Aluminum 6063 due to special properties such as low density, high corrosion resistance, good weldability and cost less than the 2000 and 7000 series have been widely employed in many fields. In this study, rolling at liquid nitrogen temperature process are used to improve the structure and mechanical properties of these alloys. In this regard, the parameters of the reduction in the thickness and aging temperature was considered. For evaluation of properties of this alloy, Tensile and hardness tests, optical and scanning electron microscope with an energy-dispersive X-ray spectroscopy (EDS) system were carried out. As well as the study of fracture surfaces by scanning electron microscope done and to determine the density of dislocations were done by X-ray diffraction. It was found that solution-treated at 520 degC duration 2 hours before the rolling, 85% rolling and 1.5 hours holding time at 130 degC after the rolling led to optimized properties. Ultimate strength was increased to about 350 MPa (almost 45 percent more than that of the as received 6063 aluminum alloy) by applying the optimal parameters while 9% elongation was achieved. Competition between recrystallization process and precipitation during aging process was observed and analyzed. Studies showed that in the sample of 85% cryorolled, the discontinuous static recrystallization process expanded faster than precipitation. While for samples of 35% and 65% rolling this behavior is not observed. The results of X-ray diffraction showed that the density of dislocation due to the lack of dynamic recovery increased after cryorolling process. After the aging process, Mg 2 Si fine precipitates that have been formed have a significant role on improving strength. Also during the aging, discontinuous static recrystallization process with bulging mechanism, resulting in modified grains and are likely to be formed ultrafine/Nano grained. By this process the good combination of strength and ductility is achieved. Keywords Cryorolling, Al 6063, UFG aluminum
