GB503070A - Improvements in and relating to the manufacture of wire - Google Patents

Abstract

503,070. Making wire; drawing. BRITISH THOMSON-HOUSTON CO., Ltd. Oct. 19, 1938, No. 30247. Convention date, Oct. 19, 1937. [Classes 83 (ii) and 83 (iv)] A method of making wire of a relatively brittle metal comprises assembling a rod of the metal within a tube of relatively ductile metal to form therewith a composite assembly, successively drawing the assembly through a series of dies to reduce the same to a predetermined diameter and then removing the ductile metal from the embedded wire of brittle material. The method is intended more particularly for the drawing of wire of a diameter of about 0À001 inch of aluminium or similar metals or their alloys. A rod 10 of aluminium is inserted in a tube 11 of copper, Fig. 1, and the assembly is subjected to a series of alternate drawing and annealing operations until the diameter of the copper is reduced to about 0À115 inch. The annealing comprises heating the wire to a temperature of 350‹ C. for 30 minutes. Four such composite wires 14 are then assembled within another copper tube 15 and the alternate drawing and annealing operations are continued until a diameter of 0À009 inch is reached after which the copper is removed by a bath of dilute nitric acid and the fine aluminium wires are washed and dried. For the second series of drawing operations a number of uncased wires of the brittle metal may be included within the tube 15 but out of contact with each other. Specification 491,206, [Group XXI], is referred to.