Enhancing the High-Temperature Tribological Performance of Cr ₃ C ₂ –NiCr/AlCrN Duplex Coatings Via Optimizing Cermet Interlayer Thickness

-NiCr/AlCrN duplex coatings against the YG6 counterpart ball at 650 °C. The results demonstrated that the cermet interlayer with a thickness of less than 100 μm provided insufficient support for the AlCrN films, leading to severe deformation and cracking. The primary wear mechanisms of the duplex coatings were oxidative wear and abrasive wear. Finite element simulation results indicated that when the cermet interlayer thickness exceeded 100 μm, the high contact stress in the frictional contact zone accelerated the rupture of the oxide film at the wear interface, leading to severe oxidative wear of the duplex coatings. The 100 μm thick cermet interlayer provided sufficient support for the AlCrN films, enabled smooth transfer of contact stress, and facilitated the rapid formation of a protective tribo-oxidation film on the wear track. Consequently, the duplex coatings exhibited optimal high-temperature tribological performance.