Evolution of microstructure for multilayered Al/Ni composites by accumulative roll bonding process

Abstract

Accumulative roll bonding process (ARB) has been used to prepare a multilayered Al/Ni composite from pure aluminum sheets and pure nickel strips, and structural evolution in the composite was observed throughout the process. As increasing the number of ARB cycle, thin Ni layer was necked and fractured. The structural formation was controlled by the co-deformation between harder Ni layer and softer Al matrix. The slip bands activated in Al matrix approached on the Ni layers, resulting in the fragmentation of Ni layers in a shearing manner. The heterogeneous strain distribution was caused by the frictions between roller and surface, as well as between Ni layer and Al matrix, which had an important effect on the structural evolution.