Effects of Nickel on the Interface Behavioral Mechanisms of Copper Alloy/Steel Bimetals

In this study, bimetallic specimens comprising copper alloy and carbon steel are prepared using a liquid–solid compound casting method. Our results elucidate the behavioral mechanism of Ni at the Cu/Fe interface, with a focus on the interfacial microstructure evolution characteristics, atomic diffusion characteristics, and mechanical properties. Based on our results, the interfaces with different Ni contents exhibit Cu/(Ni 3 P + Fe 3 P)/Fe structures, which transition to Cu/(Ni 3 P)/Fe structures as the Ni content increases. Ni reduces the minimum diffusion energy barrier at the interface, facilitating the diffusion of Fe into Cu. At a Ni content of 3%, the diffusion coefficients of Fe and Cu show the greatest enhancement, with an atomic diffusion distance of 8.7 μm. The shear strength reaches 191.3 MPa.