Hot and Cold Tensile Behavior of Al 6061 Produced by Equal Channel Angular Pressing and Subsequent Cold Rolling

The full annealing AA6061 aluminum alloy was subjected to severe plastic deformation
via the combination of equal channel angular pressing (ECAP) and cold rolling (CR) in order to refine its microstructure and to improve its mechanical properties. According to the results of hot and cold tensile tests, the combination of ECAP and CR significantly affected the final strength and ductility of studied AA6061. Four passes of ECAP followed by 90% reduction in rolling led to about 5.4 and 3.15 times increase in the yield and ultimate tensile strengths, respectively. In addition, the hot ductility and strain rate sensitivity were increased by applying ECAP plus CR. The changes in mechanical properties were attributed to the enhanced dislocation density and to the reduced grain size. The results show that a decrease in grains/subgrains size (0.37 μm) and an increase in the fraction of high angle grain boundaries, exhibited significant effect on the hot ductility of higher severe plastic deformed sample.