Numerical Simulation of Solidified Structure Formation of Al-Si alloy Casting Using Cellular Automaton Method
For the purpose of the prediction of casting structures, heterogeneous nucleation rate in the undercooled melt of solififying Al-Si alloys were evaluated by comparing experimentally observed macrostructures of solidified ingots with numerically simulated ones. Molten alloys were unidirectionally solidified in an adiabatic mold from a steel chill block located at the bottom of the mold. In the experiment, columnar to equiaxed transition (CET) was observed. A numerical simulation for grain structure formation of the sample ingots was carried out using a cellular automaton (CA) method, and heterogeneous nucleation rate in the solidifying alloys were evaluated by producing the similar structures to experimental ones. An attempt was made to predict the grain structure of conventionally cast ingots using the evaluated heterogeneous nucleation rate. However, the simulation could not predict the structure of ingot with low superheat due to crystal multiplication near the mold wall. The crystal multiplication mechanism, so-called Big Bang mechanism, was introduced into the simulation and the simulation could predict the grain macrostructure composed of columnar and equiaxed crystals that were similar to experimentally observed one.
Al-Si alloy cellular automaton method numerical simulation macrostructure of casting
Kenichi Ohsasa Kiyotaka Matsuura Kazuya Kurokawa Seiichi Watanabe
Graduate School of Engineering, Hokkaido Univ., Japan Center for Advanced Research of Energy Conversion Materials, Hokkaido Univ., Japan
国际会议
郑州
英文
2007-10-23（万方平台首次上网日期，不代表论文的发表时间）