Eddy Current Testing of Surface Cracks on GH4169 Alloy Turbine Disk

GH4169 alloy turbine disk is one of the critical components in hot end of the aeroengine. It is prone to cracks, especially surface cracks which can significantly undermine the quality of disk, resulting in fatigue fracture and thereby catastrophic failures. In this paper, eddy current testing (ECT) of surface cracks was investigated through simulations based on CIVA and experiments. The ECT probes in different configurations and parameters were modelled and impedance curves were computed. The parameter and structure of probe was determined by analyzing the signal decay rate and defect resolution. Following this, experimental investigation was carried out to verify the simulation results. It could be found that experimental results matched well with simulation results and the probe designed via simulations was applicable. The related results from both simulations and experiments are supportive of ECT of surface cracks on GH4169 turbine disk.