The variation of work hardening characteristics of Al-5 wt% Mg alloy during phase transition

The aim of this study is to investigate the effect of aging conditions on the stress−strain behavior along with microstructure changes of the Al-5 wt% Mg alloy. Following solid solution treatment and aging of specimens at temperatures ranging from 373 to 573 K for various aging times (1/4 to 4 h), stress−strain tests were performed at different testing temperatures (313−343 K). The work hardening parameters (σy, σf, χp and Y) were found to decrease continuously with pre-aging times at all aging and testing temperatures, where the softening parameters (εf and L) oppose this behavior. The variation in stress−strain parameters with increasing aging temperatures and aging times was explained on the basis of structural transformations taking place in the Al−Mg alloy. A precipitate-dislocation intersections mechanism was assumed as the rate-controlling mechanism for alloy.