本文利用相场方法对过冷镍熔体中枝晶生长过程进行了模拟,发现在过冷度低于200 K时,生长速度与过冷度之间近似呈幂函数关系,当过冷度高于200 K时,生长速度与过冷度之间基本呈线性关系.伴随着速度/过冷度之间关系的变化,枝晶尖端半径/过冷度的关系则呈现先减小后增加的趋势,并在200 K时达到最小.本文还将模拟结果与实验值和经典LKT理论进行了比较,对上述关系转变的物理机制进行了分析.
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