Effect of Section Thicknesses on Tensile Behavior and Microstructure of High Pressure Die Cast Magnesium Alloy AM50

Abstract

High pressure die cast magnesium alloy AM50 is currently used extensively in complex shaped automotive components with various cross-section thicknesses. Understanding of the effect of section thicknesses on mechanical behavior of AM50 is critical for proper design of different applications. In the present study, magnesium alloy AM50 was high pressure die cast into rectangular coupons with section thicknesses of 2, 6 and 10 mm. The prepared coupons were tensile tested at room temperature. Microstructure analysis and porosity measurement were performed on the representative specimens. The results of tensile testing show that the tensile properties including yield strength (YS), ultimate tensile strength (UTS) and elongation(Ef) decreases with an increase in section thicknesses of die cast AM50. Microstructure and porosity analyses indicate that the observed tensile behavior of die cast AM50 is primarily attributed to the level of porosity which resulted from entrapped gases during the high pressure die casting process.

Influence of Wall Stocks on Mechanical Properties of HPDC AZ91

“…Also, a large increase in elongation appears when the wall thickness of the specimens decreases, since the elongation values, 4.1%, 3.0% and 0.7% for the 2 mm, 6 mm, and 10 mm respectively. The results of the current study are consistent with the relationship between tensile properties and wall thicknesses for different types of the die casting magnesium alloys reported in the literature [6,7]. The changes in strengths and elongation should be attributed to the differences in the porosity content and the microstructure characteristics of the HPDC AZ91 alloy.…”

“…HPDC Mg components usually have various wall stocks around 5 mm and moderate mechanical properties. It is crucial to understand the relationship between the mechanical properties including ultimate tensile strength (UTS), 0.2% yield strength (YS) and elongation (e f ) and the wall stocks of HPDC magnesium alloys for the purpose of engineering design [5,6]. Previous studies were focused on the HPDC Mg alloys with relatively thin wall stocks since the nominal thickness of most current thin-wall Mg components is around 5 mm, although the effect of wall stocks on their mechanical properties was investigated [7,8].…”

Development of creep-resistant magnesium casting alloys for high temperature automotive applications

“…Another important finding is that the Al-rich eutectic α-Mg phase disappears in the PM AC52 alloy, which is usually present in die cast Mg-Al-Mn alloys [11][12][13][14]. Also, the difference in the SDAS between the edge and the center of the castings is significantly reduced through the addition of Ca.…”