Subsurface flaw detection in metals by photoacoustic microscopya
- 1 February 1980
- journal article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 51 (2) , 1152-1156
- https://doi.org/10.1063/1.327726
Abstract
The scanning photoacoustic microscope (SPAM) is used in both the conventional and phase‐contrast modes to detect a well‐characterized subsurface flaw in Al. The physical mechanism is that of thermal diffusion, with a subsurface probe depth and flaw resolution length of approximately one thermal‐diffusion length. Comparison of the dependences of the photoacoustic signal upon chopping frequency from the different regions of the sample confirm that the differential signal from the flaw corresponds to a transition from thermally thick to thermally thin boundary conditions. Experimental results are in good agreement with calculations based upon a three‐dimensional thermal‐diffusion model.This publication has 4 references indexed in Scilit:
- Optoacoustic phase angle measurement for probing a metalApplied Physics Letters, 1979
- Subsurface structures of solids by scanning photoacoustic microscopyApplied Physics Letters, 1979
- Surface and subsurface structure of solids by laser photoacoustic spectroscopyApplied Physics Letters, 1978
- Theory of the photoacoustic effect with solidsJournal of Applied Physics, 1976