Accumulative roll bonding fabrication, tensile and corrosion characterization of Zn/Al multilayered composites

In the present work, accumulative roll bonding (ARB) processing and characteristics of Zn/6 wt% Al multilayered composite sheets were investigated for the first time. The structure of the fabricated composites was evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Tensile testing and fractography were used to assess the strength and elongation of the composites. The corrosion behavior of the fabricated samples was also investigated by potentiodynamic polarization and electrochemical impedance spectroscopic tests in the 3.5 wt% NaCl solution. Despite the evolution of atomic intermixing at the interface of the layers and grain refinement, the tensile strength and elongation of the composites were reduced by increasing ARB cycles due to the domination of plastic instability introduced by the ARB process. In addition, an initial increase until the third ARB cycle followed by decrease in the corrosion tendency of the composites was found by progression of the ARB process, which was attributed to a compromise between the levels of structural defects and homogeneity. It is eventually concluded that after optimizing the mechanical and corrosion behaviors as a function of the number of ARB cycles, ARB-processed Zn/Al multilayered composites can be further considered in industrial applications.