GB1045427A - Improvements in metallurgically bonded composite metal structures - Google Patents

Abstract

1,045,427. Making composite metal articles. REVERE COPPER & BRASS INCORPORATED. March 22, 1965 [April 7, 1964], No. 12051/65. Heading B3A. A composite metal structure, e.g. a rod or a tube, is made from cold workable materials which can be metallurgically bonded together, by placing the concentric metal components of the composite one inside the other, subjecting the composite to a preliminary cold drawing operation to seat the outer component firmly on the inner component, subjecting the composite to a first cold drawing operation to reduce the cross-sectional area of the composite to an extent limited only by the cold working properties of the materials of the composite, subjecting the cold drawn composite to a first annealing operation wherein the composite is heated to the annealing temperature of the metal component having the highest annealing temperature and is held at this temperature for a length of time sufficient to anneal all of the components of the composite, and thereafter subjecting the composite to at least one additional cold drawing operation and annealing operation to reduce the diameter of the composite to the desired degree and to create a metallurgical bond at the interface of the metallic components of the composite structure. The example describes the bonding of stainless steel to cupro-nickel alloy, but other metals which may be used are steel and other ductile ferrous alloys, copper, brass and other ductile cuprous alloys, nickel alloys, tin alloys or titanium and titanium alloys. Before assembly the surfaces of the metal components to be bonded together are thoroughly cleaned and may be plated with metal, e.g. copper or silver by electro-deposition. In making a threelayer composite the inner component may be wound with a tape of the second metal and placed inside the outermost tubular component.