海水环境CrC/C固体润滑复合涂层多尺度结构设计与减摩增韧机理研究

Due to the urgent need for the high performance antifriction and antiwear coating materials of the marine engineering equipments and the insufficient research on the tribological behaviors of solid lubricant coating under the seawater-environmental conditions, this project puts forwards to the research and development of the CrC/C solid lubricant composite coating for the seawater application. Combined with the wear-corrosion resistance, high load-bearing of the chromic carbide coating and the excellent self-lubricating property of amorphous carbon materials, the CrC/C coating will possess the properties of low friction, low wear and high load-bearing. Firstly, the different scale structure design of the CrC/C composite coating will be performed by means of first-principles calculation. The chemical bonds in atomic/molecular-scale, the aggregation characteristics in nano-scale and the characteristics of transition interfaces in micro-/nano-scale of the CrC/C composite coating will be controllable fabricated by magnetron sputtering. Furthermore, the structure-activity relationship of the CrC/C composite coating between the different scale structures and the tribological performance under seawater environment will be investigated systematically. Consequently, the cooperation mechanism of antifriction and toughening for multi-scale structure characteristics of CrC/C composite coating will be analyzed prominently. At last, the principle for the multi-scale structure design of the high performance CrC/C composite coating with low friction and low wear for the seawater applications would be deduced. The implementation of this project will not only expand the basic research of the multi-environmental tribological behavior of the CrC/C composite coating but will also provide the scientific basis and technical support for the structure design and preparation of the high performance protective coating applied to seawater-environment.

针对海工装备表面防护问题的迫切需求以及海水环境固体润滑涂层现有基础研究的不足，本项目提出将碳化铬涂层耐磨蚀高承载的优点与非晶碳材料优异的自润滑性能相结合，开发兼具低摩擦低磨损高承载CrC/C固体润滑复合涂层，并深入开展其海水环境摩擦学行为研究。项目从CrC/C复合涂层原子/分子尺度键合结构、纳米尺度团聚特征和微/纳米尺度过渡界面三方面入手，借助第一性原理计算对涂层不同尺度结构特征进行设计,并采用磁控溅射技术实现涂层不同尺度结构的可控构筑。系统研究CrC/C复合涂层不同尺度结构特征与其海水环境摩擦学特性之间的构效关系；重点揭示涂层多尺度结构特征的减摩增韧协同作用机制；最终讨论提出海水环境用高性能CrC/C复合涂层低摩擦低磨损多尺度结构设计准则。本项目的实施不仅能拓展CrC/C复合涂层多环境摩擦学使役行为的基础研究，也将为海水环境摩擦副表面高性能防护涂层的结构设计与制备提供科学基础和技术支撑。

针对海工装备表面防护问题的迫切需求以及海水环境固体润滑涂层现有基础研究的不足，本项目提出将碳化铬涂层耐磨蚀高承载的优点与非晶碳材料优异的自润滑性能相结合，开发兼具低摩擦低磨损高承载CrC/C固体润滑复合涂层，并深入开展其海水环境摩擦学行为研究。项目从CrC/C复合涂层原子/分子尺度键合结构、纳米尺度团聚特征和微/纳米尺度过渡界面三方面入手，结合第一性原理计算对涂层不同尺度结构特征进行设计,并利用复合PVD技术实现涂层不同尺度结构的可控构筑。系统研究CrC/C复合涂层不同尺度结构特征与其海水环境摩擦学特性之间的构效关系；重点揭示涂层多尺度结构特征减摩增韧协同作用机制；最终讨论提出海水环境用高性能CrC/C复合涂层低摩擦低磨损多尺度结构设计准则。本项目所取得的结果主要有：1. CrCN中的C元素以硬质碳化物Cr7C3的形式在晶界区域偏聚形成“富碳”骨架网络，力学性能与耐海水腐蚀性能均有明显提升，同时涂层表面也因碳化物偏聚出现较大的微区硬度差异，承受载荷时应力不连续状态导致其摩擦系数较CrN涂层有所降低，表现出较低的磨损率。通过实验对比，显示出CrCN在水环境下服役的优越性。在海水环境下，梯度CrCN涂层在摩擦过程中对裂纹的萌生及扩展有较强的抑制作用，能有效抵制海水渗透，表现出较好的耐腐蚀性能。 2. 沉积偏压和乙炔流量对MeC/C纳米复合涂层的成分和结构有明显影响，涂层中硬质相MeC和sp3C-C含量随偏压的增加而增加。高偏压下，CrC/C涂层呈nc-C镶嵌多晶CrC结构，涂层的硬度高达43 GPa。通过特殊过渡结构设计，可以改善涂层在海水环境中的摩擦学性能。梯度多层过渡结构能防止涂层因裂纹传播而导致的剥落现象，磨损率降至10-7 mm3/Nm量级。本项目的实施不仅拓展了CrC/C复合涂层多环境摩擦学使役行为的基础研究，也为海水环境摩擦副表面高性能防护涂层的结构设计与制备提供了理论支持。