Effects of the Critical Solidification Rate on the Cooling Process of the Fused Zirconia-Corundum-Silica Material

In order to optimize the process of the fused zirconia-corundum-silica (AZS) material, by the Any- casting software,the cooling process of AZS was simulated to explore effects of the critical solidification rate of cast on solidification sequence, coagulation time, probability of shrinkage cavity and cooling rate. The result showed: When the critical solidification rate was less than 40%, the system got a bottom-up solidification sequence to guarantee the good riser feeding effect. With the increase of the critical solidification rate, the coagulation time decreased to improve the production yield and lower the cost of fused AZS material. The difference of coagulation time that obtained by the coagulation time at the bottom center of riser subtracting that at the center of cast got the maximum value when the critical solidification rate was 20%-30%, which ensured the good feeding effect of riser. When the critical solidification rate was 20%-70%, the microscopic shrinkage cavity appeared neither at the center of riser nor at the center of cast. Considering cooling rate at the bottom center of riser, the critical solidification rate preferred less than 30% to reduce the shrinkage defects. The optimized critical solidification rate should be 20%- 30%.