Paper Title
Effect of TI Addition on Microstructure and Mechanical Properties of as-Cast and Hot-Rolled Az31 Magnesium Alloys

Abstract
This study investigated the effect of Ti addition on microstructure and mechanical properties of AZ31 magnesium alloys. Ti additions were made by 0.5 and 1 wt%. Alloys were produced by conventional gravity casting in a steel mould preheated to 250 °C. A homogenization treatment at 350 °C for 24 h was performed after the casting processes. Homogenized samples were hot-rolled by 40% thickness reduction at 1 pass at 350 °C. The results showed that Ti addition above 0.5 wt% effectively decreased the grain size of both as-cast and hot-rolled AZ31 alloys. Ti addition did not led to formation of any second phases but decreased the amount of -Mg17Al12 intermetallic phases. Tensile properties were improved by Ti addition. In the as-cast alloys, the AZ31 alloy containing 1 wt% Ti showed the best mechanical properties. However, in the hot-rolled alloys, the alloys with 0.5 wt% and 1 wt% Ti addition showed similar mechanical properties which were higher than AZ31 alloy. Index Terms- AZ31 Magnesium alloys; Ti modification; microstructure; mechanical properties