High-temperature oxidation resistance of a Ti–Al–Sn–Zr titanium matrix composites reinforced with in situ TiC and Ti${}_5$Si${}_3$ fabricated by powder metallurgy

A mixture of the Ti–Al–Sn–Zr matrix powder and SiC particles was used as a raw powder to fabricate an in situ TiC and Ti${}_5$Si${}_3$ reinforced titanium matrix composites (TMCs) via low energy ball milling–cold press forming–argon-protected sintering. The effects of various content of SiCp on the microstructure, phase composition and high-temperature oxidation behavior of the composites at 750 °C and 850 °C were studied. XRD results show that the oxidation phases were mainly composed of TiO${}_2$, Al${}_2$O${}_3$, SiO${}_2$ and α-Ti. According to the SEM images, the cross-sectional morphology of oxidation at 750 °C for 100 h shows that the oxide layer (20.00 μm) in the TMCs with 10.0 vol% SiCp after oxidation was denser and thinner and was 82.13% thinner than that of the matrix (98.00 μm). The parabolic rate constant (k${}_p$) of the oxidized composites decreases with the increase of SiCp content at 750 °C and 850 °C. In particular, the composites with 10 vol% SiCp content have smaller k${}_p$. All the results show that the addition of SiCp in TMCs can improve high-temperature oxidation resistance.