Effects of Pb addition on microstructures and elemental distribution of AS-CAST AZ61 Mg alloy

Abstract

AZ61 Mg alloy contains Al and Zn, and it has a good combination of castability, strength and ductility. However, the effect of other alloying elements on AZ61 is seldom investigated. Lead is a cheap metallic material, though its vapor is hazardous, a small amount of Pb as an alloying addition will not have significant influence on the application of Mg alloys. Studies showed that the Pb addition suppresses the formation and growth of discontinuous precipitation in AZ91 alloy. In our study, a small amount of Pb element was added into the AZ61 alloy. Mechanical properties of the alloy have been improved. The microstructures were examined by the optical microscopy (OP), scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS). The elemental distribution with Pb alloying was explicitly studied. This alloy composed of [Formula: see text]-Mg phase and [Formula: see text]-Mg[Formula: see text]Al[Formula: see text] phase, while Pb element inclined to distribute in [Formula: see text]-Mg rather than in [Formula: see text]-Mg[Formula: see text]Al[Formula: see text] phase.