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

摘要

The grain refining effects of Al-Ti, AI-TiC and Al-Ti-C master alloys on commercially pure aluminum were compared, and the grain refinement mechanism of TiAl_3 and TiC among master alloys was discussed. The results show that: the grain refinement of the master alloys AI-TiC and Al-Ti toward pure aluminum mainly stems from the heterogeneous nucleation role of TiC and TiAl_3 particles, but with the extension of heat preservation time of fused mass, its role of heterogeneous nucleation will decline due to dissolution of TiAl_3 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 TiAl_3 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 TiAl_3.