The formation of bulk metallic glasses (BMGs) in ternary Cu-Zr-Ti system was investigated by a copper mold casting method. The nature of the amorphous phase was verified by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). It was demonstrated that the BMGs could be formed in a broad composition range in this system. Cu50Zr42.5Ti7.5, Cu60Zr27.5Ti12.5, Cu60Zr30Ti10 and Cu60Zr32.5Ti7.5 alloys exhibit strong glass-forming ability (GFA), and fully glassy rods of 5 mm in diameter can be obtained. In the center region of the ternary diagram, however, the GFA of the alloys was degraded due to the presence of Laves phase. The degradation of the GFA results from easy nucleation of the Laves phase in the undercooled liquid.
Hua Men, Junying Fu, Chaoli Ma, Shujie Pang, and Tao Zhang Department of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China
The glass forming ability of the [(Fe12/13Y1/13)100?xBx]96Nb2Zr2 (x=9–26) system was investigated using a series of cluster lines. Three types of clusters, an icosahedron (Fe12Y), a capped Archimedes anti-prism (Fe8B3) and a capped trigonal prism (Fe9B), as well as a binary eutectic (Fe83B17) were considered. Bulk glassy alloy rods of 3 mm in diameter were synthesized using a copper mold suction-casting method. The glass transition temperature was observed for all samples in the boron range of 15.9at%-25.7at%, with the alloy at 15.9at% of boron having the best thermal properties. The ferrous-based bulk metallic glasses (BMG) obtained have high reduced glass transition temperatures with the maximum reaching 0.63 and large supercooled liquid regions with the maximum reaching 111 K. Magnetic testing revealed a large value of coercive force and remanent magnetization, being 11 kA/m and 0.1 T, re- spectively.
Similar element substitution has been applied for improving glass forming ability (GFA) in Al 86 Ni 9 La 5 amorphous alloy. The effects of La-Ce and Ni-Co pairs on the GFA, magnetic properties and hardness of Al-Ni-La alloy were investigated by using X-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), magnetometer and hardness-tester. The results show the GFA of the samples in the order of Al 86 (Ni 0.5 Co 0.5 ) 9 (La 0.5 Ce 0.5 ) 5 < Al 86 Ni 9 La 5
Guihua Li Weimin Wang Xiufang Bian Li Wang Jiteng Zhang Rui Li Tao Huang
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.
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 formation and thermal stabilities of Cu46.25Zr46.25xAl7.5Erx (x=0 to 8) bulk metallic glasses (BMGs) were investigated. The addition of a small amount of Er (2at%) for replacing Zr effectively improves the glass-forming ability of Cu46.25Zr46.25Al7.5 alloy, and the glassy rod with a diameter of at least 12 mm can be formed. The glass transition temperature (Tg), temperature interval of su- percooled liquid region △Tx (=Tx-Tg), and reduced glass transition temperature Trg (=Tg/Tl) of Cu46.25Zr44.25Al7.5Er2 glassy alloy are 699 K, 62 K and 0.607, respectively.
Junying Fu, Hua Men, Shujie Pang, Chaoli Ma, and Tao Zhang Department of Materials Science and Engineering, Behang University, Beijing 100083, China
