Investigation of the solid self-lubricating effect on tribological properties of Al/SiC/Gr composites against steel disc

Abstract

The present work examines the tribological characteristics of cast aluminium–silicon matrix composites reinforced with silicon carbide (SiC) and graphite (Gr). The metal matrix composite samples were manufactured using stir and squeeze casting techniques, employing an Al–Si matrix alloy and integrating particulate SiC and varying quantities of graphite particles. To investigate the impact of varying amounts of graphite on the Al/SiC composite, graphite particles were included at volumetric proportions of 5, 7.5 and 10%. Before being integrated into the matrix, Cu-coating was employed on graphite particles using electroless coating to enhance the adhesion with the matrix composition. Tribological experiments were conducted on Al/SiC and the Al/SiC/Gr composites using a pin-on-disc tribometer apparatus. Al–SiC and Al/SiC/Gr samples were specifically engineered and employed as a pin, while AISI 8620 steel was utilized as a disc. Adding graphite particles to the Al/SiC composite decreased the amount of wear and friction. The utilization of hybrid Al/SiC/Gr composites resulted in the creation of tribo-layers during sliding, hence minimizing the occurrence of grooves, plowing and smearing.