NDE of complex metal surface defects and simulated pitting corrosion holes by photoacoustic imaging

In this paper, NDE of both intersecting surface defects and several types of pitting corrosions both fabricated on metal plates has been measures by the use of photoacoustic microscope (PAM). Images of surface defects, intersecting vertically and fabricated on a pure aluminum plate, were well resolved with the PAM. Simulated pitting corrosions were made by mechanical pressing with a diamond chip or steel ball or by chemical etching. Photoacoustic (PA) imaging of simulated pitting corrosions were also performed. These characteristics were interpreted with a model considering a surface area exposed to the laser beam. The abstract summarizes two independent contributions by authors (H.E., R.M,. T.H) and authors (Y.H., T.K., T.H.)