. Recently, high entropy alloys (HEAs) have shown considerable promise from both a scientific and an application perspective since they have many excellent properties. Among the huge number of HEAs, the Al0.2CoCrFeNi HEA is an established system and has been widely studied. Compared with the conventional Ni-based alloys, the Al0.2CoCrFeNi HEA has more excellent high temperature mechanical properties and better stability. Therefore, the Al0.2CoCrFeNi HEA can be considered as a promising candidate of matrix for metal matrix self-lubricating composites used in high temperature conditions. In the light of the above analysis, the objective of our study is to design and prepare HEAs matrix high-temperature self-lubricating composites with a good tribological and mechanical properties, and also to explore the friction and wear mechanisms of these materials at high temperatures. Here, we report the Al0.2CoCrFeNi HEA matrix self-lubricating composite with excellent mechanical and tribological properties that were successfully prepared by spark plasma sintering (SPS). In the composite, the molybdenum disulfide (MoS2) and graphite were used as lubricants since they have a synergistic effect of lubrication in a wide range of temperatures. Especially, the MoS2 and graphite were coated by nickel, which could decrease the reaction and decomposition of lubricants, and could also improve the bonding strength between HEA matrix and lubricants. In order to comparison, the pure Al0.2CoCrFeNi HEA was prepared by SPS, and the mechanical and tribological properties was also investigated. 2. Methods High purity Al0.2CoCrFeNi HEA powders were prepared by argon gas atomization from bulk Al0.2CoCrFeNi HEA. The HEA powders were blinded with nickel-coated graphite and nickel-coated molybdenum disulfide, and then were dry mixed in a mechanical mixer. Subsequently, the powder mixture was filled in a graphite die and sintered in a SPS furnace under vacuum. The pure Al0.2CoCrFeNi HEA was also prepared by SPS using elemental powders mixture. The phase compositions of the sintered materials were characterized by X-ray diffraction. The microstructures of the materials were investigated by scanning electron microscope, and the elements contents were analyzed by energy dispersive spectroscopy. In order to evaluate the mechanical properties of the materials, the density, hardness, compressive behavior and fracture toughness were tested. The dry friction and wear test from room temperature to 800 oC in air were tested using a HT-1000 ball-on-disk high-temperature tribometer. The ball was made of Si3N4, and the disc was made of the sintered Al0.2CoCrFeNi HEA and the HEA based self-lubricating composites. The sliding speed was 0.28 m/s, and the test loads were 5 N. After tribological test, the worn surfaces were investigated by SEM and EDS. In order to obtain the variations of phase structure in the worn surface, the specimens were analyzed by a Renishaws inVia Micro-Raman and a micro-beam XRD diffractometer. 3. Results The SPSed HEA based composite consists of three main phases: HEA’s face-centered cubic (FCC) phase, graphite and molybdenum disufide. The solid lubricants of graphite and molybdenum uniformly distributed in the microstructure of the composite, and it could be survived in the composite mainly due to the nickel coatings on the solid lubricants surface and the advantages of the SPS technology. The hardness, yield strength, compressive strength, ultimate plasticity strain and fracture toughness of the HEA are 271 HV, 610 MPa, 921 MPa and 14.25 MPa.m0.5, respectively. The good mechanical properties of the HEA based composite mainly derived from the Al0.2CoCrFeNi HEA matrix. The friction coefficient and the wear rate of the HEA base composite from room temperature to 800 oC are 0.26~0.42 and 2~8×10-5 mm3/N.m, respectively, indicating that the composite have excellent self-lubrication and wear-resistance in a wide range of temperatures. The synergistic lubrication effects

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of graphite and MoS2 is responsible for the reduction of the friction at room temperature to 400 oC, while the compound oxides formed in the sample surfaces play a key role to improve wear resistance and reduce the friction coefficient at 600 oC and 800 oC. 4. Conclusion The Al0.2CoCrFeNi matrix self-lubrication composite was successfully prepared by SPS, and the composite has good mechanical properties and excellent tribological performances. The synergistic effects of the solid lubricants and the compound oxides formed on the worn surface give the Al0.5CoCrFeNi matrix composite excellent self-lubricating effect in a wide range of temperatures. The high-performance Al0.5CoCrFeNi matrix self-lubricating composite may have broad application prospects in the mechanical equipment which served in the extreme conditions in future. Keywords: High entropy alloy, self-lubricating composite, microstructure, mechanical properties, tribological properties G-61 Effect of homogenization on hot deformation behaviour of Al0.5CoCrFeNi high entropy alloy Yu Zhang, JinShan Lin, Jun Wang, HongChao Kou State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, PR China Hot deformation behaviour of as-cast and homogenized Al0.5CoCrFeNi high entropy alloy (HEA) during isothermal compression was studied as a function of temperature (850-1000℃) and strain rate (10-3-1s-1). The microstructure of the as-cast state alloy consists fcc solid solution dendritic phases and bcc solid solution interdendritic phases. After homogenized at 1100 ℃ for 20 h, a large number of cobalt-rich phases precipitated in the matrix. Results indicated that flow stress in homogenized state is always higher than that in as-cast state under the same deformation condition. Moreover, processing maps constructed based on the dynamic material model showed that the optimum thermo-mechanical processing conditions for hot working of homogenized state were identified as 945-965 ℃/10-1.7-10-1.1 s-1 which can be easier to realize in practical production. Constitutive equations of both states that describe the flow stress alloy as a function of strain rate and deformation temperature were also established based on Arrhenius model. Keywords: High entropy alloy, Homogenization, Flow stress, Constitutive equation, Processing map G-62 High-throughput determination of interdiffusion coefficients for Co–Cr–Fe–Mn–Ni high-entropy alloys Weimin Chen1,2, Lijun Zhang2 1. Institute of Advanced Wear & Corrosion Resistant and Functional Materials, Jinan University, Guangzhou, Guangdong 510632, P.R. China 2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083, P.R. China Accurate interdiffusion coefficients are the necessities in disciplines and applications of the sluggish diffusion effect for high-entropy materials. In the present work, we proposed a high-throughput establishment of interdiffusion databank in high-entropy alloys following the strategy of Materials Genome Initiative (MGI), which integrates the advanced diffusion multiple technique, and pragmatic numerical inverse method. To demonstrate this idea, solid/solid diffusion multiples of fcc quinary Co–Cr–Fe–Mn–Ni system at 1373 K were experimentally prepared by hot–pressing technique, and the corresponding composition-dependent multicomponent

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interdiffusivity matrices were efficiently determined by newly proposed pragmatic numerical inverse method. Accurate interdiffusivity matrices along the entire diffusion paths can be obtained by using such combinational approach, forming the basis of the interdiffusion bank in high-entropy alloys. Keywords: High-entropy alloy; Interdiffusion coefficient; pragmatic numerical inverse method; diffusion multiple technique G-63 High-throughput determination of interdiffusion coefficients for Co–Cr–Fe–Mn–Ni high-entropy alloys Weimin Chen1,2, Lijun Zhang2 1. Institute of Advanced Wear & Corrosion Resistant and Functional Materials, Jinan University, Guangzhou, Guangdong 510632, P.R. China 2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083, P.R. China Accurate interdiffusion coefficients are the necessities in disciplines and applications of the sluggish diffusion effect for high-entropy materials. In the present work, we proposed a high-throughput establishment of interdiffusion databank in high-entropy alloys following the strategy of Materials Genome Initiative (MGI), which integrates the advanced diffusion multiple technique, and pragmatic numerical inverse method. To demonstrate this idea, solid/solid diffusion multiples of fcc quinary Co–Cr–Fe–Mn–Ni system at 1373 K were experimentally prepared by hot–pressing technique, and the corresponding composition-dependent multicomponent interdiffusivity matrices were efficiently determined by newly proposed pragmatic numerical inverse method. Accurate interdiffusivity matrices along the entire diffusion paths can be obtained by using such combinational approach, forming the basis of the interdiffusion bank in high-entropy alloys. Keywords: High-entropy alloy; Interdiffusion coefficient; pragmatic numerical inverse method; diffusion multiple technique G-64 Fabrication of rare-earth high-entropy alloys with giant magnetocaloric effect Yuan Wu, Yuan Yuan, Hui Wang, Xiongjun Liu, Zhaoping Lu University of Science and Technology Beijing In this paper, we report the development of rare-earth high-entropy alloys with multiple principle elements randomly distributed on a single hexagonal close-packed (hcp) lattice. The high mixing entropy stabilized the crystalline structure from phase transformation during cooling, whereas a second-order magnetic phase transition occurred at Neel temperature. The RE-HEAs exhibit a small magnetic hysteresis and the largest refrigerant capacity reported to date, along with respectable mechanical properties. Our analysis indicates that strong chemical disordering of HEAs resulted from the high mixing entropy make magnetic ordering more difficult, thus giving rise to a sluggish magnetic phase transition and enhanced magnetocaloric effect. Our findings evidenced that RE-HEAs are promising candidates as magnetic refrigerants and the alloy-design concept of HEAs surelyopens up a new route for developing high performance magnetocaloric materials. Keywords: high entropy alloy, magnetocaloric effect G-65 Grain refinement of CrCoNi multi-principal-element alloy

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Xinwang Liu1,2, Guillaume Laplanche1, Aleksander Kostka1, Suzana Fries1, Janine Pfetzing-Micklich1, Gang Liu1, Zitian Fan2, Easo George1 1. Department of Materials Design, Ruhr-University Bochum, Bochum 44801, Germany 2. State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, China The equiatomic multi-principal-element alloy, CrCoNi, as a single-phase FCC solid solution, displays excellent strength-toughness properties that exceed those of all high entropy alloys, which is considered as a promising engineering alloy at cryogenic temperatures. Cast, as a common-used method to form complex-shaped components, is a necessary technique for engineering alloys, whereas the cast multi-principal-element alloys have not be systematically investigated previously. Here we study the grain refinement of cast CrCoNi alloy and their corresponding mechanical properties. The alloys were produced by arc melting and drop casting, which are much simpler than the preparation procedures of deformed alloys by cold deformation and recrystallization in the previous studies. The cast CrCoNi alloy consists with anisotropic coarse columnar grains with the average width of more than 210 mm. Their microstructures, however, become equiaxed grains after grain modification which exhibit uniform fine equiaxed grains with the size of 76 mm nearly throughout the entire ingots. The tensile tests at an engineering strain rate of 10-3 s-1 reveals that yield strength, ultimate tensile strength and elongation to fracture are all improved by grain refinement both at 293 and 77 K. Meanwhile, the cast alloy shows the comparable mechanical properties with the alloys after cold working and recrystallization. The corresponding mechanism was also discussed related to the constitutional supercooling. Keywords: Multi-principal-element alloy; Grain refinement; Microstructures; Tensile properties G-66 Microstructure and corrosion behaviour of a Laves phase strengthened eutectic high-entropy alloy Wenyi Huo1, Hui Zhou1, Feng Fang1, Zonghan Xie2,3, Jianqing Jiang1,4 1. Jiangsu Key Laboratory of Advanced Metallic Materials, Southeast University 2. School of Mechanical Engineering, University of Adelaide 3. School of Engineering, Edith Cowan University 4. Nanjing University of Information Science and Technology Considering the inherent advantages of eutectic alloys, eutectic high-entropy alloys provide a brand new research direction for developing advanced materials. CoCrFeNiTax eutectic high-entropy alloys were produced by arc melting technique and a eutectic composition was designed. Microstructure and corrosion behaviour of the eutectic high-entropy alloy were investigated by X-ray diffraction, field emission scanning electron microscope, transmission electron microscope and electrochemical workstation. The experimental results show that the eutectic high-entropy alloy is composed of a face-centered cubic solid solution and a Laves phase. The dual-phased microstructure showed up as a nanoscale lamellar structure. The corrosion current density of the alloy is low in 3.5% (mass fraction) NaCl solution. Keywords: High-entropy alloy; Laves phase; Eutectic; Corrosion behaviour G-67 The magnetocaloric composite designed by multi Gd-Al-Co microwires with close performances Hongxian Shen1,2, Dawei Xing1, Hillary Belliveau2, Sida Jiang1, Jingshun Liu3, Haichao Sun1, Shu Guo1, Yanfen Liu1, Jianfei Sun1, Manh-Houng Phan2

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1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China 2. Department of Physics, University of South Florida, Tampa, Florida 33620, USA 3. School of Materials Science and Engineering, Inner Mongolia University of Technology, No. 49 Aimin Street, Hohhot 010051, P. R. China We have designed a new magnetocaloric composite for obtaining its effect on magnetocaloric effect (MCE) by using three kinds of soft ferromagnetic Gd-based microwire arrays with close magnetocaloric performances. The TC temperatures of these three wires are 97 K, 100 K and 101 K, respectively. However, the TC temperature of Composite sample show only one transition point at 97 K instead of three points. The Composite sample shows a smooth magnetic entropy change (ΔSM) at high applied field change (μ0ΔH=5 T) and the maximum entropy change (-ΔSM

max) and refrigerant capacity (RC) are calculated to be ~9.98 J·kg-1·K-1 and ~665 J·kg-1. Additionally, the Composite sample show close MCE properties to its components and the calculated universal master curves of Composite sample and its Gd-Al-Co components are fitted very well which explain that all these Gd-Al-Co wires show almost same MCE and magnetic transition behaviors. The results suggest that the Gd-based amorphous wires with close MCE properties can be designed as Composite sample used for magnetic refrigeration. Keywords: magnetocaloric composite, Gd-based microwires, magnetic refrigeration G-68 Corrosion behavior of Ti-Ni shape memory bulk metallic glass composites in artificia seawater and PBS solution Yanchun zhao, ruipeng mao, wenlong ma, congyu xu, shengzhong kou State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology，Lanzhou 730050 Ti-Ni shape memory bulk metallic glass composites rods was prepared by suspend melting under argon atmosphere using a water-cooled Cu mold.The microstructur and corrosion-resistance behaviors of the Ti-Ni shape memory bulk metallic glass composite has been studied by XRD,OM, HRTEM, electrochemical measurements, SEM and EDS analysis,respectively. The results show that the microstructure consists of amorphous matrix and shape memory crystal phase, presenting gradient microstructure in casting process of temperature gradient, edge for fast cooling to form random dense pile of amorphous structure, core main precipitation phase for cooling austenite phase. The as-cast Ti-Ni-based alloy exhibits passive behavior both in the artificial seawater and the phosphate-buffered saline solution. Comparing with the crystalline TC4 alloy, Ti-Ni shape memory bulk metallic glass composites exhibit significantly higher self-etching potential, lower self-etching current density and higher polarization resistance. Thus, Ti-Ni-based alloy shows lower corrosion tendency and smaller kinetic corrosion rate. Due to lower activity anion concentration in PBS solution, the alloy exhibited more excellent corrosion-resistance than in artificial seawater. No obvious pitting corrosion pits and corrosion products were found in the microstructure and the oxide film in the edge area is more compact and uniform than the core as well. Keywords: bulk metallic glass composites, microstructure, corrosion behavior G-69 Refining Effect of the Macromolecular Diffusion Barrier on Formation of Nanoporous Copper Zhenhua Dan1, Fengxiang Qin2, Nobuyoshi Hara3 1. College of Materials Science and Engineering, Nanjing Tech University

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2. School of Materials Science and Engineering, Nanjing University of Science and Technology 3. Department of Materials Science, Tohoku University The np-Cu materials in particular have a great potential for practical applications since they are cost effective compared to np-Au, electrochemically stable, and their mechanical performance is reliable. The np-Cu materials have been typically fabricated by dealloying crystalline or amorphous precursors. The uniform microstructure of np-Cu is of importance for its catalytic performance. As has been reported, the np-Cu fabricated from amorphous precursors has a relatively uniform distribution of nanopores and Cu ligaments because of its homogenous chemical composition and the microstructure of the amorphous precursors. organic macromolecules tend to be less mobile than metal adatoms and ions due to their relatively large molar weight and different long-term order structure. Polyvinylprrolidone (PVP), an organic macromolecule chemical reagent, has a long chain structure with a molar weight from 2500 to 250000 g mol1. PVP has been used as a stabilizing or capping reagent for inhibiting the growth of metal nanoparticles (NPs). It is therefore presumed that the introduction of such an organic macromolecule into the dealloying solution affects the diffusion process at the metal/electrolyte interface, making it possible to control the np-Cu structure. In this paper, the results of the investigation are reported along with a discussion of the mechanism of the refinement of np-Cu due to the presence of the PVP macromolecule. Dealloying of amorphous precursor alloys was performed in mixed solutions of different acids and polyvinylpyrrolidone (PVP, Sigma-Aldrich) with different added amounts. The molecular weight of the chain structured PVP was 55000 g mol1. The refining effect of polyvinylprrolidone (PVP) during dealloying on the formation of nanoporous Cu from a amorphous precursor alloys in mixed acidic solutions was investigated. A bicontinuous nanoporous Cu structure formed after dealloying. A significant change was observed in the pore and ligament size dealloying in the mixed solution containing acids and macro- molecular chemicals (i.e. PVP 55000 g/mol). For example: in the mixed solution containing H2SO4 and PVP, the mean sizes of pores and ligaments were 10 nm and 14 nm, whereas they were 66 nm and 84 nm in the PVP-free solution. With increasing concentration of PVP in the dealloying solutions, the size of nanopores and ligaments decreased in the following manner: the decrease was small in the PVP concentration range of 0 to 0.1 g/L (Type I), and large in the 0.1 to 10 g/L range (Type II). A decrease in the surface diffusivity of more than three orders of magnitude was noted with the addition of 10 g/L PVP. Wholly speaking, the restrictions on free diffusion of Cu adatoms due to the adsorption of PVP resulted in the formation of finer Cu ligaments than that formed in mixture acidic solution. PVP macromolecules force Cu adatoms to diffuse in a relatively narrower range, and thus smaller Cu ligaments and nanopores formed. This long chain PVP macromolecule organic molecule tend to act as a diffusion barrier for the diffusion of metal adatoms during dealloying and to elaborate the nanoporous structure. Keywords: Nanoporous copper; Amorphous precursor alloy; Dealloying; Refinement;Diffusion barrier G-70 Spark plasma sintering kinetics of Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4 amorphous soft magnetic composite Zhankui Zhao Key Laboratory of Advanced Structural Materials, Ministry of Education, Changchun University of Technology Powder metallurgy Fe base amorphous soft magnetic composites is superior performance depends on the high temperature residence time of powder metallurgy process, shows clear dynamic dependencies. This paper studies the spark plasma sintering Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4 composite materials in the process of dynamic regulation and its impact on microstructure and performance of the composite samples.

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Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4 composite with a high electrical resistivity and excellent soft magnetic properties was prepared by spark plasma sintering (SPS) at a low nominal sinter temperature. XRD and SEM results show the Fe76Si9B10P5 alloy powders remain the amorphous state and the composite is dense. A fusion zone at interface of Fe76Si9B10P5 cell body and Zn0.5Ni0.5Fe2O4 cell wall can be observed by TEM. The interface bonding based on the formation of local high temperature in SPS process was observed. The discharging energy forms an instantaneous local high temperature to complete the local sintering and densification of Zn0.5Ni0.5Fe2O4 particles. The local high temperature kinetics benefit to interface bonding and prevent crystallization of amorphous alloy due to the initial spark plasma sintering temperature and the final sintering temperature were decreased by 20-50 degree centigrade. Keywords: amorphous soft magnetic composite; spark plasma sintering; kinetics G-71 New Multicomponent Fe-based amorphous steels with excellent soft-magnetic properties developed from medium-alloy steel Fushan Li, Ran Wei, Wenshuai Zhang, Jixiang Chen, Zichao Li, Chen Chen School of Materials Science and Engineering, zhengzhou University, zhengzhou 450001, China Up to date Fe-based soft ferromagnetic amorphous alloys with practical value in industrial production still consists predominantly of less constituent elements such as Metglas2605SA1 (Fe80Si9B11 at.%). However, the combinations of good soft-magnetic properties are hardly achieved in the classical alloys comprising of less constituent elements. In this paper, multicomponent FeCrNiCoMnCuMoCPSiB amorphous steels (ASs) with combinations of good soft-magnetic properties were developed from a commercial medium-alloy steel named 1Cr4Ni2P that was used as basic raw materials. By only additions of metalloid B and Si modifying the composition of the steel, several kinds of amorphous steel were created. The AS with a proper content of metalloid additions exhibits superhigh initial effective permeability of over 228 00 at 1 kHz and saturation magnetization of over 1.45 T. The ribbon formability of the ASs is quite well, and consequently wide ribbons were produced by the current method of real production. Keywords: Fe-based amorphous alloy, amorphous steels, soft-magnetic properties, medium-alloy steel G-72 Development of Fe-based bulk metallic glasses with both high saturation flux density and high glass forming ability shuangqin chen, kefu yao Tsinghua University Fe-based soft magnetic metallic glasses have drawn substantial attention due to their high permeability, low coercivity (Hc) and low conductivity which contribute significantly to low core losses. As energy exhaustion and environment problems have threatened human sustainable development, novel high efficiency and energy saving materials, such as Fe-based soft magnetic metallic glasses are highly desired which have extensive applications of transformers, motors, sensors and other magnetic devices. However, inherent low saturation flux density (Bs) and/or low glass forming ability (GFA) of commercial Fe-based soft magnetic metallic glasses has hindered their further applications. In order to obtain fully glassy state that ensuring excellent soft magnetic properties of Fe-based alloys, certain amount of metalloid elements (B, C, Si, P) and other glass forming elements (Al, Ti, Ga, Nb, Mo, etc) are essential constituent. Whereas, those non-magnetic elements addition will diminish the Bs and all

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the Fe-based soft magnetic metallic glasses with GFA up to 1 mm, show Bs no more than 1.65 T. The basic way to raise Bs is increasing the Fe content, but which makes the alloy deviate from the eutectic point then deteriorating GFA. Consequently, developing Fe-based soft magnetic metallic glasses with both high GFA and high Bs bears profound significance. According to Pauling-Slater curve, FeCo-based crystalline alloys show higher Bs than Fe-based counterparts, and thus Co was applied to partially replace Fe of Fe-Mo-P-C-B-Si system in this work. Moreover, introducing a new element (Co) in alloy systems could increase GFA based on Inoue experimental principle for GFA. On the other hand, purify method of flux was used to dislodge excessive oxygen dissolve in the alloy to avoid heterogeneous nuclear then promoting GFA. Finally, Fe-Co-Mo-P-C-B-Si alloy was obtained with GFA up to 1 mm and Bs better than 1.7 T, which is the highest Bs of Fe-based bulk metallic glasses reported so far. The Hc was also as low as 4.5 A/m. Higher Bs and lower Hc of soft magnetic alloys conduce to smaller size of their devices and save more energy resource. In addition, the 3050 MPa compression strength and better plasticity up to 1.2% also endow the alloys a better service performance. All these make them a promising candidate for commercial applications as magnetic functional and structural materials. Keywords: Fe-based metallic glass, high Bs, glass forming ability G-73 On the magnetic anisotropy in Fe78Si9B13 ingots and amorphous ribbons: orientation aligning of Fe-based phases/clusters xin wang1, haijian Ma1, zhenhua Sheng1, shifeng Jin2, wq Xu3, M Ferry3, L Chen4, weimin Wang1 1. Shandong University 2. Institute of Physics, Chinese Academy of Sciences 3. University of New South Wales 4. Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Magnetic anisotropy in the Fe-based amorphous ribbon plays an important role in its applications and is still not fully understood. To get an in-depth understanding of it, structure and magnetic property of Fe78Si9B13 master alloy ingots and amorphous ribbons are measured by various techniques. In ingot samples, the α-Fe and Fe2B axes are parallel with the radial direction (RD) of the original cylindrical ingots, i.e. the temperature gradient direction, and their orthogonal axes align in several directions in the plane which is vertical to temperature gradient direction. The hard magnetic axis of the ingot samples is along RD, which is due to the large magnetocrystalline anisotropy energy difference between and {001} of Fe2B phases. In the plane of amorphous ribbons, the easy axis is along the ribbon width direction and the hard axis is along the direction with an angle of about 60° against the ribbon width direction. According to the structure heredity between the melts and glasses/crystals during solidification. The magnetic anisotropy in the plane of ribbon is ascribed to the orientation aligning of Fe-Si and Fe-B clusters, i.e.a hidden order beyond short-range, in Fe78Si9B13 amorphous ribbons. Keywords: magnetic anisotropy;Fe-based amorphous;orientation aligning; G-74 Fe-based soft magnetic composites properties of Ni0.5Zn0.5Fe2O4/Fe76Si9B10P5 alloy after annealing treatment Jihang Ren ChangChun University of Technology

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Abstract Iron-based amorphous alloys have attracted technological and scientific interests due to their excellent soft magnetic properties. The amorphous alloy of Fe76Si9B10P5 has been studied for structural properties analysis. In this work, it is showed that after annealing treatment Fe-based soft magnetic composites(SMCS) amorphous alloy like Ni0.5Zn0.5Fe2O4/Fe76Si9B10P5 has a exhibiting good magnetic properties . The alloy in form of cylinder of 15mm diameter and 3mm thickness with composition of Ni0.5Zn0.5Fe2O4/Fe76Si9B10P5 were prepared by spark plasma sintering at the temperature of 507℃. Fe-based soft magnetic with low core loss fabricated via surface insulation by ball milling. It prevents magnetic dilution due to the formation of the ferrite coating layer.Giving rise to effective permeability and electrical resistivity of the SMCS compared with traditional phosphate coating. The prepared cylinder sample has been treatmented for 45min in controlled way in the temperature rage 360℃-460℃. Comparative analysis of magnetic properties was carried out of particular interests for this work are advanced. Fe-based amorphous nanocrystalline alloys with low coercivity. The beneficial effects of treatment under different temperature are discussed in terms of the improved magnetic performance of Ni0.5Zn0.5Fe2O4/Fe76Si9B10P5 alloys. Keywords: Key words: annealing treatment；soft magnetic properties；coercivity. G-75 A liquid-to-liquid transformation is demonstrated in the melts of Fe-based soft magnetic alloys Bangshao Dong, Hui Gao, Zongzhen Li, Nairi Cui, Ying Li, Guangqiang Zhang, Shaoxiong Zhou Advanced Technology & Materials Co., Ltd., Beijing Key Laboratory of Energy Nanomaterials, China Iron & Steel Research Institute Group, Beijing 100081, China Aims: To explore the secrets of molten Fe-based soft magnetic alloys at high temperature, and to offer theoretical reference for designing the craft of preparing amorphous ribbons. Methods: High temperature molten metal viscometer and molecular dynamics simulation techniques. Results: The melt properties of Fe-based soft magnetic alloys, Fe78Si9B13 (1K101) and Fe73.5Si13.5B9Nb3Cu1 (1K107), has been studied. Experimental results have shown that, a steep drop of viscosity near 1350℃ and 1400℃ for the two alloys occurred during their heating processes to 1550 ℃, respectively. While the relationship of viscosity with temperature obeys the typical Vogel–Fulcher–Tammann (VFT) functions during their cooling processes. This phenomenon is also observed for the recycled scraps from amorphous ribbons. It is speculated that this transformation will recur with long enough time at temperature below 1350 ℃. Viscosity results obtained by keeping melts at 1200-1300 ℃ for 180 minutes have confirmed this prediction. More interestingly, when cool the melt at 1350 ℃ in replace of at 1550 ℃, the viscosity during the cooling process overlaps completely with the data during the heating process. These facts further demonstrate that a liquid-to-liquid transformation occurs in the melts of typical Fe-based metallic glasses at a certain temperature. Combined with the melting and crystallization knowledge of Fe-based soft magnetic alloys, the nature of transformation is regarded as the process of Fe2B clusters decompose to Fe3B clusters. The quenching and relaxing procedures have been simulated by molecular dynamics simulations for Fe78Si9B13 alloys from 1873 K to 573 K, and no evident change is found for the structure variation. This is coincided with the VFT rule of viscosity during the cooling process. These findings enrich our knowledge about the nature of Fe-based alloy melts at high temperature, and provide theoretical reference for preparing amorphous ribbons by melt-spinning techniques. Conclusions:

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1. A liquid-to-liquid transformation demonstrated from the viscosity curves occurs at near 1350℃ for typical Fe-based metallic glasses (1K101, 1K107). This transformation will recur with long enough time at temperature below 1350 ℃; 2. The simulation results coincide with the VFT rule of viscosity during the cooling process. Keywords: Fe-based soft magnetic alloys, alloy melt, clusters, viscosity, liquid-to-liquid transformation G-76 Crystallization behavior and magnetic properties in bulk Fe-Nd-B-Nb amorphous alloys Hui Xu, Xiaohua Tan, Xiaoqian Huang School of Materials Science and Engineering, Shanghai University, Shanghai, P. R. China, 200072 Fe-based bulk amorphous alloys are very attractive due to their distinguished properties and low materials cost among others. Some dense permanent magnets with high precision can be produced by annealing the Fe-based bulk amorphous precursors. However, there still exists a scientific challenge that how to ensure these alloys with an combination of good glass forming ability as well as excellent hard magnetic properties after annealing. Moreover, the relationship between the magnetic behavior and micro-structure in crystallization is unclear. In this work, effects of Nb on the crystallization behavior and magnetic properties in bulk Fe72-xNd7B21Nbx

(x=2.0-3.0) amorphous alloys were investigated. The results showed that the crystallization behavior was sensitive to Nb content. A fully dense bulk Fe69.5Nd7B21Nb2.5 (x=2.5) permanent magnet was obtained with optimum magnetic properties with the remanence of 0.63 T, intrinsic coercivity of 448.97 kA/m and maximum energy product of 36.32 kJ/m3 after annealing at 1003 K for 10 min. The XRD and TEM results showed a coexistence of the Nd1.1Fe4B4 phase, α-Fe phase and Nd2Fe14B phase. Furthermore, 2.5 at% Nb addition strengthened the exchange interaction between soft magnetic phase α-Fe and hard magnetic phase Nd2Fe14B, which improved the magnetic properties. The present work provides a new idea to develop fully dense Fe-based bulk magnets by a devitrification process. Keywords: Fe-based bulk amorphous alloys; permanent magnets; alloying elements; crystallization; remanence G-77 Magnetotransport properties of a ferromagnetic metallic glass Wenjian Liu, Na Chen, Kefu Yao School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China Research purpose Ferromagnetic metallic glasses (MGs) are of both scientific and technological importance. In this study, we focus on the magnetotransport properties of a ferromagentic Co53Fe23Ta8B16 MG. A detailed study on its Hall effect and magnetoresistance is performed to further understand the exchange interaction between local magnetic moments and charge-carriers in this ferromagnetic MG. Experiments Thin films were deposited on glass and silicon substrates by radio frequency (RF) magnetron sputtering with a sintered powder target. The structure of the thin films was investigated by using an X-ray diffractometer (XRD) and a transmission electron microscope (TEM). The magnetic properties were measured with superconducting quantum interference device (SQUID). The magnetotransport properties were examined by a physical property measurement system (PPMS-9T).

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Results The magnetic properties of the Co53Fe23Ta8B16 MG thin film evidenced its ferromagnetism nature with a Curie temperature above 600 K. An apparent anomalous Hall effect is observed in the thin film, which occurs typically in a ferromagnetic solid as a consequence of spin-orbit coupling. Additionally, the thin film exhibits an anomalous magnetoresistance (MR) effect. At low fields in which the saturation magnetization is being approached, MR is negative due to a reduction of spin-dependent scattering from the local magnetic moments aligned by the field. At relatively high fields, MR becomes positive and continuously increases with the field without saturation. Conclusions A ferromagnetic Co53Fe23Ta8B16 metallic glass thin film was produced by magnetron sputtering. The ferromagnetic thin film shows both anomalous Hall effect and unusual magnetoresistance. Such anomalous MR is supposed to arise from the quantum interference effects including weak localization and electron-electron interactions in disordered ferromagnets Keywords: ferromagnetic metallic glass magneto-transport thin film G-78 Isothermal transition from β relaxation to α relaxation in metallic glass Lijian Song, Juntao Huo, Junqiang Wang Key Laboratory of Magnetic Materials and Devices & Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China Relaxation behaviors will split into alpha relaxation and beta relaxation in glass states. It has been a long-standing question to study the nature of the relaxation modes in glasses. Here, we study the relaxation kinetics in an Au-based metallic glass upon isothermal annealing below the glass transition temperature Tg using high-rate differential scanning calorimeter. It is interesting that a little free energy change leads to hundreds of times change of activation energy. It is intriguing to find that an isothermal transition from beta relaxation to alpha relaxation. Such an isothermal transition follows the nucleation-growth mechanism. The semi-quantitative construction of the potential energy landscape was proposed to describe the transition. These results are helpful for understanding the relaxation nature in glasses. Keywords: metallic glass, relaxation behaviors G-79 Magnetic properties of U-based amorphous alloy Pei Zhang, Huogen Huang, Haibo Ke, Pengguo Zhang, Hongyang Xu, Tianwei Liu Institute of Materials, China Academy of Engineering Physics U-based amorphous alloy has been seldom studied due to its radioactivity. The poor corrosion resistance is still the main concern for the application of U-based alloys because of the high chemical activity of U. As is known, amorphization can greatly improve the corrosion resistance of La, Zr-based alloys. Besides, the heavy atom of U and its unique 5f electron may bring new light for amorphous systems study. Therefore, the amorphization of U-based alloy is important for both the application and theoretical research. The interaction between 5f electron and other valence electron can influence the magnetic properties of U-based amorphous alloys. In the present work, U-based amorphous alloy including U, Fe, Pd, Os and Sn was successfully prepared and the magnetic properties of amorphous and crystalline state U-based alloys were investigated. It is

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found that complete amorphous alloy was formed and the Curie temperature Tc for U-based amorphous alloy is about 10 K. Below Tc, it is ferromagnetic, when the temperature rises above Tc, it is paramagnetic. Besides, the coercivity of U-based amorphous alloy is much higher than its crystalline state. It can be attributed to the difference in microstructure and defect concentration. Keywords: U-based amorphous, Magnetic properties, Curie temperature, Coercivity, Microstructure G-80 Mechanical and magnetic properties of new (Fe,Co,Ni)-B-Si-Ta bulk glassy alloys Yaoxiang Geng1, Jianbing Qiang2, Yingmin Wang2, Chuang Dong2, Ojied Tegus3 1. School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China 2. Key Laboratory of Materials Modification (Ministry of Education), Dalian University of Technology, Dalian 116024, China 3. Inner Mongolia Key Laboratory for Physics and Chemistry of Functional Materials, Inner Mongolia Normal University, Hohhot 010022, China Fe-based amorphous alloys are well known for their good magnetic properties. Similar atom substitution is an effective method for enhancement the glass-forming ability (GFA) and mechanical property of Fe-based glassy alloys. Present work intends to investigate the effectiveness of the replacement of Fe by Ni and Co in Fe70B16.7Si8.3Ta5 bulk glassy alloys. The experimental results show that new Fe-based bulk glassy alloys with diameters up to 1.5 mm were formed in Fe60-xCoxNi10B16.7Si8.3Ta5 (x = 0, 10, 20 and 30) system by the copper mold casting method. The substitution of Ni and Co for Fe causes an increase in the GFA. As the Co content increases, the glass transiting temperature (Tg) and onset crystallization temperature (Tx) remain the same values, but the liquidus temperature (Tl) decreases, resulting in an increase of dc and reduced glass transition temperature (Trg, = Tg/Tl) from 1.0 mm and 0.577 to 1.5 mm and 0.621. The Fe60Ni10B16.7Si8.3Ta5 glassy alloys show lowest Tg and Tx, about 842 K and 882 K, in Fe70B16.7Si8.3Ta5 and Fe60-xCoxNi10B16.7Si8.3Ta5 serial glassy alloys. A new GFA indicator, enthalpy of supercooled liquid (ΔH), is mentioned in this work, and it is more effectively than supercooled liquid region (ΔTx) in characterization the GFA of similar atom substitution system glass alloys. Nano-indentation measurement shows that the calculated elastic modulus and hardness of bulk glassy alloys increase from 180 MPa and 15 GPa to 200 GPa and 17 GPa with increasing Co content from 0 to 30 in Fe60-xCoxNi10B16.7Si8.3Ta5 glassy alloys. The syntheses of new (Fe,Co,Ni)-B-Si-Ta glassy alloys with good mechanical and soft magnetic properties are encouraging for future development of Fe-based bulk glassy alloys as structural and functional materials. Keywords: (Fe,Co,Ni)B-Si-Ta bulk glass alloys; Glass-forming ability indicator; Mechanical property; Magnetic property G-81 Evolution of Nano-porous Structure on Fe-based Amorphous Alloys bingying ni Key Laboratory of Advanced Structural Materials,Ministry of Education,Changchun University of Technology Fe-based amorphous alloys have very excellent soft magnetic properties, catalytic activity and high mechanical strength. This paper design and optimize the composition on the basis of Fe-Si-B amorphous alloys crystallization kinetics theory, study the procedure of nano-porous structure made on Fe-based amorphous alloys by dealloying.

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We obtain the optimum process parameters by controlling the corrosion solution, solution concentration, reaction temperature and reaction time in the procedure. By using these optimum process parameters, we have prepared the nano-porous metal, on which the distribution of pores are uniform. A layer or several layers of nano-porous structure is successfully prepared by the chemical dealloying method, the average pore size of the first layer is about 180nm, the average pore size of the second layer is about 80nm and the average pore wall thickness is about 60nm. It has been found that Fe-Si-B amorphous alloys with the nano-porous structures have high efficiency of phenol degradation treatment and lead to high catalytic ability. Keywords: Fe-based amorphous alloys; nano-porous structure; dealloying; uniform distribution; porosity G-82 Detcting the slow beta relaxation by DSC compared with that by DMA Chao Zhou1,2, Lina Hu1, Yuanzheng Yue2 1. Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061, China 2. Department of Chemistry and Bioscience, Aalborg University, DK-9220 Aalborg, Denmark Study on the slow β relaxation helps us understand the glass transition and the structural evolution during cooling in metallic glass formers. We investigate the activation energy of the onset of the sub-Tg exothermic peak (Eonset) in 28 metallic glasses (MGs) through calorimetric method and its dependence of the cooling rates. The results show a correspondence between Eonset and that of the slow β relaxation (Eβ) in MGs with a fictive temperature Tf

’ derived by certain hyperquenching rate. We reveal a linear relationship between this temperature Tf

’ in hyperquenched MGs and the liquid fragility of metallic glass formers. This correlation indicates the close connection between the competition among the α and slow β relaxation modes and liquid fragility in supercooled metallic glass formers, and is qualitatively explained by the potential energy landscape. The present work provides a new simple hyperquenching-calorimetric method to characterize the β relaxation and helps to trap its structural feature in MGs. Keywords: metallic glass β relaxation glass transition G-83 Correlation between structure and glass-forming ability in CuZr Alloys: a cavity perspective huaping zhang Department of Physics, Renmin University of China, Beijing 100872, China Glass-forming ability (GFA) of metallic alloys is a key issue in the fabrication of bulk metallic glasses and their application in industry. However, the mechanism of GFA is far less understood. It has been revealed in experiments that GFA of binary CuZr alloy varies with composition, exhibiting good GFA as Cu concentration is around 50%, 56% and 64%, respectively. Although much efforts have been devoted to the origin of the composition dependence of GFA in CuZr alloy, it still remains elusive. In this work, ab initio molecular dynamics simulations were performed for CuZr metallic liquids and glasses with different compositions. By analyzing cavities in CuZr metallic glasses, it is found that the variation of cavity volume with composition is consistent with the composition dependence of GFA, suggesting a new insight into the correlation between structure and GFA in metallic glasses. The evolution of cavities in glass transition in CuZr metallic liquids were also analyzed for understanding the nature of glass and glass transition. Keywords: metallic alloy, glass-forming ability, Cu-Zr alloys, cavity

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G-83 Correlation between structure and glass-forming ability for Al86Ni14-xLax(x=3,5,9): An Ab Initio Molecular Dynamics Study fangru wang Department of Physics, Renmin University of China, Beijing 100872, China The low glass-forming ability (GFA) of Al-based metallic glasses (MGs) is bottleneck that greatly limits their potential engineering application. GFA of Al-based MGs shows strong composition dependence, but the underlying mechanism remains poorly understood. In this work, we investigated the atomic-level structure feature in model system of Al86Ni14-xLax(x=3,5,9) MGs via ab initio molecular dynamics simulations. The evolution of atomic structures with composition was systematically analyzed and a relationship between atomic structure and GFA in Al-base MGs was investigated. It is found that Al-centered icosahedral clusters are still a significant factor to influence GFA in Al-based MGs. The agreement between coordination number and local five-fold symmetry was also found to closely relate to GFA. This finding provides a better understanding for the improvement of GFA of Al-TM (transition metal)-RE (rare earth metal) MGs. Keywords: GFA, Al-based MGs, ab initio molecular dynamics simulations G-84 Correlation between liquid-liquid transition in CuZr melts and Glass forming ability of the alloys Xi Zhao, Lina Hu, Chunzhen Wang, Haijiao Zheng, Qijing Sun, Xiufang Bian Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061, China Some glass-forming liquids may have different liquid phases of the same composition but different structure, density and entropy. Here, we report the thermodynamic and dynamic evidences of a liquid–liquid transition (LLT) in ten Cu-Zr glass-forming liquids well above the liquidus temperature. By introducing the parameters F and D’ to quantify, respectively, the transition strength of liquid dynamics and cluster dynamics induced by the LLT, we find a close relationship between the F (or D’) value and the critical thickness representing the glass forming ability (GFA). For the ten CuZr alloys, the composition dependence of the F (or D’) is quite similar to that of the GFA. This indicates that the LLT is beneficial to the glass formation of CuZr alloys. A scenario concerning the evolution of local structures involved in LLT has been plotted, in which the different GFA among the CuZr alloys is attributed to the competitions between perfect icosahedra and distorted icosahedra. This scenario could explain the different heat released corresponding to the LLT in CuZr melts. This work firstly uncovers the role of the LLT in melts on the glass formation of solids and, at the same time, sheds light on the inheritance of properties of glassy solids from the aspect of the detectable dynamics of high-temperature melts. Keywords: metallic glass liquid-liquid transition glass formation G-85 Activation relaxation technique study on β-relaxations mechanism in metallic glasses haiyan xu Department of Physics, Renmin University, Beijing 100872, China β-relaxation is the source of the dynamics for glass state and has practical significance for many features and properties of metallic glasses. It closely refers to flow units and shear transformation zones in metallic glass.

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Different β-relaxation behavior has been experimentally observed in different metallic glasses. However, what causes the difference in β-relaxation in these two systems is still unclear. In this work, using the activation relaxation technique incorporated molecular dynamics simulations, the activation energy spectra, relaxation spectra and atomic structures in La55Ni20Al25 and Cu46Zr46Al8 metallic glasses were studied in detail. It is found that different distribution of activation energy and relaxation in these metallic systems reveal that β-relaxation could be more obvious in the systems with lower energy barriers, greater degree of cascade relaxation and lager size of local rearrangement regions. This finding provides a new insight into the mechanism of β-relaxation in metallic glass. Keywords: metallic glasses, β-relaxation, activation relaxation technique G-86 Formation of U-based metallic glasses Huogen Huang1, Haibo Ke1, Yingmin Wang2, Pei Zhang1, Pengguo Zhang1, Tianwei Liu1 1. Institute of Materials, China Academy of Engineering Physics 2. Key Laboratory of Materials Modification (Ministry of Education), Dalian University of Technology U-based metallic glasses, which are strongly potential materials in nuclear-related industries, have been less studied after discovered, possibly because of the radioactivity and toxicity of the key element. In previous studies, the reported glasses of this kind in about a dozen of systems show very poor glass forming ability (GFA). For example, no glass transition temperature (Tg) has been observed in their calorimetrical analysis. Therefore, their glass formation that is still unclear to date needs to be studied for developing better U-based glasses. For the preparation of uranium alloys, the purities of the starting metals were 99.5 wt.% for depleted uranium and >99.9 wt.% for the others. Alloy ingots were fabricate by arc-melting mixtures of the constituent metals in a water-cooling copper crucible in high pure Ar atmosphere. Each ingot was remelted four times to ensure compositional homogeneity. Rapid liquid-quenching was conducted with these ingots by using quartz tubes and a single copper melt-spinner at a surface velocity of ~50m/s, and ribbon samples with the dimensions of 1~3mmwide and 20~40mm thick were made. The structures of the ribbon samples were examined with an X-ray diffractometer (XRD) with Cu-Kα radiation. Differential scanning calorimetry (DSC) measurements were carried out at a constant heating rate of 0.333K/s. Various glassy alloys, which were designed near eutectics in U-Fe, U-Co, U-Ni and U-Cr systems, showed the same glass-forming tendency that they can form amorphous phase but the best glass formers were not at the eutectic compositions. The XRD results indicate that a single amorphous structure was able to obtain in U-Cr system, but not in the other systems. The DSC patterns displayed no Tg feature for all the alloys and the reduced crystallization temperature (Trx) of 0.486~0.559 for the U-Fe, U-Ni and U-Co alloys of 0.561~0.606 for the U-Cr alloys, reflecting relatively weak GFA for these glassy materials. When compared with U-Fe, U-Co and U-Ni systems, U-Cr system possessed relatively anomalous stronger GFA that contradicts the prediction based on thermodynamics, kinetics and efficient structural packing. This means thus U-Cr a potentially fundamental model system for deeply understanding the glass formation of actinide amorphous alloys. Minor alloying was applied to improve the GFA of U-Fe and U-Co systems. A variety of elements with different physical and chemical properties, including Be, Al, Si, Cu, Pd, Sn, Zr and Y, were chosen for minor alloying. It is demonstrated that Sn and Al significantly favored the GFA, Si displayed a secondary improvement, the functions of Be and Cu were slight while Pd, Y and Zr deteriorated the GFA. Evaluated from melting temperatures, electro-negativity and atomic sizes of these alloying elements, their effect on the GFA might be related to the change of the liquid stability and the crystallization-driving force.

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Most important, a series of U-Co-Al and U-Fe-Sn metallic glasses, which were designed with the addition of Al and Sn, displayed greatly improved GFA and thermal stability. On one hand, prominent Tg feature was found in the DSC patterns of some of the ternary glasses with the highest value of 625K. On the other hand, Trx can reach as high as 0.585 for U-Co-Al glasses, comparable to some bulk conventional metallic glasses. In summary, this work not only adds new members to the family of metallic glasses, but also provides some guiding knowledge for the development of novel amorphous uranium materials. Keywords: Metallic glass; Amorphous alloy; Uranium alloy G-87 Effects of pressure on structural evolution in monatomic liquid and glass J. Y Mo1, H. S Liu1, Q. L Liu1, W. M. Yang1,2 1. School of Sciences, China University of Mining and Technology, Xuzhou 221116, China 2. State Key Laboratory for Geomechanics and Deep Underground Engineering, School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, China High pressure (HP) can cause considerable impacts on atom spacing or chemical bonding, which is considered as an important factor in glass formation besides well-studied temperature and chemical composition. Recently, there have increasing reporting on the effects of pressure on the glass formation[1][2]. However, previous studies mainly focus on the effects on the nucleation and growth in multicomponent metallic glasses. Actually, by studying simple monatomic glasses, we can easily investigate the mechanism of phase transitions or related phenomena[4], since we can focus on the topological order of the atomic arrangements, neglecting the chemical orders, which is important in multicomponent systems. Molecular dynamics simulations is used to study the local structural evolution and glass formation in monatomic iron melts rapidly cooled under different pressures (0-20 GPa). The glass transition temperature Tg, the melting temperature Tm, and the supercooled liquid temperature T are calculated to study the glass forming ability, and the pair distribution function and Voronoi polyhedron (VP) analyses are employed to investigate the structure changes with pressure. It is found that the iron glasses can be formed at different cooling rates under different pressures, the critical cooling rate increases slowly when the pressure is less than 15 GPa while a steep rise shown with further increasing pressure; the melt cooled under higher pressure shows a larger fraction of Voronoi polyhedron (VP) with lower local five-fold symmetry (LFFS) [3]; moreover, with increasing pressure, the average degree of five-fold symmetry W and the fraction of BCC-type VP C are found to increase and decrease correspondingly, indicating a decreased LFFS. Results show that pressure can depress the glass forming ability and LFFS in monatomic iron glass, especially under high pressure. [1] W.H. Wang, D.W. He, D.Q. Zhao, Y.S. Yao, and M. He, Appl. Phys. Lett. 75, 2770 (1999). [2] W.H. Wang, L.L. Li, and R.J. Wang, Phys. Rev. B 62, 11292 (2001). [3] Y.C. Hu, F. X. Li, M.Z. Li, H. Y. Bai and W. H. Wang, Nature communications 6 (2015). [4] Hoang, V. V., and T. Q. Dong. Phys. Rev. B 84.17(2011). Keywords: monatomic iron glasses, Molecular dynamics simulation, local five-fold symmetry, Pressure G-88 Analytical description for the crystallization kinetics of amorphous alloys Yihui Jiang1, Feng Liu2, Shuhua Liang1 1. School of Materials Science and Engineering, Xi’an University of Technology, Xi’an, Shaanxi, 710048, China

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2. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an, Shaanxi, 710072, China Recent studies have shown the importance of controlled crystallization of amorphous alloy as its mechanical and physical properties are improved with annealing treatments. The analytical model for describing crystallization kinetics has been proposed on the basis of the Kolmogorov-Johnson-Mehl-Avrami equations. However, there are some limitations on the application of the model. In order to improve the effectiveness of this kinetic approach, it was modified and extended recently from the following aspects. (i) Taking into account multi-processes, the model with multi transformation rate peaks was applied to the crystallization of amorphous alloy with complex mechanism. (ii) By introducing the conception of fragility, the Vogel–Fulcher–Tammann relationship was incorporated into the crystallization kinetics, and the temperature-dependent activation energy was explained. (iii) With the general rate equation, the crystallization kinetics during continuous cooling annealing has been described. The recent development of analytical model suggests that it is a flexible model for describing the crystallization kinetics. Keywords: Crystallization; Kinetics; Analytical model; Amorphous alloy G-89 Characteristics of dynamic mechanical behaviors of a Ti-based metallic glass composite Guojian Lv, Jichao Qiao, Yao Yao Northwestern Polytechnical University In order to well understand the dynamic mechanical properties of bulk metallic glass (BMG) composites, Ti-based BMG composite was investigated using dynamic mechanical analysis in the current work. The data of storage modulus G’ and loss modulus G’’ were measured using single cantilever mode, the experiments were conducted with both frequency sweep and temperature sweep. The influence of the secondary crystalline phase on the dynamic mechanical response of Ti-based BMG composite is particularly analyzed. When in super-cooled liquid region, the glassy matrix is superplastic, while the dendrite is still in the solid state. Due to existence of the secondary crystalline phase, Ti-based BMG composite shows a different tendency compared with typical BMGs in both the temperature spectrum and the frequency spectrum. Based on quasi-point defects (QPD) model, the kinetic characteristics of glass transition of Ti-based BMG composites can be basically explained and quantitatively described. Our experimental findings provide an insightful information on the complex structural relaxation of BMG composites. Keywords: Metallic glass composite, Dynamic mechanical analysis, Structural relaxation, Quasi-point defects G-90 Nanoglass prepared by pulsed electrodeposition Chunyu Guo, Yini Fang, Bin Wu, Si Lan, Guo Peng, Tao Feng Nanjing University of Science & Technology Nanoglasses are a new kind of non-crystalline materials consisting of amorphous nanometer-sized grains connected by amorphous interfaces (called glass/glass interfaces). It has been found that the interfaces have an atomic and electronic structure deviating from those of the adjacent amorphous grains. As a result of the different atomic and electronic structures of the glass/glass interfaces, the properties of nanoglasses differ from the properties of the melt-quenched glass with the same chemical composition. As an example, it has been found that

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a Fe90Sc10 nanoglass is ferromagnetic at 300 K whereas the corresponding melt-quenched glass is paramagnetic, and only exhibits ferromagnetic order at a temperature below 200 K. Moreover, nanoglasses have been reported to be more ductile, more bio-compatible, and catalytically more active compared to the corresponding melt-quenched glasses. Hence, by modifying the microstructure of nanoglasses by means of controlling the size of the amorphous grains (i.e., the volume fraction of the interfacial regions) and/or by varying their chemical compositions the properties of nano-glasses may be modified in a controlled manner. The original and most frequently used route to nanoglasses has been the consolidation of nanometer-sized amorphous clusters previously generated by means of inert gas condensation (IGC) or by magnetron sputtering (MS). The development of new preparation methods for nano-glasses is desirable in order to explore the full potential of the new materials. Here, we report on a new method for preparing nanoglasses based on electrodeposition. Pulsed electrodeposition has been reported to result in nanocrystalline materials with large volume fraction of crystal/crystal interfaces, i.e. grain boundaries. Furthermore, electrodeposition is a widely adopted method to prepare amorphous films. Hence, a multi-phase pulsed electrodeposition method (MP-PED) was developed to prepare high purity amorphous films with structural features on the nanometer scale. In case of Ni-P, the pulsed electrodeposition process involves the following two steps: the formation of amorphous nanometer-sized Ni-P clusters and the subsequent growth of these clusters into a Ni-P nanoglass consisting nanometer-sized amorphous grains connected by amorphous grain/grain interface (like in a poly-crystal). The microstructure of MP-PED prepared Ni-P nanoglass was studied by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), small-angle X-ray scattering (SAXS), and X-ray photoelectron spectroscopy (XPS). The results obtained from these studies suggest that the MP-PED technique is an economical and effective way to produce high-quality nanoglasses. Keywords: Nanoglass, electrodeposition, interface G-91 Atomistic Approach to Design Favored Compositions for the Ternary Al-Mg(Cu)-Ca Metallic Glass Formation Shuai Zhao Tsinghua University As is known, the formation of metallic glasses is always a non-equilibrium process, due to the severe limitation of kinetic conditions, complicated intermetallic compounds are not able to nucleate and grow. The competing phase against the metallic glass is therefore the solid solution frequently of a simple structure. Consequently, the issue related to the glass formation is converted into comparing the relative stability of the solid solution to its amorphous counterpart, which was decided by the atomic interaction. Thus, it is a good choice to predict the glass formation compositions from interatomic potential, and tow ternary system has been well predicted. A realistic interatomic potential is constructed for the Al-Mg (Cu)-Ca system under the smoothed and long-range second-moment approximation of tight-binding formalism, and then applied in Monte Carlo simulations to compare relative stability of crystalline solid solution versus its disordered counterpart using solid solution models. Simulation results not only predict a pentagonal region, within which the Al-Mg-Ca metallic glass formation is energetically favored and the region is defined as glass formation region (GFR), but also determine the amorphization driving force (ADF), i.e. the energy difference between the solid solution and disordered state. The ADF is proposed to be correlated positively with the glass forming ability (GFA), suggesting that the larger the ADF is, the easier the amorphous alloy is to be produced or the more stable the amorphous alloy is. The predictions are fairly consistent with the experimental results reported so far.

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With the aid of ab initio calculations, the realistic interatomic potential of Al-Ca-Cu system is constructed and then applied to molecular dynamics simulation to investigate the formation of Al-Ca-Cu metallic glasses. The simulations predict a hexagonal composition region, i.e., glass-formation region, within which an amorphous alloy is energetically favored to form. Moreover, the energy difference between the solid solution and it amorphous counterpart, defined as the amorphization driving force, is also calculated. The calculation shows that the alloys locating the sub-region of AlxCa100-x-yCuy, (x=25-35; y=25-40), have larger amorphization driving forces. It suggests that the amorphous alloys in the sub-region are more obtainable or stable than others in the Al-Ca-Cu system. The simulation and calculation help understanding the metallic glasses formation and provide some guidance in designing the composition the Al-Ca-Cu glass alloys. Keywords: glass formation range, glass formation ability, termary metallic glass G-92 Amorphous Ni-Co nano-alloy catalyzed highly efficient hydrogen generation from dehydrogenation of ammonia borane Hongli Wang, Dawei Gao, Cong Wang, Zhankui Zhao College of Materials Science and Engineering, Key Laboratory of Advanced Structural Materials, Ministry of Education, Changchun University of Technology, Changchun 130012, China In this work, bimetallic NiCo nano-alloys with different crystallinities are synthesized by two different reduction methods towards mixed metal ions Ni2+ and Co2+, and then the as-synthesized NiCo nano-alloys are used as catalysts for H2 generation from hydrolytic dehydrogenation of NH3BH3 aqueous solution under ambient atmosphere at room temperature. It is found that amorphous NiCo through in-situ synthesis using NaBH4 and NH3BH3 as reductants exhibits much higher catalytic activity with an initial TOF value of 22.9 mol H2·mol catalyst-1·min-1 than crystalline NiCo through ex-situ synthesis using only NaBH4 as reductant. The excellent catalytic performance of in-situ synthesized NiCo attributes to its amorphous structure. This amorphous catalyst is likely to be useful for fuel cells, metal/air batteries, and electrochemical sensors, and could also provide excellent opportunities for studying the molecular mechanisms of heterogeneous catalysis. Keywords: Amorphous materials; Heterogeneous catalysis; Hydrogen; Nickel-cobalt; Materials science G-93 Study of the effects of metalloid elements (P, C, B) on Co-based amorphous alloys by ab initio molecular dynamics simulations Jiawei Jiang1, Qiang Li1, Haiming Duan1, Hongxiang Li2 1. School of Physics Science and Technology, Xinjiang University 2. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing In this work,Co80P14B6, Co80P13C7 and Co80B14C6 amorphous alloys are chosen to be studied by ab initio molecular dynamics simulations, so the effects of the metalloid elements (P, B and C) on the atomic structure, glass forming ability (GFA) and magnetic properties of Co-metalloid amorphous alloys can be investigated. We have analyzed the local atomic structures in the liquid (at 1600 K) and glass state (at 300 K) by pair distribution functions (PDFs), VoronoiPolyhedra (VPs) and bond pair (BPs) analyses. The analysis of the pair distribution function indicates that the first peak of gCo-Co(r) has no change in the distance in Co80P13C7 alloys, increases by 0.03 in Co80B14C6 alloy and reduces by 0.05 in Co80P14B6 alloy, as the temperature reduces from 1600 K to 300 K. The different change in the position of the first peaks of gCo-Co(r) in the three alloys with the decrease of

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temperature may be related to the different bond length between Co atoms in ferromagnetic state and paramagnetic state. The analysis of the gCo-Co(r) and gCo-M(r) PDFs indicates that the Co-Co bond length in Co80B14C6 alloy is the shortest among the three amorphous alloys and the bonding of Co-B is weaker than that of Co-C and Co-P, both which are not benefit to the GFA. Additionally, the B atom presents poor solute-solute avoidance in Co80B14C6 alloy, which hinders the GFA. The analysis of VPs indicates that the major Voronoi indices of Co-centered VPs can be regarded as, , , , and in all the three alloys, indicating that the icosahedral-like cluster frequently exist in all the three melts. The major Voronoi indices of P-centered VPs are similar to that of Co atom-centered VPs in both Co80P14B6 and Co80P13C7 alloys, i.e. the most dominated cluster for P atoms is icosahedral-like, suggesting that P atom has the similar environment with Co atoms or locate at the substitute position of Co atoms. C-centered VPs are mainly composed of and , which are referred to as the Archimedean antiprism and the tri-capped trigonal prisms (TTP), respectively, in both Co80P13C7 and Co80B14C6 alloys. B-centered VPs show obviously different index configuration in Co80P14B6and Co80B14C6 alloys. In Co80P14B6 alloy, the occupies a very large proportion, suggesting that B atoms are mainly located at the center of prism-like VPs. But in Co80B14C6 alloy, the is not the main index and the most two indices are and ,which presents icosahedral-like clusters. Therefore the analysis of VPs indicates that the P-centered cluster shows a more complex local structure in the Co-based alloy melts, thus enhancing the GFA. Based on the above analyses, we predict that the GFA of the three Co-based alloys increases in the order of Co80B14C6, Co80P13C7 and Co80P14B6. The bond pair analysis reveals that the three Co-based amorphous alloys are mainly composed of perfect and distorted icosahedral BPs such as 1541, 1551 and 1431.The analysis of DOS reveals that all the three Co-based amorphous alloys present the same weak ferromagnetism. The major magnetization isdominated by Co 3d states, and the metalloid elements of B, C and P present the similar average magnetic moments in the Co80P14B6, Co80P13C7 and Co80B14C6 amorphous alloys, which are about -0.06μB, -0.05μB and -0.02μB, respectively. Keywords: Co-based amorphous alloys; ab initio molecular dynamics simulations; glass forming ability; magnetic properties G-94 Amorphous NiCoPt/CeOx nanoparticles as highly efficient catalyst for hydrogen generation from hydrous hydrazine Cong Wang, Hong-li Wang, Zhan-kui Zhao College of Material Science and Engineering, Key Laboratory of Advanced Structural Materials, Ministry of Education, Changchun University of Technology Hydrous hydrazine (H2NNH2·H2O) is a promising hydrogen carrier material because of its high content of hydrogen (8.0wt%) and easy recharging as a liquid. Amorphous Ni8.1Co1Pt0.9/CeOX nanoparticles with low precious-metal content are synthesized by a facile co-reduction method at room temperature under ambient atmosphere. The resultant Ni8.1Co1Pt0.9/CeOX are employed as an efficient nanocatalyst towards the decomposition of hydrous hydrazine to H2, which exhibits excellent catalytic activity, 100% H2 selectivity and a high turnover frequency (TOF) value of 93.75 h-1 at 298 K. Furthermore, the amorphous Ni8.1Co1Pt0.9/CeOX catalyst obtained due to the addition of CeOX possesses much higher TOF value than that of the crystalline Ni8.1Co1Pt0.9. The development of the improved catalytic performance and low-cost catalyst with amorphous structure is believed to strongly promote the practical application of hydrous hydrazine as a hydrogen storage material. Keywords: Amorphous composite; Heterogeneous catalysis; Hydrazine; Hydrogen storage

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G-95 Design of super-multicomponent Zr-based bulk metallic glasses with high glass forming ability and low impurity-sensitivity Chen Chen1, Xiaodong Jia1, Zhikai Gao1, Huan Sun1, Ran Wei1, Fushan Li1, Tao Zhang2 1. School of Material Science and Engineering, Zhengzhou University 2. Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University High sensitivity to impurities in raw materials severely hinders the commercial application of Zr-based BMGs. However, increasing compositional complexity would be beneficial for lowering the impurity-sensitivity for this series of materials. In this work, a strategy for designing super-multicomponent Zr-based BMGs with high compositional complexity and high glass forming ability (GFA) was proposed, and a Zr50Ti4Y1Al10Cu25Ni7Co2Fe1 alloy with critical diameter (dc) of 16 mm was synthesized based on this strategy. It is found that, the GFA of this alloy is not influenced by purity of raw materials. Moreover, the alloy synthesized by low-purity raw materials has higher mechanical properties compared with those produced by high-purity ones, which is resulted from the impurity-induced nano-crystallization in the glassy matrix. This study provides a useful guideline for the development of low-cost industrial Zr-based BMG productions. Keywords: super-multicomponent, bulk metallic glass, glass forming ability, impurity-sensitivity, nano-crystallization G-96 Microstructural control via copious nucleation manipulated by in-situ formed nucleants: large-sized and ductile metallic glass composites Wenli Song1, Yuan Wu1, Di Cao1, Jie Zhou1, Fei Zhang1, Yao Zhang1, Hui Wang1, Xiongjun Liu1, Houwen Chen2, Zhenxi Guo3, Zhaoping Lu1 1. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China 2. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China 3. Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China Due to their long-range disordered atomic packing, bulk metallic glasses (BMGs) lack dislocations and slip systems, which makes them extremely brittle, especially in tension. Recently, an effective approach for surmounting this barrier is to precipitate transformable crystals in BMG matrices which give rise to large tensile ductility and work-hardening capability benefited from effects of transformation-induced plasticity (TRIP). However, all the currently available TRIP-reinforced BMG-composites have a limited dimension, yet microstructure control for producing uniform, appropriately sized precipitates during undercooling large-scale glass-forming systems is still a long-term challenge due to elemental segregation and rapid grain growth resulted from slow cooling rates. In this letter, we report a novel strategy to control precipitation behavior of the austenitic phase and obtaining large-sized BMG-matrix composites with large tensile ductility and strong work-hardening behavior. By inducing heterogeneous nucleation of the transformable reinforcement via in-situ forming potent nucleants, characteristics of the B2-CuZr austenitic phase were well manipulated, and the resultant BMG-composites having a critical diameter around 1 centimeter and showed a significant tensile strain of 7.0±1.0%, along with a work-hardening index of 0.3. Our work has important implications for developing BMG composites with outstanding properties which can be utilized as practical engineering materials.

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Keywords: bulk metallic glass composites; transformation induced plasticity; heterogeneous nucleation; work-hardening G-97 The effects of impurities on glass-forming ability and mechanical properties of Fe-based bulk metallic glasses Hongxiang Li1, Changqiu Li1, Di Cao1, Qiang Li2, Zhaoping Lu1 1. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, 100083, China 2. School of Physics Science and Technology, Xinjiang University, Urumqi, Xinjiang,830046, China Fe-based bulk metallic glasses (BMGs) have attracted much attention due to their unique properties and the plentiful resources of iron on the earth. In order to facilitate widespread uses of Fe-based BMGs as engineering materials, cost-effective mass production using the industrial raw materials under a low vacuum condition should be applied. Thus, it is unavoidable to understand effects of impurities either contained in industrial raw materials or contaminated from preparation processes, on the glass-forming ability (GFA) and mechanical properties of the Fe-based BMGs. Here, our latest results about roles of oxygen and sulfur will be reported. We found that addition of an optimum amount of either oxygen or sulfur improved the GFA while excessive doping degraded the GFA. Nevertheless, addition of even a small amount of oxygen or sulfur severely deteriorated the compressive plasticity of the Fe-based BMGs. The underlying mechanisms responsible for the observed effects of the impurities will also be discussed in detail. Keywords: Fe-based bulk metallic glasses; Glass-forming ability; Mechanical properties; Impurities. G-98 Viscoelasticy-induced Structural Anisotropy in Amorphous Materials Yang Tong1, Zhinan An2, Wojciech Dmowski2, Takeshi Egami2, P.K. Liaw1, J.J. Kai1 1. City University of Hong Kong 2. University of Tennessee-Knoxville, USA Viscoelastcity is closely related to flow behavior in amorphous materials due to a viscoelasticity-to-viscoplasticity transition. As the precursor of plastic flow in amorphous materials, the strongly-localized viscoelastic event may provide an insight into the understanding of mysterious deformation defects in amorphous materials. Here, viscoelasticity in Zr55Cu30Ni5Al10 metallic glass and amorphous selenium is investigated using synchrotron X-ray diffraction. By analyzing the 2-dimensional diffraction pattern, two types of structural anisotropy induced by viscoelasticity are revealed. Furthermore, the origin of the structural anisotropy will be dicussed. Keywords: viscoelasticity, amorphous materials, high energy X-ray diffraction G-99 Ultra-stable Ni-P nanoglass with glass/glass interface Si Lan1,2, Tao Feng1, Xunli Wang2, Chunyu Guo1, Horst Hahn1,3, Herbert Gleiter1,3 1. Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, 200 Xiaolingwei Avenue, Nanjing, P. R. China 2. Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, China

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3. Institute for Nanotechnology, Karlsruhe Institute of Technology (KIT), Karlsruhe 76021, Germany Objectives or Aims: Conventional nanoglasses (NG) are amorphous materials prepared by consolidation method using nanometer-size glassy powders. We have recently synthesized high-quality Ni-P NG using pulse electro-deposition. This paper aims for revealing the atomic-to-nanoscale structure origins of the ultra-thermal stability for NG. Methods: We studied the thermal behavior and microstructure using differential scanning calorimetry (DSC), small-angle x-ray scattering (SAXS) and time-resolved synchrotron diffraction. Results: The DSC scans revealed higher Tx of NG than those of as-cast Ni-P metallic glass (MG).Model fitting for SAXS profile of NG shows the presence ofspheroid particles with a diameter of 6-24 nm. Time-resolved synchrotron diffractionupon heatingillustrated that theappearance of the Bragg peaks for NG is ~ 33 K higher than that for MG. Careful pair distribution function (PDF) analysis revealed that the coordination shells at medium-range length scale of NG have larger atomic distance than those of MG. Conclusions: The above results indicate that there exists aglass/glass interfacial structure with unique medium range ordering (MRO), which may play an importantrole for resisting atomic re-arrangement during crystallization of NG. Our observations also support the findings of a recent simulation paper (D. Danilov, et al., ACS nano, 10, 2016) for ultra-stability of NG. To whom correspondenceshould be addressed:#tao.feng@njust.edu.cn, *xlwang@cityu.edu.hk. Keywords: Nanoglass;interface;ultrastability G-100 Cluster plus glue atom model and Fe-based multi-component transition metal metalloid bulk metallic glasses

Gul Jabeen Naz, Cuang Dong Key Laboratory of Materials Modification (Ministry of Education), Dalian University of Technology, Dalian 116024, China

It is known that bulk metallic glasses follow simple composition formulas [cluster](glue atoms) within the

framework of the cluster-plus-glue-atom model. In this model, an amorphous structure of high stability (or high

glass forming ability) is dissociated into a characteristic first-neighbor polyhedron cluster plus one or three glue

atoms located between the clusters, and the total number of valence electrons per unit cluster formula (e/u) is

close to 24. The present work is devoted to understanding the composition rule of Fe-Based multi-component

transition metal-metalloid bulk metallic glasses using the cluster formula approach. After a comprehensive survey

of typical bulk metallic glasses based on binary systems Fe-(B,P,C), only three devitrification phases are

identified, from which three principal clusters are obtained, respectively octahedral antiprism [B-B2Fe8] from

devitrification phase BFe2, capped trigonal prism [P-Fe9] from Fe3P, and capped trigonal prism [C-Fe9] from CFe3.

Then these cluster formulas matched with one or three glue atoms, so that the total number of valence electrons

per unit cluster is close to 24. So the relevant eutectic points FeB FeP, and FeC are interpreted using the cluster

formula i.e. [B-B2Fe8]Fe, [P-Fe9] P2Fe and [C-Fe9]C2Fe.

G-101 Study of Zr52Cu35Al8Co2Nb3 bulk metallic glass composites with peculiar B2 CuZr phases H.Y. Lu, Z.W. Zhu, Z.K. Li, H.M. Fu, H. Li, A.M. Wang, H.W. Zhang, H.F. Zhang*

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Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China *Corresponding author, Email: hfzhang@imr.ac.cn Limited glass forming ability (GFA) and unstable B2 CuZr phases in (Cu0.5Zr0.5)100-xAlx system restrict the sample size of the bulk metallic glass composites (BMGCs). In this work, a newly developed metallic glass composite with the composition of Zr52Cu35Co2Nb3Al8 (denotes as Z35238) with high GFA and peculiar B2 CuZr phases is investigated systematically. The microstructure and distribution of B2 CuZr are characterized by scanning electron microscope and optical microscope. Particularly, a conic as-cast sample is prepared to explore the correlation between the precipitation of the CuZr phases and cooling rate by observing its longitudinal section. Compressive tests indicate that B2 CuZr shows higher strength than the glassy matrix, which accounts for the result that the BMGC exhibits higher strength than BMG. In addition, the B2 CuZr phases precipitate steadily over a large range of cooling rates without martensitic transformation or decomposition. As a result, such peculiar B2 CuZr phases are helpful in synthesizing larger size of BMGCs without deterioration in mechanical properties. Keywords: Bulk metallic glass composite, B2 CuZr phase, Microstructure, Mechanical properties, Conic cast sample. G-102 Bulk Metallic Glass: Microscopical Heterogeneity in Macroscopical Homogeneity of Structures and Mechanical Properties Peng Xue1,2, Yongjiang Huang1,2,3, Shu Guo2, Hongbo Fan2, Zhiliang Ning2, Jianfei Sun2, Peter K. Liaw4 1. State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, China 2. School of Materials Science and Engineering, Harbin Institute of Technology, China 3. Key Laboratory of Micro-Systems and Micro-Structures Manufacturing (Harbin Institute of Technology), Ministry of Education, China 4. Department of Materials Science and Engineering, University of Tennessee, Knoxville, USA As a kind of advanced materials, bulk metallic glasses (BMGs) often offer a macroscopical homogeneity and microscopical heterogeneity in the structure and mechanical property. Here, we employee isothermal annealing on a ZrCuNiAl BMG to obtain different structural states. The Poisson's ratio of the studied Zr-based BMG gradually decreases, the hardness shows a clear transition from heterogeneous to homogeneous distributions in micro-scale, and the order of degree gradually increases in atomic scale with prolonging the isothermal annealing time. According to that, the correlation between the atomic structure and the Poisson's ratio can be illustrated by a rule of mixture, and the mechanical performance of BMG in micro-scale can be tuned by the atomic structural heterogeneity. This trend suggests that the macro-/micro-scaled mechanical properties can be finely tailored by the structural heterogeneity/homogeneity in atomic-scale. These findings have implications for better understanding the structure-property relation from the atomic level and thus, exploring high performance BMGs of high strength and high ductility. Keywords: Metallic glass; Heterogeneity; Auto-correlation function; Structure; Nanoindentation; Poisson’s ratio G-103 Martensitic transformation and superelastic behavior of Ni-Mn-Ga-Fe shape memory alloy microwires Yanfen Liu1, Xiaohua Liu1, Xuexi Zhang2, Hongxian Shen2, Jianfei Sun2 1. Department of physics, Qiqihar University

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2. School of Materials Science and Engineering, Harbin Institute of Technology The continuous polycrystalline Ni50Mn25Ga20Fe5 alloy microwires of diameter 40~50 um were efficiently prepared by melt-extraction technique. Here, with the aim to reduce the defect density, internal stress and compositional inhomogeneity in the as-fabricated microwires, a step-wise chemical ordering annealing heat treament was carried out and the effects of Fe and annealing on microstructure, martensitic transformation and superelastic behavior were studied. The results show that martensite exhibited straight and clear twin boundary after heat-treatment, these are related to decrease in defect density, internal stress and compositional inhomogeneity, increase of atomic ordering. During superelastic tests, the complete superelastic recovery appeared in the annealed microwires. The stress-induced martensite transformation (SIMT) took place at a much lower stress after annealing treatment. These stress-strain curves overlapped during loading, displaying a well reproducibility during SIMT process and higher recovery rate (~100%) compared to the as-fabricated microwires. Keywords: Melt-extraction; Ni-Mn-Ga-Fe microwires; Chemical ordering annealing; Superelasticity, Stress-induced martensite transformation G-104 Dependence of mechanical properties on microstructure of Cu-Zr-Al bulk metallic glass composites Songshan Jiang1,2, Fufa Wu2, Yongjiang Huang1, Jianfei Sun1 1. Harbin Institute of Technology 2. Liaoning University of Technology Nowadays, bulk metallic glass composites (BMGCs) with bcc B2 CuZr phase embedded within the glassy matrix have been explored to effectively circumvent the disappointed room temperature brittleness of monolithic bulk metallic glasses. In this work, we systematically investigated the microstructure and mechanical properties of a series of Cu48Zr48-xAl4Nbx (x=0, 0.3, 0.8, 1.2, 1.5, 2.0 at %) BMGCs, aiming at establishing their microstructure-properties relation. It has been found that morphology and distribution of B2 phase exert a crucial role on the mechanical properties of the studied BMGCs. The Cu48Zr47.2Al4Nb0.8 BMGCs with uniform sizes and homogeneous distribution of B2 particles possess an excellent combination of both high strength of ~1.2GPa and significant tensile plasticity of ~12%. Furthermore, the deformation-induced martensitic transformation from a cubic primitive B2 phase to a monoclinic B19’ phase was proved to account for the superior mechanical properties of the studied BMGCs. The nanoindentation results of B2-CuZr phase and glassy matrix indicated that nanohardness of B2-CuZr phase is lower than that of the corresponding matrix. The applied loading rate plays an important role on the number of the serrated flows. The macroscopic mechanical properties of the materials in a certain extent can be characterized by the micro-strength and the number of serrated flows from the two phases. The high nanohardness of two phases results in the enhanced macroscopic tensile strength of the composites, andthe more serrated flow of the two phases would lead to the better macroscopic tensile plasticity of the composite. Meanwhile, there exists a linear relationship between nanohardness and macroscopic tensile strength of the studied BMGC alloy system. Keywords: Bulk metallic glass composites; Mechanical properties; Martensitic transformation; Nanoindentation G-105 Refinement of Nanoporous Copper by Introducing Low Surface Diffusive Elements Fengxiang Qin1, Zhenhua Dan2, Nobuyoshi Hara3 1. School of Materials Science and Engineering, Nanjing University of Science and Technology

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2. College of Materials Science and Engineering, Nanjing Tech University 3. Department of Materials Science, Tohoku University A finer nanoporous copper (NPC) structure with a pore size of less than 10 nm is eagerly anticipated because this would provide a larger surface area and, therefore, better mechanical and catalytic performances. A finer nanostructure enables nanoporous metals to perform better. For instance, the yield strength of nanometer-sized ligaments of nanoporous gold increased from 880 MPa to 4.6 GPa with the decrease in the pore size from 50 to 10 nm. The Au-group (G-I) and Pt-group (G-II) elements are regarded as with low surface diffusivity, and will be hereafter referred to the abbreviation, LSDM. Since the surface diffusivity of Pd and Pt in the Pt-group is lower than that of the Au group, NPCs fabricated from Pd-/Pt-added TiCu amorphous alloys are expected to have a finer nanoporous structure with a pore size of less than 10 nm. The aim of the present study is to fabricate ultrafine cost-effective NPCs by combining their unique advantages, such as the amorphicity of the starting materials in the microstructure, and the retardations in the surface diffusion from LSDMs. In this paper, the refinement effects of NPCs by the micro-alloying of Pt-group and Au-group elements of the Ti60Cu40 base precursor alloys with low surface diffusivities are summarized and compared on the basis of morphology, surface diffusivity and microstructure. Ternary alloys with nominal compositions of Ti60Cu39M1 (M: Ni, Pd, Pt, Cu, Ag, Au) were prepared by arc melting. The micro-alloying elements were divided into two groups: the Au-group (G-I: Ag, Au) and the Pt-group (G-II: Ni, Pd, Pt). The ribbon samples were fabricated by melting spinning with a dimension of 20μm in thickness and 2mm in width. The starting Ti60Cu39M1 amorphous precursor alloys were dealloyed under the free immersion condition for 43.2 ks in 0.03M HF solution at room temperature. The micro-alloying of 1 at% metals of G-I Au-Group (Ag, Au) and the G-II Pt-Group (Ni, Pd, Pt) with the Ti60Cu40 amorphous alloy resulted in the formation of fine nanoporous copper (NPC) in the order of 6-28 nm. The smallest characteristic pore size of open cell nanoporous fcc Cu was 7 and 6 nm after dealloying the amorphous Ti60Cu39Pd1 and Ti60Cu39Pt1 precursor alloys for 43.2 ks in 0.03M HF solution, while NPC had a pore size of 39 nm after dealloying the amorphous Ti60Cu40 precursor alloy. The surface diffusivity was reduced more than 2 orders due to the introduction of low surface diffusive elements. On the basis of TEM micrographs, the refining factor increased approximately from 4 for the Ti60Cu39Ag1 precursor alloy to 1780 for the Ti60Cu39Pt1 precursor alloy. The refinement was attributed to the dramatic decrease in the surface diffusivity during dealloying. The refinement efficiency of the micro-alloying of the Pt-group elements was higher than that of the Au-group elements. The homogeneous distribution of additives in both of the amorphous precursor alloys and the final stabilized NPCs played a key role in refining the NPCs. This strategy may contribute to the fabrication of cost-effective nanoporous metals with a nanoporosity comparable to that of nanoporous Au, Pd and Pt catalysts. Keywords: Nanoporous copper; Amorphous precursor alloy; Dealloying; Refinement; Low surface diffusivity G-106 Time-resolved pair distribution function study of structure origins of phase stability in ternary Zr-based bulk metallic glasses Xiaoya Wei1, Si Lan1, Xuelian Wu1, Jie Zhou2, Zhaoping Lu2, Yang Ren3, Xunli Wang1 1. Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong 2. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing, China 3. X-Ray Science Division, Argonne National Laboratory, Argonne, IL, United States

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Objectives or Aims: In supercooled liquid region, good glass formers show high stability against devitrification [1, 2]. In this paper, we would like to illustrate the major issues concerning phase stability of supercooled metallic-glass forming liquids from the aspect of the ordering kinetics and local atom rearrangement. Methods: Here, we experimentally compare the atomic structural evolutions during amorphous-to-crystalline transformation between a good glass former, Zr46Cu46Al8, and an average glass former, Zr56Cu36Al8, upon isothermal annealing in the supercooled liquid region. In-situ synchrotron pair distribution function (PDF) measurements were conducted at Advanced Photo Source (APS) of Argonne National Laboratory (ANL) with a data rate 1 Hz. Results: The PDF analyses show that the initial states of both two glasses are nearly the same. During devitrification, the nearest new bond in Zr46Cu46Al8 formed at much larger correlation length than that in Zr56Cu36Al8. Furthermore, the incubation time of the newly-forming bonds in Zr46Cu46Al8 varies widely, while all the correlation shells of Zr56Cu36Al8 started to develop at almost the same time. In addition, Zr46Cu46Al8 finally crystallized into a crystalline phase with confined order, in contrast, Zr56Cu36Al8 crystallized into a crystalline phase with much more extended ordering. Conclusions: Our results suggest that medium-range order plays a unique role on frustrating devitrification in the metallic liquids with good glass-forming ability. [1] P.G. Debenedetti, F.H. Stillinger. Supercooled liquids and the glass transition. Nature 410, 259, 2001. [2] S. Lan, X. Wei, J. Zhou, Z. Lu, X. Wu, M. Feygenson, J. Neuefeind, X.-L. Wang. In-situ study of crystallization kinetics in ternary bulk metallic glass alloys with different glass forming abilities. Applied Physics Letters 105, 201906, 2014. Keywords: Phase stability, bulk metallic glasses, crystallization, pair distribution function G-107 Improved the magnetocaloric property of Fe-doped Gd-Al-Co microwires Jingshun Liu1,2, Qixiang Wang1, Mengjun Wu1, Yun Zhang1, Ze Li1, Hongxian Shen2 1. Inner Mongolia University of Technology 2. Harbin Institute of Technology The magnetic properties and magnetocaloric effect (MCE) of Fe-doped Gd-Al-Co microwires have been investigated. Experimental results indicated that these type microwires have entirely amorphous microstructure and smooth surface, and exhibit a relatively higher Curie temperature (~121.8K, which is more than 12K than Gd-Al-Co wires though still in the liquid nitrogen temperature range) as for the appropriate substitution of Fe for Gd, Al and Co, and a remarkable and reversible magnetocaloric effect (MCE) with no thermal and magnetic hysteresis loss. For a magnetic field change of 5 T, the isothermal magnetic entropy change (-ΔSm) for the longitudinal direction reaches as high as 10.326 J·kg-1K-1 and the refrigerant capacity (RC) achieves a relatively large value of 748.218J·kg-1. Meanwhile, the Arrott plots also indicate that the ferromagnetic-paramagnetic transition is of second-order. Therefore, it can be concluded that the obtained Fe-doped Gd-Al-Co metallic microwires are used to explore intelligent materials with enhanced MCE property for potential multifunctional applications in magnetic refrigeration field. Keywords: Gd-Al-Co-Fe microwires; Magnetocaloric effect (MCE); Isothermal magnetic entropy change; Refrigerant capacity (RC) G-108 Activated combustion high-velocity air fuel sprayed Fe–based amorphous coatings

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Jun Shen School of Materials Science and Engineering, Tongji University An FeCrMoMnWBCSi amorphous metallic coating (AMC) was deposited onto 316L stainless steel using activated combustion high–velocity air fuel (AC–HVAF) and high–velocity oxygen–fuel (HVOF) thermal spray. The microstructure and corrosion behaviour of the AMC compared with 316L stainless steel were characterised using scanning electron microscopy, energy–dispersive X–ray spectroscopy, X–ray diffraction, differential scanning calorimetry, and electrochemical methods. The erosion–corrosion behaviour was investigated using a rotating disk in simulated sand–containing seawater. Compared with the HVOF AMC, the AC–HVAF AMC exhibited a relatively denser structure with low porosity and almost nonexistent oxides, which resulted in a higher ability to resist uniform corrosion. The low donor density of the passive film formed on the AC–HVAF AMC leads to the higher pitting resistance. The amorphous phase content and micro–hardness of the AC–HVAF AMC are both higher than those of the HVOF AMC. The erosion–corrosion resistance can be considerably improved through the AC–HVAF spraying method. The erosion–corrosion damage of AMC is controlled by the mechanical damage resulting from erosion. The enhanced erosion–corrosion resistance of the AC–HVAF AMC could be related to the high hardness and compact structure resulting in the low erosion and synergy weight loss. Poster G-P1 Formation and mechanical properties of Zr56.25Al18.75(Co10-x/10Cux/10)25 bulk metallic glasses kaiming han, jianbing Qiang, yingmin Wang, chuang Dong Key Laboratory of Materials Modification (Ministry of Education), Dalian University of Technology Bulk metallic glasses (BMGs) has attracted increasing attention as structural materials owing to its many excellent properties. However, the limited critical sizes and lack of plasticity hinder widespread application of BMGs as structural materials. Therefore, large size BMGs with excellent plasticity have become one of the most important issues in the BMG community. In the paper, a series of Zr56.25Al18.75(Co10-x/10Cux/10)25 (x = 0, 1.25, 2.5, 3.75, 5) BMGs were synthesized by copper mold casting, and the effects of Cu addition on glass-formation, thermal stability together with mechanical properties of Zr56.25Al18.75Co25 alloy were investigated. The experimental results indicated that GFA and plasticity of Zr56.25Al18.75Co25 glass can be enhanced distinctly with the appropriate Cu alloying-addition, the critical diameter (Dc) of glass formation is increased from 3 mm (Cu-free) to 10 mm (x = 3.75). The uniaxial compression testing further revealed that the room-temperature plastic strain of the above best glass-former (x = 3.75), in the rod form with 3mm in diameter and a length/diameter ratio of 2:1, is about 3.5% combined with a yield strength of 2030 MPa. The enhancement of plasticity is attributed to the high microstructural heterogeneity induced by the positive enthalpy of mixing with the constitutive element (Co-Cu: +6 kJ/mol). The BMG (x = 3.75) with highest GFA and reasonably good plasticity may provide potential applications for structural materials. Keywords: Zr-based bulk metallic glass; Glass forming ability; Mechanical property G-P2 Magnetic and magnetic shielding properties of HVAF-sprayed FeSiBPNb coatings

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Jijun Zhang1,2, Jiawei Li1,2, Chuntao Chang1,2, Wuhong Xue1, Haoran Ma1,2, Xinmin Wang1,2 1. Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Zhenhai District, Ningbo, Zhejiang 315201, China 2. Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, KeyLaboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Zhenhai District, Ningbo, Zhejiang 315201, China Subject In the last decade, applications of soft magnetic amorphous and nanocrystalline alloys are of increasing interest. One example is a group of Fe-based metallic glasses, relatively high value of magnetic permeability and very low coercive field cause that these materials are usually used as core transformers, transductor, inductors and also as shields of electric, magnetic and electromagnetic fields. The latter plays an essential role in reduction of electromagnetic smog, which nowadays is one of the most severe problems in the environmental protection. In general, the effective electro/magnetic shielding requires very good soft magnets with very high magnetic permeability and low resistivity, thus it is also an important problem in the field of searching of new soft magnetic materials with unique properties. Fe-based Amorphous coatings obtained by high velocity air fuel (HVAF) technique seem to be of particular interest because they show very good magnetic properties and allow forming shields of desirable shapes. The aim of this work is to produce FeSiBPNb amorphous coatings from powders with micron scale size and analyze their microstructure and magnetic properties, particularly their magnetic shielding properties. Methods Gas atomized powders with nominal composition of (Fe0.76 Si0.09B0.1P0.05)99Nb1 (at. %) were used as the feedstock material. The powders were spherical and the diameter ranged from 25 to 50 μm. Before spraying, the powders were dried for 1 h at 423 K. Copper was chosen as the substrate. Prior the spraying coating being applied, the surfaces of the substrate were smoothed by a grinding machine, degreased with acetone, cleaned with alcohol, and grit-blasted. The thickness of all the FeSiBPNb amorphous coating were about 150 μm. All the samples were confirmed to be fully glassy by the conventional X-ray diffractometry (XRD) with monochromatic Cu Kα radiation and exhibited glass transition, supercooled liquid region and crystallization on heating in a differential scanning calorimeter (DSC). Additional observations of the cross-sectional in coating samples was performed using transmission electron microscopy (TEM). The scanning transmission electron microscopy (STEM) images and electron energy loss spectroscopy (EELS) mapping were taken. The magnetic measurements were made with a DC hysterisismeter at ambient temperature. Tapping mode and contact mode of atomic force microscopy (AFM) technique were used for obtaining the topography profiles and a series of local current–voltage characteristics (CVCs), respectively. The magnetic shielding performance was carried out in frequency range 10 kHz – 500 kHz by using Helmholtz coil method. Results Fully amorphous FeSiBPNb coatings were formed by high velocity spraying micron-sized powders onto copper pipes in air condition. The coatings are about 150–200 μm in thickness with fully dense structure and low porosity. Differential scanning calorimetry curve showed that the glass transition temperature (Tg) and the onset crystallization temperature (Tx) were 760 K and 811 K, respectively. The supercooled liquid region (△Tx = Tx -Tg) was as large as 51 K, which implied the high thermal stability of the supercooled liquid against crystallization. Coercivity (Hc), saturation magnetization (Ms), and initial relative permeability (μi) of the coatings are 15.3 Oe, 145emu/g, 232, respectively. The conductive AFM measurements reveal that the electrical conductivity of the coatings transits from the initially metallic to a nonlinear one in the intersplat regions. The magnetic shielding

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performance is good under DC magnetic field and its magnetic shielding effectiveness (SE) is 73 dB. The results indicate that the Fe-based amorphous coatings can be good for some magnetic shielding applications. Conclusions In the present work we investigated nanoscale and atomic structure and electrical conductivity of the FeSiBPNb amorphous coatings formed by HVAF technique. It has been shown that the coating presents a soft ferromagnetic character, and it has a magnetic shielding effect at DC under low frequency magnetic field circumstances. The electrical conductivity of the amorphous caoting transits from the initial high metallic, to the nonlinear one (likely semiconductive) state due to the oxidation of the intersplats. The SE arrives 73 dB at 50 kHz under static magnetic field. The results permit to conclude the FeSiBPNb alloys can be the candidate to produce coatings for magnetic applications. Keywords: FeSiBPNb coatings, HVAF, soft magnetic properities, magnetic shielding property G-P3 Electrical resistance relaxation in La55Al25Ni10Cu10 bulk metallic glass Binbin Liu, Boyang Liu, Feng Ye State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, 30 Xueyuan Road, 100083 Beijing, China Electrical resistance is always related to the electronic structure of metallic glass and sensitive to structural changes, which provides a more intuitive approach to investigate structure evolution of metallic glasses upon structural relaxation. Electrical resistance relaxation of the La55Al25Ni10Cu10 bulk metallic glass was studied using the standard four-probe method. The electrical resistance of La55Al25Ni10Cu10 bulk metallic glass decreases significantly with the structural relaxation below the glass transition temperature at 445 K. During the subsequent continuous heating, the relaxed specimen shows a reduction in the resistivity decrease at the glass transition. The relaxed electrical resistance caused by the structural relaxation during the isothermal measurement equals the changes of the electrical resistance reduction in the glass transition region in the subsequent isochronal measurements. The calculated relaxed electrical resistance as a function of the annealing time can be fitted by Kohlrausche-Williams-Watts (KWW) equation. The equilibrium value, time constant and the stretched exponent for the isochronal electrical resistance measurements at 445 K are 0.0384, 2390s and 0.66, respectively. The in-situ electrical resistance data recorded in the isothermal annealing process show the same relaxation behavior with fitting parameters 0.0362, 2033 s, and 0.74, respectively. Keywords: Bulk Metallic Glass; Electrical resistance; Structural relaxation G-P4 Microstructures and tribological properties of laser cladded Ti-based metallic glass composite coatings Xiaodong Lan1, Hong Wu1, Yong Liu1, Ling Liu2 1. State Key Laboratory of Powder Metallurgy, Central South University 2. Department of hepatobiliary and pancreatic surgery, Xiangya hospital, Central south university Objective: Titanium and its alloys have been widely used in aeronautical, biomedical and defense industries due to their low density, good mechanical properties, high strength-to-weight ratio, corrosion resistance and biocompatibility. However, its poor wear resistance is a serious concern for applications. It is expected that laser cladded Ti-based metallic glass coatings can improve the wear resistance of titanium alloys.

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Methods: Metallic glass composite coatings Ti45Cu41Ni9Zr5 and Ti45Cu41Ni6Zr5Sn3 (at.%) on a Ti-30Nb-5Ta-7Zr (wt.%) (TNTZ) alloy were prepared by laser cladding. The microstructures of the coatings were characterized by means of X-ray diffractometry (XRD), scanning electron microscopy (SEM) equipped with energy dispersive X-ray analyzer (EDXA), and transmission electron microscopy (TEM). Results: Results indicated that the coatings have an amorphous structure embedded with a few nanocrystalline phases and dendrites. A partial substitution of Ni by Sn can improve the glass forming ability of Ti-base metallic glass system, and induce the formation of nano-sized Ni2SnTi phase during the cyclic laser heating. A significant improvement in both the hardness and the wear resistance of the coatings was achieved with the addition of Sn. Conclusions: A significant improvement in the wear resistance can be achieved by laser cladding of metallic glass composite coatings. The Sn-containing coating has an even better wear resistance than that of Ti45Cu41Ni9Zr5. A good balance between the crystalline and amorphous phases can effectively improve the wear resistance of metallic glass composite coatings. The TNTZ substrate shows a typical abrasive wear, while adhesive wear is the main mechanism in the metallic glass composite coatings during sliding. Keywords: Laser cladding; Metallic glass; Coating; Tribological properties G-P5 Correlation between structure and glass-forming ability for Al86Ni14-xLax(x=3,5,9): An Ab Initio Molecular Dynamics Study fangru wang Department of Physics, Renmin University of China, Beijing 100872, China The low glass-forming ability (GFA) of Al-based metallic glasses (MGs) is bottleneck that greatly limits their potential engineering application. GFA of Al-based MGs shows strong composition dependence, but the underlying mechanism remains poorly understood. In this work, we investigated the atomic-level structure feature in model system of Al86Ni14-xLax(x=3,5,9) MGs via ab initio molecular dynamics simulations. The evolution of atomic structures with composition was systematically analyzed and a relationship between atomic structure and GFA in Al-base MGs was investigated. It is found that Al-centered icosahedral clusters are still a significant factor to influence GFA in Al-based MGs. The agreement between coordination number and local five-fold symmetry was also found to closely relate to GFA. This finding provides a better understanding for the improvement of GFA of Al-TM (transition metal)-RE (rare earth metal) MGs. Keywords: GFA, Al-based MGs, ab initio molecular dynamics simulations G-P6 Laser 3D printing of Zr-based bulk metallic glass Yunzhuo Lu, Hao Zhang, Hongge Li, Zuoxiang Qin, Xing Lu School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, People’s Republic of China Since the discovery of the first amorphous alloy, metallic glasses have received increasing scientific and technological attention due to their extraordinary mechanical, thermal and chemical properties. However, the small dimensions and the ambient brittleness of the metallic glasses still challenge the producing of large metallic glass components with complex shapes by using the traditional methods, such as copper mould casting, superplastic forming, welding. How to break through the size restriction and the difficulty in complex component fabrication is the key to achieve the large-scale application of metallic glasses. Laser 3D printing technology,

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which is a powder-based layer-by-layer shaping and consolidation process, provides an opportunity to fabricate metallic glasses without any dimensional or geometric constraint. In the present work, to obtain fully or nearly fully amorphous alloys by using this technology, we firstly designed an excellent glass-forming composition in Zr-Ti-Cu-Ni-Al system without toxic and precious elements through proportionally mixing of binary eutectics and minor addition method. We then produced Zr-based bulk metallic glasses by laser 3D printing with coaxial powder feeding method. We found that the volume fraction of amorphous phase in the deposit of 10 mm height was more than 93%. The crystallization degree did not increase remarkably with the increasing of deposited layers. Except the crystallization, there are hole-type defects and microcracks in the deposited Zr-based bulk metallic glasses. Keywords: Laser 3D printing, bulk metallic glass G-P7 Hydrogen-induced Amorphization of Zr-Cu-Ni-Al Alloys Fuyu Dong1, Songsong Lu1, Zhang Yue1, Hongjun Huang1, Xiaoguang Yuan1, Liangshun Luo2, Yanqing Su2, BinBin Wang2 1. Shenyang University of Technology 2. Harbin Institute of Technology, Harbin Arc melting was utilized in this study to produce Zr55Cu30Ni5Al10 alloys under mixed atmospheres with different ratios of high-purity hydrogen and argon. The influence of hydrogen addition on the solidification structure and glass-forming ability of Zr55Cu30Ni5Al10 alloys were studied by examining microstructures in different parts of the cast ingots. Results showed that varying degrees of crystallization structures were obtained in the as-cast button ingots after arc melting in high-purity Ar atmosphere, while finer-grained microstructures were obtained in the areas cooled at a quicker rate. By contrast, there was a completely amorphous structure in the rapidly cooled area of the as-cast button ingots fabricated by adding 10% H2 to the high-purity Ar atmosphere. The mechanism of hydrogen addition on the glass-forming ability of Zr55Cu30Ni5Al10 alloy was also carefully investigated. The mechanism of said improvement was mainly associated with the increase in atomic mismatch between the components and the negative heat of the mixture. Keywords: Zr-Cu-Ni-Al alloy; Melt hydrogenation; Solidification structure; Hydrogen-induced amorphization G-P8 Microstructure and properties of laser cladded Zr-based amorphous coating on a steel Ning Zhang, Shujie Pang, Ying Liu, Tao Zhang School of Materials Science and Engineering, Beihang University, Beijing 100191, China Metallic glasses with good corrosion resistance and high hardness are suitable to be applied as coating materials. Laser cladding is a feasible technique to produce metallic glasses on crystalline substrate. In this research, (Zr0.53Al0.1Ni0.05Cu0.3Ti0.02)99Y1 (at.%) amorphous coating (with a thickness up to 320 mm) was prepared by laser cladding on AISI 1045 steel. The microstructure from the surface of the coating to substrate was investigated by scanning electronic microscopy, X-ray diffraction and electron probe microanalysis. It was found that a gradient structure was formed after the laser cladding: amorphous surface layer, amorphous–crystalline composites transitional region and substrate. The amorphous surface layer and transitional layer exhibited higher corrosion resistance in 3.5 mass% NaCl solution than that of the steel substrate. The microhardness of the amorphous layer

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was about 4 times higher than the substrate. This study provides theoretical and experimental basis for the application of Zr-based amorphous alloys as coating materials. Keywords: laser cladding; amorphous coating; microstructure; corrosion resistance; hardness G-P9 Fabrication of self-organized nanotube coating on Zr56Al16Co28 bulk metallic glass surface Xuejie Li, hongjie Xu, Yu Jin, Tao Zhang School of Materials Science and Engineering, Beihang University Bulk metallic glasses (BMGs) have recently attracted much attention as biomedical materials. However, it is still a challenge for BMGs to develop systematic and practical surface modification techniques to increase their biocompatibility. In this work, we study the feasibility of adopting anodization as a surface modification method for Zr-based BMGs. A self-organized nanotubular layer is successfully fabricated on the surface of the Zr56Al16Co28 biomedical metallic glass in glycerol containing 0.35M NH4F and 0.5 vol % H2O. The as-formed nanotubes are amorphous and the diameter and the length of the nanotubes are approx. 60nm and 700nm, respectively. The electrochemical behaviors of the anodic nanotube in stimulated body fluid (SBF) are studied using potentiodynamic analyses. The results show that the corrosion resistance of the nanotubular layer decreases compare with the untreated metallic glass. Since most of the biomedical BMGs are Ti-based metallic glass and Zr-based metallic glasses, which are prone to form nanotublar layers in F--- containing electrolyte, the present work is promising for increasing the biocompatibility of the biomedical BMGs. Keywords: Biomedical BMGs; Nanotube; Biocompatibility G-P10 Effect of ball-milling on the structure and hydrogen absorption-desorption behavior of Zr50.7Cu28Al12.3Ni9 metallic glass powder Xiao-Yang Lu1,2, Yu-Lei Du1, Wen-He Liao1 1. School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China 2. School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China In this paper, the effect of ball-milling on the structure and hydrogen absorption-desorption behavior of the Zr50.7Cu28Al12.3Ni9 metallic glass powder produced by gas atomization was studied. The structural changes of the metallic glass powder were tested by scanning election microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC) before and after the ball-milling, and the results showed that the metallic glass powder owned excellent amorphous phase stability. The hydrogen absorption-desorption behavior changes of the metallic glass powder caused by ball-milling were measured with an automatic Sieverts apparatus. After the ball-milling, the hydrogen absorption behavior of the metallic glass powder was improved, but the hydrogen desorption behavior was still poor. For explaining the above phenomenon, the structures of the metallic glass powders were also tested by XRD and DSC after the hydrogen absorption-desorption process. Keywords: Ball-milling; Structure; Hydrogen absorption-desorption behavior; Metallic glass powder G-P11 he effects of longitude magnetic field annealing on amorphous powder cores Zichao Li1, Yaqing Dong2, Wenshuai Zhang1,1, Zhikai Gao1,2, Chuntao Chang2,1, xinmin Wang2,2, Fushan Li1

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1. Zhengzhou University 2. Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences The effects of longitude magnetic field annealing on Fe78Si9B13 amorphous powder cores were investigated. Longitude magnetic field annealing is a kind of annealing technology that magnetic lines (round and closed) along the surface of the powder cores. The annealed powder cores still keep an amorphous structure confirmed by X-ray diffraction. The magnetic domain structure was also observed by Magnetic Force Microscopy. Longitude magnetic field annealing can increase the permeability of powder core significantly. With the increase of magnetic field intensity, the permeability of annealed powder core can further increase. FeSiB amorphous powder core shows an enhanced effective magnetic permeability of 66 after longitude magnetic field annealing in 400 ℃ with 36 Oe, which is attributed to the relief of internal stress and the variation of domain structure. The permeability was improved by 5 %.The frequency stability FeSiB amorphous powder core is up to 2 MHz. The core loss and DC bias property stay a same level compared with traditional treatment. Each powder cores has the core loss of around 90 W/kg at 50 mT and 100 kHz and DC bias property of over 70 % at 100 Oe. This work provides a novel approach to improving high μe for Fe78Si9B13 powder cores and also validates the application prospect of powder core in the work condition of different ripple currents, different loads and a wide frequency (f) range (10 kHz~2 MHz). Keywords: amorphous powder core; longitude magnetic field annealing; soft magnetic properties; magnetic domain structure G-P12 B-rich bulk metallic glasses with extreme thermal, elastic, and mechanical properties Xinquan Wei Beihang University A family of bulk metallic glasses (BMGs) with high B content was produced by copper mold casting．The B concentration in the BMGs (at%) can be reached up to 40%. This kind of BMGs exhibits the ultrahigh thermal stability (the glass transition temperature up to ~1100 K), elastic moduli (Young’s Modulus up to ~290 GPa), and Vickers Hardness (~18 GPa), which are the highest values among all kind of the reported BMGs so far we known. The influences of similar and dissimilar element substitutions as solute or solvent on these properties were evaluated in detail. Furthermore, combined with the physical properties data of our novel B-rich BMGs and other typical BMG systems (14 kinds), the well-known correlations and models among thermal properties, elastic moduli and mechanical properties were validated. Keywords: Bulk metallic glasses, High B alloys, Extreme properties, Alloy design. G-P13 Ab initio molecular dynamics simulations of structure of Ca40Pt35Mg25 metallic alloys Xuan Li, Tao Zhang Beihang University The ab-initio molecular dynamics simulations were conducted to investigate the microscopic atomic and electronic structures of Ca40Pt35Mg25 metallic glasses. The structure properties such as partial pair correlation function, coordination number and Voronoi tessellation analysis were analyzed. Then the atomic charge and the

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density of states are also characterized. The Ca and Mg atoms presented typical amorphous structure with the first and second diffuse peaks in the partial pair correlation function result. However, The Pt -Pt bond was really rare in consideration of its concentration. The Ca- and Mg-centered clusters had more "icosahedral-like" Voronoi polyhedral (VP), which is typical amorphous form. The Pt-centered clusters present a result more complicated. Some liquid phase VPs were also found. Then the average charge for each element was calculated to research the electronic structure. The Pt element, with higher electronegative, is found to possess the negative charge. Keywords: Ab initio molecular dynamics; metallic glass; pair correlation; Voronoi polyhedral G-P14 Nanocarbon sol induced Biological interaction in human cell through immune mechanism and gene expression guoguo xi1,1, zhuoyang li2,2, qingping cao2,2, tao zhang1,1 1. Beihang University 2. First Hospital, Peking University Carbonbased nanomaterials have been considered as potential candidates for a wide variety of applications because of their unusual electrical, mechanical, thermal and optical properties. Nonetheless, our understanding of whether increased usage of carbonbased nanomaterials could lead to influence on humans and other biological systems is inadequate. The current experiment is focused on the cellular effect of nanocarbon sol(NCS) on human normal cells(T cells) and malignant cells(HepG2 cells). Following exposure to NCS, cell microscopy, cell viability and apoptosis and the distribution of NCS in the cells of submicroscopic structure were monitored. The results revealed that NCS interacted on cells with a certain specificity, which reduced HepG2 viability merely. Cells viability analysis indicated that NCS promoted HepG2 growth during short-term incubation and then stimulated apoptosis largely. Cells morphology almost kept unchanged after treatment. The majority of NCS existed in nucleus rather than cytoplasm. As a foreign substance, NCS caused cell apoptosis to some extent, instead of destroying normal body immune mechanism. These results can provide important reference on the biosecurity research of the carbon nanomaterials. However, the mechanism of apoptosis, which is a gene expression cause or the result of the immune system, remains to be further verified. Keywords: nanocarbon sol(NCS), HepG2 cell, immune system, cell apoptosis G-P15 Fabrication of nanoporos Ag-Au by dealloying and electro-catalysis property Cuiting Li, Tao Zhang Beihang University Electrocatalytic oxidation of small organic molecules such as CH3OH, HCOOH, HCHO by nanostructure noble materials has attracted more and more attention due to their potential application in liquid fuel cell. Nanoparticle noble metals such as Pt,Pd,Ru,Au and their alloys synthesized by most methods need supporting materials such as titania, ceria, carbon, alumina, and silica when employed as catalyst , while nanoporous materials need no supporter for their special free-standing structure. CO poisoning is also a problem of catalysis containing Pt when applied in electrocatalytic oxidation of small organic molecules . Generally binary or ternary nanoporous alloy materials show more effective catalytic activity and highly resistant to CO poisoning when used as catalyst according to the theory of “synergistic effect”.Dealloying is a easier and handier method to fabricate nanoporous materials.Based on previous work,nanoporous Ag-Au alloy with different composition and morphology are

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fabricated by chemical dealloying of amorphous precursor with a sequence component of Ag38.75-xCu38.75Si22.5Aux

(x=0,0.5,1,5). Ribbons as precursors are acheived by single roller melt spinning.The amorphous phase of precursors are confirmed by XRD.Nanoporous structure and components of those Ag-Au alloy are characterized and confirmed by SEM, EDS, TEM, HRTEM, SAED and nitrogen adsorption-desorption isotherm (BET).The width of characteristic ligament is 10-100nm, and the grain size is about 0-50nm.From the image of typical morphology about nanoporous Ag-Au by TEM,we found that the grain size of as-dealloyed sample decrease by the the increase content of Au in precursor. The catalytic activity of as-dealloyed samples towards electrocatalytic oxidation of formaldehyde were characterized by the CV technique.Each of the nanoporous products exhibits superior catalytic activity towards electro-oxidation of formaldehyde. Keywords: nanoporous materials;dealloying;amorphous;Ag-Au;catalysis G-P16 Fabrication of Cu/Cu2O nanoporous composites by dealloying from (La,Ce)-based metallic glass and their degradation properties of azo dye Na Wu, Ran Li Beihang University We presented a convenient one-step strategy to fabricate Cu/Cu2O nanoporous composites by the dealloying of a (La,Ce)-based metallic glass precursor in mixed acid solutions. The microstructural characteristics of the resulting nanoporous composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results show the nanoporous composites consisting of Cu and Cu2O phases exhibit bicontinuous interpenetrating ligament–channel structure. The degradation processes of methyl orange (MO) as a modeling pollutant were monitored using a UV-VIS spectrophotometer. The Cu/Cu2O nanoporous composites with the optimal microstructure show much higher degradation efficiency of MO than that of single nanoporous Cu or the metallc glass precursor. The degradation mechanism of the nanoporous composites was also clarified. Keywords: high entropy alloy, magnetocaloric effect G-P17 Preparation Zr-based unlimited size bulk metallic glasses using laser cladding zhiguang shi Beihang University

With laser cladding method, Bulk metallic glasses (BMGs) of (Zr0.53Al0.1Ni0.05Cu0.3Ti0.02)99Y1 was formed by multi-layered cladding. XRD and SEM images indicated the BMG was a single amorphous structure and layer by layer had good metallurgical bonding. The crystallization kinetics of (Zr0.53Al0.1Ni0.05Cu0.3Ti0.02)99Y1 bulk metallic glasses was studied by the Kissinger method. Temperature distributions and thermal profiles of the treated (Zr0.53Al0.1Ni0.05Cu0.3Ti0.02)99Y1 alloy during the laser process were simulated by finite volume method. The cooling rate of laser cladding method is near 105K/s higher than the critical cooling rate. So the melt alloy can form amorphous structure. The formation mechanism of the amorphous structure is discussed based on the experimental and simulated results.

Keywords: Laser cladding; unlimited size BMGs; Kissinger method G-P18

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Pore-size-dependent mechanical behavior of bulk metallic glass: plasticity and deformation energy released Xin Wang, Peng Chen, Lichen Zhao, Shuiqing Liu, Chunxiang Cui Key Laboratory for New Type of Functional Materials in Hebei Province, School of Material Science and Engineering, Hebei University of Technology, Tianjin 300130, P.R. China Mechanical behavior of bulk metallic glass (BMG) is very sensitive to the presence of defects on variable sizes, however, the role of cast pore on the plasticity of BMGs is rarely reported. We study the relationship between the size of single cast pore and the compression plasticity of BMG. It has been found that the plasticity and deformation energy released behavior of a Ti-based BMG both strongly depend on the size of cast pore contained. A plane energy model taken into account the cast pore has been developed, which shows that cast pore plays a key role for the rapid release of deformation energy. The presence of enclosed pore can cause heterogeneous release of deformation energy at local part around the pore due to stress concentration, which makes the released plane energy density increase to the critical value and in turn induces the macroscopic fracture of BMG. Keywords: Bulk metallic glasses; Deformation and fracture; Defects; Mechanical properties G-P19 Vacuum Brazing TC4 Titanium alloy and 304 Stainless Steel with Titanium-Based Amorphous Alloy Foil Shilei Liu, Fushan Li Zhengzhou Univeristy The microsture and interfacial reactions of The Vacuum brazed Tianium alloy (TC4) to 304 Stainless Steel (1Cr18Ni9Ti) is investigated . Dissimilar metal vacuum brazing between TC4 Tianium alloy and 304 Stainless Steel was conducted with common designed Titanium-Based Amorphous Alloy Foil . Partial dissolution of Stainless Steel substrate occurred during brazing . All the joints fractured through the gray layer in the brazed seam , revealing brittle fracture features . TiFe , Ti2Fe and TiCu compounds were found in the fratured joint brazed with Ti37.5Zr37.5Ni10Cu15 foil. The existence of Cr-Ti, Fe-Ti, Cu-Fe-Ti and Fe-Ti-V intermetallic compounds in the brazed seam caused fracture of he resultant joints. Brazing time is the vital factor of the process. Keywords: Vacuum Brazing TC4 Titanium alloy and 304 Stainless Titanium-Based Amorphous G-P20 Development of high Bs Fe(Co)SiBPCCu nanocrystalline alloys Tao Liu, Anding Wang, Chuntao Chang, Aina He, Xinming Wang Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China Fe-based nanocrystalline alloys have attracted great interests because of their excellent soft-magnetic properties, low core loss and small magnetostriction (λs). While the relatively low Bs compared with Si-steels is against the miniature of electromagnetic devices which has limited their applications. Development of the high Bs nanocrystalline alloys have been extremely desired to satisfy the long-term targets of device development to be stronger, lighter, and higher efficiency. On the basis of the component development and theoretical analysis, FeSiBPCCu nanocrystalline alloys with high Bs of about 1.78 T were readily developed. To further improve the Bs, substitution of Co for Fe, FeCoSiBPCCu nanocrystalline alloys with higher Bs above 1.84 T were also prepared. The structural dependence of Hc and the role of Cu of the FeSiBPCCu nanocrystalline alloys on the crystallization process were discussed in detail. It has been reported that the appropriate Cu content is essential for the crystallization process to provide sufficient nucleation sites while still keep the amorphous nature of the melt-spun

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ribbons. Simultaneously, the annealing process is important to obtain uniform microstructure with small grain size which will greatly improve the magnetic performance. It was interesting to find that the change of Hc as a function of annealing temperature presents as a “w” shape owing to the stress relief and the precipitation α-Fe. The introduction of small amount of Co will certainly improve the Bs due to the pure Fe-Co alloy exhibits Bs (2.45 T) higher than Fe (2.18 T) according to Slater-Pauling curves. However, the grain size increases form 26 nm to 32 nm as the content of Co increasing to 10 at. %, leading to a deterioration of the soft-magnetic properties. We believe that these high Fe content nanocrystalline alloys with extremely high Bs above 1.8 T will make these alloy system a promising candidate for future applications in electric devices. Keywords: Nanocrystalline alloy, High Bs, Soft-magnetic properties, Crystallization process G-P21 Anti-oxidation behavior and magnetic properties of FeSiBPC amorphous alloys Chengjuan Wang1,2, Keqiang Qiu1, Anding Wang2, Chuntao Chang2, Aina He2, Xinmin Wang2 1. College of material science and Engineering, Shenyang University of Technology, Shenyang, Liaoning 110870, China. 2. Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China The interest in Fe-based amorphous alloys has increased rapidly all over the world in recent decades due to their low coercivity (Hc), high effective permeability (μe), high saturation magnetic flux density (Bs) and low core loss . Previous researches showed that the introduction of the glass forming elements can improve the glass forming ability and magnetic properties of the alloys , and a series of alloys were developed. While researches about other properties including the oxidation and corrosion are ongoing. In this study, the relationship between the anti-oxidation behavior and magnetic properties of FeSiBPC amorphous alloys was carried out detailed research. To clarify the effect of oxygen content on the properties of amorphous alloys, the alloys were annealed in different oxide content atmosphere, while the already oxidized ribbons annealed in reducing atmospheres. It was found that the surface color of the oxidized alloys was obviously lighter. The oxygen pressure dependence of Hc and the oxide composition on surface were discussed in details, from which we can conclude that optimal oxide content can further improve the soft magnetic properties, while the thickness of oxide layer increased with increasing oxygen pressure. The deteriorated oxidation resistance attributed to partial nanocrystallization of α-Fe or iron oxide et al. The amorphous and crystalline oxide layers formed dependent on Fe content increased with increasing annealing temperature. In addition, that most of the Fe3+ were reduced to Fe2+ after annealing in the reducing atmospheres and the magnetic properties can further be improved. It suggests that controlling the metallic element content and oxygen pressure is a possible method to improve the magnetic properties of Fe-based amorphous alloys. For the oxidized amorphous alloys, a way to improve the magnetic properties by solving the oxidation problem is annealing in the reducing atmosphere. This study about the effect of oxidation on the magnetic properties of amorphous alloys and the providing method to improve the oxidation resistance which are very useful in the industrial environment. Keywords: Fe-based amorphous; anti-oxidation behavior; magnetic properties; reducing atmosphere G-P22 Fabrication and soft magnetic properties of novel amorphous Fe76Si9B10P5 powder cores Xiaolong Li 1. Institute of Materials Technology, CNITECH

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2. Nano Science and Technology Institute, USTC Toroid-shaped Fe-based amorphous powder cores were prepared from Fe76Si9B10P5 amorphous powder and epoxy resin as a binder under the action of ultrasound. The characteristics of gas-atomized Fe-Si-B-P amorphous powder and the relationship between magnetic properties and the content of epoxy resin were evaluated. Spherical Fe76Si9B10P5 amorphous powders, exhibiting excellent soft magnetic properties with a high saturation magnetization of 152 emu/g, which provided a superior dc-bias property for the powder cores, were successfully produced by gas atomization. Meanwhile, a stable permeability of 55 to 82 with decrease the amount of epoxy resin from 5 to 1 wt.% up to high frequency range over 20 MHz. With the increase of the epoxy resin content, the core losses are gradually reduced to the lowest value of 750 kW/m3 (f =100 kHz, Bm ＝0.1 T)when the amount of epoxy resin reach to 5 wt.%. The complete and uniform insulating layer on the surface of amorphous Fe76Si9B10P5 powders results in a defect-free structure of prepared green compacts, which consequently exhibit a higher permeability and lower eddy current losses. Keywords: Amorphous powder; Insulation-coating; Soft magnetic powder cores; Soft magnetic properties G-P23 Structural evaluation of a Fe-based bulk metallic glass system in laser 3D printing Di Ouyang, Ning Li, Lvjie Liang, Shengyong Pang, Jianji zhang, Lin Liu State key lab for materials processing and Die & Mold Technology and School of Materials Science and Engineering, Huazhong University of Science and Technology Additive manufacturing based on laser selective melting (SLM) is a promising technique for production of large size of bulk metallic glasses (BMGs) and manufacturing of complex BMG components. However, the cyclic heating and cooling coupled with extremely high temperature gradient near molten pool in SLM process caused the formation of complex microstructures and compositional heterogeneity, which affect determinatively the mechanical properties of the final products. For producing bulk metallic glasses, how to suppress crystallization in SLM process is one of the most crucial issues in this research field. In this presentation, we present a detailed study on the effect of laser processing parameters, including laser power and scanning speed, on the microstructure of the laser printed Fe-based metallic glass (Fe43.7Co7.3Cr14.7Mo12.6C15.5B4.3Y1.9 in at.%) . Based on a series of experiments, we have established a phase formation map, in which three regions including near fully amorphous, fully crystallized and partially crystallized are clearly distinguished. Low laser power density and high scanning speed favorite the formation of fully amorphous structure, while high laser power and low scanning speed promote the formation of crystallite phases. Based of the finite-element-method (FEM) simulation on temperature field distribution around molten pool in SLM process, it is concluded that the temperature and time distributions in heat-affected zone (HAZ) is responsible for the fraction of amorphous phase obtained. This work provides a clue to the structural modification in laser 3D printing of BMGs. Keywords: Laser 3D printing; Fe-based bulk metallic glasses, Phase formation, G-P24 Preparation and properties of the FeZrB based amorphous/nanocrystalline alloy with high soft magnetic Xiaotong Bao, Tao Zhang Beihang University

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The effects of minor addition of Cu on glass-forming ability (GFA), thermal stability and magnetic properties of Fe90Zr6-xB3Cux(x=0–1) alloys were investigated.The introduction of Cu slightly increases the GFA and efficiently improves the primary crystallization of α-Fe nanoparticles.The alloy with 0.3% Cu addition shows the best GFA and the fully glassy rods can be produced up to 0.05mm in diameter.The saturation magnetization of the glassy sample with 1.0% Cu addition can be enhanced from 1.54 to 1.64T after proper heat treatment due to the precipitation of a-Fe nanoparticles in the glassy matrix.The combination of large GFA and high saturation magnetization as well as low cost makes the FeZrBCu alloys as a kind of promising soft magnetic materials for industrial applications. Keywords: glass-forming ability;Amorphous;Nanocrystalline;Soft magnetic property G-P25 First results of chemcial diffusion in Fe-based liquid alloys Lang Xiang Zhong, Jin Liang Hu, Bo Zhang Laboratory of Amorphous Materials, School of Materials Science and Engineering, Hefei University of Technology The study of chemical diffusion coefficients in Fe-based liquid metals is vital for understanding of glass forming ability (GFA) and transport properties in Fe-based alloys. So far the accurate experimental diffusion data in Fe-based liquid alloys are lacking due to the complexity of the experimental measurements. Combined with the idea of the shear cell method and a recently developed sliding cell technique, a multi-slice sliding cell technique was used for diffusion measurements in Fe-Si liquid metals. The temperature-dependent diffusion coefficients were carried out. To our knowledge, it is the first accurate experimental diffusion data in Fe-based binary liquid. We demonstrated that the multi-slice sliding cell technique can measure the diffusion coefficients in Fe-based liquid metals. Moreover, it is very feasible to measure the diffusion constants in Fe-based multicomponent liquids including glass-forming liquids like Fe-Si-B. These results suggest that the multi-slice sliding cell technique has significant potentials for wide uses in the measurements of liquid diffusion for the binary and multicomponent alloys. Keywords: chemical diffusion, multi-slice sliding cell , Fe-based liquid alloys G-P26 Effects of cooling rate on the microstructure and corrosion resistance of Fe-based bulk metallic glasses in NaOH solutions Zongzhen Li, Shaoxiong Zhou, Guangqiang Zhang, Bangshao Dong, Hui Gao China Iron & Steel Research Institute Group, Advanced Technology & Materials Co., Ltd., Beijing 100081, China Fe-based bulk metallic glasses (BMGs) in a rod shape with a nominal composition of (Fe0.76Si0.09B0.1P0.05)98.25Nb1Cu0.75 were successfully developed by copper mold casting. The effect of cooling rate on the microstructure and corrosion behavior were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical polarization measurements in NaOH solution. The variation of cooling rate as the diameter of the as-cast sample increases from 1 to 3 mm is found to be responsible for the evolution of microstructure and morphology of corrosion products. It is suggested that the microstructural heterogeneity dominate the corrosion behavior of the bulk metallic glasses. Keywords: Bulk metallic glasses,Microstructure,Corrosion,Cooling rate

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G-P27 Steady state flow behavior of the FeCoNiCr high entropy alloy hardened by massive nano-precipitates Junyang He1, Hui Wang1, Yuan Wu1, Xiongjun Liu1, Taigang Nieh2, Zhaoping Lu1 1. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing, China 2. Department of Materials Science and Engineering, the University of Tennessee, Knoxville, TN, USA High-entropy alloys (HEAs) have a great potential for high-temperature applications due to their highly stable solid-solution matrix and exceptional diffusion resistance. However, our previous study on the flow behavior of a typical fcc FeCoNiCrMn HEA suggested that the HEA matrix alone is insufficient to overcome high-temperature softening. Recently, we reported development of the fcc-FeCoNiCr HEA reinforced with a high density of fine dispersed nano gama prime particulates through minor additions of Ti and Al. The extraordinary precipitation hardening at room temperature was achieved, but its effects at elevated temperatures are still unclear. In this work, we systematically investigated the flow behavior of (FeCoNiCr)94Ti2Al4 strengthened by gama prime in the temperature range of 750 to 900 °C. In contrast to the FeCoNiCrMn HEA without any precipitates, significant decrease of the steady state strain rate of ~2 orders of magnitude was observed at each temperature, and the stress exponent n increased correspondingly. Our analysis showed that, when temperature was below 850 °C, the particle shearing mechanism controlled the deformation process; whereas the temperature exceeded 850 °C, the hardening effect weakened quickly due to the dissolution of the gama prime particles. Nevertheless, the current result indicated precipitation hardening mechanism can be employed in HEAs to further enhance their mechanical performance. Keywords: High Entropy Alloy, Steady state flow behavior, Precipitation hardening, Particle shearing mechanism G-P28 Modeling and Calculation of Magnetic High-Entropy alloys Wenqiang Feng, Shaoqing Wang Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, Liaoning Province, China High-Entropy alloys are extensive investigated experimentally in recent years. To reduce research cost and shorten development cycle, computer simulations have been applied to multi-component alloys in selecting the proper elements concentration and predicting new materials with unique properties. Constructing a proper micro-structural model is the starting point of the simulation. Accurate and high-efficient computer simulation usually requires periodic boundary condition. There is no strict periodicity in the structure of HEAs. How to use periodic models to approach the real structure of these alloys is a significant problem. In this work, periodic chemical-homogeneity multi-component-alloy structures were constructed according to maximum entropy (MaxEnt) principle. The Monte Carlo algorithm was used to optimize the system configuration further. The elements composition and concentration of multi-component alloys are easily manipulated and the production of periodic random structures are computational efficient. Several CoCrFeNi-based magnetic HEAs were simulated on the constructed models and Special Quasi-random Structure (SQS) models using density functional theory techniques. The lattice parameters, enthalpies of mixing, bulk modulus were calculated [1]. The effects of Al, Mn, Pd elements on the magnetic properties of these alloys were discussed.

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[1] Wenqiang Feng, Sumin Zheng, Yang Qi, Shaoqing Wang, Periodic MaxEnt structure models for High-Entropy alloys, submitted to Intermetallics. Keywords: High-entropy alloys; Structure modeling; First-principles calculation; G-P29 Microstructure and properties of AlCrFeNi high-entropy alloy coating prepared by mechanical alloying and hot pressing sintering Caiyun Shang, Yan Wang University of Jinan The AlCrFeNi high-entropy alloy coatings (HEACs) were prepared by mechanical alloying (MA) and vacuum hot pressing sintering (VHPS) technique on Q235 substrate. The microstructures and microhardness, wear resistance and corrosion resistance of HEACs have been studied in detail. Results show that single body-centered cubic (BCC) solid solution phase appears for the as-milled powders after 30 h of MA time. It presents excellent chemical homogeneity and refined morphology with uniform particle size of about 12 μm. The microscaled particles are actually hard agglomerations of nanoscaled crystallines with crystal size of about 10 nm. The VHPS-ed AlCrFeNi HEAC, composed of a single BCC solid solution, is about 500 μm in thickness with good metallurgical bonding to the substrate. The microhardness of the AlCrFeNi HEAC is about three times that of the substrate. And it even displays more excellent wear resistance under the same condition, which might be attributed to the fact that the wear resistance is proportional to the hardness according to Archard's law. Besides, the average corrosion rate in the potentiodynamic polarization measurement of the coating is two orders of magnitude lower than that of the Q235 substrate, indicating a good corrosion resistance. Keywords: High-entropy alloy coating; Mechanical alloying; Vacuum hot pressing sintering; Wear resistance; Corrosion resistance- G-P30 In situ high-energy X-ray diffraction study of compressive deformation behavior in dual-phase high entropy alloy Lili Ma1,2, Lu Wang1, Yunfei Xue1, Zhihua Nie1, Tangqing Cao1, Yang Ren3 1. School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China. 2. School of Chemical Engineering, Qinghai University, Xining, 810016, China. 3. X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA The micro-mechanical behavior of a dual-phase (40% FCC and 60% BCC) high entropy alloy (HEA) during deformation was investigated using in situ synchrotron-based high energy X-ray diffraction (HE-XRD) technique. The alloy with nominal composition of Al0.6CoCrFeNi (molar ratio) was prepared by vacuum arc melting followed by a water-cooled copper casting method. The as-cast alloy with diameter of 2 mm has an equiaxed grain structure, and long Widmansttten side plates formed in the grains. Under compressive loading with a strain rate of 1′10-3s-1, the alloy exhibited a yielding stress of ~850 MPa and did not fail despite being compress to the engineering strain of 50%. Based on the structural evolution information obtained by tracing the diffraction patterns, the stress distribution of constituent phases and the interactions of phase-to-phase and grain-to grain were characterized. The “soft” FCC phase yielded earlier than the “hard” BCC phase, and the latter bore more stress during plastic deformation. As the main contributor of the plasticity, the deformation of FCC phase was caused by the motion of dislocations.

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Keywords: High entropy alloy; Dual-phase; Micro-mechanical behavior; High-energy X-ray diffraction; Stress distribution G-P31 Phase Structures and Formation Criterion of Topologically Close-packed Phase in CoCrFeNiMo System Alloys Ning Liu, Zhen Peng, WenDong Du, PengHui Wu, XiaoJing Wang School of Materials Science and Engineering, Jiangsu University of Science and Technology In a previous work, equal-atomic CoCrFeNiMo alloy was studied; typical dendrites and inter-dendritic structures, as well as BCC and FCC structures are obtained. A series of CoCrFeNiMo system alloys were designed by partly replacing Mo with Co, Cr, Fe and Ni elements, in order to research the microstructures, phase structures and properties of the alloys, especially, more attention are paid on the formation of intermetallic phases. Most of the alloys are composed of dendrites and inter-dendritic eutectic structures, but completely eutectic structures were observed in microstructures of CoCr1.2FeMo0.8Ni alloy, it means that the component is eutectic composition. Compared to equal-atomic CoCrFeNiMo alloy, topologically close-packed structures are found except for Co1.7CrFeMo0.3Ni, CoCrFe1.7Mo0.3Ni and CoCrFeMo0.3Ni1.7 alloys, in which only FCC structure is detected. The relation between phase structures and physical parameters such as ΔHmix, ΔR, ΔSmix, ΔX and VEC, was discussed. It was investigated that simple FCC is found when VEC≥8.08 and ΔX≤0.120, and topologically close-packed structures emerged only when ΔX>0.133, and in most cases VECCo1.5Mo0.5, Mo0.5Ni1.5 and Cu0.1Mo0.5Ni1.5 alloys. Keywords: high-entropy alloys; eutectic; phase structures; topologically close-packed phase G-P32 Microstructure, Nano-precipitation and properties of CoCrCuFeNiMnx high-entropy alloys Ning Liu, Wendong Du, Penghui Wu, zhen Peng, Xiaojing Wang Jiangsu University of Science and Technology In this paper, a new CoCrCuFeMnxNi high entropy alloy system was designed, where Mn content was changed from the molar ration 0.1 to 2.0, to investigate the effect of Mn content on the microstructures and properties of CoCrCuFeMnxNi high-entropy alloys. According to XRD analysis, simple FCC phase is found in CoCrCuFeNiMnx alloys when x Keywords: microstructure; high-entropy alloy; phase structure; hardness; compressive strength G-P33 Microstructure and mechanical properties of a refractory NbMoTaWVCr high entropy alloy fabricated by mechanical alloying and spark plasma sintering Yan Long, Xiaozhen Li, Xiaodong Chen, Nan Gao, Jinfu Zhang National Engineering Research Center of near-net-shape forming for metallic materials, School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou, 510640, China The refractory NbMoTaWVCr high entropy alloy (HEA) was fabricated by mechanical alloying (MA) and spark plasma sintering (SPS). The microstructure and mechanical properties were investigated by X-ray diffraction (XRD), scanning electron microcopy (SEM), transmission electron microcopy (TEM) and mechanical testing.

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During the MA process, only a body-centered cubic structure solid solution was formed. However, after SPS, a major matrix BCC phase and a minor precipitated phase was observed in the HEA bulk material, and the precipitated phase is mainly enriched of Ta and V. The density of the sintered bulk is 11.67 g/cm3. The sintered compact exhibits excellent compressive properties as well as extremely high hardness which should be attributed to the solid-solution strengthening. The compressive yield strength, plasticity, fracture strength and the Vickers hardness of the alloy are 3416.7 MPa, 5.3%, 3834.3 MPa and 1011.2 Hv, respectively. The NbMoTaWVCr high entropy alloy mainly exhibited intergranular fracture and plastic fracture mode. Keywords: refractory, high entropy alloy, microstructure, mechanical properties G-P34 Effect of Al content and cooling rate on the microstructure and mechanical properities of AlxCrFeNiV0.3 high entropy alloys Baoyuan Cheng, Yunfei Xue, Lili Ma, Tangqing Cao School of Materials Science and Engineering Beijing Institute of Technology, Beijing, 100081, China Asbract:The effect of Al addition and cooling rate on the microstructure and mechanical properties of high entropy alloys AlxCrFeNiV0.3(x express molar ratio; x=0.25,0.5and 0.75) were investigated. The alloys were prepared by arc melting (denoted as Ix alloys) and copper mold casting (denoted as Cx alloys, with a larger cooling rate).The phase structure of Ix alloys consisted of hexagonal and body centered cubic(BCC), and the volume fraction of hexagonal phase added with an increasing in the Al content.The hexagonal phase only appears in C0.25, namely fast cooling restrain the formation of hexagonal phase.The microstructure of Ix alloy changed from columnar crystal to dendrite with an increasing in the Al content accompanied by the increase of modulated structure existed in the interdendritic, which suggested that the Al addition facilitates the spinodal decomposition. Both the yield stress and plasticity of the Ix alloy improved with the enhancement of Al addition under compressive loading.The Cx alloys have a major promotion on yield stress with a small sacrifice on its plasticity compared with the Ix alloys.The C0.75 alloy exhibited best comprehensive mechanical properties, and the yield stress, comprehensive stress and fracture strain are1899MPa,4784MPaand 34% respectively. Keywords: High entropy alloys, Cooling rate, Microstructure, Mechanical properties G-P35 Microstructure and mechanical behavior of Co-free FeCoNiCu high entropy alloy Yilu Zhao, Tong Yang, Da Chen, Yong Yang, Ji-Jung Kai City University of HongKong A quaternary high-entropy alloy (FeCrNiCu) was systematically investigated, including crystal structure and microstructure evolution after cold-rolling. Instead of forming a single FCC phase predicted from empirical rules of HEA phase formation, a dual-phase solid solution is favored for current alloy system. Furthermore, the two solid-solution phases (namely, Cu-rich and Cu-lean phases) share the same lattice constants and form coherent interface revealed by a combination of synchrotron X-ray diffraction technique and transmission electron microscope study. Besides the micro-scale phase segregation, high density of Cu-rich nanoparticles (about 20nm) were also found in the Cu-lean phase. After cold-rolling, the microstructure change of these Cu-rich and Cu-lean phases is dramatically different. Specifically, for Cu-rich phase grain size was highly reduced by dislocation-controlled mechanism while for the Cu-lean phase dislocation, stacking fault and twinning interact together to form elongated grains.

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Keywords: dual-phase solid solution, phase segregation, high entropy alloy G-P36 Kinetics study on non-isothermal crystallization of Cu50Zr50 metallic glass qian gao Xian University of Technology To solve the problem of the stability of metallic glass, crystallization kinetics of melt-spun Cu50Zr50 amorphous alloy ribbons was investigated. The Cu50Zr50 metallic glass ribbons were successfully prepared by means of melt-spinning method. The sample structure and characteristic temperatures were tested using X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Moreover, the Kissinger, Ozawa and isoconversional approaches were used to obtain the crystallization kinetic parameters. As shown in the results, the onset crystallization activation energy Ex is less than crystallization peak activation energy Ep. The local activation energy Eα increases at the crystallized volume fraction α<0.2 and decreases at the rest, which suggests that crystallization process is increasingly hard (αα>0.2). The nucleation activation energy Enucleation is greater than grain growth activation energy Egrowth, indicating that the nucleation is harder than growth. In terms of the local Avrami exponent n(α), it lies between 1.27 and 8, which means that crystallization mechanism in the non-isothermal crystallization is interface-controlled one- two- or three-dimensional growth with different nucleation rates. Keywords: Metallic glass; Crystallization kinetics; Activation energy; Avrami exponent G-P37 Co-based bulk metallic glasses with excellent soft-magnetic properties and high strength Qikui Man1,2, Yaqiang Dong1,2, Chuntao Chang1,2, Xinmin Wang1,2, Run-wei Li1,2 1. Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences 2. Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences For Co-based amorphous alloys, It is known that CoFeSiB alloys with zero magnetostriction exhibit super-high permeability which has been subsequently developed as high-sensitivity sensor materials. However, the poor glass-forming ability (GFA) requiring high cooling rates to obtain the amorphous phase from the liquid state, resulting in the limitation of shape and dimension to be thin ribbon and wire forms. Therefore, it is demanded to develop new Co-based BMGs combination with higher GFA and good soft-magnetic properties. The thermal stability, glass-forming ability (GFA), soft-magnetic properties and mechanical properties of Co46Fe19+xB22.5Si5.5Nb7–x (x=0–2) bulk metallic glasses (BMGs) were investigated. The 5.5 at% Nb addition was found to be effective in approaching alloy to a eutectic point, resulting in an increase in GFA. By copper mold casting, BMG rods with diameters up to 5 mm were produced. Except for high GFA, the BMGs also exhibit good soft-magnetic properties, i.e., low coercive force (Hc) of 1.34–2.14 A/m, high effective permeability (μe) at 1 kHz of 2.26–3.06×104, and high fractures strength (σf) of 4010–4460 MPa. This Co-based BMG system with high strengths and excellent soft-magnetic properties is promising for future applications as a new functional material. Keywords: Metallic glasses; Magnetic properties; Mechanical properties; Glass-forming ability

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G-P38 The corrosion resistance of Fe-based bulk metallic glass with in situ sulfide particle in hydrochloride solution Shanlin Wang1, Yong Huang1, Yvbing Gong1, Hongxiang Li2 1. National Defence Key Disciplines Laboratory of Light Alloy Processing Science and Technology, Nanchang Hangkong University, Nanchang, Jiangxi, 330063, China 2. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology, Beijing, 100083, China The corrosion resistance of Fe66.6C7.1Si3.3B5.5P8.7Cr2.3Mo2.5Al2.0Co1.0S1.0 bulk metallic glass (Fe-BMG) with in situ sulfide particle fabricated with industrial raw materials was investigated in different concentration HCl solutions. The results indicate that the pitting initiation of Fe-BMG is not triggered by the presence of FeS particle, while it is an initiate site of the dissolution of alloy elements. The corrosion current density is increased with the hydrochloride concentration and the environmental temperature. A stable passivation can be observed from potentiodynamic polarization curve in 0.1 M HCl solution, and it seemly become unstable in 4 M HCl solution. The corrosion rate is higher than 105 mg/cm2 and the corrosion layer thickness exceeds 20 μm after immersed 168 h in 1 M HCl solution at room temperature. Keywords: Fe-based bulk metallic glass, Sulfide particle, Pitting initiation, Hydrochloride solution G-P39 Discharge Enhancement Effect of Amorphous Alloys Spark Plasma Aid Minggang Wang Changchun University of Technology Abstract. A inorganic nanometer powder particles were used as sintering aid to sintering good conductive amorphous alloy. In this institute we made inorganic nanometer powder particles with a granularity of 15-30 nm assembled between micron-sized amorphous powder particles were fabricated by spark plasma sintering (SPS) with varying contents of aid. Result shows that the discharge enhancement effect of inorganic nano spark plasma aid is indeed confirmed. The initial sintering temperature and the final sintering temperature are both decreased. In the case of reduced sintering temperature, they lead to higher levers of density compared with no adding inorganic nanometer powder aid particles and the amorphous structure can be retained. Keywords: spark plasma sintering，amorphous alloy sintering aid，discharge enhancement effect G-P40 Effect of Zr/Hf ratio on the non-isothermal crystallization kinetics in Zr57.4Ni8.2Cu16.4Al10Ta8 metallic glass caimin huang, Shun Li, Shuxin Bai National University of Defence Technology The Zr-Ta-Cu-Ni-Al bulk metallic glass exhibits high fracture strength (~2 Gpa) and large plastic strain (~ 16%) under uniaxial compressive loading. To develop high-density metallic glass, Hf is substituted for Zr in Zr-Ta-Cu-Ni-Al alloy.

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The ribbons of composition (Zr1-xHfx)57.4Ni8.2Cu16.4Al10 Ta8 (x=0-1) with 40-50 μm thick and 2 mm wide have been fabricated by a single roller melt spinning. In order to determine the intrinsic nature of amorphous and the amount of crystalline phases, X-ray diffraction (XRD) is employed. The crystallization kinetics of these alloys was investigated using differential scanning calorimeter (DSC) at four different heating rates under non-isothermal (linear heating) model. The thermal stability of these metallic glasses, the onset glass transition temperature Tg, the onset temperature of crystallization Tx, and the peak temperature of crystallization Tp were obtained from DSC curves. The values of various kinetic parameters such as the activation energy of glass transition Eg, activation energy of crystallization Ep and Avrami exponent n were calculated from Kissinger method, Kissinger-Akahira-Sunose (KAS) method and Flynn-Wall-Ozawa (FWO) method. The results show that the XRD patterns of these alloys are a broad scattering feature. No crystalline phase peaks are found. The crystallization behaviors of these metallic glasses are different with variation x. Crystallization kinetic parameters are similar with different calculated methods. Activation energies of glass transition Eg and glass transition temperature Tg increases with increasing Hf content due to strong bond energy. The activation energies at the beginning of the crystallization are higher than that at the end of the crystallization in the first exothermic peak. Additionally, the effects of Zr/Hf ratio on the activation and Avrami exponent were discussed. The governing nucleation and growth mechanism of crystalline phases are investigated by introducing Avrami exponent n. It is assumed that the volume fraction of crystalline phases is proportional to the area fraction of the exothermic peak. The Avrami exponent of the metallic glasses during non- isothermal process has been investigated through modified Johnson-Mehl-Avrami formalism (). The values of Avrami exponents are not the constant during the transformation range from x=0.2 to x=0.8. The different crystallization models in these series alloys, mainly controlled by the constant nucleation rate (n=4) and the constant nucleus (n=3), reveal the different microstructures in the metallic glasses. Moreover, the relation between Avrami exponents and activation energies were also discussed. The crystallization behaviors are changed from the multi-step crystallization to single step crystallization with the ratio increasing. The incubation time for crystallization, obtained from DSC curves, are also different with the variation of the Zr/Hf ratio. It is indicated the time of generating critical cluster of crystalline nucleus are changing with the content of Hf. That is, the critical clusters transforming the short-range ordering in the amorphous phase to crystalline phases are governed by the atomic diffusion. The longer incubation time and more sluggish atomic diffusion promote to maintain short-range or medium-range ordering, restricting the formation of nano-crystalline phases during the annealing or deformation. It is proposed that the properly Hf content is the most effective factor in enhancing the density and ductility of metallic glass by controlled crystallization process and sizes of nano-crystalline. Keywords: Metallic glass; Thermal stability; Crystallization kinetics; Differential scanning calorimetry G-P41 Study of crystalline transformation for Mg61Zn35Ca4 glass using isoconversional method dao zhang, wangshu lu, sen yang Nanjing University of Science and Technology Objective: In this work, the crystallization kinetics of amorphous Mg61Zn35Ca4 alloy was studied at different heating rates under non-isothermal conditions, which can be applied for further studies on the fabrication of Mg-Zn-Ca glassy alloy by laser process. Methods: The DSC curves of Mg61Zn35Ca4 glass were characterized by continuous heating at heating rates ranging from 5 to 80 K/min in TA DSC Q2000 under flowing purity argon at a flow rate of 50 ml/min. The 1st effective activation energy was determined by analysing the data using the Matusita. The variation of the 1st

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effective activation energy was analysed by the isoconversional method, Kissinger-Akahira-Sunose (KAS). The Johnson-Mehl-Avrami (JMA) model and the Sestak-Berggren (SB) model were discussed to describe the first crystallization process for the studied composition. Results: The experimental results showed that the DSC curves of the crystallization process of the Mg61Zn35Ca4 glass shift to higher temperatures with increasing heating rate. There is no explicit relationship between the heating rate and the activation energy of crystallization. The 1st effective activation energy using the KAS method decreases with the increase of crystallization fraction as well as the corresponding average temperature. The DSC curves calculated using the JMA model is nearly in agreement with the measured data only when the heating rate is low. At high heating rates, the discrepancies become large. On the other hand, the DSC curves calculated using the SB model fit quite well with the experimental data at all heating rates. Conclusion: The crystallization kinetics for Mg61Zn35Ca4 glass was analysed by the isoconversion models under non-isothermal condition. The 1st effective activation energy of crystallization was determined by using the Matusita et al. method. The 1st effective activation energy of crystallization is not constant but varies with the degree of crystallization and hence with temperature. This variation indicates that the first step transformation from amorphous to crystalline phase in Mg61Zn35Ca4 is a complex process involving different mechanisms of nucleation and growth. Simulation results indicate that the Sestak-Berggren (SB) model is more suitable to describe the crystallization kinetics. Keywords: amorphous; crystallization kinetics; isoconversional method; Mg-based alloy G-P42 Formation of calcium phosphate layer on a Ni-free Ti-based metallic glass for potential biomedical applications Wei Yang, Shujie Pang, Ying Liu, Tao Zhang Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing, China Ti-based bulk metallic glasses (BMGs) with high specific strength, low Young’s modulus, good biocompatibility and bio-corrosion resistance exhibit potential for biomedical applications. Recently, we have developed a novel Ni-free Ti47Cu38Zr7.5Fe2.5Sn2Si1Ag2 (at.%) bulk metallic glasses with superior glass-forming ability, good mechanical properties, high corrosion resistance and excellent biocompatibility as biomaterials. The preparation and formation of calcium phosphates (Ca–P) layer on the Ti-base BMG should be further investigated due to their relevance in implant materials. Moreover, the bioactivity of the BMGs is generally evaluated by the formation of bonelike apatite on metallic implants in simulated body fluid (SBF) solution before implanting. In this study, a bioactive surface layer composed of calcium phosphate compound was prepared on the surface of the Ti-based BMG by chemical treatment. It was found that pre-calcium treatment accelerated the nucleation of calcium phosphate particles. After chemical and pre-calcium treatments, following by soaking in simulated body fluid (SBF) solution, Ca-P layer was observed on the Ti-based metallic glass. The nucleation and growth of a Ca-P layer on the Ti-based BMG from SBF was investigated by using XRD and SEM. The presence of calcium and phosphorus elements was confirmed by EDS and XPS. Mechanisms of the formation and properties for the Ca-P layer of the BMG are also discussed. With the formation of the bioactive surface, the Ni-free Ti-based BMG is expected to be a promising biomaterial for orthopedic and dental implants. Keywords: metallic glass; calcium phosphates; bioactivity; simulated body fluids G-P43

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A novel Ti-based amorphous/nanocrystalline brazing filler metal for high-strength joining of Ti-6Al-4V alloy Yan Si, Lulu Sun, Shujie Pang, Tao Zhang Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191, China Titanium alloys have extensive applications in the field of aerospace, and for the brazing of titanium alloys, Ti-based brazing filler metals (BFMs) are wildly used. However, high contents of Cu and Ni (usually above 25 wt.%) in the Ti-based BFMs as the melting point depressants lead to the formation of brittle Ti-Cu and Ti-Ni intermetallic compounds, which weakens the joint mechanical properties. Compared with crystalline BFMs, amorphous/nanocrystalline BFMs exhibit desirable advantages including easy formability in a thin continuous ribbon form by spinning technology, high purity, and homogeneity in composition and structure, ect. In this work, a Ti-Zr-Cu-Co-Fe amorphous/nanocrystalline BFM with low content of Cu (8 at.%) and low liquidus temperature of 1157 K was synthesized by melt spinning. TC4 alloy was brazed with this BFM at 1203 K for 900 s in vacuum, and the brazed joint exhibited a Widmansttten structure consisting mainly of alpha-Ti, beta-Ti and Ti–Zr–rich phase, as well as a small amount of brittle intermetallics. The shear strength of the brazed joint was up to 326 ± 13 MPa. The high joint strength was mainly due to that the BFM is free from Ni and containing low content of Cu the Ni-free and low content of Cu in, which significantly reduced the brittle intermetallics in the TC4 alloy joint. Keywords: amorphous/nanocrystalline alloy; Titanium alloy; Microstructure; Mechanical property; Brazing filler metal G-P44 Effect of Rare Earth Er on Structure and Mechanical Properties of Zr-based Bulk Metallic Glasses Li Chunyan1,2*, Yin Jinfeng1, Zhao Yanchun1,2, Kou Shengzhong1,2

1.College of Material Science and Technology, Lanzhou University of Technology, Lanzhou 730050, China; 2. State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China *aemail: licywz@163.com, bemail: kousz@lut.cn, cemail: zhaoyc@lut.cn

(Zr-Cu-Ni-Al)100-xErx(x=0-3) bulk metallic glasses(BMGs) with diameters of the 3mm and the length 70mm were fabricated by copper mold suction-casting method under an argon atmosphere. Glass forming ability(GFA), thermal stability and mechanical properties of the alloys were studied by X-ray diffraction (XRD), differential scanning calorimetry(DSC), universal testing machine and scanning electron microscope (SEM). The results indicate that: with the increase of the content of rare earth Er, △T value decreases first then increases, Trg value decreases first then increases and decreases finally. It means that the thermal stability decreases first then increases, but glass forming ability decreases first then increases and decreases finally. With the increase of the content of rare earth Er, the plastic strain, modulus of elasticity, yield strength, maximum strength, and rupture strength change inordinately. When x=3, the plastic strain, maximum strength, and rupture strength of the samples are high to 23.19%, 2068Mpa and 2060Mpa respectively. Keywords: Rare earth, bulk metallic glass(BMG), structure, mechanical property Published Only Effect of lanthanum on glass forming ability and thermal stability of Al–Co–Y amorphous alloys

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zhiming wang 1. School of Mechanical and Automotive Engineering, Qilu University of Technology 2. Key Laboratory of Advanced Manufacturing and measurement & Control Technology for Light Industry in Universities of Shandong (Qilu University of Technology) The influence of La on glass forming ability (GFA) of amorphous Al84Co8Y8 was studied through substituting Y by 2at.%, 4at.%, 6%at and 8at.% La. To directly compare the GFA of Al84Co8Y8 with different addition of La, the melt-quenched alloys were fabricated by melt-spinning method at different quenching temperature. The amorphous nature of melt-quenched alloys was investigated by X-ray diffraction (XRD) and differential thermal analysis (DTA). The results indicate that Al84Co8Y4La4 has the best glass forming ability, but Al84Co8Y2La6 and Al84Co8La8 present weaker GFA than Al84Co8Y8. The investigation on thermal stability of amorphous Al84Co8Y8-xLax alloys shows that the thermal stability of amorphous Al84Co8Y8 alloy can be improved by La addition with a peak at the composition Al84Co8Y6La2. It is also found that the crystallization behavior of amorphous Al84Co8Y8 alloys was changed by the addition of La in the form of transforming from two-step crystallization process to three-step crystallization process. Keywords: Glass forming ability; amorphous Al84Co8Y8; Crystallization behavior; Lanthanum Effect of Y addition on the glass forming ability and crystallization of AI-Ni-Ce amorphous alloys Guorong Zhou, Ying Zhang, Kunyuan Zhu, Guodong Liu, Mingming Zhang, Hecheng Han School of Materials Science and Engineering, University of Jinan, Jinan, 250022, P. R. China In this paper, the effect of substituting Ni by Y on the glass forming ability (GFA), micro hardness and crystallization behavior of Al85Ni10Ce5 amorphous alloys were systematically investigated. The super-cooled liquid region of Al85Ni10-xCe5Yx (x=0, 2 at.%) alloys tends to increase with increasing Y content, which means that the addition of Y increase the GFA of Al85Ni10Ce5 alloys. At the same time, the Y additions significantly increase the micro hardness of the respective alloys. Moreover, there are a mount of nanocrystals precipitated from Al85Ni10-xCe5Yx (x=0, 2 at.%) amorphous alloys in the annealing process, which are primarily composed of fcc-Al, Al4Ce and Al3Ni phase. Keywords: amorphous alloys, glass forming ability, crystallization behavior, nanocrystals Effect of surface crystallization on magnetic properties of Fe82Cu1Si4B11.5Nb1.5 nanocrystalline alloy Fangpei Wan1, Aina He2, Jianhua Zhang1, Anding Wang2, Chuntao Chang2, Xinmin Wang2 1. College of Electrical and Power Engineering, Shanxi Key Laboratory of Coal Mining Equipment and Safety Control, Taiyuan University of Technology, Taiyuan, Shanxi 030024, China 2. Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China Fe-based nanocrystalline soft-magnetic materials have attracted worldwide attention due to their excellent magnetic properties, including low iron loss in large frequency range, high effective permeability (μe), low saturation magnetostriction (λs) and relatively high saturation magnetic flux density (Bs). In order to realize the miniaturization and higher efficiency of the electrical machinery and apparatus, increasing the Bs is a major driving force for further alloy compositions development. Recently developed Fe-based high Bs nanocrystalline alloys are relatively easily accessible by conventional casting technology, while the compositions are close to the glass formation limit, which maybe result in surface crystallization1, 2. In this study, the effect of surface

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crystallization layers on the soft-magnetic properties and core loss of Fe82Cu1Si4B11.5Nb1.5 nanocrystalline alloy ribbons was investigated. The Fe82Cu1Si4B11.5Nb1.5 nanocrystalline alloy ribbons with amorphous structure and surface crystallization were prepared by single-roller melt-spinning method with copper roller speed of 45m/s, 35 m/s and 25 m/s. It is found that the samples with surface crystallization layers not only show a wider annealing temperature range than the amorphous samples, but also have a better high frequency properties which means still maintain high permeability at high frequency. After annealing, all samples show a novel soft-magnetic properties such as low Hc of 8.9~12.4 A/m and high μe of 10100~12700, which makes the Fe82Cu1Si4B11.5Nb1.5 nanocrystalline alloy with surface crystallization has a promising application in the electromagnetic fields as 20~100 kHz, high power transformer for power-electronic device. Keywords: Nanocrystalline alloy, soft magnetic property, surface crystallization, thermal stability, Fe-based Compositional dependence of magnetic and mechanical properties of FeSiBPC amorphous alloys Xiaofeng Liang1,2, Keqiang Qiu1, Anding Wang2, Chuntao Chang2 1. School of Materials Science and Engineering, Shenyang University of Technology, Shenyang, Liaoning 110870, China 2. Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China As a new generation of soft-magnetic material, Fe-based amorphous alloys are widely used because of their excellent soft-magnetic properties including high effective permeability (μe), high saturation flux density (Bs), low coercivity (Hc) and core loss, playing an increasingly important role in electric motor, transformer, inductor, et al, which greatly affects the human living ways and tends to lower energy consumption and higher efficiency. During the annealing process, the residual stress release and structural relaxation occur, which is crucial for improving soft magnetic properties. On the other hand, the free volume, structural and chemical homogeneity will lead to the absence of center for inhibiting the shear band slippage and dispersive stress, which will induce the brittleness. The asynchronism between magnetic and mechanical properties of amorphous alloys is very an important but unclear issue. In this study, the influence of the composition on the magnetic and mechanical properties of FeSiBPC amorphous alloys was systematically investigated. It was found that all alloys had high amorphous forming ability and good soft magnetic properties after annealing. The transition temperature of bending ductility-brittleness decreases much faster than that of soft magnetic properties with the increase of Fe content. It is interesting that alloys with Fe content higher than 80 at. % exhibit good ductility before and after annealing at the optimal condition. The alloy with Fe content of 71 at. % is brittle even at as-spun state. The saturation flux density (Bs) and coercivity (Hc) decrease with decrease of the Fe content and deviate from a linear fitting tendency. The temperature asynchronism between magnetic properties and bending ductility of amorphous alloy ribbons was discussed. This work will provide the theoretical foundation for the future development of the amorphous alloy ribbons. Keywords: Fe-based amorphous alloy; Amorphous forming-ability; Soft-magnetic property; Ductile-brittle transition. Development and accelerated aging study of high Fe content amorphous alloys Pingbo Chen1,2, Anding Wang1, Chengliang Zhao1, Aina He1, Chuntao Chang1, Xinmin Wang1 1. Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China 2. Laboratory for Microstructures, Institute of Materials Science, Shanghai University, Shanghai 200444, China

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Fe-based amorphous materials have been widely used in distribution transformer cores for a long time in the U.S., Japan, India, and China. The amorphous core distribution transformers allow more than 60% reduction in no-load losses compared to conventional grain-oriented silicon steel transformers. However, the amorphous alloy Metglas2605SA1 developed thirty years ago exhibits low Bs which significantly increase the size of transformer and decrease the stability of transformer. In the recent work of our group, FeSiBPC system alloys with a distinctly high Fe content of 93.5-95.5 wt. % were prepared by component design and composition adjustment. These alloys show a good bending ductility and excellent magnetic properties after annealing, i.e., a low coercivity of 3.3-5.9 A/m, high permeability of 5000-10000 and high flux saturation density of 1.63-1.66 T. With the increase of the Fe content, the application of these alloys also needs further study. Accelerated aging tests of the high Fe content amorphous alloys were developed in a vacuum treatment process. After ten days heating at 240 oC and 260 oC, the alloys show stable good soft-magnetic properties. Through accelerated aging tests, lifetimes of both alloys were estimated through Arrhenius law with results from aging investigations. It should be noted that the alloys possess a far longer life than the transformer itself. The calculated lifetimes show these amorphous materials can maintain a long-term performance as a magnetic core in a distribution transformer. The amorphous alloys with the high Fe content comparable with that of the desired high Si alloy are promising candidates for the potential application in electric devices. Keywords: amorphous materials, high Fe content, accelerated aging Novel Fe-based nanocrystalline powder cores with excellent magnetic properties produced by cold compaction of the gas-atomized powders Liang Chang1,2, Qiang Li1, Chuntao Chang2, Yaqiang Dong2, Min Liu2, Xin-Min Wang2 1. School of Physics Science and Technology, Xinjiang University, Urumqi,Xinjiang 830046, China 2. Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China Fe-based nanocrystalline alloys have been reported to exhibit excellent soft magnetic properties including high saturation magnetization (Bs) and low coercivity (Hc), which are appropriate for magnetic core material. In this work, the (Fe0.76Si0.09B0.1P0.05)98.5Nb1Cu0.5 spherical powders with fully amorphous phase and the diameter of about 75 mm are prepared by gas atomization, and the nanocrystalline powder cores (NPCs) are obtained by annealing treatment of the powder cores fabricated by cold compaction of the gas-atomization FeSiBPNbCu amorphous alloy powders The obtained FeSiBPNbCu NPCs at optimum annealing conditions exhibit excellent magnetic properties, including stable permeability of 75 up to 103 kHz, low core loss and highly DC-bias permeability. It is considered that the excellent magnetic properties of the present NPCs may be attributed to the ultrafine α-Fe (Si) precipitated in amorphous matrix and the usage of the gas-atomized powders, which could be coated uniform insulating layer in cold compaction. Keywords: Nanocrystalline powder cores; Gas atomization; Excellent magnetic properties. Effect of Zr content on microstructure and properties of Al2NbTi3V2Zrx high-entropy alloy xinrong tan, zhongxia liu Zhengzhou university Al2NbTi3V2Zrx alloy was produced via mechanical milling followed by vacuum hot pressing and their microstructure and properties were analyzed. Results showed that the bulk was mainly consisted of simple cubic matrix and Ti-rich solid solution (hexagonal closepacked structure, HCP) and Zr-rich intermetallic. The Zr-rich

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intermetallic started to precipitate along the grain boundaries and Ti-rich solid solution disappeared as the content of Zr increased. Hardness of the alloy was correlated closely with the content of Zr and precipitated phase. The peak hardness of 570.4 HV was occurred in Al2NbTi3V2Zr0.8 alloy with high content of Zr and low precipitation. Al2NbTi3V2Zrx alloy showed more excellent corrosion resistance than Ti64 alloy in 10 wt% HNO3 solution. All the bulks had a low density in the range of 5.03–5.18 g/cm3. Keywords: Al2NbTi3V2Zrx high-entropy alloy; Zr content; Microstructure; Hardness; Corrosion resistance. The microstructure and properties of the Co2NiWV0.5Mo1.5, Co2NiWV0.5Mo2, and Co2NiWV1.0Mo2 multi-principal elements alloys Hui Jiang Key Laboratory of Solidification Control and Digital Preparation Technology (Liaoning Province), School of Materials Science and Engineering, Dalian University of Technology The Co2NiWV0.5Mo1.5, Co2NiWV0.5Mo2 and Co2NiWV1.0Mo2 multi-principal elements alloys were prepared by vacuum arc melting. The microstructure, compressive property and corrosion resistance of the alloys were investigated by means of X-ray diffraction, optical microscope, scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS), electrochemical workstation and WPM material testing machine. Results indicated that all of these alloys were composed of primary dendrite with BCC solid solution structure, inter-dendrite regions were filled with irregular and lamellar eutectic microstructures with a mixture of face-centred cubic (FCC) solid solution and Co7Mo6-type μ phase. Compression test results indicated that fracture strength of Co2NiMo2V1.0W, Co2NiMo2V0.5W and Co2NiMo1.5V0.5W alloys was 2308MPa, 1983MPa and 1861MPa, respectively. The solid-solution strengthening of the BCC matrix and the μ phase hardening were the two main factors that strengthened the alloys. Alloys corrosion resistance performance showed the alloy with higher Mo or lower V content has the better corrosion resistance. Keywords: Microstructure, Mechanical properties, Corrosion resistance Microstructure and mechanical properties of VTaTiMoAlx refractory high entropy alloys Dongxu Qiao, Hui Jiang, Li Jiang, Yiping Lu, Tingju Li Key Laboratory of Solidification Control and Digital Preparation Technology (Liaoning Province), School of Materials Science and Engineering, Dalian University of Technology Abstract: A series of refractory high-rentopy alloys VTaTiMoAlx with x=0,0.2,0.6,1 were designed and produced by vacuum arc melting. In this work the effect of added elements Al on phase composition and mechanical properties of refractory HEAs were investigated. The X-ray diffraction show that the phase composition of HEAs all are simple BCC solid solution, and the XRD pattern emerge the extraordinary slight asymmetry with the addition of Al element, because the difference of the composition between dendrite and interdendrite regions induces the tiny difference of lattice parameters. Then SEM and energy dispersive spectroscopy(EDS) indicted that the microstructure of HEAs are dendrite crystal structure. Ta, Mo element are enriched in the dendrite areas, the Al, Ti, V are are enriched in the inter- dendrite areas. The yield strength and compress strain reach maximum(σ0.2=1460MPa, ε=27%) at x=0, and decrease with the addition of Al element at romm temperature. Nevertheless, the Vickers hardness constantly improving as the Al element added, which value are 433.2HV, 450.1HV, 483.3HV, 509.4HV respectively. Keywords: Refractory high-entropy alloys, Microstructure, X-ray diffraction, Compression property.

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Effects of Cu addition on structural evolution and strengthening mechanisms of the FeCrCoMnNiCux high-entropy alloy xin xian HeFei University of Technology In this study, the FeCrCoMnNiCux (x=0, 0.25, 0.50, 0.75 and 1) alloy system are investigated, all these elements are transition metal elements of the fourth period. The FeCrCoMnNiCux (x=0, 0.25, 0.5, 0.75 and 1) alloy ingots with different content of Cu element were prepared by vacuum arc-melting with a mixture of pure metals (purity >99 wt%) on a water-cooled copper mold under the high-purity argon atmosphere, and subsequently furnace-cooled. These ingots were remelted at least five times to ensure chemical homogeneity. After polishing mechanically to smooth, the crystal structures of aloys were analyzed by a X’Pert PRO MPD X-ray diffraction (XRD) using Cu Kαradiation, the tube voltage was 40Kv and the tube current was 40mA, with the 2θ ranging from 20°to 100°at a speed of 0.2°/min. Micrographs of the ingots were shoot by the JSM-6490LV type scanning electron microscope (SEM) , and the micro-composition was analyzed by energy dispersive spectrometry (EDS). 200HV-5 Hardness tester with a load of 2 N for 15 s, was used to measure the vickers micro-hardness of high-entropy alloy, and for each specimen, measuring at least 5 pionts and a piont was measured at least five times to obtain a average value. Compression test were evaluated on samples of φ3mm×6mm with a strain rate of 3×10-4 s-1 using a computer control electronic universal testing machine CMT5105 in room-temperature . On the XRD patterns of the as-cast FeCrCoMnNiCux alloys with different Cu contents, a simple solid-solution phase with various diffraction peaks at about 2theta=43.6, 50.5, 74.7 and 90.5°corresponding to fcc structure could be observed in the alloys system of different Cu contents. Apparently, the crystalline structures of the alloy are found to consist of two fcc phase as the Cu content increasing begin from 0.5 at. %, indicating there be a crystal structure transformation, corresponding to the phase transformation result around the temperature at 1000 ℃. When the Cu concentration is less than 4.76% (x SEM micrographs of the as-cast alloys with different Cu contents show that Cu0 alloy exhibits single solid solution structure, which is consistent with the XRD result. Typical cast dendrite and inter-dendrite structures were observed in the alloys. However, the microstructure of dendrite and inter-dendrite is diverse in FeCrCoMnNiCux alloys system, which suggests Cu contents could have an effect on the growth behavior of dendrite. It is obvious that the crystal grain is big before adding Cu element, with the increasing of Cu content, the grain become homogeneous and small. To further investigate the relationship between phase formation and the Cu addition content, chemical compositions of the dendrite and inter-dendrite regions (defined as DR and ID respectively) were analyzed by EDS. The tendency of elements’ segregation can be approximately analyzed from the results. As a whole, ferrum, chromium and cobalt elements mainly exist in dendrite, and nickel element almost equilibrium distributes both in dendrite and inter-dendrite regions. When x=0, only Mn element clearly segregates to grain boundary, forming Mn-rich phases. However, with the addition of Cu element, there is obvious segregation between the grain and crystal boundary. It is obvious that copper and manganese elements segregate to inter-dendrite, forming Cu-rich and Mn-rich regions respectively. For Cu element, segregation become more serious with segregation value from 19.01% to 46.48%, along with Cu molar content increased from 0.25 to 1. It can be known that at the beginning of solidification, Cu element was pushed aside to the boundary due to the combined action of large mixing enthalpy and sluggish effect. All the mixing enthalpy between Cu element and other elements are much positive, resulting in the combinative force of Cu with other elements is the strongest among the combinative forces of the alloying elements, so it is easier for Cu element segregate to inter-dendrite than other elements after solidification.

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Compression stress-strain curves for the alloy system containing different amounts of Cu at room-temperature are showed. All FeCrCoMnNiCux alloys exhibit similar high compressive strength and excellent plastic deformation, and they can not fracture due to complete fcc structure. In addition, they show relatively low hardness around 200 Hv. The yield strength increase with the increase of Cu content, from 258.48 Mpa to 470.17 Mpa. The strain of each alloy at yield point are 1.36%, 4.30%, 3.48%, 5.72% and 6.20% respectively, showing that alloys’ ductility becomes better. In this study, the FeCrCoMnNiCux(x=0, 0.25, 0.5, 0.75 and 1) high-entropy alloys system was investigated in microstructure and compression properties. Effects of Cu on the phase formation, structure transformation and strengthening mechanisms were discussed. Based on results and analyses, several conclusions can be obtained as follows. (1)The alloy system is always a simple stable fcc structure, corresponding to the conclusion of VEC theory, and it appears a new fcc2 phase with increasing copper contents up to 0.5 molar. According to composition analyses, the fcc2 phase is likely to be Cu-rich and Mn-rich phase, due to segregation of Cu element and Mn element to inter-dendrite, which is result from positive enthalpy between Cu, Mn element and other elements. (2)The alloy system exhibits an excellent ductility and relatively low micro-hardness, because of the fcc solid solution structure. However, both the yield strength and hardness of the alloys almost linearly increased with the Cu content increased, it seems that continually adding Cu element into the alloy, promoting the segregation of Cu and Mn element, and refined grain size, playing a role of strengthening hardening. Keywords: High-entropy alloy; Structure transformation; Compression properties; Strengthening mechanisms Laser cladding in-situ synthesis of high entropy alloy coating on Ti-6Al-4V alloy: microstructure and properties characterization Zhaobing Cai1,2, Xiufang Cui2, Xin Wen1, Zhe Liu2, Meiling Dong1, Yang Li1,2, Guo Jin1 1. Institute of Surface/Interface Science and Technology, Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China 2. College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China In order to improve the surface properties of Ti-6Al-4V, high-entropy alloy coatings were prepared by in-situ laser cladding on the surface of Ti-6Al-4V substrate. The microstructure, micro-hardness, corrosion resistance and wear resistance were investigated. The results show that high-entropy alloy coating was composed of BCC HEA phase, α-Ti (HCP) phase and (Ni, Co)Ti2 (FCC) phase. The micro-hardness of high-entropy alloy coatings is much higher than that of Ti-6Al-4V substrate. The high-entropy alloy coating also has a better corrosion resistance than Ti-6Al-4V substrate, even superior to 304SS in 3.5wt.% NaCl solution at room temperature. Compared with Ti-6Al-4V substrate, the high-entropy alloy coating has a greater wear resistance with the wear mass loss decreased 28.2% and 23.1%, respectively. Wear patterns of Ti-6Al-4V substrate and high-entropy alloy coatings are the coexistence of adhesive wear and abrasive wear, but the wear degree of high-entropy alloy coatings is lower. Keywords: laser cladding; in-situ synthesis; high-entropy alloy coating; EPMA; properties characterization Influence of Size of Spraying Powders on the Microstructure and Corrosion Resistance of Fe-based Amorphous Coatings Prepared by HVAF Jin Jiao1, Qiang Luo1, Shoujiang Qu1, Xianshun Wei1, Yong Wang2, Yixuan Wu1, Mingwei Cai1, Jun Shen1 1. Tongji University

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2. Northeast Petroleum University High-velocity air fuel (HVAF) spray process was used to prepare Fe-based amorphous coatings with the composition of Fe49.7Cr18Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 on 304 stainless steel substrates using different sizes of feedstock powders. Morphology, microstructure and thermal stability of the gas-atomised powders and as-sprayed coatings were characterized using X-ray diffraction, differential scanning calorimetry and scanning electron microscopy. Corrosion resistance of the coatings in 3.5 wt% NaCl solution was evaluated by potentiodynamic polarization test. Results show that the microstructure and corrosion resistance of the coatings are influenced by the size of feedstock powders. Amorphous fraction and density of the coatings decrease with the increase of powder size. The coating sprayed with the coarsest powders exhibits the worst pitting corrosion resistance. The morphology of corroded coating surface shows that corrosion damage primarily occurs in the matrix, not crystals. The detailed investigation by SEM/EDX indicates that the concentrations of Cr, Mo, and W in the crystal are much higher than those in the matrix. This work demonstrates that Fe-based amorphous coatings sprayed by HVAF with high fraction of amorphous phase and low porosity are promising for industrial application in marine environment. Keywords: Amorphous coating, Corrosion resistance, HVAF, Powder size