Microstructure and properties of Ti-Al-Sn-Zr-Nb-Si matrix composite reinforced with in-situ TiC and Ti5Si3 prepared by powder metallurgy

In this experiment, the Ti-Al-Sn-Zr-Nb-Si matrix composites reinforced with in situ TiC and Ti5Si3 were successfully prepared via low-energy ball mill-cold pressure-argon gas protection sintering. The effects of different contents of SiCp (3.5 vol%, 7 vol%, and 10 vol%) on the microstructure and properties of the composites were studied. The experimental results show that the surface of the composites exhibits a network structure due to the deposition of the Ti solid solution and the reinforcing phase at the grain boundary. The metallographic microstructure of the as-sintered composites indicates that the addition of SiCp in the composite material can refine the grain, and the grain size of the composite decreases with the increase of SiCp content. In addition, the microhardness of the composites is significantly enhanced with the increase of SiCp content. However, the increase in SiCp content will impact the compactness of the composites.