Computational thermodynamics to identify Zr–Ti–Ni–Cu–Al alloys with high glass-forming ability

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• 作者：Hongbo Cao ; Dong Ma ; Ker-Chang Hsieh ; Ling Ding ; William G. Stratton ; Paul M. Voyles ; Ye Pan ; Mingdong Cai ; J. Thomas Dickinson and Y. Austin Chang
• 关键词：Bulk metallic glass ; Thermodynamics ; Multicomponent phase diagram calculation
• 刊名：Acta Materialia
• 出版年：2006
• 出版时间：June 2006
• 年：2006
• 卷：54
• 期：11
• 页码：2975-2982
• 全文大小：537 K

文摘

We have used a thermodynamic computational approach to identify the compositions of Zr–Ti–Ni–Cu–Al alloys exhibiting low-lying liquidus surfaces, which tend to favor the formation of bulk metallic glasses. Guided by these calculations, we have identified several series of new Zr-based alloys with excellent glass formability, some of which can be cast into glassy rods up to 14 mm in diameter. These alloys exhibit wide undercooled liquid regions (T_x − T_g) up to 85 K and high Vickers hardness from 550 to 700 kg/mm². The best glass-forming alloy is Zr₅₁Ti₅Ni₁₀Cu₂₅Al₉. The computational thermodynamic approach coupled with the reduced glass transition temperature criterion of Turnbull can rapidly identify regions of alloy composition suitable for experimental tests for glass formation. The glass-forming ability of the alloys we studied can be understood in terms of the relative liquidus temperature in a thermodynamically calculated temperature vs. composition section through a multicomponent phase diagram. It does not follow several other proposed thermodynamic or topological criteria. Our general approach may be extended into a universal tool to identify alloys with good potential to form bulk glasses.