Effect of Ti3SiC2 Amount on Microstructures and Properties of TiAl Matrix Composites

The TiAl matrix composites were manufactured using spark plasma sintering under the conditions of 1100 °C/10 min/30 MPa. The effect of Ti3SiC2 amount on microstructure and properties of TiAl matrix composites was investigated. Ti3SiC2 was homogeneously distributed in the TiAl matrix, and it partly decomposed to form Ti5Si3 and TiC. The TiAl matrix with 30 wt.% of Ti3SiC2 exhibited the lowest friction coefficient and wear rate of 0.507 and 1.35´10-4 mm3N-1m-1 at room temperature and 0.423 and 0.21´10-4 mm3N-1m-1 at 550 °C, while the compression strength reached the maximum value of 1080 GPa at room temperature and 640 GPa at 550 °C, respectively. The hardness reached the value of 5.1 GPa. The TiAl matrix composites had a lower friction coefficient and wear rate at 550 °C than at room temperature. A Ti3SiC2 lubricating film was formed on the friction surface of the TiAl matrix composites after friction test at room temperature, while a Fe-Ti-Al-Si-oxide lubricating film was formed after friction test at 550 °C. The wear mechanisms of the TiAl matrix composites with the Ti3SiC2 addition were mainly abrasive wear and adhesive wear at room temperature and 550 °C, respectively.