Wear Behaviors of MoSi2 at Elevated Temperatures
MoSi2 was prepared by SHS, and then pressed under 300 MPa at room temperature and sintered at 1600 °C for 1 h in a vacuum furnace. The tribological properties of MoSi2 against Al2O3 in the temperature range from 700°C to 1100 °C were investigated. Microphotographs and phases of the worn surface of MoSi2 were observed by SEM and XRD. Results showed that MoSi2 has well friction and wear properties below 900 °C. When temperature rises from 900 °C to 1000 °C, wear rate of MoSi2 is raised by 20.8% which is attribute to the change of wear mechanism. The main wear mechanisms of MoSi2 are adhesion and oxidation at high temperatures. When over 900 °C, because of ductile - brittle transition characteristic of this material, plastic deformation and fracture are also found on the worn surface of MoSi2. This leads to the high wear rate of MoSi2.