GB874514A - Improvements in or relating to welded bi- or multi-metallic tubular junction pieces - Google Patents

Abstract

874,514. Extruding composite tubes; welding by pressure. ETABLISSEMENTS AUTROUSSEAU & CIE. May 29, 1959 [June 3, 1958], No. 18416/59. Classes 83 (2) and 83 (4). A bi-metallic or multi-metallic tubular connecting element 1, 2, Fig. 7, is made by cold pressure welding together two slugs respectively of copper and aluminium, or alternatively cold welding these slugs to the ends of an intermediate slug of a third metal, and then cold extruding the composite block thus formed into a tube with the weld surface or surfaces of conical form. Metal slugs 1, 2, Fig. 2, of copper and aluminium are cold pressure welded together in dies 3, 4. The weld bead 6 is then removed by a shear ring 7, Fig. 3 (not shown) and the compound slug 1, 2 is then cold backwardly extruded by a punch 10 in a die 9, Fig. 5, to cup shape, Fig. 6 (not shown), with the weld junction lying on a conical surface. The closed end is then removed to form the element of Fig. 7 with its weld junction 5. In another embodiment, Fig. 9 (not shown), the element is formed by direct extrusion using a ram with an integral mandrel. The starting workpieces may be of tubular or cup shape, Figs. 10, 11 (not shown). In another embodiment an intermediate slug of a third metal is cold welded between the slugs of copper and aluminium. The element may be used to connect together copper and aluminium tubes by simple butt or resistance welding these tubes to the respective ends of the element.