Multiscale study of cold-rolling deformation on mechanical and corrosion behaviors of AA2024-T4 aluminum alloy

This study has been conducted to investigate the effects of plastic deformation of an AA2024 aluminium alloy by cold rolling to 25%, 50% and 75% and then heat-treating and naturally ageing for 20 days to T4 on the microstructure and the electrochemical behavior. To characterize the microstructural modifications different techniques have been applied such as X-ray Diffraction (XRD) to demonstrate the intermetallic phases formed, Optical Microscopy (OM) and Scanning Electronic Microscopy (SEM) to evaluate their microstructures and grain size. Moreover, the surface topography has been measured to establish the roughness effect on the mechanical response when subjected to tensile, fatigue and micro-indentation tests. The corrosion behaviour was evaluated by Potentiodynamic Polarization Scanning, Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS). The results revealed that cold-rolled samples with 50% plastic deformation show a smoother topography and exhibit the best compromise between mechanical and corrosion resistance. [Display omitted] •Microindentation measurements highlight a direct-relationship (HIT vs. rolling rate), with the highest value for 75% rolling degree (2.1 ​± ​0.16 ​GPa).•Optical profilometry reveal the smoothest topography for cold rolling samples at 50% deformation degree, and the roughest for those rolled at 75%.•The fatigue tests indicate that a 50% rolling degree has higher fatigue resistance compared to other degrees and even without rolling.•The obtained Corrosion Penetration Rate affirms the best corrosion behavior for samples having undergone a plastic deformation of 50%, and the lowest ones for those rolled at 75%.•The best compromise between mechanical and anticorrosion properties is demonstrated for specimens' cold-rolling at 50%.