L2 droplet interaction with α-Al during solidification of hypermonotectic Al–8 wt.% Bi alloys
L2 droplet interaction with α-Al during solidification of hypermonotectic Al–8 wt.% Bi alloys
复制标题
DOI：
10.1016/j.actamat.2009.02.041
复制
发表时间：
2009-06
期刊：
影响因子：
9.4
通讯作者：
P. Schaffer;R. Mathiesen;L. Arnberg
中科院分区：
文献类型：
--
作者：
P. Schaffer;R. Mathiesen;L. Arnberg
迄今为止，铝基超共晶合金的研究主要集中在熔滴运动和凝固动力学方面，而对熔滴与凝固前沿之间的相互作用关注有限，而凝固前沿对第二相在α-Al基体中的最终分布起决定性作用。目前的工作提出了从定向凝固实验的结果与Al-8重量%铋合金。结果发现，具有大半径的液滴经常被推动，而小液滴则被吞没。这与已经提出来解释固体颗粒的推动/吞没的许多模型相矛盾，并且可以部分地归因于这样的事实，即虽然固体颗粒模型仅考虑在前进的凝固前沿之前不受溶质梯度影响的单个、非相互作用的颗粒，已经发现液滴-液滴相互作用和局部溶质梯度对于超单元素合金中的液滴推动/吞没行为是关键的。
Studies of Al-based hypermonotectics have so far focused mainly on droplet motion and coagulation dynamics, with limited attention given to the interaction between droplets and the advancing solidification front which is decisive for the final distribution of the second phase within the α-Al matrix. The current work presents results from directional solidification experiments with Al–8 wt.% Bi alloys. It was found that droplets with large radii were frequently pushed and small droplets were engulfed. This is contradictory to the many models that have been proposed to explain pushing/engulfment of solid particles and can in part be ascribed to the fact that while solid-particle models only consider single, non-interacting particles that remain unaffected by solutal gradients ahead of the advancing solidification front, droplet–droplet interaction and local solute gradients have been found to be critical for droplet pushing/engulfment behaviour in hypermonotectic alloys.