Ultrasonic measurements for the prediction of mechanical strength

Results are presented on the scattering of ultrasonic waves from defects embedded in metals and on the influence of these defects on the mechanical properties. A simple correlation has been discovered between an empirical expression for the ductility of a sample containing a single void and the back-scattered ultrasonic power derived from scattering theory. An expression is derived which relates the ductility (reduction in cross-sectional area at tensile fracture) with the high-frequency (15 MHz) back-scattered ultrasonic signal in an approximately linear fashion. The data obtained on diffusion bonded Ti-alloy samples are in good agreement with the predictions. These results open the door to the prediction of ductility from ultrasonic measurements.