极端环境下服役自润滑结构陶瓷的构建与寿命评估

Lubrication under extreme environments has been the key factors to affect the security, high efficiency and stable operation of mechanical system and restrict the development of high-end equipment. The project proposes to realize the performance improvement of ceramic matrix self-lubricated composites based on the bionic design, interface regulation and matrix toughening. Two kinds of self-lubricated structural ceramics that can be suitable for harsh marine environments and ultra-high temperature conditions will be developed, respectively. The reliability control and life prediction of self-lubricated structural ceramics under extreme environment will be studied. The investigation mainly includes the following three respects. First of that is to realize the reliability control of the materials under extreme environments using design and optimization of their macro/micro structures. The influence and control method of macro/micro structures on the properties of materials will be investigated. Second of that is the conducting of friction and wear tests under extreme environments. The rule of service behavior and performance evolution of the materials will be investigated and their performance evaluation system and database will be also established. Third of that is to determine the control factors of material failure, and further to model the theory and method of life prediction, early detection of failure and life assessment of key parts and materials served in extreme environments based on finite element simulation and analysis of performance degradation. The investigation can provide a basis for the lubrication design of high-end equipment parts, which has great significance on the solution of lubrication failure under extreme environments and expanding the application of structural ceramics.

极端环境下的润滑问题已成为影响机械系统安全、高效、稳定运行和制约高端装备发展的关键因素。本项目提出采用仿生设计、微界面调控和基体强韧化来实现陶瓷基自润滑复合材料的性能提升，构建适用于恶劣海洋环境和超高温工况服役条件的自润滑结构陶瓷。拟开展自润滑结构陶瓷在极端环境下的可靠性控制与寿命预测研究，主要包括三个方面：其一，基于材料宏/微观结构设计与优化，实现其在极端环境下的可靠性控制，并研究宏/微观结构对材料性能的影响规律和控制方法；其二，开展极端环境下材料的摩擦磨损试验，研究材料的服役行为和性能演变规律，建立完善的性能评价体系及数据库；其三，确定导致材料失效的控制因素，基于性能退化过程分析和有限元仿真模拟，提出其在极端环境下寿命预测、失效早期监检测、材料与关键零部件的寿命评估理论和方法，为高端装备机械部件的润滑设计提供依据，对解决极端环境下的润滑失效问题和拓展结构陶瓷的应用领域具有非常重要的意义

极端环境下的润滑问题已成为影响机械系统安全、高效、稳定运行和制约高端装备发展的关键因素。本项目开展的主要研究内容包括三个方面：其一，基于材料宏/微观结构设计与优化，实现其在极端环境下的可靠性控制，并研究了宏/微结构对材料性能的影响规律和控制方法；其二，开展了极端环境下材料的摩擦磨损试验，研究了材料的服役行为和性能演变规律，建立了自润滑结构陶瓷评价体系；其三，确定了导致材料失效的控制因素，结合性能退化过程分析和数值计算，提出了其在极端环境下的寿命评估方法。基于上述研究，本项目采用仿生设计和微界面调控，构建出系列适用于强腐蚀（海水、强酸强碱）和超高温工况服役条件的自润滑结构陶瓷，深入研究了材料在极端环境下的服役性能，阐明了自润滑结构陶瓷在极端环境下摩擦磨损和性能退化机理，并揭示了材料成分、宏/微观结构与摩擦磨损性能之间的关系规律，建立了自润滑结构陶瓷的性能评价体系及寿命评估技术。其中，Al2O3/Mo层状自润滑复合陶瓷的表观韧性和抗弯强度分别可达8.1MPa∙m1/2和634MPa，经1000°C/25°C温度下的50次循环热震后，材料的韧性和抗弯强度保持率分别可达98.8%和85.3%，并且在800 °C与Al2O3陶瓷对摩时的摩擦系数可低至0.43。此外，通过对PcBN/hBN纤维独石结构复合陶瓷的磨损量和磨损率的大量测试，拟合出了材料磨损体积和磨损率随时间变化的曲线，根据磨损体积随时间的演变规律及其对应关系，初步预测和评估了其服役寿命。以上研究成果可为机械部件的润滑设计提供依据，对解决极端环境下的润滑失效难题和拓展结构陶瓷的应用领域具有重要意义。