LAUSR

Abstract The wear resistance and tribological characteristics of alumina/graphene layered and fiber-reinforced composites were investigated under dry sliding conditions at applied loads of 10 N and 50 N in the air. The experimental materials were prepared by a combination of electrospinning-calcination-chemical vapor deposition and spark plasma sintering. Graphene-coated Al2O3 microfibers were used to form layers in layered monolithic alumina/graphene-coated Al2O3 microfibers composite, and as reinforcements for the alumina matrix in the fiber-reinforced composite. The microstructure, deformation, and damage characteristics were studied. Both composites show a lower coefficient of friction in comparison to alumina with the lowest value of 0.42 for the fiber-reinforced composite measured at a load of 10 N. At the load of 10 N the composites exhibit very high wear resistance with values of wear rate 2.78 × 10−8mm3/(N·m) for the layered and 1.74 × 10−8mm3/(N·m) for the fiber-reinforced composite, in comparison to the wear rate of Al2O3 with a value of 5.35 × 10−6mm3/(N·m). The significant improvement in the wear resistance of the composites was associated with the improved mechanical properties and formation of a protective tribofilm on the wear tracks by the multilayered graphene present on the surface of Al2O3 microfibers and alumina debris, which provided the lubricating effect for the composites.