The applications of ultrasonic backward radiation from a layered substratesubmerged in liquid

A theoretical model was developed for the angular profiles of ultrasonic ba ckward radiation by the single transducer, pulse-echo method. Parts of the velocity dispersion curves for Ni/Al layered substrates with various bondin g qualities were constructed using the backward angular radiation profiles. It was shown that the angular profiles of the insonified region were relat ed to interface bonding qualities. An inclined C-scan method was used to re ceive backward radiation waves from a glass substrate with 1 and 3 mm notch ed gratings. The results show that the inclined C-scan method could be usef ul in the evaluation of a surface area. (C) 2000 Elsevier Science Ltd. All rights reserved.