摘要
利用相场法模拟了不同单向对流及混合对流作用下Ni-Cu合金的枝晶形貌、溶质分布,研究了横向对流及线性流速对定向柱状晶偏转和重熔的影响。结果表明:对流对枝晶形貌、溶质分布影响较大。在不同对流作用下,上游区域枝晶生长较快、二次枝晶臂发达;下游区域枝晶生长受到抑制,横向发育的主枝晶干向上游方向偏转,上游侧和下游侧枝晶间形成了溶质富集区,固-液界面存在较严重的溶质偏析。定向生长中对流作用会加剧柱状枝晶的局部重熔和缩颈断裂,并随着流速的增加,一次枝晶间熔断的二次枝晶逐渐减少,溶质富集程度增加。
A phase field model was used to simulate dendritic morphology and solute distribution of the Ni-Cu alloy under different unidirectional convection and mixed convection,and the effect of lateral convection and linear flow rate on deflection and remelting of directional columnar crystal was studied.The results showed that the convection had a large influence on the dendritic morphology and solute distribution.Under different convection conditions,the dendrites grew faster in the upstream region,and the secondary dendrite arms were developed;the dendrite growth in the downstream region was inhibited,the laterally developed main dendrites deflected towards the upstream direction,and the solute enrichment zone was formed between the dendrites in the upstream region and the downstream region,thus resulting in a serve solute segregation at the solid-liquid interface.The convective action in directional growing would aggravate the local re-melting and necking fracture of columnar dendrites,and with the increase of flow rate,the number of secondary dendrites fused between primary dendrites decreased and solute enrichment increased.
作者
彭霞林
肖红
李伟红
易兵
秦伟
何浩
PENG Xialin;XIAO Hong;LI Weihong;YI Bing;QIN Wei;HE Hao(Hunan Valin Lianyuan Iron&Steel Croup Co.,Ltd.,Loudi Hunan 417000,China;Hunan Zhongke Electric Co.,Ltd.,Yueyang Hunan 414000,China)
出处
《上海金属》
CAS
2021年第4期69-76,共8页
Shanghai Metals
关键词
相场法
对流
溶质偏析
枝晶偏转
枝晶重熔
phase field method
convection
solute segregation
dendrite deflection
dendrite re-melting
