Influence of Cu on the mechanical and tribological properties of Ti3SiC2

Ti3SiC2/Cu composites with different contents of Cu were fabricated by mechanical alloying and spark plasma sintering method. The phase composition and structure of the composites were analyzed by X-ray diffractometry and scanning electron microscopy equipped with energy dispersive spectroscopy. The mechanical and tribological properties of Ti3SiC2/Cu composites were tested and analyzed compared with monolithic Ti3SiC2 in details. The results show that the Cu leads to the decomposition of Ti3SiC2 to produce TiCx, Ti5Si3Cy, Cu3Si, and TiSi2Cz. The friction coefficient and wear rate of the composites are lower than that of monolithic Ti3SiC2, which is ascribed to the fixing effect of hard TiCx, Ti5Si3Cy, and Cu3Si to inhibit the abrasive friction and wear. However, at elevated temperatures (ranging from room temperature to 600°C) the friction and wear of the composites are higher than those at room temperature. Plastic flowing and tribo-oxidation wear accompanied by material transference contribute to the increased friction and wear at elevated temperatures.