Study on the Coupled Creep‐Fatigue Damage Characteristics of Single Crystal Blade Tenons Under High‐Speed Rotation and High‐Temperature Environments

ABSTRACT To investigate the coupled creep‐fatigue damage failure at the turbine blade tenon in aero engines, a high‐temperature rotating test system was developed to simulate the actual service conditions of turbine blades. Creep‐fatigue tests were then conducted using single crystal turbine blades under high‐speed rotation and high‐temperature conditions. Cracks occurred in the tenon region under the interaction of creep and fatigue, with the crack initiating at the root of the first‐stage tenon teeth. Fractographic and stress analysis considering the anisotropy of the single crystal alloy revealed that high‐stress cyclic loading was the primary factor leading to the failure of the tenon region, while creep also contributed to the damage. The creep‐fatigue damage characteristics of blade tenons were analyzed using the Smith–Watson–Topper model and the Larson–Miller model based on the critical plane method. The critical location and creep‐fatigue life were determined, showing good agreement with test results.