Influence of Wall Stocks on Mechanical Properties of HPDC AZ91

Abstract

AZ91, as one the most popular magnesium alloys is widely employed for various engineering applications in the automotive industry. They are primarily made from high pressure die cast processes (HPDC) with different wall stocks, which affect their engineering performance. Understanding the effect of thick wall stocks on mechanical behaviors of HPDC AZ91 is crucial for proper design of lightweight components to meet desired engineering requirement. In this research, a conventional high pressure die casting process was utilized to prepare rectangular specimen of AZ91 with wall thicknesses of 10 mm, 6 mm and 2 mm. Tensile testing, porosity measurement and microstructure analyses were carried out on prepared specimens at room temperature. The mechanical testing evaluation reveals that, as the wall stocks of AZ91 deceases, their tensile properties including yield strength (YS), ultimate tensile strength (UTS) and elongation (ef) increase. The porosity content caused by air entrapment and the dendritic structure due cooling mechanisms should be responsible for the resultant mechanical properties.