Effect of Ca addition and heat treatment on the A390(S)/AM60(L) interface microstructure

Abstract

Overcasting is a new kind of dissimilar joining technique used to produce the aluminum(solid)/magnesium(liquid) bonding bi-metallic material in this study. For the Al/Mg (A390/AM60) bi-metallic samples, the interface microstructures are the research points, which directly influence the mechanical properties. It is, therefore, of vital importance to find a method to improve the interface microstructures. This research focused on the effect of the calcium (Ca) addition in the liquid Mg alloys and the heat treatment on the A390/AM60 interface microstructures of the bi-metallic samples. The testing results showed that, with Ca addition in AM60, owing to two possible reasons, the interface microstructure and the shear strength of the A390/AM60 bi-metallic samples could be improved. The heat treatment could further improve the interface microstructure and the mechanical properties by dissolving β-Mg17Al12 into α-Mg and destroying the Mg2Si layer structure.