Nanocrystalline alloys have more strength in comparison to conventional coarse grain alloys, while they exhibit lower ductility. This decrease in ductility can be improved by bimodal size distribution of grains (combination of nano and micro grains). In a bimodal microstructure, nanocrystalline grains increase the strength, while microcrystalline grains improve the strain hardening and ductility. Al-Zn alloys (Al-7000 justify; MARGIN: 0cm 0cm 0pt; unicode-bidi: embed; DIRECTION: ltr" Key words: Bimodal structure, Al alloys, Mechanical alloying, Spark plasma sintering, hot rolling.
