The interface microstructure and phase constitution of Nb/316L composite plates fabricated by explosive welding

Niobium has a reputation for its superior superconducting, high strength and corrosion resistance at elevated temperatures. In this work, the explosive welding technique was successfully performed to join Nb/316L dissimilar metals. To reveal the phase constitution and texture distribution at the joining interface, the EBSD test was carried out. It was concluded that an irregular large wavy structure of fine crystal, sub-grains and twin structures was formed. In addition, the recrystallised structures, substructures, deformed structures and local internal stress at the joining interface were attributed to severe plastic deformation and rapid solidification of liquid metal. Furthermore, six different deformation textures and recrystallisation textures were confirmed at the joining interface due to severe plastic deformation and dynamic recrystallisation.