Suppressing abnormal grain growth and switching precipitation behaviors in ZK60 Mg profile by inducing pre-tension

Abstract

The pre-tension was induced to suppress the abnormal grain growth (AGG) of ZK60 Mg profile during solution treatment. The effects of pre-tension on the microstructure evolution and mechanical properties were studied, and the suppressing mechanism was discussed. If the pre-tension strain was larger than 10%, AGG during solution could be effectively inhibited, resulting in a sharp decrease in the grain size. The suppression effects were realized by restricting the orientation dependent of AGG and promoting static recrystallization. The pre-tension reset the distributions of stored energy and sizes of the grains with 〈11–20〉 and 〈10–10〉 orientations, and thus retarded the orientation dependent of AGG. Moreover, the pre-tension introduced a mass of dislocations, twins, and stacking faults, all of which promoted the occurrence of static recrystallization, and the grain structure was further refined. The pre-tension accelerated the precipitation kinetics during aging, resulting in fine and dense precipitates. With the increase of pre-tension strain, the strength of ZK60 Mg profile monotonically increased.