15. Failure Modes, Defect Characterization, and Accept/Reject Criteria
High frequency acoustic imaging represents a powerful technique for the nondestructive evaluation of optically opaque materials. In this report the Scanning Laser Acoustic Microscope (SLAM) is used to detect and characterize flaws in ceramics. SLAM micrographs showing typical examples of cracks, laminar flaws, porosity and solid inclusions. are presented. The various flaw types are easily differentiated on the basis of their characteristic acoustic signatures. The importance of an imaging approach to the nondestructive evaluation of ceramics is demonstrated.
Yuhas, D. E.; McGraw, T. E.; and Kessler, L. W., "Differentiation of Various Flaw Types in Ceramics Using the Scanning Laser Acoustic Microscope" (1980). Proceedings of the DARPA/AFML Review of Progress in Quantitative NDE, July 1978–September 1979. 93.