Volume Effects in Bulk Metallic Glass Formation
Volume Effects in Bulk Metallic Glass Formation
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DOI：
10.1557/proc-554-21
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
A. Yavari;A. Inoue
中科院分区：
文献类型：
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作者：
A. Yavari;A. Inoue
简要评述了快速凝固非晶合金和大块玻璃中的原子体积效应。据回顾，在高过冷度下，在生长前沿释放对应于凝固时摩尔体积减小的体积可以通过粘度降低急剧加速熔体中的晶体生长。然后提出了一种估算混合体积ΔV mix的方法，Δ V mix是负的元素添加到玻璃形成液体合金。据认为，负ΔV混合降低了易形成玻璃的合金中的原子迁移率，从而允许在冷却期间抑制微晶的成核和生长。ZrCuNi系统被用作应用这种推理的一个例子。结果表明，Al或Ti添加到ZrNiCu合金导致强烈的负ΔV混合和预期的急剧下降，在熔体中的扩散控制的晶体生长动力学。
Atomic volume effects in amorphous alloys obtained by rapid solidification and in bulk glasses are briefly reviewed. It is recalled that at high undercoolings, the release at the growth fronts, of the volume corresponding to the reduction of the molar volume upon solidification can sharply accelerate crystal growth in the melt through viscosity reduction. A method is then proposed for estimating the volume of mixing ΔV mix which is negative for elemental additions to glass-forming liquid alloy. It is argued that negative ΔV mix reduces atomic mobility in easy glass-forming alloys thus allowing the suppression during cooling, of nucleation and growth of crystallites. The ZrCuNi system is used as an example for applying this reasoning. It is shown that Al or Ti addition to ZrNiCu alloys lead to strongly negative ΔV mix and expected sharp drops in diffusion-controlled crystal growth kinetics in the melt.