近年来随着国家对火星和金星等相关星系深空探测战略的实施, 开发特殊环境如CO2气氛中的重载超滑技术具有重要的研究意义。该文以高硬度低含氢碳膜和低硬度纳米银掺杂改性二硫化物薄膜构成的异质界面摩擦副为研究对象, 探究该体系的力学特性、纳米结构和摩擦学行为。重点分析了在0~3.2 GPa宽载荷域内GLCH/WS2-Ag和SUJ2/WS₂-Ag润滑系统的宏观超滑行为及影响因素。基于接触界面摩擦层的表面形貌与纳米结构表征, 揭示了滑动区域应力诱导类石墨烯纳米转移膜和WS₂剪切层的形成规律, 阐释了接触界面原位形成的多相有序化摩擦膜对润滑系统超高压超滑构筑的作用机理。

Objective: Superlubricity is a state of motion characterized by near-zero friction and negligible wear on tribo-affected materials. It represents a groundbreaking technological approach to mitigating friction-induced material degradation and mechanical equipment failure. From a surface engineering perspective, achieving superlubricity relies heavily on the design and development of both bulk and surface tribo-materials. Solid superlubricity can be achieved under specific conditions, such as ultra-high vacuum or dry inert gaseous environments, and offers distinct advantages, including the ability to sustain high normal loads and extreme temperatures. Diamond-like carbon and layered materials such as molybdenum disulfide can achieve superlubricity through their inherent surface characteristics. However, in the practical operating conditions of mechanical components, the complex and often harsh contact environments present significant challenges for a simple, homogeneous lubricant to sustain exceptional lubricity. Heterogeneous systems composed of at least two types of lubricants offer a promising solution. Methods: This research investigates a heterogeneous tribo-interface composed of hard hydrogenated carbon films and nanocrystalline-doped transition metal disulfides. The hard hydrogenated carbon films were synthesized by an ion beam deposition system using hydrocarbon gaseous sources as processed precursor. Specific molecular structure such as aromatic-ring species like methylbenzene (C₇H₈) was chosen for tuning the superior property and surface passivation capacity in the film. The correlation between the sp²/sp³ ratio and hydrogen content in the carbon matrix can be controlled by the pulse-biased ion energy. The silver-doped MoS₂ or WS₂ films were prepared by the ion beam assisted magnetron sputtering method. Multilayered structures were established by alternatively depositing each individual layers using different modes. Afterwards, the study focuses on characterizing the mechanical properties, nanostructures, and tribological behaviors of the system. Results: The macroscale superlubricity performance and its influencing parameters, particularly the contact pressures ranging from 0 to 3.2 GPa, are analyzed for the tribo-systems GLCH/WS₂-Ag and SUJ2/WS₂-Ag. A superlow friction coefficient (COF < 0.01) was achieved for a wide range of contact pressure, generally with the decreasing evolution trend as the gradual increasement in the applied normal load regardless of the counterface materials. The heterogeneous sliding interfaces are even capable of bearing a maximum Hertz contact pressure of 7.78 GPa, corresponding to an average value of 3.2 GPa. The duration test further verifies the robustness of the system with a prolonged sliding life-span in the term of 330 000 reciprocating cycles (1 353 m) along with a very low material wear rate. The in-depth analysis of the morphologies and nanostructures of tribofilms at the contact interface reveals the stress-induced evolution of graphene-like carbon transfer layers and WS₂-derived shear bands occurred along the sliding interface. Conclusions: The above results emphasize that the in-situ formed composite structure provides a synergetic lubrication effect for the maintenance of a superlubricity state in harsh contract conditions. These findings clarify the mechanisms underlying the in-situ formation and ordering of multiple lubricating phases, enabling superlubricity under ultra-high contact pressures.