Fabrication of Mg-Zn-Y-based quasi-crystal by pouring melt into different cooling media  

作　　者：Wang Zhifeng Zhao Weimin Qin Chunling Hur Bo-Young 

机构地区：[1]School of Materials Science and Engineering,Hebei University of Technology,Tianjin 300130,China [2]Light Metals Group,Korea Institute of Materials Science,Changwon 642-831,Republic of Korea [3]School of Nano and Advanced Materials Engineering,Gyeongsang National University,Jinju 660-701,Republic of Korea

出　　处：《China Foundry》2012年第3期207-214,共8页中国铸造（英文版）

基　　金：supported by Natural Science Foundation of Hebei Province, China (E2010000057, E2010000121, E2012202017);International S & T Cooperation Program of China (2010DFA51850)

摘　　要：Mg-Zn-Y-based quasi-crystal （QC） alloys were fabricated by pouring melts into different cooling media. The effects of different cooling rates on the QC morphology, size, volume fraction and micro-hardness were studied. Multi-component Mg-Zn-Y-based QC alloys were synthesized based on amorphous design principle. QC morphology transformation and its influencing factors were analyzed. Micro/nano spherical quasi-crystals （QCs） were fabricated through a wedge-shaped copper mould and their forming mechanism were discussed by atoms cluster theory, optimum cooling rate theory and the known crucial criteria. The results of research show that with the cooling rate reduced, the solidified morphology of QC phase changes from near-spherical, micro petals （1 to 2 um） to big petals （20 um） and finally grows up to bulk pentagon or hexagon （200 to 400 um）. Multi-component micro-spherical QCs possess higher value of micro-hardness than petal-like QCs with the same components, and also higher than ternary micro-Mg-Zn-Y QCs. The fine master alloys containing micro-QCs （0.4 um） and nano-QCs （about 300 nm and 40 nm） have been fabricated correspondingly on the middle and the tip of wedge-shaped castings. A morphology evolution schematic diagram of Mg-Zn-Y-based QCs is included in this paper.Mg-Zn-Y-based quasi-crystal (QC) alloys were fabricated by pouring melts into different cooling media. The effects of different cooling rates on the QC morphology, size, volume fraction and micro-hardness were studied. Multi-component Mg-Zn-Y-based QC alloys were synthesized based on amorphous design principle. QC morphology transformation and its influencing factors were analyzed. Micro/nano spherical quasi-crystals (QCs) were fabricated through a wedge-shaped copper mould and their forming mechanism were discussed by atoms cluster theory, optimum cooling rate theory and the known crucial criteria. The results of research show that with the cooling rate reduced, the solidified morphology of QC phase changes from near-spherical, micro petals (1 to 2 μm) to big petals (20 μm) and finally grows up to bulk pentagon or hexagon (200 to 400 μm). Multi-component micro-spherical QCs possess higher value of micro-hardness than petal-like QCs with the same components, and also higher than ternary micro-Mg-Zn-Y QCs. The fine master alloys containing micro-QCs (0.4 μm) and nano-QCs (about 300 nm and 40 nm) have been fabricated correspondingly on the middle and the tip of wedge-shaped castings. A morphology evolution schematic diagram of Mg-Zn-Y-based QCs is included in this paper.

关 键 词：QUASI-CRYSTALS cooling media magnesium alloy Mg-Zn-Y-based alloys 

分 类 号：TQ444[化学工程—化学肥料工业] TG154.4[金属学及工艺—热处理]