Effect of SiC particles on the microstructure evolution and mechanical properties of aluminum during ARB process

The effect of the addition of SiC particles on the microstructural evolution and mechanical properties of aluminum strips during accumulative roll bonding (ARB) was studied. Nanostructured Al/7 vol.% SiCp composite sheets were produced by ARB at room temperature. Monolithic Al sheets were also produced by the ARB process to compare with the composite samples. The fabricated composites after 8 ARB cycles showed a fairly homogeneous distribution of the SiC particles without significant porosities. Elongated ultrafine grains were formed in the ARB processed specimens of both the monolithic Al and Al/SiCp composite. It was found that the grain refinement is accelerated by the presence of the SiC particles, so that the Al matrix of the ARB processed composite showed finer grain sizes with the higher fraction of high-angle grain boundaries than the monolithic Al specimen. It was also found that the tensile strength of the ultrafine grained Al/SiCp composite was about 1.33 times higher than that of the ultrafine grained monolithic aluminum.