外场诱导非晶碳膜中程有序纳米结构的生长、调控及与性能相关性

Amorphous carbon films as a new generation of solid lubrication material, can exhibit very low friction coefficient (<0.01) under specified conditions, and has a wide application prospect in high-tech fields. In recent years, it has been found that special medium range order structure endows the carbon films with some excellent properties, such as high hardness, high elastic recovery and low wear, which would be the ideal way to overcome the disadvantages of brittleness, short service life of carbon films. However, how to design and controllable growth of specific medium range ordered structure in carbon films is not properly addressed. In this application, a new method is introduced to grow and control the specific medium range ordered structures in carbon films based on the out-field (including catalysis and plasma action) induced growth effect, which have been found during the target poisoning process in our early study. Firstly, the type, size and sputtering parameters of the metal target are important factors during the processes of catalytic precursor formation and then precursor sputtering, so the correlations of these factors and the microstructure of the precursor and as-prepared carbon film are investigated systematically in oreder to clarify the formation mechanism and control principle of the medium-range order structure. Secondly, the effects of the type, quantity and size of the nanostructure on the hardness, toughness, wear life of the carbon films are studied, and the relationship between the medium-range order nanostructure and properties of carbon films are further revealed. This research will improve the level of understanding of the nature of the structure and performance of amorphous carbon films, and have important theoretical value and guiding significance to further design microstructure, improve performance, and promote the practical application of amorphous carbon films in high-tect fields.

非晶碳膜作为一种在特定条件下摩擦系数极低（<0.01）的新一代固体润滑材料，在高技术领域具有广阔的应用前景。近年来，人们发现特殊中程有序结构可以赋予碳膜强韧一体化、低磨损等特性，是克服其脆性大、寿命短缺点的理想途径，然而如何设计并可控制备具有特定中程有序结构的碳膜，还没有妥善解决。本项目提出采用金属靶外场诱导生长碳膜的制备方法，基于我们在靶中毒现象中发现的靶面催化与等离子体共诱导生长效应，通过控制靶材种类、靶面形态调节靶面前驱体的纳米结构，进而实现碳膜特定中程有序结构的可控生长。研究制备参数对前驱体及薄膜微观结构的影响，获得外场诱导中程有序结构的调控规律；研究中程有序结构原子排列方式、数量及尺寸对薄膜力学、摩擦学性能的影响，揭示薄膜中程有序结构与性能的相关性及作用机理。本研究对于认识碳膜材料结构和性能的本质、建立结构设计与调控新原理、并指导性能提升、推动其高技术应用具有重要的理论意义。

非晶碳膜是新一代固体润滑材料，在高技术领域具有广阔的应用前景。近年来，人们发现除了短程有序结构，特殊中程有序结构是决定非晶碳膜性能的关键因素，可以克服其高载易脆以及寿命短的性能缺陷。本项目基于在靶中毒现象中发现的靶面催化与等离子体共诱导生长效应，提出在溅射靶面催化诱导生长纳米结构前躯体，再溅射成膜的制备思路。系统考察了镍、铜、钛以及石墨四类靶材的催化诱导效应，通过靶面形貌、反应气源比、溅射电流、偏压等制备参数的调控，成功实现了石墨烯、富勒烯和碳纳米管三类纳米结构在非晶碳薄膜中的构筑和调控生长，充分验证了所提出的外场诱导中程有序结构生长效应的可行性，阐明了外场诱导中程有序结构的形成机理，建立了调控规律和方法。在此基础上，研究了非晶碳膜中三类纳米结构特征与力学、摩擦学性能之间的相互关系，明确了局域中程有序结构的增韧与延寿机制，结合对石墨烯、富勒烯纳米材料优异真空摩擦学特性起源的研究，揭示了石墨烯、富勒烯结构与优异摩擦学性能之间的关联和摩擦机理，进一步指导中程有序纳米结构设计，实现了碳薄膜的真空耐磨寿命跨数量级的提升，发展出真空、惰性环境中具有极低摩擦系数、长寿命的新型超润滑碳薄膜材料（摩擦系数<0.01、寿命>106转），全面达到并MoS2空间润滑薄膜GJB3032-97摩擦磨损性能指标，建立了碳薄膜在大载、真空等苛刻工况下的延寿新方法和原理，为解决空间领域的特殊润滑问题提供理论基础和材料支持。目前已被中国航天科技集团西安航天精密机械研究所正式确定为《卫星用三浮陀螺关键技术》预研项目中动压气浮轴承的表面润滑材料，经多次地面环境模拟以及寿命考核试验，性能合格，批产供货20余批次，将在航天新型型号装备上获得应用。