Grain refinement of Mg-Li-Al cast alloys by adding typical master alloys

Commercial Al-3Ti-1C and Al-5Ti-1B master alloys were added in order to refine the grains of Mg-Li-Al alloys. The effects of their addition levels on grain refinement of Mg-Li-Al cast alloy were investigated and the mechanism of the grain refinement was discussed. The results showed that the addition of Al-3Ti-1C master alloy reduced the grain size of LA141 cast alloy from 900 mu m to 400 mu m, while the addition of Al-5Ti-1B master alloy reduced the grain size of LA51 cast alloy from 500 mu m to 240 pm. The grain refining mechanism was the heterogeneity nucleation of TiC and TiB(2), because of less than 10% mismatches of TiC/beta-Li and TiB(2)/alpha-Mg.