Effects of Interlayers on Interfacial Structure and Mechanical Properties of Zr/Stainless Steel Explosion Welded Joints

The explosive welding technique was employed to bond R60702 zirconium rod with 022Cr19Ni10 stainless steel clad pipe using Ta and Ti as the interlayer, respectively. R60702 zirconium/022Cr19Ni10 stainless steel composite rod components were fabricated successfully. The interfacial microstructure observation and the mechanical properties of the composite bars were examined. The results indicate that an interface structure characterized by the combination of wavy and curved morphologies is formed under the both interlayers, and the interfacial bonding quality is good. When Ta is used as the interlayer, the interfacial plastic deformation is more pronounced, the amplitude of the interface wave is larger, and a relatively developed vortex structure has formed. There is a distinct mixed region of Ta, Fe, Cr, and Ni elements within the vortex. The tensile shear strength of the joint with Ta interlayer reaches 324 MPa, which is 11.0% higher than that of the joint with the Ti interlayer. Fracture in the Ti-based joint occurs at the stainless steel-Ti interface, whereas the cracks in the Ta interlayer joint originate from a localized area at the interface between Ta and zirconium, and propagate along the wavy bonding interface.Both joint fracture surfaces exhibit mixed fracture characteristics, with both ductile and brittle fractures present. The higher shear strength of the Ta-interlayer joint may be related to the mechanical interlocking effect produced by its more pronounced wavy and vortex interfaces, as well as its larger effective bonding area.