钛表面基于非晶微通道输运TiSiN/Ag（Cu）涂层精细结构演化及磨蚀污损协同抑制机理研究

In order to improve poor wear resistance and biofouling resistance of titanium metal in seawater, the super hard TiSiN/Ag(Cu) coatings have been designed and prepared based on the contact stress simulation calculation, cooperative multiscale structure, surface/interface optimization and nano slow release by ion plating and magnetron sputtering. The coatings with low toxicity, environmental protection and high efficiency have an excellent tribocorrosion resistance and biofouling resistance. The tribocorrosion dynamic law and interaction mechanism of wear and corrosion were studied based on the analysis from the macro, micro and nanoscale levels by the high throughput test from in situ multi-channel of tribological behavior and electrochemical information. The size effect and self-healing mechanism of the crack during the tribocorrosion were revealed. The evolution of the fine structure were controlled based on amorphous micro-channel transport of Ag(Cu), and mechanism of its controlled release was studied. The effect and mechanism of tribocorrosion on the release of Ag(Cu) were investigated. It is revealed that the chemical mechanism of curing process for the fouling on the coating surface, competition between biological-material-seawater multiple interface and nature law of the role of antifouling coatings. The tribocorrosion resistance and antibiofouling properties of the TiSiN/Ag(Cu) coatings were collaborated and optimized. The results will expand the synergy theory of the biofouling and tribology for the hard coatings in marine environment and provide technical support for the manufacturing capability of the key components of the engineering equipment in hash marine environment.

本项目针对海洋环境用钛金属易生物污损和耐磨性差的瓶颈问题，基于接触力学计算模拟、跨尺度结构协同、表界面优化和纳米缓释技术，结合离子镀与磁控溅射技术特点实现耐磨蚀、低毒环保和高效长效TiSiN /Ag(Cu)防污涂层的可控制备。从宏观-细观-微纳米等多角度切入，通过摩擦学行为与电化学信息原位多通道高通量试验，研究涂层摩擦与腐蚀协同作用的规律和机制，阐明磨蚀微裂纹萌生和自愈合的尺寸效应、动力学行为和机制。基于非晶微通道输运调控涂层精细结构，研究Ag(Cu)的微量可控释放规律及其纳米缓释机制，探讨磨蚀对其释放的作用规律和机制。明确污损生物在材料表面固化结合过程中的化学作用机制，阐明生物－材料－海水多重界面作用下的竞争关系，揭示涂层防生物污损作用的规律和本质。研究结果将拓展海洋环境超硬功能涂层生物污损和摩擦学协同作用理论，为全面提升我国严酷海洋环境中装备关键部件核心制造能力提供技术支撑。

采用多弧离子镀技术沉积制备了TiSiN与Ag（Cu）复合涂层。发现TiSiN-Ag（Cu）共沉积涂层中Ag（Cu）元素在涂层表面出现严重聚集现象，不利于涂层的耐磨蚀和长效抗菌性能。为此设计了TiSiN和Ag（Cu）多层结构涂层，利用TiSiN层非晶与纳米晶复合结构的阻隔可实现Ag（Cu）的缓慢释放实现长效抗菌性能，通过Ag的含量和分布调控减小对TiSiN超硬层的力学性能的影响。TiSiN/Ag多层涂层的硬度达到了35.9 GPa，TiSiN/Cu多层涂层最高硬度可以达到40GPa。通过计算发现Ag在两相界面上的扩散系数最小为0.1545 eV，Ag主要通过Si3N4或TiN两相界面运动扩散。涂层中Ag释放速率测试发现释放量在三天的数量非常大，第8-15天之后趋于稳定，释放量维持在一个非常低的值，但仍具有很好的杀菌效果。Ag原子在退火过程中扩散到TiSiN/Ag涂层中的微裂纹位置，实现TiSiN/Ag涂层的微裂纹自修复，微裂纹愈合后的涂层仍具有良好的耐腐蚀及抗海藻贴附性能。海水中摩擦状态下TiSiN/Ag涂层出现磨损与腐蚀交互作用，当材料外加电位越正，磨损腐蚀交互作用量越高，主要损耗形式为腐蚀对磨损的促进。功能因子Ag和Cu元素的引入使TiSiN涂层具有优异的防生物污损能力，涂层中释放的Ag（Cu）可有效杀死微生物和抑制海藻的生物污损腐蚀。浸泡藻液后的TiSiN涂层的磨蚀率增大，是未浸泡时的1.48倍。TiSiN/Ag(Cu)涂层的磨蚀率没有明显增加，还略有降低。Ag（Cu）功能因子的引入可以显著提高涂层的抗生物污损和磨蚀协同损伤能力。