Unveiling the mechanical, friction, and wear responses of SiC+Gr reinforced copper hybrid composites developed by powder metallurgy (P/M) technique

Abstract The mechanical, friction, and wear properties are very crucial in applications such as bearing materials, carbon bushes, and electrical contacts. The present study involved the fabrication of copper-based self-lubricating hybrid composites, for which copper was chosen as matrix, graphite (Gr) and silicon carbide (SiC) were selected as reinforcements. These hybrid composites were synthesized using the powder metallurgy (P/M) a zero waste technique, where an equal quantity of graphite (Gr) and silicon carbide (SiC) were reinforced in the matrix. There were four samples prepared and designated as S1, S2, S3, and S4. Then the microstructural, mechanical, friction, and wear behaviours of the fabricated hybrid composites were studied. The XRD evaluation of composites indicates the absence of any intermediary reaction taking place between the copper and reinforcing particles. The micrographs of the composites displayed a consistent dispersion of reinforcement particles throughout the copper matrix. The pin-on-disk tribometer was utilised to perform dry sliding wear experiments under loads varying from 10 to 30 N, sliding velocities of 1–2 m s −1 , and constant sliding distances of 2000 m. The addition of 3 wt% of both graphite and SiC reinforcement results in a hardness of 93.6 HV, which is 60.36% greater than the hardness of pure copper (56.5 HV). Studies indicate that the wear rate and coefficient of friction (COF) of composites decrease as the amount of reinforcement increases. Specifically, the composite containing 9 wt% of both graphite and SiC demonstrates the lowest level of wear. The wear rate exhibited an upward trend with the applied load and sliding velocity for each material. The examination of the deteriorated surface also indicates that delamination is the main process of deterioration for pure copper specimens. SiC and graphite-reinforced composites have experienced different types of wear mechanism, such as adhesive, abrasive, oxidative, and delamination wear. The synergistic effect of SiC (enhancing strength) and Gr (reducing friction) leads to improved wear resistance, making these composites promising for applications requiring both durability and low friction.