Effect of Sand Materials on Appearance and Dimensional Accuracy of Casting in Expendable Pattern Casting Process

Abstract

The effect of the sand materials on the appearance and dimensional accuracy of the casting in the expendable pattern casting (EPC) process was investigated experimentally. The aluminum alloy casting of the simple shape with the rib was cast by EPC process, and the dimensional change of the casting from the expendable polystyrene (EPS) pattern was measured. When the natural silica sand was filled loosely, the positive different dimension of casting from the EPS pattern was caused, and the leaching of the molten metal due to cracks in the coat wall was observed. However, when the artificial sand was filled, even with loose filling, the different dimensions of the casting were small.