THE USE OF SCANNING ACOUSTIC MICROSCOPE FOR FLAW DETECTION IN METALLIC MATERIALS

Abstract

The main objective of this paper is to understand the principles and
theories behind the operation of the equipment, and its architecture.
The advantages and limitations of the scanning acoustic microscope
are also investigated by imaging a set of samples. The principle of
operation of a scanning acoustic microscope is producing magnified
acoustic images of the surface or interior of a solid by passing highfrequency
focused acoustic pulses through the material and
displaying the received signal in the image fo rm as shades of grey.
The Significant advantage to be- gained in using scanning acoust ic
microscope fo r producing images are the ability of acoustic wQ\'es to
penetrate opaque material and the distinctive origin ofcontrast in the
mechanical properties of the specimen, Three. sets of samples are
observed under the scanning acoustic microscope and they are
Vickers hardness indention samples. quenched samples and porosity
samples. It is found that the results obtained for the samples are
subjected to the overall ability of the equipment used. The operating
frequency was one of the most significant limiting factors in this
work, as the resolution obtained was not as high as would be
favourable. However, satisfactory images with distinctive contrast