Probing elementary dislocation mechanisms of local plastic deformation by the advanced acoustic emission technique

To gain a deeper insight into fundamental processes of localised plastic deformation, we propose a new strategy for micro-mechanical testing combining the micro-scale scratching and analysis of low amplitude acoustic emissions (AE) accompanying dynamic dislocation processes in solids. The analysis of the AE spectral density reveals its strong dependence on crystallographic orientations of the grains along the indenter path, thus reflecting the finest features of the local dislocation activity. Adding a temporal dimension with a sub-microsecond resolution, the proposed methodology substantially enhances the existing capacity of micro-mechanical testing and can be used in a wide range of testing schemes. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.