Effect of Ca addition on the microstructure and creep behaviour of AZ91 Mg alloy

Abstract

The lower density and higher specific mechanical properties of the magnesium and its alloys are attracting the great attention of the automakers from the perspective of automobile fuel economy and reducing the environmental impact. The AZ91 magnesium alloy has excellent mechanical properties

however, its application is limited by its poor creep resistance. In the present study, the effect of Ca addition and squeeze casting on the microstructure and creep behaviour of AZ91 Mg alloy has been investigated. Tensile creep test is conducted at temperatures of 150 and 175 °C under 50 MPa stress. The study shows an increase in creep resistance with Ca addition. Microstructural investigations with scanning electron microscopy confirm that the precipitation of thermally stable Al2Ca phase with skeleton morphology leads to increased creep resistance. © 2023