Mo-Al-B系可加工陶瓷基高温固体润滑复合材料的制备及其机理研究

To solve the friction and wear issues at high temperatures in the aerospace industry is to be extremely urgent. Therefore, developing novel solid lubricating composites, which combines high-temperature tolerant, anti-oxidation and wear resistant properties, is essential. Novel Mo-Al-B system ceramics possess excellent high-temperature oxidation resistant, high-temperature mechanical and machinable properties, which are suitable for the high-temperature solid lubrication applications. In this project, the machinable Mo-Al-B system would be employed as the matrix of high-temperature solid lubricating composites. The composites, which have superb lubricating properties at a wide temperature rage, would be prepared using powder metallurgy methods by steering the compositions of raw materials, designing the lubricating styles, doping with the reinforcements and optimizing the preparation process. The relationships between microstructure, mechanical and high-temperature tribological properties would be systemically investigated. Besides, in order to shed light on the friction and wear mechanisms as well as the lubricating effects, the tribological behaviors at different temperatures would be also studied. The tribological properties would be further optimized based on the tribological mechanisms of Mo-Al-B system. More importantly, it would provide theoretical supporting and reference values in the high-temperature tribological fields, if this project can be executed successfully.

航天工业等高温苛刻使役环境下面临的摩擦磨损问题亟待解决，因此发展具有优异耐高温、抗烧蚀氧化和抗磨减摩性能且兼具良好高温力学性能的固体润滑复合材料势在必行。新型的可加工Mo-Al-B系陶瓷兼具了陶瓷材料耐高温氧化、高温力学性能优异和金属材料可加工的特点，适宜用作高温固体润滑复合材料的基体材料。本项目拟选用可加工Mo-Al-B系陶瓷作为高温基体，通过调控体系元素组分配比，设计固体润滑方式，复合增韧增强相，优化制备工艺，利用粉末冶金技术制备具备工程应用价值的Mo-Al-B系陶瓷基宽温域固体润滑复合材料。研究材料体系的微观组分、力学性能和高温摩擦学性能的相互关联和作用机制，揭示复合材料体系表界面的宽温域摩擦学行为变化规律，阐明相关摩擦磨损和润滑机理，并以此来进一步指导优化完善复合材料体系。本课题的成功实施对解决高温苛刻工况下复杂形状零部件所面临的摩擦磨损问题具有重要的理论意义与应用价值。

材料在高温使役环境下的摩擦、磨损和润滑问题日益突出，发展具有优异耐高温、抗氧化和抗磨减摩性能的固体润滑材料是够解决高温苛刻工况环境下摩擦磨损问题的有效途径。该项目以Mo-Al-B陶瓷体系为对象，采用粉末冶金方法制备了具有可加工特性的MoAlB陶瓷及其相关复合材料，系统研究了元素组分和制备工艺等参数对材料体系微观结构、力学性能的影响作用机制，获得了多种兼具力学性能和润滑特性的MoAlB陶瓷基固体润滑复合材料。系统研究了复合材料烧结前后的相转变以及微观结构变化，探讨复合材料微观结构和组分对其硬度、压缩强度、弯曲强度以及断裂韧性等力学性能的影响，并通过改善材料的制备工艺来进一步调整材料的微观结构和相组分，达到复合材料力学性能与润滑性能的协同优化。着重考察了宽温域条件下不同配副、载荷与滑行速度对MoAlB陶瓷基固体润滑复合材料摩擦学行为的影响规律，探索复合材料的在不同温度条件下的摩擦学特性，明确复合材料的最佳使役工况；利用多种表征手段分析材料在高温摩擦过程中的物理和化学变化，如摩擦氧化和相变、润滑膜的性质（厚度、覆盖程度）及形成、转移、破裂再生等机制，揭示MoAlB陶瓷基固体润滑复合材料的润滑机理和摩擦磨损机制。相关成果能够为Mo-Al-B系复合材料在高温使役环境下的摩擦学应用提供数据支撑，具有重要的理论参考价值。