Processing, microstructural, and mechanical characterization of extruded 6013 aluminum alloy

Abstract

The 6013-aluminum alloy is used in automotive applications due to its higher levels of mechanical strength. This work aimed to characterize the microstructural and mechanical properties of this alloy obtained in various stages of industrial processing. The alloy was subjected to homogenization, extrusion and solubilization, tempering, and artificial aging processes. The microstructure was characterized by optical (OM), scanning electron (SEM), transmission electron microscopy (TEM), and X-ray diffraction technique (XRD). In the as-cast condition, the present phases in the 6013-alloy were almost completely precipitated at the α phase grain boundaries. Homogenization and solubilization during the extrusion process strongly reduced the amount of these precipitates. The α-phase morphology showed a heterogeneous distribution along the thickness of the extruded profile, with recrystallized grains close to the surface and many work-hardened grains inside. The aging heat treatment significantly increased the extruded profile mechanical strength. In the analysis of the present phases, it was possible to identify, in addition to the α-Al phase, the compounds precipitated in greater quantity, such as Mg2 Si, β-AlFeSi, and α-AlFeSi.