基于显微组织演变的涡轮叶片损伤分析

涡轮叶片作为航空发动机和燃气轮机重要的热端部件,在复杂温度场、应力场及氧化腐蚀等环境下工作,面临多种损伤失效风险。为了阐明涡轮叶片涂层损伤模式,总结了现阶段涡轮叶片涂层工艺、特点及其显微组织构成。在结合叶片材料热力耦合试验中相的演变规律研究成果基础上,对服役不同时间和类型的涡轮叶片基体和涂层系统的显微组织进行分析,并与原始组织对比;确定了各种服役组织损伤形式,主要包括涂层系统退化、原始缺陷导致的裂纹扩展、过热损伤及γ′相的退化等;初步给出了涡轮叶片损伤机理和服役环境评估,提出后期涡轮叶片工程化应开展的研究工作和注意事项,从而实现由服役叶片失效后分析向使用前预防的转变,完善涡轮叶片正向设计体系。

Damage Analysis of Turbine Blades Based On Microstructure Evolution

As an important hot section component of aeroengine and gas turbine,turbine blade works in complex temperature field,stress field,oxidation and corrosion environment,and faces a variety of damage and failure risks.In order to clarify the damage mode of turbine blade coating,the process,characteristics and microstructure of turbine blade coating at present were summarized.Based on the research results of phase evolution in thermodynamic coupling test of blade materials,the microstructure of turbine blade substrate and coating system with different service time and type wass analyzed and compared with the original microstructure.Various service damage types were determined,mainly including degradation of coating system,crack propagation caused by original defects,overheating damage and degradation ofγ′phase.The damage mechanism and service environment assessment of turbine blades were given preliminarily,and the research work and matters needing attention for turbine blade engineering were put forward in the later stage,so as to realize the transformation from post-failure analysis of turbine blades to preventive analyses,and improve the forward design system of turbine blades.