基于纳米结构AgTMxOy的原位分解和摩擦诱导再生设计高强度镍铝基温度自适应润滑复合材料

In view of the difficulties in the design of lubrication materials with high strength and temperature-adaptive lubricating function in wide temperature range, the design and fabrication of elements-reinforced NiAl-based temperature-adaptive lubricating composites were proposed by incorporating nanostructured silver-containing ternary oxide (AgTMxOy), utilizing the design ideas of in-situ decomposition of the AgTMxOy phases through solid phase reaction in hot pressing process and regenerated by friction-induced chemical reaction. The physical and chemical processes of the friction-induced regeneration of AgTMxOy phase in a wide temperature range, as well as the intrinsic link between the lubricating films generated by friction reactions and tribological properties of material would be systemically investigated. The influences of the strengthening phases, morphologies and sizes of nanostructured AgTMxOy phases on the in-situ decomposition and friction-induced regeneration of AgTMxOy at different temperatures would be expounded. The mechanisms of the interaction between alloying elements, nanostructured AgTMxOy and the friction-induced chemical reaction products, as well as the preparation process on the mechanical and tribological properties of composites materials in wide temperature range would be clarified. The principles of design and construction of lubricating composite materials with high strength and temperature-adaptive lubricating function in wide temperature range would be proposed. This project would provide a theoretical basis and data support for the development of temperature-adaptive lubricating materials, enrich and develop the theoretical system of solid lubricating materials, which would be of scientific significance and application value of engineering.

针对宽温域润滑复合材料的强度和温度自适应润滑功能设计的难点，提出以NiAl金属间化合物为基体，通过引入纳米结构含银三元氧化物（AgTMxOy），利用其在热压过程中的原位固相反应分解及摩擦诱导再生的设计思想，制备合金元素增强的NiAl基温度自适应润滑复合材料；系统研究AgTMxOy相在宽温域摩擦中再生的物理化学过程及其摩擦反应润滑膜与材料摩擦学性能之间的内在联系，探索不同温度下强化相及纳米AgTMxOy相的形态、尺寸对AgTMxOy原位分解和摩擦诱导再生的形成和分布的影响；阐明合金元素、纳米AgTMxOy、摩擦化学反应产物及其之间的交互作用和制备工艺对材料在宽温域内机械性能和摩擦学性能的影响机制；提出宽温域内具有高强度和温度自适应润滑功能的复合材料设计组配原则；为发展温度自适应润滑材料和技术提供理论依据和数据支持，丰富和发展固体润滑材料的理论体系，具有重要的科学意义和工程应用价值。

高温等极端工况环境中的机械设备及其零部件的摩擦磨损与润滑问题一直是摩擦学和材料学领域的研究前沿和热点。以先进发动机为代表的高温机械，对宽温域（室温～1200℃）具有稳定可靠连续润滑性能的高强度、轻量化材料提出了更为迫切的需求。目前国内外相关相关宽温域连续润滑复合材料的强度设计和相界面控制研究却鲜有文献报道，更缺乏系统深入的研究。本项目通过固溶强化、弥散强化的复合强化机制制备高强NiAl基体；利用水热反应制备不同纳米结构形态的AgTMxOy，通过AgTMxOy相热压原位分解的低温润滑相Ag与金属氧化物，改善材料的界面相容性，进而提高复合材料的强度；同时利用复合材料在高温摩擦过程摩擦化学反应再生高温润滑相AgTMxOy的复配及协同，实现材料在宽温域内力学性能和摩擦学性能的优化。制备了NiAl-不同纳米形态钼酸银（纳米线、纳米棒、纳米颗粒）、NiAl-AgNbO3、NiAl-Ag2Nb4O11、NiAl-AgNbO3/AgVO3等复合材料体系，考察了其显微组织结构和宽温域内的力学和摩擦学性能及相关机理，研究了AgTMxOy相分解和摩擦诱导再生的机理。研究发现，钼酸银纳米线的添加较纳米棒和纳米颗粒可明显提高复合材料的力学性能和摩擦学性能，同时发现AgNbO3和AgVO3复配显著提升NiAl的密度和显微硬度等力学性能，其高温下的磨损率较单独添加AgNbO3和AgVO3分别降低了约80%和92%，归因于摩擦诱导重生的AgNbO3和Ag3VO4共同的润滑作用使得NABV复合材料800 ℃的摩擦系数和磨损率都最低。提出了宽温域内具有高强度和自适应润滑性能的材料的设计构筑原则和与配方体系相适应的关键制备技术。本研究为发展我国航空、航天等国家战略高技术领域迫切需求的新型宽温域高强度连续润滑材料积累理论数据和技术支持，对丰富和发展高温固体润滑材料的理论体系，具有重要的科学意义和工程应用价值。