Comparative analysis of inhomogeneous plastic flow in bulk and ribbon metallic glasses monitored by acoustic emission

Aiming to gain a better insight into the phenomenological description and mechanisms of inhomogeneous plastic deformation in metallic glasses, we review the currently available experimental data on the acoustic emission (AE) behaviour in these materials under load and compare the results for typical ribbon-shaped and bulk metallic glasses. It is shown that the AE patterns reflecting the kinetics of shear banding are very much alike for both kinds of glasses (as-cast and as-spun) despite a gross difference in the quenching rate during manufacturing, geometry and loading conditions. It is also shown that the stress drops during serrated plastic flow in BMGs are triggered by short time localised shear events having a comparatively large scale although no simple correlation between the stress drops and AE amplitudes is found. (C) 2010 Elsevier B.V. All rights reserved.