Identification of Process Parameters in Electromagnetic Pulse Welding and Their Utilisation to Expand the Process Window

Abstract

Impact welding, represented by the industrial processes explosion welding and electromagnetic pulse welding, offers unique advantages over conventional welding processes, especially fusion welding. The joint is produced during a high speed impact between two workpieces without additional heating or melting. Thus, even dissimilar metals can be joined. However, in contrast to fusion welding, the fundamentals are understood to a significantly lesser extent. In this publication, the effect of the density of the surrounding gaseous medium is investigated. The results show that a lower density results in a higher weld strength. At higher densities, a weld can even be inhibited completely. High speed images of the impact indicate that this is caused by the obstruction of the so-called jet due to the increased air resistance. In general, “jetting” describes the ejection of oxides, dirt and superficial material from the closing gap during the impact. It is presumed to be essential for the formation of the bond.