Effect of Ti on microstructure and properties of electromagnetic stirred Al-18wt.%Mg2Si alloy

By adding different amounts of Ti into the electromagnetic stirred Al-18wt.%Mg2Si alloy, the effect of Ti element on the microstructure and mechanical properties of the alloy was studied. The experimental results show that the microstructure is refined after modification with Ti, which is related to the heterogeneous nucleation of TiAl3 particles on the α-Al matrix. With the increase of Ti content and holding time after stirring, the primary Mg2Si phase is refined firstly and then coarsened, and correspondingly, the mechanical properties of the alloy show a trend of increasing at first and then decreasing. When the addition of Ti is 0.5wt.% and the holding time is about 20 min, the refinement effect of primary Mg2Si phase is the most significant and the mechanical properties of the alloy are optimal.