Effect of counterface balls on the friction layer of Ni3Al matrix composites with 1.5 wt% graphene nanoplatelets

Abstract

Research on the friction layer is needed to minimize friction- and wear-related mechanical failures in moving mechanical assemblies. Dry sliding tribological tests of Ni3Al matrix composites (NMCs) with 1.5 wt% graphene nanoplatelets (GNPs) sliding against different counterface balls are undertaken at the condition of 10 N–0.234 m s−1 in this study. When sliding against GCr15 steel, a uniform and thick friction layer is formed, resulting in a lower friction coefficient (0.29–0.31) and wear rate (2.0–3.1 × 10−5 mm3 N−1 m−1). While sliding against Al2O3 and Si3N4, the formation and stability of the friction layers are restricted in the severe wear regime, and the NMCs exhibit higher friction coefficients and wear rates. Therefore, various counterface balls have a great effect on the stability and thickness of the friction layer, thus affecting the tribology performance of NMCs. The result also shows that GNPs exhibit enrichment and self-organized microstructures in the friction layer. In addition, the friction layer is also found to be divided into two layers, protecting the subsurface from further damage and reducing shear.