面向干切削的软涂层纳织构自润滑刀具的基础研究

Combined with the self-lubricating behaviours of the soft coating and the nanoscale surface texturing, the concept, the design method, and some key scientific issues of the self-lubricating dry cutting tools with soft coatings deposited on the nanoscale textured rake face are proposed. The main processes are as following: firstly, nanoscale surface textures are made on the rake face of the cutting tools by femtosecond laser, and then WS2 solid lubricants with low shear strength are coated on the textured rake-face. As the hard wear resistance phases and the soft lubricating phases are coexisted alternately, stable boundary lubricating film will be formed at the tool-chip interface, which can be served as lubricating additive during dry cutting processes, and can contribute to the decrease of the friction between the chip and the rake face. The design theory of the self-lubricating dry cutting tools with soft coatings deposited on the nanoscale textured rake face will be established based on the studies on the coupling mechanisms of the soft coating and the nanoscale surface texturing. By analyzing its cutting perforance, the effect of nanoscale surface textures on the storage and the release of solid lubricants are determined, the formation processes of the lubricating film are analyzed, and the anti-friction model and mechanisms will be also proposed. Finally, this project will provide theoretical foundation for the design and development of new dry cutting tools.

将软涂层和纳织构两种减摩效应有机结合，提出全新的面向干切削的软涂层纳织构自润滑刀具的概念、设计思路和若干关键科学问题。其主要原理是在刀具前刀面刀-屑接触区加工出纳米级织构，在纳织构中沉积WS2固体润滑剂软涂层，制备出软涂层纳织构自润滑刀具，使刀具表面硬质耐磨相与软质润滑相相互交替共存，干切削时在刀-屑界面形成稳定的边界润滑层，达到改善干切削过程摩擦润滑状态的目的。通过对纳织构的设计、纳织构表面沉积固体润滑剂的成形机理、工艺和调控方法研究，建立软涂层纳织构自润滑干切削刀具的设计理论；通过对软涂层自润滑和纳织构自润滑双重功能的耦合作用机制的研究，阐明纳织构对固体润滑剂存储和释放的影响规律，分析刀具表面润滑膜的形成机制及其磨损过程的演变规律，揭示其减摩和抗磨机理，构建面向干切削的软涂层纳织构自润滑刀具的理论和技术体系。为指导干切削刀具的设计和发展新的干切削刀具的润滑方法提供重要的理论基础。

将软涂层和微织构技术相结合，提出了全新的软涂层微织构自润滑刀具的概念和设计思路，研制开发出具有软涂层自润滑和微织构自润滑双重功能的软涂层微织构自润滑刀具。建立了软涂层微织构自润滑刀具切削力和切削温度的理论模型，分析了刀具表面微织构和刀具表面软涂层对切削力和切削温度的影响规律，结果表明：微织构能够减小刀-屑接触长度，软涂层能够降低刀具前刀面刀-屑接触区的平均剪切应力，两者均能降低切削力和切削温度。研究了飞秒激光在刀具表面加工微织构的制备工艺，探索各个工艺参数对加工微织构的影响，成功制备出微织构刀具。系统研究在微织构刀具表面进行固体润滑剂涂层的PVD制备工艺，探索不同涂层工艺参数对软涂层性能的影响，确定了微织构表面进行WS2软涂层的最佳制备工艺参数，制备出了软涂层微织构自润滑刀具。系统研究了软涂层微织构自润滑刀具的摩擦磨损特性和切削性能，阐明了微织构和软涂层对刀具摩擦磨损特性和切削性能的影响规律，揭示了软涂层微织构自润滑刀具的润滑作用机理，即：微织构刀具表面涂覆有软涂层，可在刀-屑界面形成边界润滑层，可减小刀-屑界面之间的摩擦；微织构可减小刀-屑接触面积，降低切削力和切削温度；刀具表的微织构增加软涂层与基体间的接触面积，提高了软涂层的界面结合强度；微织构还能够收集磨损的润滑涂层，进而提供二次润滑。.本课题的相关研究成果已发表基础理论研究论文27篇，其中：国际刊物20篇，被SCI收录20次，获国家发明专利授权5项。本项目研究的理论成果获山东省高等学校优秀科研成果一等奖和二等奖各一项(自然科学奖)；已培养毕业博士生4名和硕士生2名，达到了预期目标。