盐溶液中铁基耐蚀金属的摩擦行为机理及调控研究

The rubbing wears of iron-base anti-corrosion metal materials in saline solution environment is a significant factor in determining the quality and life of marine equipment. Studying the friction mechanisms of iron-base anti-corrosion materials and the method of controlling friction is of great value and guidance for the development and application of marine equipment. To the problems in saline solution the friction mechanism of iron-base anti-corrosion metal materials is difficult to be directly clarified and metallic equipment is easy to failure resulted from friction in saline solution. This project presents a new approach that firstly investigating the friction characteristics of iron-base anti-corrosion metal materials in saline solution on the macroscopic and microscopic scales and exploring the chemical and physical properties of the friction interface, and then using numerical computation, finite element modelling and molecular dynamics calculation to analyze the friction mechanism in saline solution. Three methods of metal surface modification, adding different kinds of water-base lubricants and controlling the potential that with alone or combined were used to control the friction behavior of iron-base anti-corrosion metal materials in saline solution, and acquiring the effective way to control the friction of anti-corrosion metal in saline solution. The study on the influencing mechanism of saline solution to friction behavior of anti-corrosion metal and controlling friction actively in saline solution in this project has important guiding significance to the lubrication and the reduction of wear in marine equipment, and contributes to the buildup of marine power.

海水环境中铁基耐蚀金属的摩擦磨损是影响海洋装备质量与寿命的一个重要因素，研究盐溶液中铁基耐蚀金属材料摩擦行为的机理与摩擦控制方法对海洋装备的研发与应用有重要的理论指导价值。针对盐溶液中铁基耐蚀金属摩擦行为机制难以直接探明以及盐溶液中金属装备容易摩擦失效的问题，本项目提出首先在宏观和微观尺度上研究盐溶液中铁基耐蚀金属的摩擦行为并表征摩擦界面，再通过数值计算、有限元模拟分析以及分子动力学分析得出盐溶液中铁基耐蚀金属摩擦行为机制的方法；通过金属表面改性，添加不同类型的水基润滑剂以及控制电位进行单独调控或者共同调控铁基耐蚀金属表面的摩擦行为，获得有效的控制盐溶液中耐蚀金属摩擦行为的方法。本项目关于盐溶液中铁基耐蚀金属摩擦行为的机制以及摩擦主动控制的研究对海洋环境中金属装备的减磨润滑具有重要的指导意义，对加快建设海洋强国起到推动作用。

盐溶液中摩擦副的摩擦行为机理和调控研究是海洋科学、生物医药、水资源利用等领域装备发展的基础研究问题。本项目主要研究内容如下：首先利用NaCl和聚乙烯醇（PVA）以一定的比例混合配置了一款具有极压润滑性能的水基润滑剂，结果显示所配置的水基润滑剂能够在高于700 MPa接触压力下实现稳定超滑，研究表明极压超滑可归咎于混合润滑剂的动压效应以及Na+的水合效应协同作用。乙醇/水的混合溶液能显著弱化磨粒与界面的结合力，使摩擦界面更加清洁，超滑稳定性更好。其次，利用电位控制，在NaCl溶液中实现了SiO2微球与金属电极之间的摩擦行为在高摩擦与超滑之间的快速可逆转换，转换的原因归咎于金属电极界面水分子相结构的转变。通过摩擦二项式拟合，确定了正电位下的高摩擦由界面氢键作用引起，正电位下摩擦力和载荷的非线性关系由界面梯度分布的氢键强度引起。不同电性的SiO2微球均展现出同样的电控摩擦规律，但摩擦机制有所差异。另外，利用等离子喷涂的方法在金属表面制备了一种金属/有机复合涂层，涂层表面的低表面能使涂层具有一定的疏水和抗磨特性。涂层表面的“绒毛”状纳米结构是由熔融有机颗粒被高速飞行的金属氧化物挥发物打碎所致。本项目一系列的研究对金属界面科学的发展以及设计可控金属摩擦器件有重要的理论意义。