Effects of Sb addition on the modification of Mg 2Si particles and high-temperature mechanical properties of cast Mg–4Zn–2Si alloy

Abstract

The effect of 2 wt.% Si and 0.2 wt.% Sb on the microstructure and high temperature mechanical properties of a cast Mg–4Zn alloy was investigated. Impression creep, hot hardness, and shear punch tests were used to evaluate the mechanical properties of the alloys at 200 °C. Addition of Si and Sb resulted in the formation of the thermally stable Mg 2Si and Mg 3Sb 2 intermetallic compounds, respectively. By the addition of Sb, the morphology of Mg 2Si particles changed from Chinese script to a more rounded edge type, being capable of providing better plasticity during shear deformation. The presence of thermally stable intermetallic particles and the modified morphology of Mg 2Si particles significantly improved the high temperature mechanical properties of the material.