Effect of topologically close-packed clusters on glass-forming ability of rapidly supercooled MgCuY alloy

• DOI: 10.1016/j.jmrt.2022.05.004
• Publication Date: 2022-05-06T08:33:59Z
• Authors: Yuan-wei Pu; Li-li Zhou; Yong-chao Liang; Ze-an Tian; Qian Chen; Li Zhang; Jia-jun Ma; Yun-fei Mo; Rang-su Liu; Ting-hong Gao; Quan Xie
• Keywords: Nanoclusters; Supercooling; Coordination number; Atomic radius

The glass-forming ability (GFA) of metallic glasses can be enhanced by adding trace elements, but it is difficult to explain the reasons from microcosmic viewpoint due limitation experimental conditions. Therefore, in order reveal effects elements on GFA, rapid solidification process Mg65Cu(35-x)Yx (x = 5,10,15,20,25) ternary alloys are simulated molecular dynamics (MD) this paper, then short- and medium-range order, thermodynamics investigated. average atomic potential energy shows that GFA becomes stronger monotonically with increase Y element. S433 S544 evolve into S555 higher fivefold symmetry packing density during solidification, which topologically close-packed (TCP) clusters mainly composed S555. And TCP system has because easy connect each other form large-sized nanoclusters, larger size nanoclusters have a smaller displacement, hinders crystallization. As atoms slower dynamic characteristics than atoms, element clusters, thus plays promoting role for GFA.