STRUCTURAL PERSPECTIVE.

Abstract

Acoustic microscopy is a technique for visually revealing on a microscopic level localized changes in elastic properties of materials. Other microanalytical techniques reveal the atomic and chemical composition of a sample. But the acoustic microscope measures point-by-point reactions of a material to a periodic stress wave. Acoustic microscopy adds a new dimension to materials evaluation. The sonically transparent nature of many optically opaque substances permits internal examination and characterization of one of the most important aspects of materials - i. e. , microelastic features. Subsurface defects, flaws, inclusions, and disbonded areas can be detected without resorting to destructive sectioning procedures. The acoustic microscope characterizes materials and detects differences in performance either statically or under stress. Other techniques provide structural information that is, at best, indirectly related to mechanical behavior.