Continuous acoustic emission during intermittent plastic flow in α-brass

The Portevin–Le Chatelier effect which is usually associated with discontinuities in plastic flow has been studied in α-brass using an acoustic emission (AE) technique. It is found that intermittent plastic flow in the high-strain-rate regime corresponding to A-type serrations on the stress–strain diagram is accompanied by a continuous AE signal reflecting a smooth dynamics of emitting sources. No individual transient AE signals, which could be associated with rapid dislocation avalanches, have been resolved at different timescales.