Modeling grain refinement for undercooled single-phase solid-solution alloys
Modeling grain refinement for undercooled single-phase solid-solution alloys
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DOI：
10.1016/j.actamat.2011.04.021
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发表时间：
2011-07
期刊：
影响因子：
9.4
通讯作者：
Haifeng Wang;Feng Liu;Y. Tan
中科院分区：
文献类型：
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作者：
Haifeng Wang;Feng Liu;Y. Tan
建立了过冷单相固溶体合金快速凝固的晶粒细化模型，该模型将枝晶破碎模型与整体凝固动力学模型相结合，使得枝晶破碎沿着凝固过程（如糊状区凝固过程）发生。与Karma模型相比，该模型不仅可以预测枝晶的断裂时间，还可以预测枝晶间液相完全凝固的时间。因此，该模型可以预测，在缺乏实验数据（例如，平台持续时间），微观结构的转变。将该模型应用于Ni-15 at.%深过冷合金的快速凝固过程Cu合金，模型预测值与实验结果吻合较好。在此基础上，研究了两相区凝固过程中毛细作用和反向扩散对枝晶破碎的影响，以及反向扩散和冷却速率对组织转变预测的影响。
A grain-refinement model for rapid solidification of undercooled single-phase solid-solution alloys was developed in which a combination of the model of dendrite fragmentation with the model of overall solidification kinetics allows dendrite fragmentation to occur along with the solidification process (e.g. during mushy zone solidification). Compared with Karma’s model, the dendrite break-up time as well as the time for the interdendritic liquid to be solidified completely can be predicted. Thus, the model can predict, in the absence of experimental data (e.g. the plateau duration), the microstructure transition. The model was applied to describe the rapid solidification of undercooled Ni–15 at.% Cu alloy, and a good agreement between the model predictions and the experimental results was obtained. On this basis, the effects of capillarity and back-diffusion on dendrite fragmentation during mushy zone solidification, as well as the effects of back-diffusion and cooling rate on the prediction of the microstructure transition, were found.