航空发动机材料摩擦学研究进展

Advances in Tribology of Aero-Engine Materials

机械产品中的摩擦磨损问题不可避免,且严重影响装备性能与寿命可靠性。航空发动机是飞机的心脏,针对该类复杂机械产品的摩擦磨损问题更应得到高度重视.通过材料摩擦学行为调控,可有效减轻或排除航空发动机中的摩擦磨损问题,大幅抑制发动机功能精度衰减,提高其寿命稳定性.为系统有序地开展航空发动机材料摩擦学研究,在本文中以典型三代涡扇发动机为例,按冷端至热端结构顺序,阐述进气道、风扇、中介机匣、压气机、燃烧室、涡轮和尾喷口等关键部位涉及摩擦磨损部件及材料的摩擦学服役工况、主要磨损类型和磨损机制.结合发动机整机故障分析结果,有针对性的选择4种具有代表性的航发材料作为摩擦学重点研究对象,即叶片尖端与封严涂层的高速刮擦、主轴轴承滚动接触疲劳与滑擦损伤、钛合金叶片的微动损伤、动密封装置中石墨的摩擦磨损及其寿命评价台架试验.从材料摩擦学损伤演变规律、磨损机制、耐磨功能设计和表面改性等角度综述国内外研究进展,提出航发材料摩擦学研究技术路线,即从材料级摩擦磨损实验复现航发零件磨损失效特征出发,实现基于摩擦学行为调控原理获得材料耐磨减摩功能化改进,最终采用模拟工况摩擦学实验台架验证新材料摩擦磨损性能.此外,针对新一代航空发动机对材料耐磨减摩性能的更高要求,从宽温域润滑、腐蚀-磨损交互作用和新材料摩擦学数据库等方面展望航发材料摩擦学研究发展方向.

Tribological problems are inherent in mechanical systems and have significant implications for their performance and reliability.The complicated aero-engine requires special attention to the friction and wear as the heart of the aircraft.Effective control of material tribological behavior is a potent strategy for mitigating wear in aero-engines.This approach not only minimizes the tribology damage but also inhibit precision degradation,ultimately enhancing the long-term stability and reliability of aero-engines.This review offers an introduction of the critical frictional couples found in a classical third-generation turbine engine.These frictional couples span the spectrum from the engine's low-temperature sections,such as the air inlet and fan,through to the high-temperature sections,including the intermediate casing,compressor,combustion chamber,and turbine,among others.The operation condition,tribology mechanism and failure severity of these wear components are introduced.The selection of the four key research areas in aero-engine tribology was based on the failure analysis of the aero-engine.They are the high-speed rubbing of blade tip against seal coating,the rolling contact fatigue and sliding damage of the main shaft bearing,the fretting damage of titanium alloy blade,and the friction wear and bench test of graphite of dynamic sealing device.All these research areas are reviewed from various perspectives,including the evolution of material properties related to tribology behavior,wear mechanisms,wear resistance,and surface modifications.The research roadmap for the aero-engine materials tribology is proposed.Initially,the wear failure characteristics of the damaged components should be reproduced by tribology test from the material-level tribology test.Subsequently,the improvement in friction reduction and wear resistance of the materials would be achieved by the investigation on wear mechanism.Finally,the tribology performance of the optimized material is validated on the simulated condition tribological test rigs.Furthermore,the development trends in the research of aero-engine materials tribology are briefly outlined,including wide-temperature lubrication,corrosion-wear interactions,and material tribology databases due to the higher demands on material performance for the next-generation aero-engines.