Dynamics of the acoustic emission source during a martensitic transformation

Abstract
The authors have analysed the acoustic emission signals generated during the thermoelastic martensitic transformation of a Cu-Zn-Al alloy using a broad-band detection system. The analysis has been restricted to rise times which contain information related with the dynamics of the transformation mechanism. The results show the existence of two well separated rise-time signal populations. The average values of each class are 0.2+or-0.1 mu m and 2.2+or-0.5 mu m. The presence of signals with a characteristic 'fine structure' superimposed on the mean long rise-time wave has been attributed to a jerky character of the martensitic growth process.