高性能TiAl基润滑与抗磨材料的设计、制备及摩擦学机理研究

TiAl-based alloys have very important application potential as a kind of new light-weight high temperature structural materials. Now, it is critical to develop lubrication and wear-resistance solutions for TiAl based alloy under vacuum and high temperature conditions etc. The addition of lubricant and anti-wear agent into TiAl alloy is an effective strategy, but there are some critical issues involving the phase reaction between matrix and lubricant, low strength caused by compositing and lacking understanding on the tribological mechanism of TiAl-based alloy. In this proposal, the characteristic of multi-phase or multi-scale for lubricant and anti-wear component, surface treatment of TiAl alloy powder and control of preparation process are employed to realize reaction adjustment and obtain high performance. In more details, we will systematically study (1) construction of the effective criterion for structure/composition design and processing for performance regulation; (2) the friction and wear laws of TiAl alloy and its composites under high temperature and simulated aerospace environments; (3) deeper understanding of lubricating and wear mechanisms of the materials. (4) elucidating the role of frictional surface and interface tribochemistry, structure and mechanical properties evolution on the tribological properties. We expect the significant beneficial outcomes from this proposal that provides theoretical foundation and technical support for lubrication and wear resistance of the TiAl-based alloy in practical applications.

TiAl基合金是新一代航空航天用轻质耐高温结构材料，在实际应用中涉及到高温、真空等苛刻环境下的润滑和耐磨问题亟待解决。设计高性能TiAl基自润滑与抗磨材料是一种有效策略，但存在基体与润滑剂易反应、复合后强度低以及基体摩擦学相关机理认识不足的问题。本项目拟利用润滑抗磨组元和相应前驱体多元多尺度特性、基体粉末表面处理以及制备工艺调控来实现材料组分反应可控和高性能化。揭示材料组成与摩擦学和力学性能之间的关联，构筑组分/结构设计准则和性能调控工艺。通过研究TiAl基合金及其润滑与抗磨复合材料在模拟空间和高温等苛刻环境下的摩擦学行为规律，阐明其润滑和磨损机制，探讨材料摩擦表界面反应、组织结构和力学性能演变的作用机制来指导TiAl基润滑与抗磨材料的设计制备。本项目的成功实施将为TiAl基材料在实际应用中涉及到的润滑抗磨问题提供理论依据与技术支持。

本项目围绕基体与润滑剂易反应、复合后强度低以及摩擦学相关机理认识不足等制约高性能TiAl基润滑与抗磨材料制备等关键科学问题，主要研究内容如下：（1）提出构筑高含量三维网状结构陶瓷相增强TiAl基复合材料，解决复合材料耐磨与强度不兼容这一国际性技术难题，成功制备TiAl-Ti2AlC和TiAl-Ti5Si3两类网状结构材料，掌握网状结构形成机制和关键工艺；（2）设计一种新型自蔓延一步法合成基体@石墨烯核壳粉体，解决润滑剂与基体易反应的问题，成功制备了球形钛@多层石墨烯核壳粉体材料，正在优化球形TiAl@石墨烯核壳粉体制备工艺；（3）在国际上率先开展TiAl基复合材料高温和高温真空等模拟空间环境下的摩擦学性能和机理研究，揭示氧化和复合化元素对材料抗磨损性能和机制的作用规律。本项目的研究将深入认识TiAl基润滑与抗磨损材料的设计制备理论，丰富摩擦学基础知识，为解决航空航天和汽车等领域的新型TiAl基合金结构部件的润滑抗磨问题提供理论依据和技术支撑。