Evaluation of transient heat transfer coefficient evolution in EN 43000 gravity castings towards chills with different interface conditions

Heat exchange phenomena in foundry processes are governed by the heat resistance through contact interfaces between metal and casting tools. As known, physical and geometrical aspects play a fundamental role on the heat transfer conditions during the solidification process. This high dependence of heat transfer coefficient (HTC) by process variables determines the experimental method as the only way for a correct evaluation of heat fluxes during the cooling phase. The evolution of HTC between EN43000 aluminum alloy and two different metallic chills was here investigated by means of an experimental gravity casting device and by developing an investigation approach based on inverse method and numerical analysis. The accuracy of achieved results was evaluated by comparison between measured and predicted values of temperature in the cast and through some considerations on the efficiency of the adopted method and his application capabilities to the numerical simulation of industrial casting processes.