Application of high velocity impact welding at varied different length scales

Three complementary impact welding technologies are described in this paper. They are explosive welding, magnetic pulse welding, and laser impact welding, which have been used to provide metallurgical bonds between both similar and dissimilar metal pairs. They share the physical principle that general impact-driven welding can be carried out by oblique impact but are used at different length scales from meters to sub-millimeter. The different length scales require different kinds of systems to drive the process, and the scales themselves can give different weld morphologies. Metallographic analysis on cross-sections shows a wavy interface morphology which is likely the result of an instability associated with jetting, which scours the surfaces clean during impact. The normalized period and amplitude of the undulations increase with increasing impact energy density. Microhardness testing results show the impact welded interface has a much greater hardness than the base metals. This can lead to weldments that have strengths equal to or greater than that of the weakest base material.