Ultrasonic resonance measurements were performed on interstitial-free and commercial C-steels which were subjected to plastic deformation. The specimens had a trapped-mode cylindrical geometry which localized resonant vibrations and minimized acoustic losses. The deformation caused an increase in Q-1, and a corresponding decrease in velocity which partially recovered with time. The frequency dependence, and the relative magnitude of the velocity changes during recovery, were found to be inconsistent with a single Debye form of the Granato-Lücke over-damped dislocation model. A distribution of Debye functions which arose from a random distribution of pinning points also failed to explain the experimental results.

Dislocation Damping after Plastic Deformation in Interstitial-Free and Carbon Steels. W.Johnson: Journal of Alloys and Compounds, 2000, 310[1-2], 423-6