Influence of graphite on tribological properties of SiC/Cu/Gr composites with SiO2–Cu2O glass boundary

SiC/Cu/Gr composites with a boundary of SiO2–Cu2O glass phase (GP) were manufactured through the hot pressing sintering process at a temperature of 950 °C. The influence of graphite (Gr) on the mechanical properties and tribological behavior under high-temperature were purposefully investigated. The microhardness of 1.37 ± 0.02 GPa is achieved by SiC/Cu/Gr composites with a graphite content of 1 vol%. The friction coefficient decreases significantly to 0.64 ± 0.02, while the average wear rate is as low as 2.2 × 10−3±0.02 mm3/(N·m) at a friction temperature of 500 °C. The results indicate that the excellent lubrication effect of graphite is utilized in the SiC/Cu/Gr composites, leading to a significant improvement in its high-temperature wear resistance performance. This behavior is attributed to the molten state of GP at high temperatures, which acts as a “binder” promoting high interface bonding strength between particles, coupled with the solid-phase lubrication provided by graphite. This research work provides a direction for developing and applying materials conducive to high-temperature contact conductivity.