Explosive Cladding Research Articles

Developments in Explosive Welding

THE possibility of explosive cladding was first recognised in 1957, when it was noted in explosive forming that if a metal die was employed and an excessive charge was used then the metal sheet which was being formed became welded to the die. Since that time numerous papers have been published, for instance Davenport and Duvall (Ref. 1), Pearson (Ref. 2), Holtzman and Ruderhausen (Ref. 3), Boes (Ref. 4), and Bahrani and Crossland (Ref. 5) to mention but a few. All the early work was devoted to the application of cladding, and it is only during the last two or three years that the applicability of the process to tube welding, lap welding, welding of tees has been mentioned. At the present time the main potential fields of application are to the cladding of dissimilar metals over large areas and the welding of tubes to tube plates.

Explosive cladding of thin steel tubes with copper: An exploratory study

Experiments are described in which the internal surfaces of 2·0 in. o.d. × 0·125 in. wall steel tubes were explosively clad with 0·062 in. thick copper, and the bonds evaluated. Jetting occurred using Cordtex charges and the bond shear strengths exceeded that of the copper. A technique for absorption of the excess explosive energy is described which should permit the process to be used with a wide range of workpieces.

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

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.