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

Research on the friction layer is needed to minimize friction- and wear-related mechanical failures in moving mechanical assemblies. Dry sliding tribological tests of Ni 3 Al 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 mm 3 N −1 m −1 ). While sliding against Al 2 O 3 and Si 3 N 4 , 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.