Statistical analysis of acoustic emission events in torsional deformation of a Vitreloy bulk metallic glass

The characteristics of acoustic emission events produced during torsional deformation of bulk metallic glass samples were statistically analyzed. The amplitudes of these events, and waiting time between them, follow power-law distributions, indicating correlated shear band initialization processes. Time correlation within groups of events is demonstrated statistically. This correlation can be traced back to sequences of events with exponentially decreasing waiting times. The appearance of event sequences is explained by considering the stress field around a shear band of finite length and by the resulting intermittent formation of the bands.