Numerical simulation of macrosegregation during solidification of binary alloys  

作　　者：Wu-Tao Tu Hou-Fa Shen Bai-Cheng Liu 

机构地区：[1]Key Laboratory for Advanced Materials Processing Technology,Ministry of Education, School of Materials Science and Engineering, Tsinghua University

出　　处：《Rare Metals》2016年第8期591-597,共7页稀有金属（英文版）

基　　金：financially supported by the National Basic Research Program of China (No. 2011CB012900);the Tsinghua University Initiative Scientific Research Program (No. 2012THZ01013)

摘　　要：Macrosegregation as a consequence of solidifi- cation of a binary Pb-48 wt% Sn alloy in two-dimensional rectangle cavity was investigated by two-phase model instead of the common used continuum model. The macroscopic transport of mass, momentum, species and energy was cou- pled with the microscopic descriptions of grain nucleation and growth. The mathematic equations of the two-phase model were discretized on staggered grids and solved by the finite volume method. The final tin concentrations along different heights over the bottom face were compared with the ex- periment measurements. Simulations with different mi- crostructure parameters （second dendrite arm spacing （SDAS）） were conducted to ascertain the influence of microstructure on the final macrosegregation. The results show that with the decrease in SDAS value, the drag force as the resistance to relative motion between solid and liquid phase increases, and the macrosegregation during solidification is alleviated.Macrosegregation as a consequence of solidifi- cation of a binary Pb-48 wt% Sn alloy in two-dimensional rectangle cavity was investigated by two-phase model instead of the common used continuum model. The macroscopic transport of mass, momentum, species and energy was cou- pled with the microscopic descriptions of grain nucleation and growth. The mathematic equations of the two-phase model were discretized on staggered grids and solved by the finite volume method. The final tin concentrations along different heights over the bottom face were compared with the ex- periment measurements. Simulations with different mi- crostructure parameters （second dendrite arm spacing （SDAS）） were conducted to ascertain the influence of microstructure on the final macrosegregation. The results show that with the decrease in SDAS value, the drag force as the resistance to relative motion between solid and liquid phase increases, and the macrosegregation during solidification is alleviated.

关 键 词：MACROSEGREGATION Two-phase model SOLIDIFICATION Second dendrite arm spacing 

分 类 号：TG111.4[金属学及工艺—物理冶金]