A combination of aluminium strip and brass mesh to process a refined structure composite via accumulative roll bonding: A characterization study

Abstract

In the present study, a dissimilar composite consisting of commercially pure aluminium and 70–30 brass alloy was manufactured using the accumulative roll bonding process. For microstructural evaluations, optical microscopy, scanning electron microscopy, and electron back-scattered diffraction were employed. It is indicated that after the 3rd ARB pass, the bonding between the reinforcements and matrix strengthened. However, after the 5th pass, the formation of micro-cracks along the Al/brass interface was observed. These cracks accompanied by the separation of matrix/particle led to fracture of the composite from the base metal as confirmed by fractography of the failed specimen. Also, the average diameter of Al grains was estimated to range from 1.2 μm (between brass particles) to 850 nm (near brass fragments). The micro-texture study of the selected areas indicated the evolution of P and Q components known as recrystallization texture near the brass particles. Above all, mechanical evaluations were conducted using Vickers microhardness and tensile tests. Results revealed a dramatic increase in the composite ultimate strength and hardness and then saturation as compared to that of Al without brass fragments. However, a sudden drop in hardness occurred for the composite at the 3rd pass.