Unveiling the electrochemical performance and passive film properties of AA2024 aluminum alloy processed through severe plastic deformation with nanostructured architecture

The current work has undoubtedly provided new insights into the correlation between grain refinement and crystallographic texture on the passive and electrochemical response of annealed and nano-grained AA2024 aluminum alloy in phosphate buffer solution (pH = 9). Nano-grained AA2024 alloy, which typically has an average grain size of 150–100 nm with a more uniform microstructure, was successfully processed through the eight-cycle cross accumulative roll bonding (CARB) technique. The findings reveal that as a result of the grain refinement process, the passive response of the nano-grained AA2024 was significantly enhanced compared to its coarse-grained counterpart in phosphate buffer solution. Furthermore, the combination of grain refinement and high-intensity {011} orientations, i.e., Goss {011}<100>, Brass {011}<211>, and P {110}<221 > texture components, supplied the optimal conditions for developing oxide passive films with superior corrosion protection performance relative to the coarse-grained counterpart. Consequently, these findings illustrate that the CARB technique can effectively form a thick and less defective passive layer with superior protection properties in the AA2024 alloy.