Interface characterization of Cu18150/Al1060/Cu18150 laminated composite produced by combined cast-roll and hot-roll technique

This study investigates the interface characterization of a Cu/Al/Cu laminated composite fabricated through a combined cast-roll and hot-roll technique. The composite, measuring a total thickness of 0.9 mm, comprises cast-rolled Cu18150 (0.15 mm), Al1060 (0.45 mm), and hot-rolled Cu18150 (0.4 mm). Notably, the hot-rolling interface of Al1060 demonstrates enhanced mechanical interlocking due to high-temperature deformation, leading to robust bonding and a homogeneous microstructure, while the cast roll interface exhibits different bonding characteristics due to less deformation during casting. X-ray diffraction analysis reveals significant intermetallic compounds (IMCs), particularly Al 2 Cu, which contribute to the composite's mechanical properties. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) analyses elucidate the formation of IMCs at the interfaces, with predicted formation sequences influenced by Gibbs free energy data. Electron backscatter diffraction (EBSD) analysis indicates that hot rolling promotes grain refinement in Cu18150, resulting in a homogeneous structure with elongated fine grains, while Al1060 shows nonuniform grain distribution. Mechanical testing reveals a tensile strength of 367.4 MPa and an elongation-to-failure of 6.2%, indicating a well-balanced composite suitable for engineering applications. Fracture analysis suggests that failure initiates at the interfaces due to stress concentrations exacerbated by the brittleness of certain IMCs. The findings highlight the potential of Cu/Al/Cu laminated composites for applications requiring high strength and ductility, paving the way for further research into optimizing processing techniques for enhanced performance. • The Cu/Al/Cu multilayered composite has a total thickness of 0.9 mm, comprising distinct layers of cast-rolled and hot-rolled copper and aluminum. • The upper interface of Al1060 exhibits improved mechanical interlocking due to high-temperature deformation, resulting in a robust bond and homogeneous microstructure. • SEM and EDS analyses show the formation order of IMCs influenced by Gibbs free energy, with CuAl 2 forming preferentially during processing. • EBSD analysis indicates that hot rolling leads to fine grain structures in copper, while aluminum shows nonuniform grain distribution. • Fractures initiate at the interfaces due to stress concentrations from brittle IMCs, with ductile behavior observed in the aluminum layer. • The absence of lamination post-tensile testing signifies strong interlayer adhesion due to significant atomic interdiffusion during hot rolling.