Sliding wear behavior of copper alloy impregnated C/C composites under an electrical current

The wear behavior of copper-impregnated carbon fiber reinforced carbon composites (C/C composites) was investigated using a block-on-ring type wear tester during application of a DC electrical current. Three types of C/C composite contact strip materials were tested. The wear test was carried out at a constant sliding speed of 55.6 m/s with a normal load of 59 N, and applied electrical currents ranging from 100 to 500 A. The arc-discharging rate, which is defined as the ratio of arc-discharging time to total sliding time, ranged from 0% to 35%. We also investigated the thermal and oxidation properties of the C/C composites with the laser flash method and TG-DTA. The results of the wear experiments indicate that the wear of copper-impregnated C/C composite contact strips was proportional to the arc discharge energy, which can be calculated from measurements of contact voltage and electrical current. The C/C composite contact strips with high strength carbon fiber were more likely to wear under high arc discharge energy conditions. The C/C composites made of higher strength carbon fiber have lower thermal conductivities and were more likely to be pyrolyzed or degraded by oxidation than the C/C composite with lower strength carbon fiber. These differences are thought to contribute to the difference in the wear behavior.