Effect of Ti on microstructure and mechanical properties of die-cast Al-Mg-Zn-Si alloy

Abstract

The Al-11.0Mg-2.6Si-4.0Zn-0.6Mn (wt%) alloy is a new developed high strength die cast alloy which can be used for structural parts in the automotive and aerospace industry. In this study, the effect of various amount of Ti on microstructure evolution and mechanical properties of Al-11.0Mg-2.6Si-4.0Zn-0.6Mn (wt%) alloy under as-cast and T6 heat treatment conditions are investigated. The addition of Ti results in the formation of Al3Ti intermetallic phase, and the volume fraction and forming temperature increases with the increase of titanium content. With 0.1wt% Ti addition, the best mechanical properties of the alloy. The yield strength (YS), ultimate tensile strength (UTS) and elongation reach up to 350 MPa, 440 MPa and 3.29% respectively after heat treatment. Titanium content should be controlled below 0.10%.