新型宽温域自润滑复合薄膜的可控制备、构效关系及机理研究

In view of the issues on the controllable preparation of composite lubricating films with the designed morphologies and microstructure, as well as the structures-lubricating properties relationship in wide temperature range，the design fabrication, tribological behavior and lubrication mechanism in wide temperature range were investigated. The lubricating composite films that constitute of hard ceramic and low-, medium-, high-, temperature lubricating phases would be prepared by using the pulsed laser deposition (PLD) techniques, through the films composition designing and deposition-process-controlling. It is expected the deposited composites films with the dense polycrystalline or amorphous structure where the multiple lubrication phases in the form of nanoscale equiaxed grains would be uniformly dispersed in matrix phase. The effects of the components and deposition parameters on crystal structure, phase distribution, morphologies, grain sizes and tribological properties of the composite lubricating films would be investigated by mean of morden analytical tools, so as to reveal the relationship between the microstructure and tribological properties of the composite films. The principles of the synergistic effect of multi-lubricating phases and tribochemical reaction, the lubricating mechanisms in wide temperature range would be explored and clarified. Ultimately, the new self-lubricating in wide temperature range composite films with designed microstructure would be fabricated. This project would not only enrich and improve the theoretical knowledge of controllable design of tribology composite films, but also furnish a theoretical and technical reference for the exploration of new self-lubricating composite films.

针对复合润滑薄膜中特定组织形态、微观结构的可控制备及其结构与薄膜宽温域润滑性能的构效关系问题，开展陶瓷基自润滑复合薄膜的设计制备、宽温域摩擦学行为及润滑机理研究。利用脉冲激光沉积技术研制以硬质耐磨陶瓷为基体复配低、中、高温润滑相的复合薄膜，通过组分设计和工艺调控，以期获得多种润滑相以纳米尺度等轴晶粒均匀弥散分布于基体相中的多晶组织或非晶结构，考察薄膜组分与沉积工艺对复合薄膜相结构、元素分布、组织形态、晶粒尺寸及性能的影响，研究复合薄膜微观组织结构与摩擦学性能之间的构效关系，探讨多相复配的协同效应及摩擦化学反应对薄膜润滑性能的影响机制，阐明复合薄膜宽温域下的润滑机理，最终制备出具有特定组织结构的宽温域自润滑复合薄膜。本项目将丰富和完善摩擦学复合薄膜的可控设计与制备理论，为新型宽温域自润滑复合薄膜的开发与探索提供理论依据和技术参考。

本项目针对润滑复合薄膜中组织形态、微观结构及其与薄膜宽温域摩擦学性能的关系问题，采用脉冲激光沉积技术制备了TiN/MoS2/Ag、VN/Ag和Mo–V–Ag–O等一系列纳米结构复合薄膜，研究了沉积工艺、润滑相对复合薄膜组织结构和力学性能的影响，阐明了复合薄膜在宽温域内的润滑机理。主要结果如下：.1.与纯TiN薄膜相比，由于润滑相MoS2、Ag的复配使得TiN/MoS2/Ag薄膜的力学性能明显降低。薄膜在低温时段主要依靠MoS2和Ag的协同润滑作用而具有很小的摩擦系数，在0.05-0.1之间；在高温时段通过摩擦化学反应生成了高温润滑相-TiO2、MoO3、钼酸银起到了协同润滑作用，显著降低了薄膜在高温时段的摩擦系数。.2.室温下所沉积的VN薄膜呈较为疏松的柱状晶组织；而300℃下沉积的VN薄膜呈致密的等轴晶组织，相比之下后者具有较高的力学性能，在宽温域内具有优异的摩擦学性能。随着试验温度的升高，VN发生连续的氧化并生成了一系列具有润滑特性的Magnéli相氧化钒，这些氧化物使薄膜的摩擦系数随温度的升高而降低。.3.制得了fcc-VN和fcc-Ag纳米晶共存的VN/Ag纳米结构复合薄膜，随着Ag含量的增多，薄膜的力学性能逐渐降低。含Ag量为16 at.%时薄膜的摩擦学性能最佳，COF从室温下的0.3连续降低至900℃时的0.08。低温下，Ag改善了VN/Ag复合薄膜的摩擦学性能并起到主导润滑作用；当温度在500℃及以上时，通过高温摩擦化学反应所形成的氧化钒(V2O5、V6O11、V6O13)以及钒酸银(Ag3VO4、AgVO3)对VN/Ag复合薄膜的协同润滑起到关键作用，实现了VN/Ag复合薄膜在宽温域内的连续润滑。.4.较高的基底温度可减少Mo-V-O-Ag纳米结构复合薄膜的内部缺陷并提高薄膜的力学性能。当摩擦温度从RT升高到500℃时，复合薄膜的摩擦系数由室温下的0.91降低到500℃时的0.24，主要归因于VnO2n±1、MoO3、AgVO3和Ag2Mo2O7的协同润滑作用。. 经过4年的工作，完成了研究目标，取得的结果为宽温域润滑复合薄膜的研发提供了有价值的理论依据和技术参考，并有望在高温机械摩擦磨损防护领域获得应用。在国内外学术期刊上发表论文14篇，其中SCI收录13篇，申请国家发明专利4项，培养年轻教师晋升副教授3名、研究生3名。