GB632564A - Improvements in or relating to the manufacture of titanium in a cold-malleable form - Google Patents

Abstract

The Specification as open to inspection under Sect. 91 refers to the formation of titanium carbide and boride by reaction between carbon tetrachloride or boron trichloride with titanium tetrachloride and magnesium. This subject-matter does not appear in the Specification as accepted.ALSO:Cold-malleable titanium is produced by reacting titanium tetrachloride vapour with fused magnesium at substantially atmospheric pressure in a protective gas atmosphere, inert to both reactants and to the reaction products and free from oxygen and nitrogen, at a temperature such that any substantial ebullition of the magnesium is avoided. The magnesium charge, in a molybdenum lined steel crucible, is placed in a quartz tube which is first induction heated to about 200 DEG C. whereupon a small quantity of titanium chloride is introduced for drying purposes: argon is then supplied and an arc struck between calcium electrodes to remove any oxygen or nitrogen. The temperature is then raised to 800 DEG C. and titanium chloride dripped on to the fused magnesium, the temperature being controlled during the reaction by controlling the rate of introduction of the titanium tetrachloride or by varying the high frequency current. When the reaction is substantially complete, further titanium chloride is introduced and the temperature raised 1150 DEG C., the furnace then being cooled and evacuated to remove traces of titanium tetrachloride. The crucible is then bored out and the chips treated first with water and then with dilute hydrochloric acid, ground, treated again with hydrochloric acid, washed with water and alcohol and dried at 120 DEG C.; they are then heated for three hours at 500-700 DEG C., briquetted and sintered or fused on a thorium oxide layer. As alternatives, magnesium or barium may be used in place of calcium and either may be vapourized in a crucible; magnesium and titanium tetrachloride may be introduced simultaneously; the magnesium chloride may be separated from the titanium by fusion in a vacuum or in an argon atmosphere. After fusion on sintering the titanium may be deformed at 700 DEG C., followed, if desired, by deformation at a lower temperature, and then annealed at 500 DEG C. in a gas flame or in an electric furnace: it is then hot rolled and cold stretched. The titanium may be used in flashlight powder. The Specification as open to inspection under Sect. 91 comprises also (a) the subject-matter of Specification 632,632, (b) the use of any titanium halide, (c) reaction in a vacuum or in a hydrogen or mixed hydrogen-inert gas atmosphere, (d) the use of calcium, lithium, strontium and barium as reducing agents, (e) the use of steel crucibles lined with tungsten, tantalum, niobium, vanadium, chromium, titanium, zirconium, hafnium or thorium, (f) the production of iron-titanium alloys by reaction in the presence of iron carbonyl or ferric chloride and of aluminium-titanium alloys by the use of a calcium-aluminium alloy as reducing agent, (g) the additional step of treating with hydrofluoric acid between the steps of treatment with hydrochloric acid and washing with water and alcohol, (h) the use of oxides or titanates of alkaline earth metals instead of thorium oxide, (i) the use of other refractory metals and of borides and carbides of refractory metals as fusing bases or as crucible materials e.g. a crucible may be formed of titanium carbide with titanium as a binding agent, (j) the heating of the fused or sintered titanium in a fused salt bath comprising 50 per cent of potassium carbonate and 50 per cent of lithium carbonate. This subject-matter does not appear in the Specification as accepted.