Enhanced high temperature properties of low pressure cast AZ91 Mg alloy

Improving the mechanical properties especially the high temperature properties of Mg-Al Mg alloy is a challenging task for the researchers. The mechanical properties of these alloys are highly sensitive to the microstructure which can be controlled through proper processing methods. In the present work, an attempt has been made to improve the microstructure and mechanical properties of AZ91 using low pressure casting method. The results show that the low pressure cast AZ91 alloy exhibits better mechanical properties both at room and high temperature (up to 200 degrees C). Improved creep behaviour at 150 degrees C is also observed with low pressure castings. The improvement in mechanical properties is attributed to the fine structure and lesser casting and filling related defects.