基于摩擦诱导抗菌增强的CrSiCN水润滑涂层的改性及性能研究

Aiming at the problem that the surface of water lubricated parts is easy to be attached by microorganisms in water and the wear rate of CrSiCN coating is high, the project proposes to sudy the modification of CrSiCN based coatings and their tribological, corrosive and antibacterial properties in water environment based on the principle of friction induced antibacterial enhancement. The effect of molybdenum (Mo) and silver (Ag) doping on the microstructure and mechanical properties of CrSiCN is investigated, and then the strengthening and toughening mechanism of CrMoAgSiCN coatings is elucidated. The tribological properties of CrMoAgSiCN cotaings/different friction pairs in different water environments are studied, and the friction and wear mechanisms of CrMoAgSiCN coatings in different water environments are revealed. The electrochemical corrosion properties of CrMoAgSiCN cotaings in differen water environments are investigated, and then the coupling mechanism of friction and corrosion for coatings in water environment is explained. The antibacterial properties of CrMo(Ag)SiCN coatings and their friction surfaces in the different bacterial environments are invertiagted to reveal the influence of Mo and Ag contents on the antibacterial properties of worn surface on the CrMoAgSiCN coatings, and then the mechanism of friction enhanced antibacterial effect is elucidated. Finally, the theory of composition and structure design of water- lubricated coatings in different water environments is put forward .

针对水润滑部件表面易被水中微生物附着和CrSiCN涂层存在磨损率高等问题，本项目基于摩擦诱导抗菌增强原理，提出CrSiCN基涂层的改性及其在水环境中摩擦腐蚀和抗菌性能研究。探讨钼（Mo）和银（Ag）掺杂对CrSiCN基涂层结构和力学性能的影响，阐明CrMoAgSiCN涂层的强韧化机理。研究CrMoAgSiCN涂层/不同摩擦副的水润滑摩擦学特性，揭示CrMoAgSiCN涂层在不同水环境下的摩擦磨损机理。研究CrMoAgSiCN涂层在不同水环境下的电化学腐蚀特性，阐明涂层在水环境中的磨损与腐蚀耦合机制。弄清CrMo(Ag)SiCN涂层及其摩擦表面在不同细菌环境下的抗菌性能，揭示Mo和Ag对CrMoAgSiCN涂层摩擦表面抗菌性的影响规律，阐明涂层的摩擦诱导抗菌增强机理。最后，提出基于摩擦诱导抗菌增强的水润滑涂层成分和结构的设计方法。

随着中国远洋探测和南海诸岛国防防卫需要，我们的海洋装备和航空装备都面临磨损和腐蚀的问题。本项目基于减磨耐蚀与抗菌功能需求，提出了Mo和Ag掺杂改性CrSiCN涂层结构及其摩擦诱导抗菌增强特性研究。随着Mo含量增加至11.85 at.%，CrMoSiN涂层中形成(Cr, Mo)N固溶体，且硬度逐渐增加。由于涂层致密的微观形貌和Mo元素的钝化行为，高Mo含量涂层具有较高的电荷转移电阻和较低的腐蚀电流密度。MoO3和SiO2•2H2O摩擦层的协同润滑，CrMoCN涂层在海水中的摩擦学性能与Mo靶电流成正比。当Mo靶电流为2.5 A时，涂层显示出最高的开路电压、电荷转移电阻和极化电阻。由于固溶强化，低C的CrMoSiCN涂层在Mo含量为10.3 at.%时表现出最优的膜/基结合力和力学性能。高Mo含量增加了摩擦腐蚀协同作用造成的材料损失，但降低了由纯摩擦行为引起的涂层损失。随着钼含量的增加，CrMoSiCN涂层硬度先增后降。当Mo含量为10.1 at.%时，涂层显示最高的硬度为24.8 GPa。当与SiC，Si3N4，ZrO2和Al2O3球在海水中对磨时，Mo含量最高的CrMoSiCN涂层均表现出最低的摩擦系数。在电化学腐蚀后，涂层表面生成含有MoO3和Cr2O3的半透明钝化膜，提高了涂层的耐腐蚀性。在摩擦诱导后，磨痕表面MoO3与水反应生成了水合氢离子和钼酸，能有效地杀灭了大肠杆菌和金黄色葡萄球菌，其抗菌率分别达到98.4%和96.1%。当CrMoN/Ag涂层中Ag含量为1.87 at.%时，涂层最高硬度为25.4±1.4 GPa。涂层的耐腐蚀性随着Ag含量的升高而逐渐减弱，而其摩擦腐蚀特性受力学性能和含Ag润滑氧化物的综合影响。CrMoSiCN/Ag涂层的纳米复合结构中含有(Cr, Mo)N固溶体、Ag纳米晶和非晶SiCNx基质。在Ag靶电流为0.4 A时，涂层硬度增加至最大为21.0±0.7GPa。随着Ag靶电流增加至1.0 A，涂层的摩擦腐蚀损失体积降低。由于在磨痕上形成了具有杀菌作用的MoO3(Mo2O72-)和Ag2Mo2O7摩擦层，CrMoSiCN/Ag涂层显示出摩擦诱导抗菌增强效应。