Hardening and softening in selected magnesium alloys

The paper deals with the influence of temperature and solute atoms on the stress relaxation behaviour. Examples will be given on the deformation behaviour of selected magnesium alloys ZE41 and QE22. The testing temperature and strain rate strongly influence the behaviour. The temperature and strain rate dependences of the yield stress are in some cases non-monotonic. Post-relaxation effect—an increase of the flow stress after stress relaxation is analysed in relation to the dynamic strain-ageing effect. The activation volume is calculated using the strain rate change experiments, and the non-conservative motion of jogs is estimated as a possible thermally activated process.