Ultrasonic methods Scanning Acoustic Microscopy

Applications The physical principle of measurement is similar to the scanning acoustic microscopy discussed in the Section 14.23, but applications and the method of data processing are essentially different. Sonic methods were used in the following applications to filled materials the effect of particle size and surface treatment on acoustic emission of filled epoxy, longitudinal velocity measurement of tungsten filled epoxy, and in-line ultrasonic measurement of fillers during extrusion. Numerous parameters related to fillers can be characterized by this non-destructive method. 

A wide-field pulse scanning acoustic microscope (WFPAM) was used in the reflection mode at the driving frequencies of / = 25 — 50 — 100 MHz to measure the local values of ultrasonic velocities and elastic moduli (the microacoustic technique) and to visualize the bulk microstructure of a specimen (scanning acoustic microscopy). The method makes it possible to measure the elastic characteristics of small specimens and inclusions [26,27]. 

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