Comparative Assessment on Microstructure and Properties of in-situ TiC + Ti5Si3 Reinforced Ti-Al-Sn-Zr Matrix Composites by Spark Plasma Sintering and Argon Protected Sintering.

The effects of SiC particles (SiCp) on high temperature oxidation behavior of titanium matrix composites (TMCs) under different powder metallurgy processes were investigated. In situ TiC + Ti₅Si₃ reinforced titanium matrix composites were prepared by discharge plasma sintering (SPS) and argon protective sintering (APS). The results show that the two processes have a negligible effect on the composition and hardness of the samples, but the hardness of the two samples is significantly improved by adding SiCp. The apparent porosity of SPS process is obviously smaller than that of APS process, whereas, the apparent porosity increases slightly with the addition of SiCp. The oxide layer thickness and mass gain of the samples obtained by SPS process are smaller than those obtained by APS process. The oxide thickness and mass gain of both processes are further reduced by adding SiCp. The SPS composites showed the best high temperature oxidation resistance. Therefore, TMCs with SiCp by SPS can effectively improve the high-temperature oxidation behavior of the materials. [ABSTRACT FROM AUTHOR]