Configuration-dependent collision states and interfacial response in cylindrical explosive-welded metallic composites: a review

Cylindrical explosive welding is used to produce dissimilar-metal tube–rod and tube–tube composites; however, curvature, finite annular gaps, and radial collapse or expansion make the local collision state configuration dependent. This review examines parameter design for tube–rod inward collapse and tube–tube inward and outward configurations. It evaluates the role of equivalent-planar relations in defining initial charge and stand-off estimates and examines the configuration-specific conversions and finite-gap kinematics required to determine local collision velocity, collision angle, and contact pressure. Evidence from time-resolved measurements, position-matched numerical extraction, interfacial morphology, reaction-zone chemistry and microstructure, local mechanical response, and component-scale performance is synthesized to assess proposed parameter ranges. The review shows that velocity–angle relations can guide initial screening, but final design ranges must be established for the specific material pair, geometry, loading arrangement, and spatial–temporal collision location. The resulting framework links process configuration to local collision conditions, interfacial response, and component performance, and identifies the evidence needed to develop configuration-specific design criteria.