Review of the weldability window in explosive welding processes

Explosive welding is a solid-state joining technique that employs explosive energy to propel the flyer plate into oblique collision with the base plate, forming a metallurgical bond at the interface. The process parameters, such as the loading ratio, the nature of the explosive, the standoff distance, and the surface finish, determine whether the resulting interface is straight, wavy, or contains reaction compounds. Due to the intricate nature of the process, researchers have developed a weldability window, a theoretical model for selecting parameters that yield optimal bonding. The weldability window is bounded by lower, upper, left, right, and jetting boundaries, all of which are influenced by the properties of the participant metals. Operating within the boundaries of the window results in a wavy interface, which is considered ideal. The incorporation of an interlayer in explosive welding shifts the boundaries, expanding the weldability window by up to 40 % and enhancing process versatility. Similarly, researchers successfully reported the development of a tri-axial weldability window that considers three parameters. This review explores the evolution of the weldability window, its theoretical underpinnings, parameter optimization, and opportunities for future research in the field.