Abstract
An AA6082 alloy deformed by equal channel angular pressing (ECAP) was studied. The evolution of microstructure as a function of the strain imparted was evaluated by optical microscopy (OM), scanning electron microscopy (SEM) coupled with an electron backscattered diffraction (EBSD) detector, X-ray diffraction (XRD) and Differential Scanning Calorimetry (DSC). XRD showed that MgSi2 precipitates developed in the ECAPed specimens. Texture analysis showed the apparition of two types of textures, one associated with shearing deformation and the second due to the recrystallization phenomena. Mechanical strength properties measured by tensile tests increased in the first ECAP pass, and then progressively diminished. This phenomenon was associated to the activation of continuous softening phenomena. Calorimetric analysis indicated a slightly rise in the recrystallization temperature of the deformed specimens. Also, the stored energy increased with rising ECAP passes due to the production of new dislocations. The average geometrically necessary dislocation (GND) density, measured by EBSD, increased with increasing ECAP passes. However, the rate of increase slows down with the progress of ECAP passes.
Peer Reviewed