Case study on the failure analysis of turbojet compressor blades

With a turbojet compressor that had its blades fractured during laboratory tests, this work carried out a failure analysis aiming at characterizing the problem, identifying the fracture mechanism and proposing a potential post-manufacturing improvement. Typical steps of a failure analysis were performed, including visual and fractographic analyzes via stereomicroscopy and scanning electron microscopy. The evidence indicated that the component failed due to fatigue, with the presence of very evident striations on the fracture surface, due to a high surface roughness. Therefore, it was considered suitable to propose a shot peening treatment on the product as a way of inducing residual compressive stresses and hindering the process of nucleation of a fatigue crack.