Tribological Performance of Carbon/copper Composite and Carbon/aluminum Composite under Dry Sliding Condition

Carbon/copper(C/Cu)composite and carbon/aluminum(C/Al)composite were fabricated by diecasting molten copper or aluminum into porous carbon matrix at high temperature and high pressure.Dry sliding wear tests under different normal loads and sliding speeds were performed using a reciprocating friction and wear testing machine.Worn surfaces were analyzed by Scanning Electron Microscope(SEM)and Energy Dispersive Spectrometer(EDS).Testing results show that the wear rate increases with increasing the normal load and sliding speed.Friction coefficient of C/Cu composite is higher while the wear rate is lower than that of C/Al composite.Friction coefficients of both C/Cu and C/Al composites increases and then decrease with increasing the normal load and reaches a maximum of 0.228 and 0.206 at 5N,respectively,and then descends. Friction coefficient of C/Al composite decreases with an increase in the sliding speed and reaches a minimum of 0.155 at 0.05 m/s,and then ascends.Whereas,C/Cu composite shows its insensitivity in the friction coefficient to the sliding speed.Wear mechanism of the composites mainly combines abrasive wear,adhesive wear and fatigue wear.However,oxidative wear occurs during the sliding process of C/Al composite. Meanwhile,addition of copper or aluminum significantly increases the mechanical properties of composites.