Tensile Deformation Behaviors of Ultrafine Grained Al-Fe-Si Alloy Sheets

Ultra-fine grained AA8011 alloy sheets manufactured by the accumulative roll-bonding (ARB) process exhibited unique tensile deformation behavior. Tensile strength of the ARB processed AA8011 sheets increased up to three cycles, but then showed nearly the same value after three cycles. Meanwhile, the total elongation grew significantly with an increasing nember of ARB cycles. It was found that the strain-rate sensitivities (m) of the AA8011 sheets increased up to 0.047 by the ARB process. A large number of high-angle boundaries were introduced by the ARB process and the fraction of high-angle boundaries reached 70% after eight ARB cycles. In this paper, we discusse the increase in total elongation on the basis of strain-rate sensitive deformation of the material, which is also correlated with dynamic recovery.