Graphene-enhanced tribological performance of polycrystalline high-entropy alloys: Nanoscale simulation and experimental investigation

This study investigates the influence of graphene on the nanoscale tribological behavior of polycrystalline FeNiCrCoCu high-entropy alloys (HEAs) using molecular dynamics simulations and nano-scratch experiments. The results reveal that the adsorption of graphene significantly enhances the friction reduction and wear resistance of HEAs. Graphene acts as a solid lubricant to form a uniform interfacial layer, which improves thermal dissipation, dislocation evolution and stress distribution. This mitigates wear debris accumulation and thus reduces friction-induced damage. The four-layer graphene achieves the optimal balance of interfacial lubrication, stress buffering and thermal conductivity, reducing the friction coefficient of HEAs to 0.121, a 68.66 % reduction compared to raw HEAs. Nano-scratching experiments further show that the use of moderate graphene leads to even dispersion, which promotes the formation of a stable lubricating layer, thereby reducing the friction coefficient to 0.093, a 39.61 % decrease compared to raw HEAs. This work provides insights into optimizing graphene-enhanced HEAs for improved nanoscale tribological performance, offering potential applications in high-performance coatings and microelectromechanical systems.