Free growth and instability morphologies in directional melting of alloys.
Free growth and instability morphologies in directional melting of alloys.
复制标题
DOI：
10.1103/physreve.65.051604
复制
发表时间：
2002-05
期刊：
影响因子：
--
通讯作者：
D. Benielli;N. Bergeon;H. Jamgotchian;B. Billia;P. Voge
中科院分区：
文献类型：
--
作者：
D. Benielli;N. Bergeon;H. Jamgotchian;B. Billia;P. Voge
在圆柱体中定向熔炼透明丁二腈-丙酮合金的过程中，原位和实时地观察到熔化形态的动态变化，即由于相界形态的不稳定性而导致的块体固体和液体树枝晶中的液滴。特定的图案与晶界有关。提出了一种基于自由生长但具有随时间变化的过热度的液态夹杂物横向生长模型。与普遍认为的相反，结果表明，自由熔化不仅仅是自由晶体生长的逆转，主要是因为溶质在固体中的扩散要低得多，这施加了边界层方法。
The dynamics of melting morphologies, namely, liquid droplets in the bulk solid and liquid dendrites due to morphological instability of the phase boundary, is observed in situ and in real time during directional melting of transparent succinonitrile-acetone alloys in a cylinder. Specific patterns are associated to grain boundaries. A model based on free growth but with time-dependent superheating is proposed for the lateral growth of the liquid inclusions. Contrary to what is largely believed, it is shown that free melting is not the mere reversal of free crystal growth, basically because solute diffusion is much lower in the solid, which imposes a boundary layer approach.