GB812819A - Improvements in and relating to the extrusion or other high pressure flow-working oftitanium - Google Patents

Abstract

812,819. Extruding; forging. NATIONAL RESEARCH DEVELOPMENT CORPORATION. May 15, 1956 [May 20, 1955], No. 14688/55. Class 83 (4). A method of forming articles from titanium by pressure flow-working, in which the titanium is provided with a ductile metallic coating which acts as a lubricant during the working. The coating may be of aluminium, aluminium alloyed with niobium, silver, or silver alloyed with manganese, tin, cadmium or zinc. The coating is applied by electrodeposition, metal spraying, or dipping in a bath of molten coating metal especially when aluminium is used as the coating. In this case the titanium is first cleaned in a fused caustic bath to remove oxide scales and after neutralizing the caustic, the titanium is plunged into a bath of aluminium at 650‹ C. The coated titanium may be worked immediately at this temperature or the temperature may be further raised, for example, by lowfrequency induction heating. Alternatively the coated titanium may be allowed to cool and be subsequently re-heated and worked. The working operation may comprise extrusion at a temperature of 800‹ C., impact extrusion or warm extrusion. A sheet of glass cloth may be wrapped around the coated titanium billet before extrusion and in this case the extruded product may be subsequently de-scaled by treatment in a sodium hydride or fused caustic bath. Alternatively the working operation may comprise die forging using only a thin coating of ductile metal on the titanium. Specification 684,013 is referred to. Reference has been directed by the Comptroller to Specification 749,365.