Investigation of texture, grain structure, electrical conductivity, electromagnetic interference shielding, and mechanical features of Aluminium/Brass composites

Although laminated composites are extensively used in transportation components due to their high strength-to-weight ratio, limited attention has been given to their electrical conductivity and electromagnetic interference (EMI) shielding properties. To this end, aluminium-matrix and brass-matrix composites were processed by the accumulative roll bonding (ARB) method. The composites were prepared from 3-layer, 5-layer, and 7-layer sandwiches at different equivalent strains ranging from 0.8–5.6. Observation of microstructures demonstrated the increased number of interfaces and grain boundaries at higher equivalent strains. As the number of layers in sandwiches increased, grain refinement and the size of fragments decreased. By increasing the equivalent strain and number of layers, the electrical conductivity decreased while the EMI shielding increased. These changes are attributed to increased scattering at interfaces, dislocations, and grain boundaries. After an equivalent strain of 5.6 in a 7-layer sandwich, the electrical conductivity and electromagnetic shielding values of aluminium-matrix composites were 21.5% IACS and 38.2 dB while they were 10.3% IACS and 25.2 dB in brass-matrix composites. Also, after the equivalent strain of 5.6 in 7-layer sandwiches, the maximum ultimate strengths of 983 and 920 MPa were obtained in brass-matrix composite and aluminium-matrix composite, respectively.