Hot workability analysis of extruded AZ magnesium alloys with processing maps

The processing conditions applied to deform wrought magnesium alloys greatly affect their final microstructure and mechanical properties. Defining an applicable processing window in terms of the ranges of temperatures and strain rates to achieve a homogeneous microstructure is a prerequisite for process optimization, since magnesium alloys show a peculiar deformation behaviour. By using trustworthy input data from uniaxial hot compression tests, processing maps were constructed for the alloys AZ41, AZ61 and AZ80. These maps clearly indicate the conditions leading to dynamically recrystallized homogeneous microstructures after hot deformation, as verified by analysing the microstructures after hot deformation under different conditions. It is found that a strain rate of 5 s−1 and a temperature of 375 °C for AZ41 and 325 °C for both AZ61 and AZ80 would result in dynamically recrystallized homogeneous microstructures.