Experimental and numerical investigation of microstructure and mechanical behavior of titanium/steel interfaces prepared by explosive welding

This paper presents a systematic study of structure and mechanical behavior of Ti/Fe explosive-bonded interfaces. The transient fluid-like behavior at the bonding zone is simulated using Smoothed Particle Hydrodynamic (SPH) numerical method. The interface is featured by a wave structure, resulted from heavy plastic deformation during the explosive welding. Melted zone resulted from the trapped jetting is surrounded by strongly deformed bulk materials. Fe2Ti intermetallic compounds with a mixture of FeTi+Fe phases are observed in the melted zone. A reaction layer (~700 nm) consisted of nano-sized FeTi grains is formed at Ti/Fe material boundary. Nanoindentation tests and fracture observation confirm the brittle nature of Fe-Ti intermetallics formed in the explosive-bonded joint. Extremely temperature accumulated near the interface leads to recovery and recrystallization in deformed grains, which can accommodate relatively large strain near the interface.