GB1042952A - - Google Patents

Abstract

1,042,952. Welding by pressure. E. I. DU PONT DE NEMOURS & CO. April 3, 1963, No. 13169/63. Addition to 923,746. Heading B3R. [Also in Division C1] In forming a continuous metallurgical bond between metal layers, a juncture is formed between two layers with an angle of at least 1 degree therebetween and up to 60 degrees, a layer of a detonating explosive is positioned on the external surface of at least one of the layers and the explosive is initiated so that at least one of the ratios of the collision velocities to the respective sonic velocities of the layers is less than 1À2 and when each of these ratios is greater than 1À0 the angle between the adjacent metal layers in the collision region exceeds the maximum value of the sum of the deflections produced in the layers by oblique shock waves. A metal layer 1, Fig. 1 (not shown), rests at one end on a metal layer 2 and is supported from the latter at the other end by a bar 4, the layer 2 rests on a support 3 of metal, wood or gypsum cement and a layer of detonating explosive 5 is provided on the layer 1. In a modification metal layers 1, 2, Fig. 2 (not shown), each carrying a layer of detonating explosive 5 rest on support means 3. The layer of explosive may be initiated simultaneously over the entire surface or may be initiated from one side or the other or from a point at a corner edge or centre steel, copper, aluminium, iron, titanium, niobium, chromium, cobalt, nickel, beryllium, magnesium, molybdenum, tungsten, copper, gold and their alloys may be welded and each layer may be a single metal, an alloy or a composite of two or more layers and may be of graduated thickness or curved, dished or bent. More than two layers may be bonded, e.g. by providing an interleaf between two outer layers. The metal layers may meet at a line or point or may be spaced a small distance at the line or point close to the intersection line of the planes of the layers. A layer of cast, granular, gelatinous, flexible or fibrous explosive based on pentaerythritol, tetranitrate, cyclotrimethylene-trinitramine, trinitrotoluene or ammonium nitrate may be used and held in position by tape, glue etc. with possibly an intermediate buffer layer of polyester foam or film, water, tape etc. An assembly of layers to be bonded may be placed on each side of a single explosive layer. The bonded metals may be drawn, extruded or rolled. Details are given for bonding layers of stainless steel to mild steel, of mild steel to mild steel, and of copper to nickel. Details are also given for bonding titanium to titanium using an interlayer of stainless steel, of mild steel to stainless steel using a three-layer interlayer of copper, mild steel and copper, of copper to copper using an interlayer of mild steel and of stainless steel to stainless steel using an interlayer of silvercopper alloy.