The origin of acoustic emission during deformation of aluminium and an aluminium–magnesium alloy

Abstract

The acoustic emission power during deformation of pure aluminium single crystals and polycrystals, and specimens of A1 1·3wt% Mg, has been measured. In pure aluminium the acoustic emission activity increased with grain size to approach the levels of activity from single crystals, whereas the emission activity of the Al 1·3wt% Mg solid solution exhibited a peak at a grain size of ∼80 μm, and samples with large grain size generated almost no detectable emission. A model is presented for acoustic emission by a dislocation, and is used to explain the observed emission dependence upon grain size in both metals.