Destructive Inspection of Weld Defect and its Nondestructive Evaluation by Photoacoustic Microscopy

In this study, the nondestructive evaluation (NDE) of an internal defect introduced in the welded region of an aluminum plate has been demonstrated by photoacoustic microscopy (PAM). The internal defect is a blowhole and an incomplete fusion, which were formed in the weld metal during welding. Experiments were carried out at different modulation frequencies. Furthermore, a stereoscopic image of the fractured specimen was obtained by destructive inspection using scanning laser microscopy (SLM) and compared with a photoacoustic (PA) amplitude image. The size of the internal weld defect measured by both methods was approximately the same.