Friction and wear behavior of GNPs functionalized carbon fiber reinforced polymer matrix composites under high-frequency reciprocating conditions

The effect of normal load on the reciprocating sliding behavior of plain weave woven carbon fibers (CF) and graphene nanoplatelets (GnPs) coated unidirectional carbon fiber strands (GCF) reinforced polymer (CF-GCF/epoxy) composites was investigated. The normal load was varied from 50 N to 90 N at the interval of 10 N. The high frequency of reciprocating motion (5 Hz) was considered. Nearly 13 500 cycles were employed with a stroke length of 1.5 mm. The tensile behavior of CF-GCF/epoxy composite was also investigated keeping longitudinal direction of GCF along the loading direction. The fractured samples and worn surfaces were analyzed under scanning electron microscopy. It was observed that the surface of GCF was rough which increased its interlocking tendency with the matrix and hence increased the tensile strength. The friction coefficient increased with increase of load up to 80 N and decreased afterward, whereas wear loss exhibited increasing trend with increase in load. However wear loss showed a slight decrease in slope beyond 70 N load. Fiber fragments in wear debris were observed at high loads. Although the friction film was also observed at high loads, the abrasion furrows were not significantly visible. The plasticity of matrix and the formation of friction film depicted the friction and wear behavior of CF-GCF/epoxy composites.