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研究了深过冷条件下三元Ni80Cu10Co10合金的快速枝晶生长,采用电磁悬浮无容器处理方法获得了335K(0.2TL)的最大过冷度.X射线衍射分析与差示扫描量热分析均表明,凝固组织为α-Ni单相固溶体.随过冷度增大,凝固组织显著细化,并且当过冷度达110K时,凝固组织的形态由粗大形枝晶转变为等轴晶.深过冷条件下溶质截留效应增强,使得微观偏析程度减小.对不同过冷度下合金枝晶的生长速度进行了实验测定,当过冷度超过284K后,生长速度呈现下降趋势.在大过冷度时,Cu和Co溶质元素的引入,显著降低了Ni80Cu10Co10合金的枝晶生长速度.
The rapid dendritic growth of ternary Ni80Cu10Co10 alloy under deep overcooling was investigated, and the maximum undercooling at 335K (0.2TL) was obtained by using the electromagnetic suspension-free vessel process.The results of X-ray diffraction and differential scanning calorimetry , And the solidified microstructure was α-Ni single phase solid solution.The solidification microstructure was refined remarkably with the increase of undercooling degree, and the morphology of solidified structure transformed from coarse dendrite to equiaxed crystal when the undercooling reached 110K. The effect of solute retention is enhanced under cold conditions, so that the degree of micro-segregation is reduced.The growth rate of alloy dendrites under different undercooling is experimentally determined, the growth rate shows a downward trend when the undercooling exceeds 284K, Degree, Cu and Co solute elements introduced, significantly reducing the dendritic growth rate Ni80Cu10Co10 alloy.