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采用丁二腈-丙酮透明模型合金研究了不同晶体取向的晶粒在定向凝固条件下的平界面失稳过程.实验选择了三个界面失稳后具有不同生长形态的典型晶粒作为研究对象,分别为择优生长枝晶、倾斜枝晶和海藻晶.结果表明可发展为择优生长枝晶的晶粒的平界面失稳孕育时间和初始扰动波长最小,海藻晶次之,倾斜枝晶最大,这与以往的解析结果和相场模拟结果一致.同时,实验观察发现可发展为择优生长枝晶和倾斜枝晶的晶粒的界面非稳态演化过程与海藻晶显著不同,这表明平界面失稳的非稳态演化过程与晶体取向相关.
In the experiment, the interface instability of grains with different crystal orientations under directional solidification condition was investigated by using succinonitrile-acetone transparent model alloy. Three typical grains with different growth morphologies after interface instability were chosen as the research object, Respectively, for the optimal growth of dendrites, dendrites and seaweed crystals.The results show that the growth of preferentially grown dendrites grain boundary instability incubation time and the initial disturbance wavelength minimum, seaweed crystal, the largest inclined dendrites, which Which is consistent with the results of the previous analysis and phase field simulation.At the same time, experimental observations show that the interfacial unsteady evolution of grains that can develop into preferred growth dendrites and slanted dendrites is significantly different from seaweed grains, indicating that the flat interfacial instability The unsteady evolution is related to the crystal orientation.