Cyclic deformation behavior of as-extruded Mg–3%Al–1%Zn

The cyclic deformation behavior of extruded magnesium alloy Mg–3%Al–1%Zn (AZ31) was studied under plastic strain amplitude and stress amplitude-control at room temperature. A significant cyclic hardening asymmetry of stress amplitudes between compression and tension was observed under constant plastic strain amplitude-controlled cycling. The possible reasons for this phenomenon are discussed by a combination of hysteresis loop analysis and in situ observation of twinning and untwinning during one loading cycle using electron backscatter diffraction.