Failure analysis of blades and vanes of a compressor for a gas turbine engine

The flame-out occurred during the ground slide for take-off. As a result of immediate disassembly and inspection after failure, damages to blades and vanes were observed from the stage IV of a compressor. In particular, all stator vanes of stages IV and V, five rotor blades of stage V, and a rotor blade of stage VI were failed. In a fractured stator vane of stage IV, a fatigue-fracture surface, which was originated from the tip, appeared. However, the origin of fatigue cracking was not observed due to severe oxidation and wear. In the case of rotor blades at stages V and VI, the fatigue cracking was initiated from the nick damage part. The same nick damage was also observed in the stator vane of stage V, but fatigue cracking started from the convex surface. Comparing the microstructures of sound and fractured products showed that the convex surface of the fractured product had coarser grains compared to that of the sound product. This indicates that the coarse grains led to premature failure by fatigue cracking.