Characterization and performance study of the interface structure of explosion welded copper/steel composite tube
In order to study the relationship between the existence type of grains in the copper/steel bimetallic composite pipes and mechanical properties,T2 copper/316L composite pipes were fabricated using explosion welding technology,and a detailed analysis of the interface morphology and microstructure of the copper/steel metal composite pipes was made.The results show that the bonding interface of the composite pipe features both a flat interface and a periodic wavy interface,with the wavy bonding region exhibiting an average wavelength of 203 μm and a wave height of 58 μm.Elements on both sides of the composite pipe bonding interface undergo interdiffusion,resulting in a diffusion layer thickness of 1 μm.The grain size on the Fe side of the interface is relatively small,gradually increasing with the distance from the bonding interface.Nanoindentation experiments reveals that the nanoindentation hardness at the peak of the wavy interface reaches 3.16 GPa,whereas at the trough it is 2.44 GPa.Furthermore,the hardness near the peak is consistently higher than that near the trough,with the hardness on the Fe side exceeding that on the Cu side.The distribution pattern of mechanical properties obtained from nanoindentation experiments aligns with the distribution pattern of the microstructure.