An Investigation on Grain Refinement Mechanism of Master Alloys Al-Ti, Al-TiC and Al-Ti-C Toward Pure Aluminum

Abstract

The grain refining effects of Al-Ti, Al-TiC and Al-Ti-C master alloys on commercially pure aluminum were compared, and the grain refinement mechanism of TiAl3 and TiC among master alloys was discussed. The results show that: the grain refinement of the master alloys Al-TiC and Al-Ti toward pure aluminum mainly stems from the heterogeneous nucleation role of TiC and TiAl3 particles, but with the extension of heat preservation time of fused mass, its role of heterogeneous nucleation will decline due to dissolution of TiAl3 and aggregation and precipitation of TiC. The preferable grain refinement effects of Al-Ti-C master alloys toward pure aluminum are mainly due to the fact that when TiAl3 and TiC particles are acted commonly as heterogeneous nucleation particles, the heterogeneous nucleation effect of TiC particles will be enhanced because of the presence of TiAl3.