Numerical Simulation of Macrosegregation Caused by Thermal-Solutal Convection and Solidification Shrinkage Using ALE Model

• 来源期刊: 金属学报（英文版）
• 年，卷（期）: 2019,（11）
• 页码范围: 1396-1406
• 页数: 11页
• 语种: 英文

摘要

Solidification shrinkage has been recognized as an important factor for macrosegregation formation.An arbitrary Lagrangian-Eulerian (ALE) model is constructed to predict the macrosegregation caused by thermal-solutal convection and solidification shrinkage.A novel mesh update algorithm is developed to account for the domain change induced by solidification shrinkage.The velocity-pressure coupling between the non-homogenous mass conservation equation and momentum equation is addressed by a modified pressure correction method.The governing equations are solved by the streamline-upwind/Petrov-Galerkin-stabilized finite element algorithm.The application of the model to the Pb-19.2 wt％Sn alloy solidification problem is considered.The inverse segregation is successfully predicted,and reasonable agreement with the literature results is obtained.Thus,the ALE model is established to be a highly effective tool for predicting the macrosegregation caused by solidification shrinkage and thermal-solutal convection.Finally,the effect of solidification shrinkage is analyzed.The results demonstrate that solidification shrinkage delays the advance of the solidification front and intensifies the segregation.