Microstructure evolution and mechanical properties of pure aluminum deformed by equal channel angular pressing and direct extrusion in one step through an integrated die

Abstract

In this paper, billets of Al-1080 were successfully processed by ECAP up to 1 pass, and a combination of ECAP + extrusion with extrusion ratios of 2 and 8 through a newly designed integrated die at room temperature. The combination of ECAP + extrusion processes was observed to produce finer grain sizes with greater fractions of high angle grain boundaries (HAGBs) than the ECAP. The average grain size was further decreased and the fraction of high angle grain boundaries (HAGBs) was increased with the increase of the extrusion ratio. Direct extrusion after ECAP enhanced the mechanical properties (tensile strength and hardness) with conserving reasonable degree of ductility (elongation %). ECAP and ECAP + extrusion processed samples, showed large dimple size in the tensile fracture surfaces with clear ductile fracture mode. (C) 2014 Elsevier B.V. All rights reserved.