纳米织构化二硫化钨基润滑薄膜的可控构筑及其摩擦学性能研究

Surface texturing has been recognized as an effective means of surface engineering to improve tribological properties of sliding surfaces. Based on the objective to improve the wear resistance of the lubricating films and to utilize the textured structure to store and to repair the lubricants of the lubricating films, in this project, we scheme to prepare WS2-based textured lubricating films by sputtering WS2 film onto the electrodeposited Ni nanocone arrays with stainless steel as substrates. Through the optimized design, the prepared lubricating films could show good wear resistance due to the high hardness of the electrodeposited Ni. Meanwhile, the Ni nanocones could play a role in storing as well as repairing the WS2 lubricants. Both will lead to an improved tribological performance of WS2 lubricating films. Further, textured metal doped WS2 lubricating films can be prepared by co-sputtering towards improving the tribological properties in ambient conditions or in humid air. The role of Ni nanocones on the growth of WS2 as well as the nano-textured structure on the tribological properties will be clarified by corresponding characterization analysis. The microstructure and the synergistic effect of Ni nanocones and WS2 films on the tribological properties will be explained deeply. The influence of Ni nanocone textured structure as well as lubricant storing and repairing on the nano-textured WS2 based lubricating composite films will be interpreted deeply. Finally, it will provide a new way to design and prepare nano-textured lubricating film materials for applications.

基于润滑薄膜的纳米织构化的设计理念，兼顾薄膜耐磨性的提高以及织构结构对润滑剂的储存和修复作用，在不锈钢基体上采用电化学沉积镍纳米锥阵列结构，之后溅射沉积WS2润滑薄膜，制备纳米织构化WS2基润滑复合薄膜。重点突破纳米织构化WS2基润滑薄膜体系的可控构筑，设计制备出可以同时发挥硬质金属镍的耐磨性能和纳米织构对WS2润滑剂的储存和修复功能，以实现WS2润滑薄膜摩擦学性能的提高。并进一步对WS2薄膜进行金属（Ti、Ni等）掺杂，以实现纳米织构化WS2基润滑薄膜在大气、湿度条件下的润滑稳定性以及耐磨寿命的提高。阐明镍纳米锥阵列结构对WS2薄膜生长的作用机制和织构化结构对润滑薄膜摩擦学性能的作用，揭示纳米锥结构、WS2薄膜的微结构以及两者之间的协调对其摩擦学行为的影响，深度诠释织构化结构、润滑剂储存和修复对WS2基润滑复合薄膜性能的作用机制，为高性能的纳米织构化润滑薄膜材料的设计和制备提供新的途径。

在航空航天系统中，机构运动部件表面的减摩耐磨性能对整个航天系统的运行稳定性具有决定性的影响。特别是在空间环境条件下的特殊工况，迫切需要具有适合多重环境的长寿命新型固体润滑材料以适应快速发展的航天科技。本研究针对空间环境润滑性能较好的WS2润滑材料，研究了金属掺杂对二硫化钨薄膜摩擦学性能的影响，提出通过纳米织构化设计，制备了纳米织构化二硫化钨固体润滑薄膜，提高薄膜的润滑稳定性及薄膜的润滑寿命，并对织构化结构对薄膜的润滑性能的作用机制进行了阐述。结果总结如下：.1. 采用射频共溅射方法开展了WS2-软金属复合薄膜的制备及其微观结构和摩擦学性能的研究。结果表明，添加金属Ag在一定程度上诱使了WS2柱状晶的细晶化，Ag含量优化后的WS2-Ag复合薄膜在真空及潮湿大气环境下的润滑寿命得到了显著提高。WS2-Cu复合薄膜在金属Cu含量较低薄膜具有疏松结构，随着金属Cu含量的增加，WS2基薄膜的非晶化与致密化程度均逐渐升高。在摩擦过程中，两类复合薄膜经历了不同的摩擦磨损机制，然而均有利于发挥WS2基质的低摩擦、高耐磨特性。.2. 采用电化学沉积技术制备了结构可控的Ni纳米锥阵列结构，之后采用射频磁控溅射技术制备了织构化的WS2-Ni薄膜。由于薄膜与基体结合强度较低，我们进一步开发了采用物理气相沉积技术实现纳米织构薄膜的构筑。采用中频磁控溅射技术，制备了不同表面结构的CrN硬质薄膜。研究发现，通过控制薄膜沉积过程中的Ar和N2的流量比，可实现CrN薄膜在（111）方向的优先生长，而CrN自身的柱状晶生长模式进一步促进薄膜表面形成了纳米锥状阵列结构。通过在纳米锥状阵列结构表面的CrN薄膜表面溅射沉积WS2润滑薄膜，制备了纳米织构化二硫化钨固体润滑薄膜。摩擦学试验结果表明，所制备的织构化二硫化钨润滑薄膜摩擦学性能相比纯二硫化钨薄膜有了显著提高，摩擦寿命提高两倍，这主要归因于CrN纳米锥状阵列结构提高了WS2与基体材料的结合强度，同时起到了对润滑剂的储存和修复作用。