Structural and mechanical properties of EN AW 6082 aluminum alloy produced by equal-channel angular pressing

Abstract

At the VSB-TU Ostrava a piece of equipment was installed for verifying the equal-channel-angular-pressing (ECAP) technology, used for investigating the effect of deformation on the evolution of the structure and mechanical properties of alloy EN AW 6082. This alloy was subjected to ECAP consisting of four passes. During the pressing deformation forces were measured and the pressure in the die was calculated. Higher values of strain hardening were found and a higher pressure was measured in the matrix with smaller radii of the curvature of the edges. After the third pass, the tension in the matrix with a diameter of 0.5 mm reached the values of up to 1560 MPa. As a result of the extrusion, a grain refinement was achieved resulting in the development of a substructure. The ultimate strength of alloy EN AW 6082 was determined to be in the range from 220 MPa to 230 MPa. Moreover, a penetration test was performed, determining the values of the mechanical properties to be from 250 MPa to 260 MPa. The investigated samples were then subjected to light microscopy and to a SEM analysis. Numerous deformation slip bands were observed. Fracture surfaces resulting from a transcrystalline permanent ductile failure manifested indistinctive shearing borders, and they contained numerous pits with small particles.