US 3839020 A
An alloy sponge of titanium or a zirconium base metal is produced by admixing a halide of an additive alloy element with titanium tetrachloride or zirconium tetrachloride, and thereafter reducing both simultaneously with a metallic alkali to produce said alloy of titanium or zirconium.
Description (OCR text may contain errors)
Honma et al.
Inventors: Shunzo Honma; Minoru Harada,
both of Takaoka, Japan Nippon Soda Company, Ltd., Tokyo, Japan Assignee:
Notice: The portion of the term of this patent subsequent to June 13, 1989, has been disclaimed.
Filed: June 11, 1971 Appl. No.: 152,406
US. Cl. 75/84.5 Int. Cl. C22b 53/00, C22b 61/02 5] *Oct. 1, 1974  Field of Search 75/84.5
 References Cited UNITED STATES PATENTS 2,828,199 3/1958 Findlay 75/84.5 X 3,004,848 10/1961 Hansley et al. 75/84.5 X 3,669,648 6/1972 Homma et al. 75/84.5
Primary Examiner-Leland A. Sebastian Assistant Examiner-R. E. Schafer Attorney, Agent, or Firm-Oblon, Fisher, Spivak, McClelland & Maier ABSTRACT An alloy sponge of titanium or a zirconium base metal is produced by admixing a halide of an additive alloy element with titanium tetrachloride or zirconium tetrachloride, and thereafter reducing both simultaneously with a metallic alkali to produce said alloy of titanium or zirconium.
3 Claims, No Drawings BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a process of producing an alloy sponge of a titanium or zirconium base metal, and more particularly to a process of producing a titanium or zirconium alloy sponge, containing alloy elements such as, for example, aluminum, tin, tantalum, molybdenum, vanadium, etc.
2. Description of Prior Art Heretofore, industrial manufacturers of titanium or zirconium sponge have generally concentrated their efforts on achieving high lelves of purity, and very little attention has been directed toward solving those problems attendant in the inclusion of impurity additives into the pure metal sponge. In producing titanium or zirconium alloys, it has been usual to melt a mixture of the pure titanium or zirconium sponge with an appropriate quantity of an additive metal. Usually, the predetermined quantity of the additive is mechanically combined with the pure titanium, or zirconium sponge, such as by mechanically mixing the sponge metal with the additive, or by coating the additive onto the sponge metal. The mixture is then pressed into briquettes and the briquettes are connected to form bars of predetermined dimensions. The thus-formed bars are then subjected to are melting in a vacuum or in an inert atmosphere, whereby the bars are used as consumable electrodes, in order to form the necessary alloy melt. 'Such conventional processes, however, have not been considered to be entirely satisfactory from the point of view of efficient manufacturing production, since the steps necessary to integrate the pure titanium sponge or pure zirconium sponge, with the additive metal, in the formation of the briquettes, is quite complicated. Moreover, under certain conditions of additive metal distribution in the briquettes, significant amounts of segregation could occur in the product alloy. For instance, it has been found that due to the very great difference between the melting points of titanium or zirconium and certain additive elements, such as tantalum, tungsten, molybdenum, etc., it has not been possible to obtain complete alloying of the additive metal with the titanium. In some instances, no alloying at all is obtained, and in other instances, only small amounts of alloying is obtained, which can cause quite serious segregation effects to occur. Likewise, if the additive metal has a melting point which is significantly lower than titanium, such as is the case with aluminum, tin, etc., it has been found that serious segregation can occur, or low additive metal yields will be obtained, because of the extremely high vapor pressures these additives have at the titanium melting temperature.
ln order to alleviate these problems, it has been suggested to introduce the additive element in the form of a mother alloy, such as an alloy of the type of aluminum-vanadium, aluminum-molybdenum, aluminumchromium-vanadium, etc., but even this expedient hasnot proven entirely satisfactory. For example, in the case of titanium-tantalum type alloys, or titaniummolybdenum type alloys, alloying of the mother alloy with titanium or zirconium is quite difficult and is generally not considered to be an effective solution to the problem.
A need exists, therefore, for a commercially suitable technique for alloying any of a variety of additive elements with titanium or zirconium, which is economically efficient and which will produce a uniform, highly pure alloy sponge.
SUMMARY OF THE INVENTION zirconium base metal whereby the titanium or zirconium alloy ingots can be easily produced.
These and other objects have now herein been attained, in one aspect, by providing a process wherein a halide of an additive alloy element is admixed with titanium tetrachloride or zirconium tetrachloride, and with a metallic alkali, and thereaftersimultaneously reducing the additive halide and the titanium or zirconium tetrachloride to produce metallic titanium :or zirconium.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS According to the present invention, a titanium or zirconium sponge material is produced by admixing titanium tetrachloride or zirconium tetrachloride with a halide of an additive element. The mixture is then simultaneously reduced by contact with an alkali metal.
Suitable alkali metals useful in this process include sodium and potassium, although sodium is most preferred from an industrial point of view.
The additive halide may be in the form of a chloride, fluoride, iodide or bromide, but most preferred are the chlorides or fluorides. Suitable additive halides usable in the present invention may be, for example:
Al Aluminum chloride AlCl Si Silicon tetrachloride SiCl, V Vanadium tetrachloride VCl, Mo Molybdenum pentachloride MoCl, Cr Chromium trichloride CrCl Sn Tin tetrachloride SnCl, Ta Tantalum pentachloride TaCl;
(Potassium heptafluorotantalate) KJaF, Fe Ferric chloride FeCl Mn Manganese chloride MnCl- Hf Hafnium tetrachloride HfCl, Zr Zirconium tetrachloride ZrCl, W Tungsten pentachloride WCl Nh Niobium pentachloride NbCl, Co Cobalt chloride CoCl, Ni Nickel chloride NiCl Cu Cuprous chloride CuCl P Phosphorus pentachloride PC], S Sulphur dichloride SCl C Carhon tetrachloride CCI, Zn Zinc tetrachloride ZnCl, Be Beryllium chloride BeCl Y Yttrium chloride YCl, Pd Palladic chloride PdCl Pt Platinic chloride PClg The additive halide may be used in the physical form of a solid or liquid. If the additive halide is liquid, it is preferable that it be premixed with liquid titanium tetrachloride before adding it thereto. On the other hand, if the additive halide is solid, it may be added in the form of fine powder or as a suspension in the titanium tetrachloride.
When the additive element is being added to zirconium tetrachloride, which is solid at room temperatures, the zirconium tetrachloride may be gassified into the reactor through a sublimation furnace and the additive element may be simultaneously reduced with the gaseous zirconium tetrachloride in either a solid or liquid form.
In the subject reaction, the alkali metal may be used in stoichiometric or less than stoichiometric amounts, although if the total of the titanium or zirconium tetrachloride and the additive halide is 0.5 or preferably 1 to 2 percent more than the stoichiometric amounts, with respect to the metallic alkali, the alloy sponge obtained thereby may have a beautiful metallic gloss, and a lower Brinell hardness than the gloss and hardness of similar alloys prepared by conventional methods.
One of the unique aspects of the present invention is that the relatively large quantity of heat generated during the reduction of the titanium or zirconium tetrachloride to a lower chloride or free metal state, is advantageously used to reduce the difficulty reduceable additive halide. For this reason, it has been found that if the additive halide is added to a lower chloride of titanium or zirconium, and simultaneously reduced with the metallic alkali, reduction is quite difficult and a high quality alloy sponge cannot ordinarily be obtained. However, various types of suitable alloys may be obtained according to the process of the present invention.
In the preferred practice of the present invention, the titanium or zirconium tetrachloride, and the halide of the additive alloy element is simultaneously partially reduced with metallic alkali at a temperature of between 600 to 800C, so as to reduce most of the titanium or zirconium tetrachloride to the elemental metal form and to its lower chloride form, and to reduce most of the additive alloy to its elemental metal form. The reaction temperature should then be increased to about 900 to 950C. for l to hours. This technique provides a titanium or zirconium alloy which is characterized by large crystals having a relatively stable surface, which can be easily purified by leaching, and which is essentially devoid of surface impurities. This alloy also contains only a negligible quantity of hydrogen gas absorbed on its surface. Accordingly, the present invention results in a higher quality alloy sponge than heretofore obtainable, except by extraordinary procedures.
After the atmosphere in the reduction reactor is sufficiently replaced with an inert gas, such as argon, the predetermined amount of metallic alkali is charged to the reactor. The reactor is then heated and maintained at a temperature of 600 to 800C, preferably 600 to 700C. while the titanium or zirconium tetrachloride and the additive halide are gradually charged to the reactor in a predetermined ratio. An air cooled reactor jacket which is also heatable, may be provided to maintain the reaction conditions within the required range. The total charge of metallic alkali may be introduced at one time to the reactor, or it may be charged simultaneously or sequentially with the tetrachloride and the additive halide. When the tetrachloride is titanium tetrachloride, the rate of introduction of the tetrachloride and the additive halide may be adjusted by a flowmeter, and a feeder may be provided with a vibrator or the like. After the reactants are completely charged to the reactor, the reactor is further heated to a temperature of above 900C. for l to 10 hours in order to complete the reaction. The product is then cooled, removed and washed with water, with dilute mineral acid solution, or with hydrochloric acid. A high purity titanium or zirconium alloy sponge of uniform composition may then be obtained. This alloy sponge may be pressed into briquette form and are melted in an inert atmosphere or in vacuo. lngots of titanium or zirconium alloy having an evenly distributed composition, can be produced by pressing into the briquettes after crushing and mixing the sponge of titanium or zirconium base metal, even if the ratio of the admixed base metal halide and the additive element varies, or segregation in the composition of sponge causes, because of the total amount of both halide of base metal and additive elements is predetermined desirably.
Having now generally described the invention, a further understanding of the invention can be obtained by reference to certain specific Examples which are presented herein for purposes of illustration only, and are not intended to be limiting unless otherwise specified.
EXAMPLE (Ti-Al-Sn) 96.2 kg of metallic sodium, filtered and refined under an argon atmosphere, was charged into an iron reactor of 640 X 1600 mm. in size. The reactor was heated to 600C. in an electric furnace. Then, 186 kg. of titanium tetrachloride containing 2.74 kg. of tin tetrachloride was charged into a raw material weighing tank, and 12.4 kg. of aluminum chloride crystals were charged into a powder charging tank. Both were then charged into the reactor vessel in such a manner that the ratio of both materials were held at a predetermined rate. The reaction temperature was maintained at 630 to 750C. to effect the primary reaction. The aluminum chloride was continuously charged in such a manner that the charging amount thereof was adjusted by using a vibrator. After approximately 12 hours, the aluminum chloride was fully introduced. The reactor was heated to 950C. for 5 hours to complete the secondary reaction, and the reacted product was cooled and discharged. After the reacted product had been leached with l,000 liters of 1 percent hydrochloric acid and had then been washed, the product was dried in vacuo at 60C. The alloy sponge thus obtained had a grain size of 2-60 meshes and was black in color. A yield, or available percentage, of percent was obtained. In examining a dispersion of the constituents of the additive alloy in a specimen, it was found that it contained 4.6 to 5.1% Al and 2.4 to 2.7% Sn indicating the composition as Ti5Al-2.S Sn. A hydrogen content of 0.0022 to 0.0026 percent was also found. Thus, a uniform and superior titanium alloy sponge containing only a slight amount of hydrogen was obtained. This specimen was formed into a briquette which was arc melted to form an ingot button. The Brinell hardness o the button was 276 to 283.
EXAMPLE 2 (Ti-Al-Sn) Using the iron reactor described in Example 1, 305 kg. of titanium tetrachloride containing 4.8 kg. of tin tetrachloride and 26.8 kg. of aluminum crystals were charged into the reactor, together with 160 kg. of metallic sodium. The reactor was heated to 640 to 730C. and maintained at this temperature. The other steps described in Example 1 were performed. The product thus obtained was a black sponge and its yield percentage was 87 percent. Analysis of this product showed that it was a titanium alloy sponge containing 5.0% A1 and 2.4% Sn, and 0.0022 percent hydrogen. This sponge product was formed into briquettes which were are melted to form a button ingot. The Brinell hardness of the button was 282.
EXAMPLE 3 (Ti-Al-V) 97.9 kg. of metal sodium was filtered and refined under an argon atmosphere and was charged into the iron reactor used in Example 1. The reactor was heated to 600C. by an electric furnace, and 185.8 kg. of titanium tetrachloride containing 7.6 kg. of vanadium tetrachloride and 14.8 kg. of aluminum chloride crystals were charged into the iron reactor vessel such that the ratio of the reactants corresponded to predetermined ratios. The reactants were then heated to 620 to 750C. After the reactants had been completely charged to the reactor within 5 hours, the reactor was further heated to 930 to 960C. for 5 hours to complete the reaction. The product was cooled and discharged, and was leached with 1,000 liters of 1 percent hydrochloric acid and washed. [t was then dried in vacuo at 60C. The product obtained had a grain size of 2 to 60 meshes and was black in color. lts yield percentage was 85 percent. The constituents of the alloy sponge were found to be 5.9% A1 and 4.0% V. Thus, a titanium alloy sponge having the composition of Ti- 6A1-4V of commercial titanium alloy, was obtained. lts hydrogen content was 0.0030 percent. This sponge was formed into a briquette which was melted to form an ingot button. The Brinell hardness of the button was found to be 310.
EXAMPLE 4 (Ti-Ta) Using the iron reactor vessel described in Example 1, 188.1 kg. of titanium tetrachloride was charged into the raw material weighing tank, and 5.42 kg. of potassium fluoric tantalum crystal was charged into the reactor charging tank. 92.8 kg. of metallic sodium was charged into the reactor and was heated at 650C. under an argon atmosphere. Thereafter, titanium tetrachloride and potassium fiuoric tantalum were charged into the reactor at a predetermined ratio for 8 hours. The reactor was heated at 720 to 780C. The materials in the reactor were then heated to 930 to 960C. for 5 hours to complete the reaction. The product obtained was cooled and discharged and leached with 800 liters of 1 percent hydrochloric acid and then washed. It was dried in vacuo at 65C. and it was found to be black in color with a yield percentage of 84 percent. The prod- EXAMPLE 5 (Ti-Al) Using the iron reactor described in Example 1, 192 kg. of titanium tetrachloride was charged into a raw material weighing tank, and 7.4 kg. of finely crushed aluminum chloride was added thereto. The mixture was agitated continuously. 96.9 kg. of metallic sodium was charged into the reactor vessel and it was heated to 600C. under an argon atmosphere. Thereafter, aluminum chloride suspended in titanium tetrachloride was gradually dropped into the reactor over an 8 hour pe- EXAMPLE 6 (Zr-Sn) 503 kg. of metallic sodium, filtered and refined under an argon atmosphere, was charged into the iron reactor described in Example 1 which was heated to 700C. in an electric furnace. A mixture of gaseous zirconium tetrachloride and tin tetrachloride in a ratio of 125.8 kg. of zirconium tetrachloride to 1.650 kg. of tin tetrachloride, corresponding to 98.5% Zr to 1.5% Sn, was heated to 350C. and charged into the reactor. The temperature of the reaction was held at 720 to 780C. After the raw materials were completely charged to the reactor over a period of approximately 12 hours, the materials were heated to 900 to 950C. for 6 hours to complete the reaction. The product obtained was leached with 1,200 liters of 1 percent hydrochloric acid, and then was washed and thereafter dried in vacuo at 65 C. The product thus obtained was a gray sponge and its yield percentage was found to be 83 percent. As a result of analysis of the additive alloy constituents, the product was found to contain 1.3 to 1.6% Sn showing the composition of 1.5Sn-Zr alloy. The alloy also was found to contain 0.0032 percent hydrogen. This sponge was formed into briquettes which were are melted to form button ingots having a Brinell hardness of 135.
EXAMPLE 7 (Zr-Nb) 608 kg. of metallic sodium was filtered and refined under an argon atmosphere, heated at 650C., in an electric furnace and charged into the iron reactor described in Example 1. A mixture of gaseous zirconium tetrachloride and niobium pentachloride of a predetermined ratio of 150.1 kg. of zirconium tetrachloride to 3.64 kg. of niobium pentachloride, corresponding to 97.5% Zr to 2.5% Nb, was heated at 350C. and charged into the reactor. The reaction was effected at 700 to 760C. After the reactants were completely charged into the reactor over a period of approximately 10 hours, the materials were then heated to 920 to 960C. for 6 hours to complete the reaction. The product was cooled and discharged and leached with 1,000 liters of 1 percent hydrochloric acid. It was then washed and dried in vacuo at C. to obtain a gray sponge. The yield percentage of the sponge was 82 percent and the alloy constituents were found to be 2.2 to 2.4% Nb and 0.0035 percent hydrogen.
All of the button ingots obtained by arc melting the titanium or zirconium alloy sponge, as described in the above Examples, had glossy metal skins and had similar hardness to that produced by conventional processes. This clearly indicates that the process of this invention is suitable for providing a high quality alloy sponge.
In addition to the alloy compositions described in the above Examples, the process of the present invention may also be equally applied to obtaining alloy compositions such as, for example: Ti-SAl-lMo-lV, Ti-Al- 2Cr-1Fe, Ti-6Al-6V-2Sn, Ti-8Mn, Ti-4Al-3Mo-lV, Til3V-1lCr-3Al, Ti-l5Mo-5Zr, Ti-5Al-5Sn-5Zr-2CrlFe, Ti-0.2Pd, Ti-l1Sn-5Zr-2.5Al-0.25Si, in case of titanium Zr-Sn-Fe-Cr (ND-Nb base metal, series Zr-Cr- Mo-(Fe) series, in case of zirconium base metal.
Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the invention. Accordingly,
What is claimed as new and intended to be covered by Letters Patent of the United States is:
l. A process of producing an alloy sponge of a titanium or zirconium base metal, which comprises;
introducing titanium tetrachloride or zirconium tetrachloride, one or more alloy element metal hali cles selected from the group consisting of AICI SiCl VCh, MoCl SnCl TaCl K TaF FeCl MnCl CrCl HfCh, ZrCh, WCI NbCl CoCl NiCl CuCl, PCl SCl CCl ZnCh, BeCl YCl- PbCl and PtCl and a metallic alkali as a reducing agent into a reactor vessel having no mixing means,
is metallic sodium.