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Formation and corrosion properties of Fe-based bulk metallic glasses

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International Journal of Minerals,Metallurgy and Materials 2010年第3期17卷 323-326页

作者： Chun-lei Zhu Qing Wang Jie Zhang Ying-min Wang Chuang Dong School of Material Science and Engineering Dalian University of Technology Dalian 116024 China

Bulk metallic glass （BMG） formation was explored in the Fe-B-Si-Nb alloy system though combined use of the atomic cluster line approach and the minor alloying strategy. The basic ternary compositions in the Fe-B-Si system were determined by the intersection points of two cluster lines, namely, Fe-B cluster to Si and Fe-Si cluster to B. 3at% -4at% Nb was added to the quaternary Fe-B-Si-Nb alloy. The casting experiments revealed that good glass-forming ability （GFA） occurred at the （Fe73.4Si8.2B18.4）96Nb4 composition, and 3-mm diameter BMG samples were made. The glass transition temperature （Tg）, crystallization temperature （Tx）, and supercooled liquid region （△Tx=Tx-Tg） of this BMG were measured to be 866, 889, and 23 K, respectively. The BMG shows a high Vickers hardness of about Hv 1164, a Young＇s modulus of 180 GPa, and a good corrosion resistance in the solutions of 1 mol/L HCl and 3wt% NaCl.

关键词： bulk metallic glasses (BMG) cluster atomic cluster corrosion glass-forming ability

A first-principle study of the structural and electronic properties of amorphous Cu-Zr alloys

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Science China(Physics,Mechanics & Astronomy) 2011年第2期54卷 249-255页

作者： TIAN Hua LIAO YunLong ZHANG Chong ZHAO JiJun WEN Bin WANG Qing DONG Chuang Key Laboratory of Materials Modification by Laser Ion and Electron Beams (Dalian University of Technology) Ministry of Education Dalian 116024 China School of Materials Science and Engineering Dalian University of Technology Dalian 116024 China College of Advanced Science and Technology Dalian University of Technology Dalian 116024 China

The atomic and electronic structures of amorphous CuxZr100-x(x=36,46,50,56,64) alloys were simulated using first-principle calculations within a 400-atom *** pair correlation function,coordination numbers,local cluster structures and electronic density of states were *** agreements between the theory and the experiments were *** amorphous alloys exhibit different local cluster structures and can all be explained with cluster formulas [cluster](glue)1,3,where the clusters are derived from known Cu-Zr *** is always a pseudogap in the density of state at the Fermi level.

关键词： bulk metallic glass local atomic structure electronic structure

Fe-B-Y-Nb bulk metallic glasses in relation to clusters

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Science China(Physics,Mechanics & Astronomy) 2008年第4期51卷 421-426页

作者： CHENG Xu WANG Qing CHEN WeiRong DONG Chuang State Key Laboratory of Materials Modification Dalian University of TechnologyDalian 116024China Department of Mechanical Engineering Dalian UniversityDalian 116622China

Bulk metallic glass formations in the Fe-B-Y-Nb quaternary alloy system were in-vestigated by using the cluster line rule in combination with the minor alloying principle. The Fe-B-Y ternary system was selected as the basic system and the intersections of cluster lines were taken as the basic ternary compositions. The basic compositions were further alloyed with minor amounts of Nb. After 3-5 at.% Nb was added,the basic composition Fe68.6B25.7Y5.7,which was developed from the most densely packed cluster Fe8B3,formed 3 mm bulk metallic glasses. These quaternary bulk metallic glasses (Fe68.6B25.7Y5.7)100-xNbx (x=3-5 at.%) are expressed approximately with a unified simple composition formula: (Fe8B3)1(Y,Nb)1. The (Fe68.6B25.7Y5.7)97Nb3 bulk metallic glass has the largest glass forming ability with the following characteristic parameters Tg=907 K,Tx=1006 K,Tg/Tl=0.644,γ=0.434,and longness t=22 mm. The combination of the cluster line rule and the minor-alloying principle is a promising new route towards the quantitative composition design of multi-component metallic glasses.

关键词： bulk metallic glass Fe-B-Y-Nb alloys cluster composition design

Correlation between supercooled liquid region and crystallization behavior with alloy composition of La-Al-Cu metallic glasses

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Science China(Physics,Mechanics & Astronomy) 2011年第9期54卷 1608-1611页

作者： ZHANG QingChao PANG ShuJie LI Yi ZHANG Tao Key Laboratory of Aerospace Materials and Performance (Ministry of Education) School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics Beijing 100191 China Department of Materials Science and Engineering National University of Singapore Singapore 117576 Singapore

Bulk metallic glasses (BMGs) with large supercooled liquid region are promising materials for superplastic forming. In this paper, we demonstrate a microstructure-based strategy to pinpoint the composition with the largest supercooled liquid region in La 86 x Al 14 Cu x (x=16 at%-20 at%) metallic glass system. By monitoring the changes in crystallization behavior of the glassy alloys with composition to search for the alloys exhibiting eutectic crystallization, the glassy alloys with the largest supercooled liquid region in the given alloy system can be found. The metallic glasses with Cu contents of 16 at%-19 at% exhibited two crystallization peaks, and the primary crystallization product was identified to be α-La by means of DSC, XRD and TEM. The increase in Cu content resulted in the decay of the primary crystallization peak and the increase in onset temperature of crystallization, leading to the enlargement of supercooled liquid region. By further suppressing the α-La primary crystallization with increasing Cu content up to 20 at%, the eutectic crystallization of α-La and LaCu 13 through one crystallization reaction occurred upon heating, where the largest supercooled liquid region of 65 K for La 66 Al 14 Cu 20 glassy alloy was located. This study indicats that, in a given glassy alloy system, a larger supercooled liquid region can be achieved by optimizing the alloy compositions to suppress the primary crystallization.

关键词： bulk metallic glass supercooled liquid region crystallization

Effects of crystallization on corrosion behaviours of a Ni-based bulk metallic glass

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International Journal of Minerals,Metallurgy and Materials 2012年第2期19卷 146-150页

作者： Sen Liu Lu Huang Shu-jie Pang Tao Zhang Key Laboratory of Aerospace Materials and Performance(Ministry of Education) School of Materials Science and EngineeringBcibang UniversityBeijing 100191China

The effects of microstructure change on the corrosion behaviours of Ni55Nb20Ti10Zr8Co7 bulk glass-forming alloy were investigated in 1 mol/L HCl and 0.5 mol/L H2SO4 solutions. Different microstructures of the Ni-based alloy were achieved by annealing the bulk glassy rod prepared by copper mould casting. The microstructure, grain size, grain distribution, and phase composition were characterized. Electrochemical behaviours of the Ni-based alloy were revealed by static immersion and anodic potentiodynamic polarization tests. It is indicated that the corrosion behaviours of the Ni-based bulk glass-forming alloy are related to its microstructures, while the fully crystallized alloy exhibits a relatively lower corrosion resistance than those of the amorphous states.

关键词： bulk metallic glasses nickel alloys microstructure corrosion crystallization

Cluster-based composition rules for ternary alloy systems

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International Journal of Minerals,Metallurgy and Materials 2007年第S1期15卷 1-3页

作者： Chuang Dong1, 2), Qing Wang1), Weirong Chen1), Qingyu Zhang1), Jianbing Qiang1), and Yingmin Wang1) 1) State Key Laboratory of Materials Modification, Dalian University of Technology, Dalian 116024, China 2) International Center for Materials Physics, Chinese Academy of Sciences, Shenyang 110016, China

The cluster-based composition rule in ternary alloy systems including quasicrystals, bulk metallic glasses, crystalline phases and Lave phases-related body-centered cubic (BCC) solid solution forming systems was summarized. The so-called cluster line in a ternary phase diagram refers to a straight composition line linking a specific binary cluster to the third element. The compo- sition ranges of quasicrystals and bulk metallic glasses can be determined by the direct use of cluster lines, where two cluster lines intersect at the optimum phase forming composition. Furthermore, the alloys on the cluster line in Laves phase-related BCC solid solution alloy systems have larger hydrogen storage capacities.

关键词： cluster line composition design quasicrystals bulk metallic glasses hydrogen storage alloys

Crystallization of amorphous Ni-Zr alloys during heating with molecular dynamics simulations

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International Journal of Minerals,Metallurgy and Materials 2007年第S1期15卷 73-76页

作者： Quanwen Yang, Shujie Pang, and Tao Zhang Department of Materials Science and Engineering, Beihang University, Beijing 100083, China

The heating processes of amorphous NixZr100-x(x=10, 16.7, 33.3) alloys were investigated with molecular dynamics simu- lations. The simulation results show that the crystallization of amorphous alloys during heating is controlled by the heating rate and the alloy’s composition. The slower heating rate depresses the crystallizing temperatures and the melting temperatures of the amor- phous alloys. Crystallization can be eliminated at rapid heating rates, the critical value of which decreases with increasing Ni content of the studied amorphous Ni-Zr alloys. Different crystalline structures formed during crystallizing depend on the heating rate, and the transition between crystalline structures was observed in the heating processes.

关键词： amorphous alloy heating crystallization molecular dynamics simulation

Mg-Cu-Zn-Y-Zr bulk metallic glassy composite with high strength and plasticity

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International Journal of Minerals,Metallurgy and Materials 2007年第S1期15卷 43-45页

作者： Wei Tian, Shujie Pang, Hua Men, Chaoli Ma, and Tao Zhang Department of Materials Science and Engineering, Beihang University, Beijing 100083, China

Mg65Cu20Zn5Y9Zr1 bulk metallic glass matrix composite with a diameter of 2 mm was produced by copper mold casting. Upon cooling the Mg65Cu20Zn5Y9Zr1 melt, Mg2Cu acicular crystalline phase precipitates uniformly with a size of about 20 μm long and 1 μm thick while the remaining melt undergoes glass transition. Room temperature compression tests revealed that the high fracture strength up to 830 MPa and the plastic strain of 2.4% before failure are obtained for the Mg-based bulk metallic glass matrix composite. The formation of the Mg2Cu phase was proposed to contribute to high strength and plastic deformation of the material.

关键词： Mg-based alloy metallic glass matrix composite acicular crystalline phase strength plasticity

Formation and mechanical properties of ductile Fe-based amorphous alloys using a cast iron with minor addition of B and Al

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International Journal of Minerals,Metallurgy and Materials 2007年第S1期15卷 46-49页

作者： Kun Tian, Shujie Pang, Hua Men, and Tao Zhang Department of Materials Science and Engineering, Beihang University, Beijing 100083, China

Fe-based amorphous alloys with ductility were synthesized using the commercial cast iron QT50 (denoted as QT) with the combining minor addition of B and Al by single roller melt-spinning. The melt-spun (QT1-xBx)99Al1 (x is from 0.006wt% to 0.01wt%) amorphous alloys exhibit onset crystallization temperatures and Curie temperatures of 759-780 and 629-642 K respectively, and whi- ch increase with B content. The amorphous ribbons are ductile and can be bent 180° without breaking. With the increase in B content from 0.006wt% to 0.01wt%, the Vickers microhardness of the amorphous alloys increases from Hv 830 to Hv 1110. The effects of the additional B and Al elements on the glass forming ability and mechanical properties were also discussed.

关键词： amorphous alloy Fe-based alloys cast iron rapid solidification mechanical property