Recrystallized grain refinement of a 5083 aluminum alloy by differential speed rolling

For the purpose of grain refinement, recrystallizing behavior of differential-speed-rolled sheet of a 5083 aluminum alloy were studied by the electron back scatter pattern (EBSP) as well as optical and transmission microscopy observation, and compared with those of conventionally rolled sheet. In the same reduction, tensile strength, yield strength and hardness of differential-speed-rolled sheet are higher than those of conventionally rolled sheet. After annealing, the recrystallized grain size in differential-speed-rolled sheet is finer than that in conventionally rolled sheet. Especially, fine recrystallized grains with an average size of 2.7 μm were obtained in 91% differential-speed-rolled sheet. The fine grains might have been evolved in such a way that a lot of fine zones with high misorientation are invited by the complicated plastic deformation, peculiar to differential speed rolling with additional shear deformation, and they become continuously fine grains during subsequent annealing.