过冷度对Ni-Cu合金枝晶偏析影响的相场法模拟

发布时间：2018-01-14 22:14

本文关键词：过冷度对Ni-Cu合金枝晶偏析影响的相场法模拟　出处：《中国有色金属学报》2016年01期 　论文类型：期刊论文

更多相关文章： Ni-Cu合金 相场法 过冷度 枝晶偏析

【摘要】：采用耦合热扰动的相场模型,对Ni-Cu合金枝晶生长中的枝晶形貌和微观偏析进行计算和分析,并研究过冷度对其凝固过程中溶质分布的影响。结果表明:随着过冷度的增加,二次枝晶变的更发达,枝晶主干变细,一次枝晶干轴对称中心处的溶质浓度升高,一次枝晶干和二次枝晶臂间富集的溶质更多。过冷度越大,固液界面前沿溶质扩散层越薄,枝晶的微观偏析越严重,即溶质微观偏析程度随过冷度的增大而增大。
[Abstract]:The dendritic morphology and microsegregation in dendritic growth of Ni-Cu alloy were calculated and analyzed by the coupled thermal perturbation phase field model. The effect of undercooling on solute distribution during solidification is studied. The results show that secondary dendrite becomes more developed and dendrite trunk becomes thinner with the increase of undercooling degree. The concentration of solute at the axisymmetric center of primary dendritic stem increases, and the concentration of solute between primary dendritic stem and secondary dendritic arm increases. The larger the undercooling degree, the thinner the solute diffusion layer at the front of the solid-liquid interface and the more serious the microsegregation of the dendrite. That is, the microsegregation degree of solute increases with the increase of undercooling degree.
【作者单位】：中北大学材料科学与工程学院;
【基金】：科技部国际科技合作项目(2014DFA50320) 国家自然科学基金资助项目(51574207,51574206,51204147,51274175) 山西省国际科技合作项目(2013081017,2012081013)~~
【分类号】：TG146.15
【正文快照】： Ni-Cu合金在工业领域有着非常重要的应用,其结晶方式为树枝状生长,一次枝晶臂两侧存在大量二次枝晶[1]。在其实际凝固中难以得到完全均衡态的组织,只能进行非平衡凝固。凝固过程中溶质元素的重新分配会造成合金元素在晶粒内部和晶界的分布不均匀,从而导致成分偏析[2]。溶质的

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