Abstract
Acoustic emission (AE) was monitored and analysed during tensile tests at room temperature
(RT) of extruded magnesium alloy AZ31 (Mg-2.9wt.%Al-0.98wt.%Zn-0.29%Mn).
Hydrostatically and indirectly extruded rods were water-cooled or air-cooled, respectively, and
exhibit different microstructures, e.g. a variation of the grain size, as well as different mechanical
properties. The validity of the Hall-Petch relation was proven. The results are explained in terms
of dislocations glide and deformation twinning during plastic deformation.
