Effect of annealing on pure aluminum L2 prepared by equal channel angular pressing

Industrial pure aluminum L2 was pressed by equal channel angular pressing (ECAP) for 4 passes, then the metal was annealed in the range of 150°C to 300°C for different times. The experimental results showed that after the alloy was pressed for 4 passes, the original coarse equiaxed grains were refined to quasi-equiaxed grains and grain size is 1 μm. Compared to pressed state, the hardness of the alloy remains unchanged, while the tensile strength and prolongation increased 9% and 18% respectively after the alloy was annealed at 150°C for 2 hours. When the annealing temperature was higher than 200°C, the more stronger recovery occurred and the hardness of the alloy decreased. The hardness of the alloy decreased as the annealing temperature increased.