Microstructure, mechanical properties and electrochemical behavior of AA1050 processed by accumulative roll bonding (ARB)

Abstract In this work, the effect of ARB process on the microstructure, mechanical properties and electrochemical behavior of AA1050 was investigated. X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM) images were used for measuring the crystallite and grain sizes of samples. TEM micrographs and XRD plots revealed that with increasing the number of ARB cycles, the grain/crystallite size of sample decreased and eventually nanostructured AA1050 achieved after 9 cycles of ARB with average crystallite size around 91 nm. Results of the microhardness and tensile tests demonstrated that mechanical properties of samples improved as the number of ARB cycles increased. Scanning electron microscopy (SEM) micrographs of fracture surfaces illustrated that ductile fracture occurred in all samples. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) results showed that passive behavior of the ARBed samples improves compared to the annealed AA1050 sample. Moreover, the Mott–Schottky analysis and EIS measurements showed that increasing the number of ARB cycle offer better conditions for forming the passive films.