Numerical and Experimental Investigation of Multi-axial Forging of AA6082 Alloy

Multi-axial forging is a useful technique for producing ultrafine-grained structures in bulk materials bymeans of severe plastic deformation. The workpiece is subjected to a specific plastic strain in the multi-axial forging process by repeatedly upsetting along all three axes by rotating the sample by 90 degrees between the two passes; this leads to the accumulation of a large plastic strain in the material. The shape of the product does not change, as equal compressive strain is applied in all directions. Severe plastic deformation methods such as multi-axial forging can be used for producing lightweight high-strength Al alloys with ultrafine-grained structures. In this study, as-cast AA6082 has been multiaxially forged with a true strain of 0.1 in each direction, leading to a total effective strain of 0.3 in each cycle. The strain inhomogeneity from center to the surface has been predicted by a finite element simulation of the multi-axial forging with a Voce hardening model, and it has been correlated with an experimentally determined hardness variation. The peak loads in all of the passes have also been compared.