Inspection of Aircraft Engine Components Using Induction Thermography

Abstract

Induction thermography technique is assessed experimentally on aircraft engine parts with fatigue cracks using a three-loop coil. Results show that induction thermography can detect cracks in engine parts, with inspection time of less than 1 s. Coating surface to increase the part emissivity improved the signal to noise ratio but was not necessary for the crack detection. Despite high local heat gradient resulting from the parts' edges, cracks were still detectable. This edge effect introduced more challenges to detect short cracks. Relatively, longer cracks were easier to detect. The optimal observation time, in the experiments, was between 0.1 s and 0.25 s. Inspection of the engine disc with complex geometry was feasible using the induction thermography technique. However, in this case only some of the cracks were detected. Similar findings were also obtained from the 3D multiphysics finite element modelling.