Microstructure analysis and observation of peculiar mechanical properties of Al/Cu/Zn/Ni multi-layered composite produced by Accumulative-Roll-Bonding (ARB)

In the present study, the microstructure and tensile properties of a Al/Cu/Zn/Ni multi-layered composite after various accumulative roll bonding (ARB) passes were evaluated. The results showed that during the early steps of the ARB process, the Ni layer was undergone fracture as the first material. By increasing the ARB cycles to the third one, besides the Ni layer, the Cu layer was also gone through fracture. In contrast, in the Zn layer, only a severely localized necking was seen. Eventually, by the fifth cycle of ARB process a uniform distribution of Ni, Cu and Zn was created within the Al matrix. As well, from the second cycle onwards, CuZn5 intermetallic compound was formed in the Cu and Zn interface because of the stress that induced by rolling process. By increasing the number of ARB cycles to the third one, the elongation of composite improved. Even though the elongation decreases at higher number of passes; however, it is higher than initial passes.

Automated summary

In this study, the microstructure and tensile properties of a multi-layered Al/Cu/Zn/Ni composite after various ARB passes were evaluated. It was found that the Ni layer fractured first, followed by the Cu layer, while the Zn layer only showed localized necking. With increased ARB cycles, a uniform distribution of Ni, Cu and Zn was achieved within the Al matrix, and the formation of CuZn5 intermetallic compound at the Cu and Zn interface was observed. The elongation of the composite improved with increasing ARB cycles, although it decreased at higher number of passes.