Ostwald ripening kinetics of angular grains dispersed in a liquid phase by two-dimensional nucleation and abnormal grain growth
Ostwald ripening kinetics of angular grains dispersed in a liquid phase by two-dimensional nucleation and abnormal grain growth
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DOI：
10.1016/s0955-2219(01)00370-3
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发表时间：
2002-05
影响因子：
5.7
通讯作者：
Muyung-Koo Kang;Doh-Yeon Kim;N. Hwang
中科院分区：
文献类型：
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作者：
Muyung-Koo Kang;Doh-Yeon Kim;N. Hwang
基于分散在液相基体中的固体颗粒的角形形状指示奇异界面的事实，基于二维（2-D）形核制定了角形颗粒粗化动力学并进行了数值求解。为了比较，扩散控制的粗化的球形形状的晶粒也解决了数值。解决方案表明，粗化的2-D形核诱导异常晶粒生长，而扩散控制粗化没有。这一结果与一般实验观察一致，即液相烧结中的异常晶粒生长仅发生在有棱角晶粒的系统中。最大晶粒尺寸的平均值的比例单调增加，随着时间的2-D成核粗化，而它在扩散控制粗化下降。在二维形核控制粗化过程中，人工添加的大晶粒（比平均晶粒大10倍）成为异常晶粒，而在扩散控制粗化过程中则没有。
Based on the fact that the angular shape of solid grains dispersed in the liquid matrix indicates a singular interface, the coarsening kinetics of angular grains was formulated based on 2-dimensional (2-D) nucleation and solved numerically. For comparison, diffusion-controlled coarsening of grains with a spherical shape was also solved numerically. The solutions showed that coarsening by 2-D nucleation induced abnormal grain growth whilst diffusion-controlled coarsening did not. This result agrees with the general experimental observation that the abnormal grain growth in liquid phase sintering takes place exclusively in the system with angular grains. The ratio of the largest grain size to the average increased monotonously with time in coarsening by 2-D nucleation whilst it decreased in diffusion-controlled coarsening. The artificially-added large grain (10 times larger than the average) became the abnormal grain in 2-D nucleation controlled coarsening but did not in diffusion-controlled coarsening.