The Role of Through-Thickness Variation of Texture and Grain Size on Bending Ductility of Al–Mg–Si Profiles

Abstract

Requiring a high strength and concurrently a high ductility in materials is generally a demand for opposing properties in dislocation slip deforming materials, such as Al–Mg–Si wrought alloys. However, these are essential mechanical properties for safety parts in the mobility sector. While the strength of Al–Mg–Si wrought alloys is mainly governed by the state and density of the secondary precipitates, the deformation behavior and ductility are affected by both precipitates and crystallographic texture. The deformation during extrusion leads to the formation of characteristic textures in the bulk, which are distinct to a plane-strain deformation, and a peripheral coarse grain (PCG) layer beneath the surface. This PCG layer can have a detrimental effect on the bending ductility, which assesses the crashworthiness. However, an appropriate texture in the bulk can counteract the detrimental effect of PCG and increases the bending ductility at high strengths. Subsequently, based on EBSD investigations of bending deformed microstructures, a way to enhance bending deformation capability in Al–Mg–Si profiles is proposed.