某型航空发动机涡轮叶片服役微观损伤研究

Working under the severest condition, turbine blade is the most important and crucial part of aero-engine. The working performance of the whole aero-engine highly depends on turbine blades. Damage inevitably occurs on the turbine blades during operation. As turbine blades are expensive and difficult to manufacture, ensuring the blades work reliably and making full of the turbine blades are important for safety service aero-engine. The microstructural damage in the service process of the turbine blade of an aero engine is investigated and summarized. The results show that the microstructural damage is mainly based on the coarsening and rafting of the precipitate phases. A set of evaluation methods characterized by precipitate phase size is established. Hardness test of turbine blades is carried out. The result shows that with the degradation of microstructure, the hardness in various positions of the blades decreased. Finally, the low cycle fatigue test was carried out at 850℃/810 MPa for different heat exposure conditions of the turbine blade materials. The results show that with the degradation of microstructure, the low cycle fatigue properties of the alloy decreased, indicating that the fatigue resistance of the turbine blade materials declined with microstructural damage.