Scanning Photoacoustic Microscopy of Aluminum with Aluminum Oxide, Roughness Standards, and Rubber
Abstract
Scanning photoacoustic microscopy (SPAM) and related thermal wave imaging techniques are emerging as methods of nondestructive evaluation (NDE), applicable to surface and near-surface characterization. The usefulness of these methods results from sensitivity to thermal properties, such as diffusivity and boundary conditions, near the point of the surface being probed. Through this sensitivity to localized thermal properties, SPAM can examine beneath the surface of an opaque material for voids, closed or open cracks, and inclusions. The maximum probe depth is approximately 2 mm, and the technique is particularly sensitive to flaws at depths from about 1 micron to 300 microns. The probe depth can be controlled experimentally. SPAM is also well suited to automatic data acquisition. Some applications of SPAM and related thermal wave techniques to the studies of: aluminum with dispersed Al2O3 particles; surface roughness standards; and rubber track shoe pad material have been described. Similar applications for thermal wave images for color encoding at TACOM; coated samples; surface geometry; and dispersion in rubber samples have been described. In this final report, the best photoacoustic detection techniques for imaging intristic rubber structure; thermal wave studies ceramic coasted samples; thermal wave imaging of hollow turbine blades; and the capabilities of photoacoustic microscopy of monolithic silicon nitride and silicon carbide ceramics are discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 10, 1985
- Accession Number
- ADA169160
Entities
People
- D. C. Bryk
- D. N. Rose
- L. D. Favro
- P. K. Kuo
- R. L. Thomas
Organizations
- Wayne State University