Effect of Ce addition on castability, mechanical properties and electric conductivity of Al–0.3Si–0.2Mg alloy

Abstract

Effect of rare earth (RE) element cerium on castability, mechanical properties and electric conductivity of Al–0.3Si–0.2Mg alloy was investigated. With Ce addition, the fluidity of Al–0.3Si–0.2Mg alloys is increased and the hot tear sensitivity (HTS) is decreased remarkably, and the optimum Ce addition level is about 0.2%. Significant improvement of castability (especially the HTS) is attributed to the remarkable grain refinement from Ce addition. Ce addition also leads to a remarkable rise in electric conductivity, mainly due to the reduction of Fe and Si solutes in α-Al solution. T7 heat treatment further improves the electric conductivity. However, in the case of T7 condition, Ce-induced improvement of conductivity is not considerable. An excellent combination of castability, strength and conductivity can be obtained with 0.3%Ce addition in the studied alloy.