Significant improvements in mechanical properties of AA5083 aluminum alloy using dual equal channel lateral extrusion

Dual equal channel lateral extrusion (DECLE), as a severe plastic deformation (SPD) process, was employed for improving the mechanical properties of AA5083 aluminum alloy. Several experiments were conducted to study the influences of the route type, namely A and B, and pass number on mechanical properties of the material. The process was conducted up to 6 passes with decreasing process temperature, specifically from 573 to 473 K. Supplementary experiments involving metallography, hardness and tensile tests were carried out in order to evaluate the effects of the process variables. The hardness measurements exhibited reasonably uniform distributions within the product with a maximum increase of 64% via a 6-pass operation. The yield and ultimate strengths also amended 107% and 46%, respectively. These significant improvements were attributed to the severe shear deformation of grains and decreasing pass temperature, which intensified the grain refinement. TEM images showed an average grain size reduction from 100 mu m for the annealed billet to 200 nm after 6 passes of DECLE. Finally, the experimental findings for routes A and B were compared and discussed and some important conclusions were drawn.