Annealing strengthening of pre-deformed Mg–10Gd–3Y–0.3Zr alloy

• Gd has larger strengthening effect than that of Y.
• Strengthening effect increases with increase of twin density.
• Too long annealing time at low temperature decreases the strength slightly.
• Segregation of solute atoms at twin boundary is unstable at high temperature.

In the present work, pre-deformed Mg–10Gd–3Y–0.3Zr solid solution alloy was annealed, followed by subsequent compression, and the interaction between solutes and twin boundaries was analyzed. It is found that the segregation of solute atoms to deformation twin boundaries during annealing leads to the increase in strength of Mg–10Gd–3Y–0.3Zr alloy, and Gd solute atom has a larger strengthening effect than that of Y. The strengthening effect increases with increase of twin density, annealing time and annealing temperature. However, too long annealing time at low temperature decreases the strength slightly due to the recovery. It is verified that the ordered segregation of solute atoms at the deformation twin boundary becomes unstable at high temperatures, which gives rise to the rapid decrease in the strength.