The advancement of aerospace and polar technologies has increased the demand for lubricants capable of delivering stable performance under extreme temperature conditions while minimizing friction and wear. However, existing lubrication systems remain inadequate for reliable operation within a broad thermal range of −50 to 350 °C. In this study, we propose a wide-temperature lubricant formulation comprising chlorophenyl silicone oil (CPSO) as the base fluid, polydiethylsiloxane (PDES) as a compatibilizer, and pentaerythritol ester (PET) to enhance high-temperature anti-wear performance. At low temperatures (−50 to 25 °C), the lubricant functions primarily via hydrodynamic mechanisms, maintaining fluid lubrication, although friction tends to increase with decreasing temperature. Above 200 °C, a friction-induced nanotribofilm composed of metallic compounds and amorphous silicon oxides forms on the surface, markedly enhancing the anti-wear and friction-reducing properties. At 300 °C, the hybrid lubricant reduces the wear rate of M50 steel by 86% and 61% compared with CPSO and PDES alone, respectively. Overall, this lubricant demonstrates outstanding tribological stability across a wide temperature range, offering crucial insights and support for the development of advanced lubrication technologies suitable for extreme environments.

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, micro-vibration, 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, multi-scale strengthening strategies-including compositional design, microstructural refinement, binder phase optimization, grain-scale engineering, PVD/CVD thin films, and surface texturing-are summarized and comparatively assessed with respect to their effectiveness across varied tribological conditions. Finally, emerging trends are discussed, with emphasis on multi-field 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.