Khan S, Naylor D, Ravindran C

Abstract: An investigation of the interfacial heat transfer coefficient (IHTC) in the Lost Foam Casting of aluminum alloy has been conducted. The IHTC, which is a measure of the thermal resistance between the casting and the mold, was found using an inverse heat conduction method. The IHTC was measured between a plate casting and an unbonded sand mold to determine the effect of the casting section thickness and refractory coating thickness on the IHTC. Overall, the IHTC was found to have a value in the range of approximately 40-160 W/m2K, depending upon the specific process parameters. In general, as the casting thickness increased, the IHTC increased. In addition, a three-component resistance model of the interface was proposed and compared to experimental results. The model was found to predict the effect of refractory coating thickness on the IHTC. Furthermore, it was found that the contact resistances at the metal/coating and coating/mold interfaces were a significant component of the overall thermal resistance.

Keywords: Casting, Coating thickness, Heat transfer coefficient, Interfacial, Lost foam casting, Section thickness.