Strain hardening of as-extruded Mg-xZn (x=1, 2, 3 and 4 wt%) alloys

The influence of Zn on the strain hardening of as-extruded Mg-xZn (x = 1, 2, 3 and 4 wt%) magnesium alloys was investigated using uniaxial tensile tests at 10(-3) s(-1) at room temperature. The strain hardening rate, the strain hardening exponent and the hardening capacity were obtained from true plastic stress-strain curves. There were almost no second phases in the as-extruded Mg-Zn magnesium alloys. Average grain sizes of the four as-extruded alloys were about 17.8 mu m. With increasing Zn content from 1 to 4 wt%, the strain hardening rate increased from 2850 MPa to 6810 MPa at (sigma-sigma(0.2))= 60 MPa, the strain hardening exponent n increased from 0.160 to 0.203, and the hardening capacity, He increased from 1.17 to 2.34. The difference in strain hardening response of these Mg-Zn alloys might be mainly caused by weaker basal texture and more solute atoms in the alpha-Mg matrix with higher Zn content. (C) 2018 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.