GB1342117A - Fibrous metal filaments - Google Patents

Abstract

1342117 Making filaments; extruding BRUNSWICK CORP 19 April 1971 [29 Jan 1970] 20790/71 Headings B3A and B3P [Also in Division E1] A metal filament, which may be solid, tubular of bimetallic, is made by surrounding a blank 14, Fig. 21, of the filament metal with a matrix metal 50, constricting the assembly and then removing the matrix. After sheathing the blank with the matrix, which may be swaged thereon (Example 4), a number of these assemblies 12, Fig. 10, are placed in parallel within a can 16 to which end caps 17, 23 are welded and the can is evacuated through pipe 26 which is subsequently pinched and welded at 26b; a heater 27 facilitates an improved vacuum. Spacers (19, Fig. 6, not shown) or metal powder (21, Fig. 7, not shown) may surround the assemblies within the can. The resultant bundle (31, Fig. 11, not shown) is then constricted by hot extrusion through heated dies (32). The extruded workpiece has its ends trimmed by cutters (36, Fig. 12, not shown) and is then subdivided into shorter lengths (35, Fig. 13, not shown) by cutting wheels (38). Each length (35) has end pieces (39, 40, Fig. 14, not shown) welded thereto and after reheating, is further extruded through dies (41, Fig. 15, not shown). Alternatively the bundle may be compacted by upsetting in a closed die, Fig. 4 (not shown), or by hot rolling, Fig. 16 (not shown), or by hot extrusion followed by hot rolling. Thereafter the workpiece is cold drawn in stages through dies (44, Fig. 17, not shown) with intermediate annealing. The cold drawing may be omitted or the hot working steps may be eliminated and only the cold drawing is then performed. Finally the matrix material and the can are removed by electrochemized dissolution, thermal removal, selective oxidation, mechanical removal or by acid leaching with nitric or phosphoric acid. When forming a tubular filament, a hollow starting workpiece 14 has a matrix core 49 which is subsequently removed. The final filament may be of tubular hexagonal cross-section, Fig. 24 (not shown). The filament may be made of nickel, stainless steel, titanium or titanium alloy. Bi-metallic filaments may comprise: copper or mild steel core surrounded by stainless steel; Monel metal (RTM) core surrounded by stainless steel or niobium or tantalum or beryllium; mild steel core surrounded by nickel-base super alloy or nickel or aluminium or titanium; copper core surrounded by gold or platinum; aluminium core surrounded by copper or mild steel or magnesium; molypermalloy core surrounded by copper. The sheathing matrix may be of mild steel, copper, aluminium or aluminium alloy, stainless steel, Monel metal (RTM). The can may be of mild steel copper or Monel metal (RTM). Many examples are given.