海水环境下金属表面微纳织构疏水化的摩擦学效应及机理的研究

Metal and its alloys are of great technological importance for a number of applications in industry and in consumer goods, due to their combination of mechanical properties and chemical stability under aggressive environments. However, tribocorrosion occurs when alloys are involved in a sliding contact in the marine environment. In this project, the hydrophobic surfaces are proposed to prevent direct contact of metal surface with seawater, thus improving the corrosion resistance and the tribological properties of alloys. We focus on the design and fabrication of hydrophobic surface with low friction and long duration on stainless steel and titanium alloy. The friction-reducing and wear resistance performance of hydrophobic surface under seawater is evaluated. The relationship between the dynamic wetting properties of hydrophobic surface with its tribological effects is investigated. The project is including the following 3 parts, 1) the methods used to produce optimal hydrophobic effect, 2) the effect of surface texture on mechanical durability of hydrophobic surface, and, 3) the non-wetting mechanism of hydrophobic surface in reducing friction and wear under seawater. After the project, we hope to establish a new insight of using hydrophobic films to reduce tribocorrosion of metal materials in the marine environment.

针对金属材料在海水环境下易发生腐蚀磨损的问题，提出了在金属基体上构筑疏水表面阻止海水与表面的直接接触、改善材料耐腐蚀性能和提高减摩抗磨性能的研究思路，其核心理念是在不锈钢及钛合金两种基体上设计和构筑低摩擦、长寿命的疏水表面，研究海水润滑下疏水表面的减摩、耐磨特性，探讨摩擦过程中疏水表面的润湿状态的动态变化规律以及与摩擦学性能之间的相关性。研究内容包括：1）金属基体上疏水表面的理论设计和工艺制造及控制技术；2）表面微纳结构对疏水表面的水下稳定性及机械稳定性的有效调控；3）海水润滑下疏水表面的非润湿减摩、耐磨作用机制的研究。本项目的研究成果为在金属基体上设计并制备减摩、耐磨表面提供一种新思路，期待为减少金属材料在海水环境下的腐蚀磨损做出一点具有实际意义的贡献。

在腐蚀性介质中，金属材料由于同时受到力学、化学以及电化学因素及其交互作用而导致严重的腐蚀磨损，在金属材料表面构筑功能性防护薄膜是解决这一问题的关键。本项目提出了在金属材料表面构筑疏水薄膜阻止腐蚀性离子与金属表面的直接接触以同时改善材料耐腐蚀和摩擦学性能的研究思路，重点开展了金属材料表面具有耐蚀、低摩擦和长寿命的疏水薄膜的制备及腐蚀磨损性能的研究，其核心理念在于根据基体金属材料的表面物理化学特性，使用包括化学氧化法、水热法、溶胶凝胶法、化学镀及热氧化法等多种方法在金属表面构筑特定结构的微纳表面织构，然后采用低表面能有机小分子或高分子修饰织构表面，实现对表面润湿性和摩擦学性能的双重调控。实验发现，通过这种方法在多种金属材料表面构筑的疏水薄膜不仅有效阻止了腐蚀性离子与金属基底的直接接触，显著提高基底金属材料的耐蚀性能，更利用了表面微纳织构的减摩效应、低表面能分子薄膜的纳米润滑效应以及他们之间的耦合，在干摩擦及腐蚀性介质中均表现出极为优异的减摩和耐磨性能。研究结果无疑为金属材料在腐蚀性介质中腐蚀磨损问题的解决提供了必要的科学基础与技术途径。