Graphene nanoplatelet modified basalt/epoxy multi-scale composites with improved tribological performance

The wear performance of non-toxic and respiratory non-hazardous natural fiber reinforced epoxy composites has steadily become an important design parameter due to their increasing applications in self-lubricating and sliding components in contact with metal counterparts. Epoxy matrix has weak wear resistance, and reinforcing the matrix with nano-sized particles has been shown to improve the tribological performance of the resulting multi-scale composites. For this, the epoxy matrix was reinforced with various concentrations of GNPs, and the BF/EP composites were fabricated via the vacuum bagging method, subsequently. The tensile strength and modulus were enhanced up to 42.5 and 74.5% compared to the bare BF/EP laminates, respectively. Moreover, the ball-ondisk wear tests revealed that GNP reinforcement was reasonably effective in reducing the coefficient of friction (23%) in contact areas. As a result, GNP reinforced BF/EP composites exhibited 60% higher wear resistance. In addition to well-known solid lubricant characteristics of GNPs, thermal camera recordings were identified that the improved thermal conductivity in all directions was also responsible for the enhanced tribological performance. The microscopic studies identified the related micro-scale mechanisms responsible for the improved tribological performance of the multi-scale composites. We proposed a unique wear mechanism to represent the tribological behavior of the GNP reinforced BF/EP composites based on electron microscopy and thermal camera recordings.