The isothermal compression deformation behavior of Mg-Zn-Gd-Y-Zr alloy was performed on gleebl-3500 thermal simulator.The results reveal that the stress is increased with the increase of the strain.After reaching a certain value

the stress begin to decrease

and with temperature increase or strain rate decrease

stress decrease rate is decreased.The stress-strain curves presnt a typical dynamic recrystallization behavior.With increasing in deformation temperature or decreasing in strain rate

recrystallized grain fraction is increased

and recrystallized grain size is coarsened with severely broken of the coarse second phases.By analyzing the true stress-strain curve

the material parameter values of Mg-Zn-Gd-Y-Zr alloy were calculated and the constitutive equation was established.The thermal processing maps of the alloy were established based on the dynamic material model theory

and the optimal thermal processing parameters are presented as follows:deformation temperature of 400～450℃and strain rate of 0.01～0.001 s

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.