Microstructure Evolution and Mechanical Properties of Extruded Mg-Al-Zn-Sn Alloy Sheets

Abstract

The microstructure and mechanical responses of the AZ31 with the addition of 1.8% Sn alloys have been studied and compared. Mg alloy sheets were prepared with metal model casting method and subsequent processes by conventional extrusion (CE) and differential speed extrusion (DSE). Mg alloys were hot extruded at 400oC with the extrusion ratio of 101:1. The microstructure of Mg alloy sheets was examined by optical microscopy (OM) and scanning electron microscope (SEM). The results indicated that the grains were dynamically recrystallized after the extrusion process. Moreover, DSE process dramatically enhanced the room temperature ductility of the extruded sheets. It was also presented that the Mg alloy processed by DSE exhibite a classical dimple structure as a result of slip accumulation and ductile tear.