The tribological properties and wear mechanism of copper coated graphite doped Sialon ceramic composites at wide range temperature from 25 to 800 °C

High-performance Sialon composites with excellent tribological properties were successfully fabricated by doped copper coated graphite. Results showed that Sialons have an excellent wear resistance (wear rate at 10−6 mm3/Nm) at 25 °C. When the temperature increases to 200-600 °C, the wear rate of β-Sialon composites decreases about 5-10 times compared to S0. Especially for S2 (the content of copper coated graphite is 30 wt%) at 600 °C, the wear rate decreases by an order of magnitude and the friction coefficient is reduced to 0.5, which is 37.5% lower than S0. The self-lubrication mechanism of Sialons ascribed to the synergistic effect of graphite and copper at wide range temperature.