Study on preparation, microstructure and properties of gradient composite interlayer with copper/steel

In order to optimize the interface performance of copper/steel bimetallic composite and avoid the degradation of the composite performance owing to the difference of thermal-physical properties, HS211/ER50-6 composite structure was fabricated by arc additive technology, and Fe–Ni and Cu–Al flux-cored wires were designed as transition materials to realize the gradient connection of the interface area. Microstructure observation and mechanical properties testing were used to characterize the properties of the samples. The results showed that gradient connection can be achieved by adding the transition layer of Fe–Ni and Cu–Al flux-cored wires. Fe-rich phases with different morphologies were found in the interface region, which strengthened the matrix as the second phase. The corrosion resistance of the Fe–Ni transition layer region was better than Cu–Al, and the impact absorption energy reached 925 kJ/m2. The tensile strength of Fe–Ni samples reached 326.5 MPa, and the fracture location of the two groups of samples were both the copper side deposition.