Study On Aluminium Matrix Multilayered Composite Produced By Accumulative Roll Bonding

Al/AZ31 and Al/Cu multilayered composite was produced by accumulative roll bonding (ARB) processing. An scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS) was used to characterize the cross-section of the ARB processed Al/AZ31 and Al/Cu multilayered composite. The microstructure of the Al constituent layer in the Al/AZ31 multilayered composite were also observed by a transmission electron microscope (TEM), the constituent phase at the interface of the Al/Cu multilayered composite were analyzed by the X-ray Diffraction (XRD). The micro-hardness of the cross-section of the Al/AZ31 and Al/Cu multilayered composite material were also measured.The results show that the Al/AZ31 and Al/Cu multilayered composite could be fabricated successfully after the ARB processing. The grains of the constituent layers were fined, so the strength of the Al/AZ31 and Al/Cu multilayered composites were improved with increasing the rolling cycles. The micron-scale diffusion layers at the Al/AZ31 and Al/Cu interfaces of the multilayered composites were observed, and the thickness of the diffusion layer increases with the increase in the ARB cycles. The Vickers hardness shows that there exists gradient hardness at the Al/AZ31 interface diffusion layer. The structure of the interface diffusion layer and the influence of the interface layer on the strength of the multilayered composite were analyzed based on the experimental results. It was also shown that Vickers hardness was also increased gradually with the rolling cycles, and compared with the later slow increment of the hardness, there was a big jump in the first cycle. The tensile test of the Al/Cu multilayered composite after the ARB processing shows that there was a peak tensile strength and a good elongation for the Al/Cu multilayered composite in the first cycle of the ARB processing and the mechanical properties were excellent. But the strength decreased badly to the lowest and a peak elongation occurred in the second rolling cycles. As the rolling cycles increased, strength increased gradually and elongation decreased gradually from the second cycles. Accumulative roll-bonding is a method to achieve a metallurgical bonding between different materials, the main bonding mechanism is the diffusion mechanism, which is achieved through the heating before rolling and the accumulative strain, the higher of the rolling temperature and the reduction of the rolling process, the more fully of the diffusion process, and this process has a decisive impact on the combination intensity. The intermetallic compounds at interface diffusion layer have a great influence on the overall performance of the material.