Tribological mechanisms and performance optimization strategies of cemented carbides under extreme service conditions

Cemented carbides, composed of hard carbide phases and metallic binders, are extensively employed in extreme tribological environments involving high-load dry friction, elevated-temperature cutting, erosive particle flows, cyclic impact, microvibration, and corrosive media. In response to increasing performance demands under such complex service conditions, this review systematically evaluates the tribological behaviors and failure mechanisms of cemented carbides under adhesive, abrasive, fatigue-induced, oxidative, erosive, fretting, and corrosion-induced wear conditions. The critical influence of carbide phase type and grain scale, binder chemistry and mean free path, and microstructural configuration on interfacial degradation pathways is clarified, establishing a structure-driven, mechanism-based framework that links microstructural descriptors with damage evolution and dominant wear modes. On this basis, multiscale strengthening strategies, including compositional design, microstructural refinement, binder phase optimization, grain-scale engineering, physical/chemical vapor deposition (PVD/CVD) thin films, and surface texturing, are summarized and comparatively assessed with respect to their effectiveness across various tribological conditions. Finally, emerging trends are discussed, with emphasis on multifield coupling mechanisms, cross-scale wear modeling, low-Co and environmentally benign binder systems, powder-metallurgy-enabled, and adaptive surface engineering. This review provides theoretical guidance and design strategies for achieving high reliability and long-term service durability of sintered cemented carbides in extreme tribological environments.