Nondestructive Evaluation of Internal Defect in Weld Metal by Photoacoustic Microscopy

In this study, the nondestructive evaluation (NDE) of an internal defect in the weld metal of an aluminum plate has been demonstrated using a photoacoustic microscope (PAM). The internal defect was fabricated inside of a metal plate by welding. The NDE of the position and size of the internal defect was carried out using the PAM. In addition, X-ray tomographic imaging was also carried out for comparison with the obtained PAM images. The depth direction and size of the internal defects were obtained from photoacoustic (PA) amplitude images and the signal intensity distribution.