Producing nanocrystalline bulk Mg-3Al-Zn alloy by powder metallurgy assisted hydriding-dehydriding

► The nanocrystalline bulk Mg-3Al-Zn alloy with an average grain size of 48 nm has been produced by powder metallurgy assisted hydriding-dehydriding. ► The nanocrystalline Mg-3Al-Zn powders with an average grain size of 5.9 nm were produced by ball milling in hydrogen for 60 h. ► The highest microhardness of the nanocrystalline bulk alloy reached 872.5 MPa,which is about three times that of the coarse-grained AZ31. ► The consolidated samples of 60 h milled had a final density of 1.77663 ± 0.006 g/cm3, which corresponded to 97.57 ± 0.3% of theoretical density.