| 摘要: |
| 二硫化钼（MoS2）薄膜因其独特的结构特征，层间易滑移，作为固体润滑剂在航空航天、核能、机械电子等领域已得到广泛应用。然而，MoS2 对环服役境极其敏感，易在大气、高温等条件下发生氧化，导致其摩擦学性能下降，寿命大幅缩短。为了提高并改善 MoS2 薄膜的环境适应性，采用非平衡磁控溅射技术成功制备 MoS2 / WB2 纳米复合和超晶格结构薄膜。 研究发现，WB2的引入可以促使 MoS2沿（002）晶面择优生长，获得的薄膜表面光滑、结构致密；相比于复合结构，MoS2 / WB2 超晶格薄膜具有更高的硬度（~7.9 GPa）和硬 / 弹比（0.097）。得益于 MoS2（002）晶面沿基底方向的平行排布和纳米多层界面的构筑，MoS2 / WB2超晶格薄膜展现出优异的中性盐雾耐腐蚀性能；特别地，超晶格薄膜在盐雾腐蚀试验前后均保持较低的摩擦因数和磨损率，而复合薄膜经历盐雾腐蚀后摩擦性能大幅衰减。这与超晶格薄膜高的硬 / 弹比和优异的耐腐蚀性能密切相关，有助于对偶球表面形成连续且致密的摩擦转移膜。 |
| 关键词: MoS2 / WB2超晶格薄膜 盐雾环境 耐腐蚀性能 摩擦学性能 |
| DOI：10.11933/j.issn.1007-9289.20231230005 |
| 分类号:TH117；TB37 |
| 基金项目:国家自然科学基金（52375220）. |
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| Tribological Properties and Corrosion Resistance of MoS2 / WB2 Superlattice Structure Films in Salt Spray Environment |
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GAO Zhenrong1，2，LI Jinlong1，REN Siming1
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1.Key Laboratory of Marine Materials, Ningbo Institute of Materials Technology and Engineering,Chinese Academy of Sciences, Ningbo 315201 , China ；2.Collage of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou 310014 , China
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| Abstract: |
| Molybdenum disulfide (MoS2) has been extensively utilized as a solid lubricant in various high-performance industries, including aerospace, nuclear energy, mechanical engineering, and electronics, owing to its exceptional lubricating properties that arise from its unique layered structure that facilitates easy shear between basal planes. However, a major challenge for MoS2 thin films is their inherent sensitivity to environmental conditions, particularly exposure to atmospheric moisture, salt fog, and high temperatures, which can cause oxidation. This oxidation compromises tribological performance and significantly reduces the service life of the films, and thereby, limiting their applicability in harsh environments. To address these limitations, the development of MoS2 based films with enhanced environmental stability is a key research topic. In this study, we successfully synthesized MoS2 / WB2 nanocomposite and MoS2 / WB2 superlattice films using unbalanced magnetron sputtering, a versatile and effective thin-film deposition technique. The primary objective was to enhance the environmental adaptability and mechanical properties of MoS2 films while maintaining their low-friction characteristics. The experimental findings revealed that the introduction of WB2 ot only promoted the preferential growth of MoS2 along the (002) crystal plane, but also resulted in the formation of films with smooth surfaces and dense microstructures. These structural enhancements are crucial for improving the environmental stability and tribological performance of the MoS2 films. Notably, the MoS2 / WB2 superlattice film exhibited superior mechanical properties when compared with its nanocomposite counterpart, with a hardness of approximately 7.9 GPa and a high H / E ratio of 0.097. These properties are primarily attributed to the abundant MoS2 (002) planes aligned parallel to the substrate and nano-multilayer interfaces within the superlattice structure, which collectively contribute to the enhanced resistance of the film to environmental degradation. One of the most significant findings of this study is the remarkable corrosion resistance of the MoS2 / WB2 superlattice film in a neutral salt spray environment. The film maintained a low friction coefficient and wear rate before and after exposure to corrosive conditions. Specifically, the friction coefficient in an atmospheric environment was approximately 0.06, with a wear rate of 1.94× 10–7mm3 / (N·m). After five days of salt spray corrosion, the friction coefficient increased slightly to 0.10, with a wear rate of 7.15× 10–7mm3 / (N·m). Even after ten days of salt spray exposure, the film exhibited friction coefficients of 0.13 and a wear rate of 9.01× 10–7mm3 / (N·m), indicating minimal degradation and exceptional durability. Conversely, the composite film structure showed a significant deterioration in friction performance after a similar salt spray exposure, underscoring the superior environmental stability of the superlattice design. The mechanisms underlying the enhanced performance of the MoS2 / WB2 superlattice film are closely linked to its high H / E ratio and excellent corrosion resistance, which facilitate the formation of a continuous and dense tribofilm on the surface during sliding. This tribofilm, primarily composed of MoS2 nanosheets and metal oxide (MeOx) particles, acts as a protective layer, reducing direct contact at the sliding interface, and thereby, minimizing friction and wear. The persistence of low friction coefficients and wear rates even after prolonged exposure to corrosive environments highlights the potential of MoS2 / WB2 superlattice films for applications under harsh conditions, where high mechanical performance and environmental stability are required. MoS2 / WB2 uperlattice films developed in this study represent a significant advancement in the field of solid lubricants. The combination of high hardness, excellent corrosion resistance, and sustained low-friction performance under corrosive conditions makes these films highly suitable for use in demanding environments, such as aerospace and nuclear energy sectors. The novel approach of integrating WB2 into a superlattice structure with MoS2 not only addresses the environmental sensitivity of traditional MoS2 films, but also opens new avenues for the design of high-performance solid lubricants with enhanced durability and reliability. This study provides a robust foundation for future research aimed at optimizing the composition and structure of MoS2-based nanocomposite films to improve their tribological properties and environmental resistance. |
| Key words: MoS2 / WB2 superlattice film salt spray environment corrosion resistance tribological property |
