Ultrasonic characterization of the effect of cold work and grain size in copper and 68:32 brass sheets

The effectiveness of ultrasonic velocity measurements was evaluated as a means for non-destructive characterization of cold-rolled Cu and 68:32 brass sheets. An apparatus was designed to generate and receive the zeroth symmetrical mode of ultrasonic Lamb waves in thin Cu and brass sheets. The effect of angular variations in propagation direction with respect to the rolling direction on the measured Lamb wave velocities is shown. Interpretation of the variations of ultrasonic Lamb wave velocity were related to deformation mechanisms and texture development in Cu and 68:32 brass sheets. Results show that the grain size and cold work influence the velocity as well as the texture of Cu and 68:32 brass sheets. Results indicate the possibility of using ultrasonic Lamb wave velocity as a tool to monitor elastic anisotropy.