Microstructure and Mechanical Properties of Squeeze Cast AZ91D Magnesium Alloy 2005-01-0330
Squeeze casting is considered a “high integrity” casting process because it imparts qualities (higher tensile properties, in particular ductility due to reduced or absence of porosity in the matrix, and the ability to heat treat) to a metal that are difficult to achieve with conventional casting techniques including gravity permanent mold (GPM) and high pressure, high velocity (HPDC) die casting.
In recent years, the squeeze casting process has been widely used with various aluminum alloys to manufacture near-net shape automotive components requiring high strength, ductility or pressure tightness. However, with the emphasis on weight reduction, lower cost and improved performance of structural components, alternative lightweight materials including magnesium are now being seriously considered. Unfortunately, the use of magnesium as a structural material has been hindered by the lack of data on mechanical properties and the lack of new improved casting methods.
This paper, therefore, reviews the squeeze casting process and provides information on microstructures and mechanical properties of squeeze cast AZ91D magnesium alloy before and after heat treatment (T4 and T6 temper). The data obtained from this investigation are then compared with those from commonly used die casting aluminum alloys.