On determining the phase-selection principle in solidification from undercooled melts—competitive nucleation or competitive growth?
On determining the phase-selection principle in solidification from undercooled melts—competitive nucleation or competitive growth?
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DOI：
10.1080/0950083042000271090
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发表时间：
2004-07
影响因子：
1.2
通讯作者：
M. Li §;S. Ozawa;K. Kuribayashi
中科院分区：
文献类型：
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作者：
M. Li §;S. Ozawa;K. Kuribayashi
对过冷金属和氧化物熔体已发表文献的调查表明，凝固过程中的相选择可以分为成核控制或生长控制。已经确定了各种合金系统的相选择途径的共同特点。人们认识到，当竞争的稳定和亚稳相共享相同的结晶特性，并具有可比的界面动力学系数，成核控制的原则适用于在深过冷熔体中的初级相形成。然而，可以有两个或三个数量级的差异，在竞争相的界面动力学系数，无论是有序的金属间化合物和无序的固溶体之间，或具有高水平的复杂性的结晶相和简单的晶体之间。在这种情况下，生长控制的原则将适用;更具体地说，具有更快的生长动力学的相应该是有利的，而具有缓慢界面动力学的竞争对应物应该在高过冷度下被抑制。根据这一原理，在考虑稳定和亚稳相图时，提出了一些简单的预测。本文概述了适用本分类法的具体条件。未来的工作需要阐明非常快速凝固条件下的相竞争。
A survey of the published literature on undercooled metallic and oxide melts suggests that phase selection during solidification can be categorized as nucleation controlled or growth controlled. Common characteristics governing the phase-selection pathway have been identified for various alloy systems. It is recognized that when competing stable and metastable phases share the same crystalline characteristics and have comparable interface kinetic coefficients, the principle of nucleation control applies for primary phase formation in a deeply undercooled melt. However, there can be a difference of two or three orders of magnitude in the interface kinetic coefficients for competing phases, either between an ordered intermetallic compound and a disordered solid solution, or between a crystalline phase with a high level of complexity and a simple crystal. In such cases, the principle of growth control will apply; more specifically, the phase with the faster growth kinetics should be favoured and the competing counterpart with sluggish interface kinetics should be suppressed at high undercoolings. Some simple predictions are suggested on the basis of this principle when considering stable and metastable phase diagrams. The specific conditions under which the present categorization is applicable are outlined. Future work is required to elucidate phase competition under conditions of very rapid solidification.