Numerical Simulation of Boundary Heat Flux Transients and Thermal Field of the Mould during Gravity Die-casting

Abstract

Experiments were conducted to study the effect of heat flux transients at the metal/mould interface on the thermal field of the mould during gravity die-casting. A serial solution of the inverse heat conduction problem (IHCP) was used for determining multiple heat fluxes at the metal mould interface during casting of Al-Cu alloy in cast iron mould. The temperature history of the casting and the mould during solidification was recorded using mineral insulated K- type thermocouples. Computer interfaced data logger was used for temperature data acquisition. The measured temperatures were used as input to the IHCP algorithm for simulating multiple heat fluxes at the boundary. The effect of interfacial air gap formation on boundary heat flux transients and thermal field of the mould was studied. It was observed that the interface heat flux varies both spatially and temporally due to non-uniform interfacial air gap formation and affects the thermal field in the mould. The variation of heat flux induces variation in the cooling rate and hence a variation in the microstructure of the casting.