Effects of deformation routes on the evolution of microstructure, texture and tensile properties of AA5052 aluminum alloy

Abstract

Effects of deformation routes on the evolution of dislocation density, microstructure, texture and mechanical properties of AA5052 aluminum alloy during equal channel angular pressing (ECAP) were investigated in this research. The results of microstructural study showed that homogeneous ultrafine grain structures with average grain size of less than 500 nm were developed after 6 passes ECAP regardless of route of deformation. Although, route C was found to be more effective in grain size reduction. The results showed that higher dislocation density (i.e. 2.48 × 1011 cm−2) was formed in the matrix when the material deformed via route A, while a finer ultrafine grained structure having higher fraction of high angle grain boundaries (HAGBs) was formed in route C for the same amount of deformation. Bθ and B̅θ components of <110>θ fiber texture with different intensities were developed after 6 passes ECAP via both routes. Results obtained for mechanical properties showed that hardness, yield strength (YS) and ultimate tensile strength (UTS) of the deformed material increased substantially after 4 passes of ECAP. However, with further deformation to 6 passes, the YS remained constant in route A and decreased in route C. The reasons for such behavior were discussed in this research. Hardness and tensile strength were found to be affected by grain size, dislocation density and texture developed during ECAP. Variations of these parameters and their effects on flow properties of the material were discussed in this research.