Effects of trace Ti on the microstructure and properties of casting Mg-9Al magnesium alloy

The purpose of this research is to study the influence of trace Titanium (Ti) on the microstructures and properties of as-cast Mg-9Al alloy. We found that Ti could increase the corrosion resistance of the alloy inNaCl solution. The addition of trace Ti in Mg-9Al cast alloy improved the properties greatly. The elongation (δ₅) of the alloys was also improved greatly with Minor addition of Ti as low as 0.015wt%. The improvements on the mechanical properties and corrosion resistence were mainly due to the inhibition of Ti to the heterogeneous nucleation during solidification and the modification of β phase. As the Ti additional amount increases, the grain of as-cast Mg-9Al alloy coarsens rapi- dly. Meanwhile, the β phase was refined and changed from semi-netted shape to short rods or even spheres.