Ambient temperature compression tests with concurrent acoustic emission measurements were performed on a hydrostatically extruded, fine-grained, round bar of the alloy parallel to the extrusion axis. A multiple increase in the acoustic emission count rates to peak intensities was detected with increasing strain. An analysis of the samples tested to specific values of strain using electron backscattering diffraction revealed that (10•2) twins first appeared in large grains and that only with increasing strain do smaller grains tend to twin.

Grain Size Effects on Deformation Twinning in an Extruded Magnesium Alloy Tested in Compression. P.Dobroň, F.Chmelík, S.Yi, K.Parfenenko, D.Letzig, J.Bohlen: Scripta Materialia, 2011, 65[5], 424-7