离心力作用下Al/SiC_p系统二维凝固过程的数值模拟

NUMERICAL SIMULATION OF A1/SiC_p SYSTEM TWO DIMENSION SOLIDIFICATION PROCESSING BY CENTRIFUGAL CASTING

采用数值计算方法对离心浇铸下Ａｌ／ＳｉＣｐ系统的二维凝固过程进行了研究．给出了各种因素对最终颗粒分布的影响结果表明，从外侧面冷却时凝固件中颗粒的分布由内侧向外侧可依次分为以下区域：颗粒体积分数为零区、颗粒梯度区、颗粒堆积区以及最外侧的梯度薄层。外部介质对流换热系数减小时、颗粒堆积区和颗粒体积分数近似为零区范围将增大，而颗粒梯度区范围则会减小：颗粒尺寸增大或铸模转数增加时。

A numerical investigation of Al/SiCp two dimension solidification process during centrifugal casting is conducted. The effects of various processing parameters were explored. It is found that there exit some different zones from inside to outside when solidification is from outside: the denuded region where the particle volume fraction is nearly zero, particle gradient region, particle packed region and a thin gradient region. Lower heat transfer coefficient results in slower solidification and hence a larger denuded zone and a larger particle packed zone, but a smaller particle gradient zone. Larger particle size or higher rotational velocity leads to faster particle velocity and hence a larger denuded zone and a larger particle packed zone, but a smaller particle gradient zone.