Deformation behavior of fine-grained 5083 Al alloy at elevated temperature

The microstructure evolution of the fine-grained 5083 Al alloy was investigated in annealing temperature range of 150-300 degrees C. Then the effects of the different annealed microstructures on high-temperature deformation behavior were further studied. The results indicate that the initial recrystallization temperature is about 200 degrees C. By tensile tests at 380-570 degrees C and in strain rate range of 4.17 x 10(-4)-1.0 x 10(-2) s(-1), the optimum superplastic parameters are obtained as follows: the annealed temperature 250 degrees C, the tensile temperature 550 degrees C and the strain rate 4.17 x 10(-4) s(-1). With the aid of scanning electronic microscopy (SEM), the fractography of the alloy after the superplastic deformation was analyzed. The results reveal that intergranular cavities with fine size and homogeneous distribution are beneficial to superplastic deformation.