摘要
通过试验和模拟的方法分析了选晶器引晶段的晶粒组织演化规律和不同情况下等温线的形态分布,以及倾斜等温线下晶粒竞争生长的过程,同时研究了螺旋段的选晶行为。结果表明,引晶段的不同高度具有不同的组织形态,引晶段主要靠晶粒间的竞争生长作用优化晶粒取向,不同形态的等温线下晶粒的优先生长方向不同。螺旋段主要靠螺旋通道对枝晶生长的几何约束选择晶粒,确保只有一个晶粒进入型腔生长成为单晶组织。
The grain structure evolution of the starter block and morphology of the isotherm under different conditions were simulated and experimented as well as the process of grain growth under the inclined isotherm.And the grain selection behavior in spiral block was investigated.The results reveal that the different heights of the starter block present different structural morphology.The starter block mainly optimizes the grain orientation by the competition between grains,and the preferential growth directions of the grains under different isotherms are different.The spiral block mainly selects the grain by the geometric constraint of the spiral channel on the dendrite growth,ensuring that only one grain entering the cavity and growing into a single crystal structure.
引文
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