复合铸锭包覆铸造的数值模拟

建立了一个用来描述4045/3003复合铸锭包覆铸造过程的数学模型，对包覆铸造过程中的流场和温度场进行了数值计算，重点针对铸造速度对流场、温度场的影响规律，并将计算结果和实验测温结果进行了对比.结果表明，适当提高铸造速度有利于两种合金的复合，但是铸造速度过大时，导致芯材支撑层厚度太薄、温度太高，以致复合界面处发生重熔，复合失败，为保证包覆铸造过程的顺利进行，较为合理的铸造速度应为100mm/min.计算结果和实验测温结果存在良好的对应关系，微观组织表明两种合金的结合是一种冶金结合，模拟结果可有效预测界面复合成功与否，对进一步优化包覆铸造工艺方案提供科学指导.

Numerical Simulation on Cladding Casting of Composite Ingot

A mathematical model was developed to describe the process of cladding casting of 4045/3003 composite ingot. The flow field and temperature field in the casting process were simulated to investigate the effect of casting speed on flow field and temperature field， which was also compared with temperature measurements during the process of cladding casting. The results showed that proper increasing the casting speed can contribute to the compounding of two alloys， but excessive speed will make the supporting outer surface so hot and thin that the interface remelted and thus the test failured. The reasonable casting speed for a smooth cladding casting is 100mm/min. Moreover， there is a good agreement between the calculated results and the measured results. The interface microstructure shows that the bonding of two different alloys are metallurgical bonding. The simulated results can predict whether the two alloys could composite together successfully or not， which provides a scientific guidance for optimizing the process of cladding casting.