Sixth Paper: Explosive Welding and Cladding: An Introductory Survey and Preliminary Results

Abstract

This paper reviews the published literature on the explosive welding of metals and the related subject of pressure welding. The mechanism of explosive welding is closely associated with that of shaped charges with metal linings, so a brief résumé of the theory of such charges is given. It is also noted that fluid waves are sometimes generated at the weld interface in explosively welded joints, and the mechanism of their generation is discussed. Experiments are reported on the explosive cladding of mild steel with stainless steel, 70/30 brass, and high-conductivity copper. These have been aimed at establishing the effect of impact angle, weight of charge, and the thickness of the flyer plate on the form of the weld achieved. The mechanical strength of the welded joints has been investigated by shear, tension, and bend tests, and the variation of hardness across the weld interface has also been examined. Results of these various tests are presented and discussed. It is concluded that explosively cladded material has some advantages over conventionally pressure cladded material. In particular it is probable that the strength of the welded interface is much stronger. With large charges and small angles of impact it is possible for the parent plate to suffer from shock damage which can be clearly seen under a microscope, but it is not known if this is harmful to the mechanical properties. Hardness is increased each side of the interface but a reduced value is measured close to the interface.