Microstructure and mechanical properties of low pressure cast AZ91 magnesium alloy

Abstract

The increase in usage of Mg alloy components in automobiles demands continuous research in materials and process development. Improvement in mechanical properties, especially the high temperature properties of AZ91 magnesium alloy, is the need of the moment. In the present work, an attempt has been made to improve the microstructure and mechanical properties of AZ91 using an indigenously designed and developed Low Pressure Casting (LPC) set-up. The Low Pressure (LP) cast AZ91 alloy shows better mechanical properties both at room and high (up to 200°C) temperatures. The improvement in mechanical properties is attributed to the fine structure and less casting and filling related defects seen in the castings obtained by LP process. Using this process, defect-free, quality thin casting having thickness of 2 and 3 mm have been successfully cast.