Effects of pre/post-aging treatment on the mechanical properties and texture of asymmetrically rolled 6061 aluminum alloy: formability and planar anisotropy

Abstract

6061 aluminum (Al) alloys were asymmetrically rolled to apply shear deformation, and the effects of pre/post-aging treatment on the mechanical properties and texture evolution were analyzed. The texture was analyzed using electron backscattered diffraction (EBSD), and the formability and planar anisotropy of the specimen were evaluated using the r¯-value and Δr-value calculated from the plastic strain ratios (r-values). Regardless of the aging conditions (no aging, pre-aging, and post-aging), asymmetric rolling yielded higher strength than symmetric rolling. Pre-aged specimens, regardless of the rolling method (symmetric rolling or asymmetric rolling), exhibited higher strength than the post-aged specimens. To develop the <111>//ND shear texture throughout the specimen, asymmetric rolling in a supersaturated solid solution without an initial precipitate was more effective than asymmetrically rolling an aged-hardened specimen. Considering the strength, formability (r¯-value), and planar anisotropy (Δr-value) of the 6061 Al alloy, the asymmetrically rolled pre-aged specimen had the best mechanical properties. These results show that the strength and formability of the 6061 Al alloy can be improved and its planar anisotropy can be reduced using a combination of asymmetric rolling and control of the aging sequence. This work demonstrates how the deformation and heat treatment of Al alloys could be used to increase the adoptability of Al alloys for automobiles.