A novel Automatic Defect Detection Method for Electron Beam Welded Inconel 718 Components using Inductive Thermography

In this article Induction Thermography is applied to inspect Inconel 718 Electron Beam Welded and Tungsten Inert Gas Welded components with cracks that can go down to 180 μm. Satisfactory experimental results have been obtained despite the non-propitious electrical and thermal conduction properties of the material. A crack detection algorithm that uses as input phase images obtained from the FFT transformation has also been developed. It takes advantage of the rotational symmetry of the 'Butterfly-like Patterns' to convert them by using a polar Discrete Fourier Transform into 2D Gaussian like distributions that allow the identification of cracks.