Numerical simulation of thermal-fluid coupled field in casting mouth during rheocasting-rolling of semi-solid magnesium alloy

摘要

In the initial stage of rheocasting-rolling of semi-solid AZ91D magnesium alloy, the semi-solid slurry was injected into the casting mouth. The whole process was investigated by the VOF model in this paper. The influents of the geometric shapes of casting mouth on temperature field and flow field in casting mouth was analyzed. The numerical simulation results showed that flow field was very chaotic in the casting mouth with rectangular section, air was involved in the slurry, quality of the strip was badly impacted. But flow field was very gentle in the casting mouth with arcuate cross-section. Coupled numerical simulation in steady stage of rheocasting-rolling of semi-solid AZ91D magnesium alloy was done under different inflow temperature, distribution of temperature field, Solid fraction in casting mouth of arcuate cross section was obtained. This provided the basis for optimizing the processing parameters in rheocasting-rolling of semi-solid AZ91D magnesium alloy.