GB1433526A - Jacketed wire and method of producing the same - Google Patents

Abstract

1433526 Producing composite wires G RAU 11 April 1973 [13 April 1972] 17462/73 Heading B3A [Also in Divisions C7 and H1] In a method of producing a composite wire in which a metallic core 1 is placed in a metallic jacket 2, the core and jacket are subjected to plastic shaping and annealing, and a gas is allowed to permeate the jacket to cause a gasmetal reaction at the jacket/core interface to produce an insulating layer 3. The metal which takes part in the gas-metal reaction may be from the core, the jacket or an intermediate layer previously provided at the interface. In a preferred embodiment a silver jacket is reduced on to a core of copper-nickel alloy, and the composite wire is annealed in air or oxygen for 3 hours at 800 degrees, an oxide layer being formed at the surface of the core. Alloys of nickel and chromium may be alternatively used for the core, especially a nickel alloy including aluminium to which small amounts of calcium and/or cerium may be added. The jacket may be copper, and the gas may be nitrogen or may cause a carbon reaction to occur.