Effect of asymmetric rolling in relief rolls on the microstructure evolution and mechanical properties of aluminum and copper workpieces

• new method for obtaining of thick sheets from non-ferrous metals was investigated; • method consists of asymmetric rolling in relief rolls and alignment in smooth rolls; • asymmetry effect increased the grain refinement intensity by approximately 30%. The impact of a novel deformation method on the microstructure evolution and mechanical properties of Al6063 aluminum alloy and C11000 copper alloy was investigated. The laboratory experiment was conducted in three successive stages. Following rolling in relief rolls, the workpiece was subjected to two-stage alignment in smooth rolls. The relief rolls exhibited an asymmetry coefficient of 1.5, attributable to the discrepancy in roll diameters: the lower roll had a diameter of 300 mm, while the upper roll had a diameter of 200 mm. To assess the efficacy of the investigated deformation scheme, the outcomes were contrasted with those of symmetrical rolling in relief rolls with subsequent alignment, as well as with conventional rolling in smooth rolls. The analysis of microstructure evolution demonstrated that three deformation cycles are sufficient to refine the initial grain by more than three times for the Al6063 alloy and by more than four times for the C11000 alloy. Conversely, the absence of an asymmetry effect has been observed to reduce the intensity of grain refinement by approximately 30% in both cases. An analysis of the changes in mechanical properties revealed that the investigated deformation technology is the most effective method among the studied deformation routes, as it allows for the highest values of strength indicators to be obtained.