Optimizing the strength and ductility of AZ91 Mg alloy by ECAP and subsequent aging

We report an effective approach to achieve an excellent combination of high strength and good ductility in the AZ91 Mg alloy. The approach involves solution heat treatment, equal channel angular pressing (ECAP) and subsequent aging. This approach is effective in accumulating dislocations and promoting the formation of large spherical precipitates during ECAP. The aging produced much finer precipitates with uniform distribution inside the grains. The hierarchical precipitate structure produced by the current approach rendered high strength and good ductility.