局部修复热障涂层系统的再役损伤机理研究

Repairing of thermal barrier coating (TBC) system after service is an important part of the whole-life management of gas-turbines. Evaluation method during re-service life is the fundamental basis to judge the quality of local-damage-repaired TBC system. The knowledge on interfacial damage mechanism during re-service life is the key to build the evaluation methods. In this proposal, we aim to understand the damage mechanism of repaired-coating/substrate interface and repaired-coating/undamaged-coating interface in the local-damage-repaired TBC system during re-service life. First, combined with interface fracture mechanics and in-situ high-temperature mechanics experimental methodology, the real-time microstructure evolution of the two interfaces will be acquired. Second, the photo-stimulated luminescence spectrum experiments and indentation tests will be performed for investigation of the two interfaces’ residual stresses accumulation and interface performance degradation behaviors. And then, a numerical model considering interface microstructure evolution, interface residual stresses accumulation and interface performance degradation will be built to illustrate the interfacial damage evolution mechanism. Understanding interfacial damage evolution mechanism will provide theoretical basis for the evaluation method of local-damage-repaired TBC system during re-service life.

热障涂层服役一定时间后需要进行局部修复，这是重型燃气轮机全寿命管理的重要一环。修复后热障涂层的再役性能评价，是确定其能否满足再役要求的基本依据。阐明局部修复热障涂层的双界面（修复涂层/基体界面、修复涂层/未损伤涂层界面）再役损伤机理，是建立其再役性能评价方法的关键。本项目以局部修复热障涂层为对象，开展双界面再役损伤机理研究，结合界面断裂力学理论与原位高温断裂实验方法，获得局部修复热障涂层的双界面微观组织演变行为，揭示双界面残余应力累积与结合性能退化规律，进而构建考虑微观组织演变-残余应力累积-结合性能退化关联性的界面再役损伤数值模型，为局部修复热障涂层的再役性能评价方法提供理论基础。

热障涂层服役一定时间后需要进行局部修复，这是重型燃气轮机全寿命管理的重要一环。修复后热障涂层的再役性能评价，是确定其能否满足再役要求的基本依据。为此，项目组通过三年的持续研究：揭示了重型燃气轮机热障涂层局部剥落诱发的超温损伤机制，探究了热障涂层局部剥落过程中的关键结构参数对其损伤行为的影响；提出了局部剥落热障涂层的结构修复方法，获得了局部修复热障涂层粘接层表面粗糙度对界面TGO应力的影响；提出了局部修复热障涂层再涂覆过程中的涂层热应力检测方法，以及其再服役过程中的热障涂层界面氧化物（TGO）残余应力与界面损伤的检测方法。进一步，在上述研究成果基础上，与东方汽轮机有限公司共同申报了“燃机/航机热障涂层局部损伤评价方法”等3项发明专利，并建立了东方汽轮机有限公司“重型燃机热障涂层损伤容限评价规范”（DB57.18.3-2022），为东方汽轮机有限公司重型燃机热障涂层的工程制备、评价、修复再制造等关键工艺的确定提供了理论依据。相关成果获陕西省技术发明一等奖、机械工业科技进步二等奖等。