JP6616522B2 - Method for producing tantalum and niobium alloys - Google Patents

Description

The present specification relates to a method for producing tantalum and niobium alloys. The present description also relates to factory and intermediate products of tantalum and niobium alloys made using the methods described herein.

Tantalum is a hard, ductile, acid resistant, and highly conductive metal having a density of 16.65 g / cm ³ . Tantalum has a high melting temperature of 3020 ° C. Tantalum is often used as an alloy additive and often combined with niobium to increase the corrosion resistance of niobium. When mixed with metals such as niobium, tantalum has excellent resistance to a wide range of corrosive environments including mineral acids, most organic acids, liquid metals, and most salts.

Niobium is less dense than tantalum (16.65 g / cm ³ ) (8.57 g / cm ³ ), but has similar physical and chemical properties (similar hardness, ductility, acid resistance, and conductivity) to tantalum. Including). Niobium has a melting point temperature of 2477 ° C. As mentioned above, niobium and tantalum can be alloyed together or alloyed with other elements to make niobium or tantalum alloys. Niobium and tantalum alloys have properties suitable for a variety of applications, such as, among others, aerospace, chemical processing, medical, superconducting, and electronics markets.

  In a non-limiting embodiment, a method for producing a tantalum alloy includes performing an aluminothermit reaction to reduce tantalum pentoxide powder to tantalum metal.

  In another non-limiting embodiment, a method for producing a niobium alloy includes performing an aluminothermit reaction to reduce niobium pentoxide powder to niobium metal.

  In another non-limiting embodiment, a method for producing a tantalum alloy comprises: tantalum pentoxide powder; at least one of iron (III) oxide powder and copper (II) oxide powder; barium peroxide powder; And conducting an aluminothermit reaction using a reaction mixture containing aluminum metal powder.

  In another non-limiting embodiment, the method for producing a tantalum alloy or niobium alloy comprises tantalum pentoxide powder and / or niobium pentoxide powder; iron (III) oxide powder and / or copper (II) oxide powder. Barium peroxide powder; aluminum metal powder; and tungsten trioxide powder, molybdenum trioxide powder, chromium (III) oxide powder, hafnium dioxide powder, zirconium dioxide powder, titanium dioxide powder, vanadium pentoxide powder, and tungsten metal powder. Performing an aluminothermit reaction using a reaction mixture comprising at least one of them.

  In another non-limiting embodiment, a method for producing a niobium alloy includes niobium pentoxide powder; iron (III) oxide powder and / or copper (II) oxide powder; barium peroxide powder; aluminum metal powder; And at least one of tantalum pentoxide powder, tungsten trioxide powder, molybdenum trioxide powder, chromium (III) oxide powder, hafnium dioxide powder, zirconium dioxide powder, titanium dioxide powder, vanadium pentoxide powder, and tungsten metal powder. Carrying out an aluminothermit reaction using a reaction mixture comprising

  In another non-limiting embodiment, a method for producing a tantalum alloy comprises: tantalum pentoxide powder; at least one of iron (III) oxide powder and copper (II) oxide powder; barium peroxide powder; Performing an aluminothermit reaction using a reaction mixture comprising aluminum metal powder; and at least one of niobium pentoxide powder, tungsten metal powder, and tungsten trioxide powder.

  In another non-limiting embodiment, a method for producing a tantalum alloy includes placing a reaction mixture in a reaction vessel. The reaction mixture comprises tantalum pentoxide powder; at least one of iron (III) oxide powder and copper (II) oxide powder; barium peroxide powder; aluminum metal powder; and niobium pentoxide powder, tungsten metal powder, and three At least one of the tungsten oxide powders. The aluminothermit reaction is initiated between the reaction mixture components.

  In another non-limiting embodiment, a method for producing a tantalum alloy includes tantalum pentoxide powder, iron (III) oxide powder, copper (II) oxide powder, barium peroxide powder, aluminum metal powder, and tungsten. Forming a reaction mixture comprising metal powder. The magnesium oxide powder layer is disposed on at least the bottom surface of the graphite reaction vessel. The reaction mixture is placed on top of the magnesium oxide powder layer in a graphite reaction vessel. A tantalum or tantalum alloy ignition wire is placed in contact with the reaction mixture. The reaction vessel is sealed inside the reaction chamber. A vacuum is established inside the reaction chamber. The ignition wire is energized to initiate an aluminothermite reaction between the reaction mixture components. The aluminothermit reaction produces a reaction product comprising a monolithic and fully consolidated alloy regular and a separated slag phase. The alloy regular includes tantalum and tungsten. The slag phase contains aluminum oxide and barium oxide. The reaction product is cooled to ambient temperature. The reaction product is removed from the reaction vessel. Slag and regulars are separated.

  It is understood that the invention disclosed and described herein is not limited to the embodiments summarized in this summary.

  Various features and characteristics of the non-limiting and non-exhaustive embodiments disclosed and described herein can be better understood with reference to the following drawings.

FIG. 1A is a flow diagram illustrating the flow of a process for producing a tantalum alloy factory product from a tantalum pentoxide feedstock. FIG. 1B is a flow diagram illustrating a process flow for producing a tantalum alloy factory product from a tantalum metal feedstock. FIG. 2A is a photograph of an aluminothermit reaction product containing well-defined separated regular and slag phases. FIG. 2B is a photograph of the regular shown in FIG. 2A after removing the slag phase. It is a cross-sectional schematic diagram of an aluminothermit reaction vessel (not proportional to the original size). It is a cross-sectional schematic diagram of an aluminothermit reaction vessel (not proportional to the original size). FIG. 3 is a schematic diagram of a perspective view of an aluminothermit reaction vessel (not to scale). FIG. 2 is a schematic view of a perspective view of an aluminothermit reaction vessel sealed inside a reaction chamber (not to scale). 2 is a scanning electron microscope (SEM) image of the microstructure of a tantalum alloy regular produced by an aluminothermite reaction with a tantalum pentoxide reactant.

  The reader will understand other portions in addition to the foregoing details upon review of the following detailed description of various non-limiting and non-exhaustive embodiments in accordance with this specification.

  Various embodiments are described and illustrated herein so that the function, operation, and performance of the disclosed method for producing tantalum alloys can be fully understood. It is understood that the various embodiments described and illustrated herein are non-limiting and non-exhaustive. Thus, the present invention is not necessarily limited to the description of the various non-limiting and non-exhaustive embodiments disclosed herein. The features and characteristics illustrated and / or described with respect to various embodiments may be combined with the features and characteristics of other embodiments. Such modifications and variations are intended to be included within the scope of this specification. Accordingly, the claims are amended to enumerate any feature or characteristic that is expressly or implicitly stated in this specification or that is expressly or inherently supported by this specification. Can be done. In addition, Applicant reserves the right to amend the claims to positively disclaim features or characteristics that may exist in the prior art. Accordingly, any such amendments will comply with the requirements of 35 USC 112 (a) and 132 (a). Various embodiments disclosed and described herein can include, consist of, or consist essentially of features and characteristics as variously described herein.

  Also, any numerical range recited herein is intended to include all sub-ranges with the same numerical accuracy encompassed within the recited range. For example, the range “1.0-10.0” includes all subranges between (and including) the minimum value of 1.0 listed and the maximum value of 10.0 listed, That is, it is intended to have a minimum value of 1.0 or more and a maximum value of 10.0 or less, such as 2.4 to 7.6. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations included therein, and any minimum numerical limitation listed herein is also included therein. It is intended to include all numerical limitations higher than that given. Accordingly, Applicant reserves the right to amend the specification, including the claims, to explicitly list any sub-ranges encompassed by the range explicitly recited herein. Since all such ranges are intended to be inherently described herein, amendment to explicitly list any such subranges is not subject to 35 USC 112. It complies with the requirements of (a) and 132 (a).

  All patents, publications, or other disclosure materials identified herein are hereby incorporated by reference in their entirety unless otherwise indicated, but are expressly described herein. To the extent that they are consistent with the description, definitions, expressions, or other material disclosed. Accordingly, to the extent necessary, the clear disclosure set forth herein will supersede any conflicting material incorporated herein by reference. Any material, or part of it, that is stated to be incorporated herein by reference, but that conflicts with existing definitions, expressions, or other disclosure material described herein, Incorporated to the extent that there is no discrepancy between the disclosure materials. Applicant reserves the right to amend this specification to explicitly list any subject matter or portions thereof incorporated herein by reference.

  The grammatical articles “one”, “a”, “an”, and “the”, as used herein, unless otherwise indicated, “at least one” or “one or more”. Intended to include. Thus, an article is used herein to refer to one or more (ie, “at least one”) grammatical article objects. By way of example, “a component” means one or more components, and thus, in some cases, two or more components are contemplated and may be employed or used in the practice of the described embodiments. it can. Further, the use of the singular noun includes the plural and the use of the plural noun includes the singular unless the context of use otherwise requires.

The metals tantalum and niobium can be initially obtained from tantalum-containing and niobium-containing ores such as, for example, tantalite and niobite (Columbite), ie (Fe, Mn) (Ta, Nb) ₂ O ₆ . Generally speaking, if these ores contain more tantalum than niobium, the ores are called tantalite, and if the ore contains more niobium than tantalum, the ore is niobite or columbite. Called. These ores are mined and processed by crushing, gravity separation, and treatment with hydrofluoric acid (HF) to produce metal fluoride complexes such as H ₂ (TaF ₇ ) and H ₂ (NbOF ₅ ). be able to. Tantalum fluoride and niobium fluoride can be separated from each other through liquid-liquid extraction using water and organic solvents such as cyclohexanone. The separated metal fluoride can be further processed to produce an industrial feedstock.

Tantalum fluoride can be treated with, for example, potassium fluoride salt to precipitate potassium heptafluorotantalate.
H ₂ (TaF ₇ ) _{(aqueous solution)} +2 KF _{(aqueous solution)} → K ₂ (TaF ₇ ) _(solid) + 2HF _{(aqueous solution)}
The potassium heptafluorotantalate precipitate can be collected and reduced with molten sodium to produce refined and purified tantalum metal.
K ₂ (TaF ₇ ) _(Liquid) + 5Na _(Liquid) → Ta _(Solid) + 5NaF _(Liquid) +2 KF _(Liquid)
Alternatively, tantalum fluoride may be treated with ammonia to precipitate tantalum pentoxide.
2H ₂ (TaF ₇ ) _{(aqueous solution)} + 14NH ₄ OH _{(aqueous solution)} → Ta ₂ O _{5 (solid)} + 14NH ₄ F _{(aqueous solution)} + 9H ₂ O
The production of tantalum pentoxide using ammonia is cheaper than the sodium reduction process, and therefore tantalum pentoxide is a less expensive chemical product than virgin sodium reduced tantalum metal.

Similarly, niobium fluoride can be treated with potassium fluoride salt, for example, to precipitate potassium oxypentafluoroniobate, which is collected and reduced with sodium, hydrogen, or carbon and refined. Purified niobium metal can be produced. Alternatively, niobium fluoride may be treated with ammonia to precipitate niobium pentoxide.
2H ₂ (NbOF ₅ ) _{(aqueous solution)} + 10NH ₄ OH _{(aqueous solution)} → Nb ₂ O _{5 (solid)} + 10NH ₄ F _{(aqueous solution)} + 7H ₂ O

  The production of niobium pentoxide using ammonia, like the production of tantalum pentoxide using ammonia, is less expensive than the sodium, hydrogen, or carbon reduction process, and therefore niobium pentoxide is less than the reduced niobium metal of virgin. It is an inexpensive general-purpose chemical product.

Refined and purified tantalum and niobium metals produced through the reduction process are mainly used in the commercial production of electronic components such as capacitors and high power resistors. Thus, the cost of virgin reduced tantalum and niobium metals as industrial feedstock, as determined by demand from the electronics industry and the costs associated with the reduction process, is relatively high. With such a high cost, which may result in problems to the manufacturer of tantalum and niobium alloys as well as factory production products. Manufacturers of tantalum and niobium alloys as well as factory production product, not necessarily require the input material having a refining and purity levels are achieved by the reduction process. Furthermore, alloying tantalum and niobium with other metals requires costly powder processing to produce compacts suitable for electron beam melting to homogenize and refine alloy chemicals. .

  Tantalum and niobium have higher melting temperatures than most metals. Thus, alloying of tantalum and niobium with each other and / or with other elements that also have a relatively high melting temperature, such as tungsten, molybdenum, zirconium, titanium, hafnium, or vanadium, for example. Usually requires hot pressing and use of an electron beam furnace to melt a compact comprising a mixture of sintered tantalum powder and alloying element powder. Tantalum and niobium are also relatively ductile. Thus, for example, non-alloy tantalum or niobium scrap or virgin metal produced through a reduction process must typically be embrittled by hydroprocessing, after which the tantalum or niobium can be ground into a powder form. Hydrogenated tantalum or niobium powders must also be dehydrogenated and then hot pressed and sintered with other alloying element powders to produce compacts that are fed into an electron beam melting furnace. . This hydrogenation-dehydrogenation (HDH) process requires substantial capital and operational infrastructure (including hydrogenation furnaces, crushers, compressors, vacuum furnaces, and press / sinter equipment), and tantalum and niobium The alloying adds considerable additional costs over the already expensive virgin reduced tantalum or niobium metal inputs.

  Downstream electron beam melting of pressed and sintered powder compacts containing tantalum, niobium, and / or other alloying elements can be further problematic. On a macroscopic scale, tantalum and niobium powders and other alloying element powders are homogeneously blended prior to pressing and sintering. However, the obtained molded body does not contain a homogeneous solid solution containing an alloying element completely dissolved in a tantalum base material or a niobium base material. Instead, the compact is a discrete, isolated, alloying element, such as tungsten, molybdenum, zirconium, titanium, hafnium, or vanadium, distributed in a relatively continuous region or phase of tantalum metal. Region or inclusion. The discrete alloying element region and the tantalum region or niobium region of the multiphase microstructure correspond to respective powder particles that form a compact by metal bonding with each other.

  Electron beam melting of compacts homogenizes and refines the alloy composition and completely dissolves as a solid solution in a uniform microstructure, reduced levels of relatively volatile trump elements, tantalum or niobium matrix. It is intended to produce ingots with specific alloying elements uniformly dispersed. However, in practice, it may be difficult to achieve liquid phase mixing of refractory materials such as tantalum, niobium, tungsten, molybdenum, zirconium, titanium, hafnium, or vanadium by electron beam melting. For example, if the molten pool is relatively small and the molten pool lacks overheating, sufficient liquid phase mixing may be prevented. Furthermore, when the molten material is dropped from the compact into the molten pool in the electron beam melting furnace, dispersion of constituent materials of the alloy may be reduced. Current industrial scale electron beam melting furnaces also lack the ability to cause auxiliary physical agitation of the molten pool, which will improve alloy dispersion and homogenization of the alloy constituents.

The method described herein does not produce tantalum alloys or niobium alloys and factory products from virgin reduced or scrap tantalum metal or niobium metal feedstock, but tantalum pentoxide or niobium pentoxide. It is intended to produce tantalum or niobium alloys and factory products from feedstock. In various embodiments, a method for producing a tantalum alloy or niobium alloy comprises performing an aluminothermite reaction to reduce tantalum pentoxide powder to tantalum metal or reduce niobium pentoxide powder to niobium metal. Can be included. FIGS. 1A and 1B are provided by the aluminothermit reaction method described herein (FIG. 1A) as compared to a method using a tantalum metal feedstock to produce a tantalum alloy factory product (FIG. 1B). 2 is a flow diagram illustrating operational infrastructure savings. A similar comparison can be made between the aluminothermite reaction and powder metallurgy production of niobium alloy factory products .

  The aluminothermit reaction method described herein includes (1) the need for a relatively expensive virgin reduced tantalum or niobium metal; (2) an expensive HDH process; and (3) for electron beam melting. The pressing and sintering operations necessary to produce a powder molded product are not necessary. The methods described herein directly produce consolidated tantalum or niobium alloy regulars that can be directly charged to an electron beam melting furnace to refine a tantalum alloy or niobium alloy composition. The tantalum alloy or niobium alloy regular produced by the aluminothermic reaction method described herein also includes an alloying element that is completely dissolved in the tantalum matrix or niobium matrix, thereby providing direct electron beam melting. And the casting of a tantalum alloy or niobium alloy ingot having a uniform microstructure and an alloying element fully and uniformly dispersed in the tantalum or niobium matrix.

As used herein, the term “aluminothermit reaction (s)” is used between an aluminum metal (which functions as a reducing agent) and a metal peroxide and / or metal oxide (which functions as an oxidizing agent). Refers to a high temperature exothermic redox chemical reaction. The aluminothermit reaction produces an aluminum oxide (Al ₂ O ₃ ) -based slag and a reduced metal content. As used herein, the term “regulus” (and its plural form, “reguli”) refers to the consolidated and solidified metal or alloy portion of the reaction product of an aluminothermit reaction. Point to.

  FIG. 2A is a photograph showing an aluminothermit reaction product containing well-defined regularity and well-defined slag phase. During and / or after the aluminothermit reaction, the oxide reaction products can coalesce into a low density slag phase and the metal reaction products can coalesce into a dense alloy phase. These phases can separate and solidify to a well-defined alloy regularity and a separated slag phase, for example as shown in FIG. 2A. FIG. 2B is a photograph of the regular shown in FIG. 2A after removing the slag phase. The metal reaction products of the aluminothermit reaction can coalesce and solidify to produce a monolithic and fully consolidated non-brittle alloy regular, as shown, for example, in FIG. 2B.

The use of an aluminothermit reaction to produce a tantalum alloy or niobium alloy reduces (1) the specific alloy constituent; (2) the melting temperature of the resulting tantalum alloy intermediate product or niobium alloy intermediate product . Volatile (sacrificial) alloy constituents; and (3) Metal reaction products are melted and coalesced into tantalum or niobium alloys, and the molten reaction products solidify to monolithic and fully consolidated Heat sufficient to achieve a reaction temperature that causes the molten slag reaction product to phase separate from the molten metal reaction product so as to produce a non-brittle tantalum or niobium alloy regular and a separated slag phase. Selecting the reactants to be produced.

  Tantalum alloys that can be produced using the methods described herein include, for example, binary tantalum-niobium alloys (eg, Ta-40Nb (UNS R05240)) and binary tantalum-tungsten alloys (eg, Ta -2.5W (UNS R05252) and Ta-10W (UNS R05255)). Ta-40Nb nominally contains 40 wt% niobium, balance tantalum and unavoidable impurities; Ta-2.5W nominally contains 2.5 wt% tungsten, balance tantalum and unavoidable impurities. As well as Ta-10W nominally contains 10 wt% tungsten, the balance tantalum and inevitable impurities. Niobium alloys that can be produced using the methods described herein include, for example, binary Nb-Ta alloys, such as Nb-7.5Ta (nominally 7.5 weight percent tantalum, the balance Niobium and unavoidable impurities), such as binary Nb-Ti alloys (including, for example, 40-55 wt% titanium, or any subrange or value included therein, such as 47-53% titanium), Binary Nb-Zr alloys, ternary Nb-Ti-Ta alloys, ternary Nb-Zr-Ta alloys, and multi-component alloys, such as 9.0 to 11.0% hafnium by weight, 0.7 Examples include alloys containing ˜1.3% titanium, up to 0.7% zirconium, up to 0.5% tantalum, up to 0.5% tungsten, the balance niobium and unavoidable impurities.

  For example, to produce a particular tantalum alloy or niobium alloy chemical, in various embodiments, the reactants are aluminum metal powder (as a reducing agent), tantalum pentoxide powder (as a tantalum source and oxidant), And / or niobium pentoxide powder (as a niobium source and oxidant). In other embodiments, for example, to produce a specific tantalum-tungsten alloy chemical, the reactants are aluminum metal powder (as a reducing agent), tantalum pentoxide powder (as a tantalum source and oxidant), and Tungsten trioxide powder (as tungsten source and oxidant) may be included. In other embodiments, for example, to produce a specific tantalum-tungsten alloy chemical, the reactants are aluminum metal powder (as a reducing agent), tantalum pentoxide powder (as a tantalum source and oxidant), and Tungsten metal powder (as an inert tungsten source) may be included. In other embodiments, for example, to produce a specific niobium-titanium alloy chemical, the reactants can be aluminum metal powder (as a reducing agent), niobium pentoxide powder (as a niobium VEGF trap source and oxidant), And titanium dioxide powder (as titanium source and oxidant). The reactive or inert source of other alloying constituents for tantalum-based or niobium-based alloys produced by the aluminothermite reaction is based on the alloy composition of the target to be produced and is also described herein. It can be determined by one skilled in the art in view of the disclosed information.

  Tantalum and tantalum-based alloys such as Ta-40Nb, Ta-2.5W, and Ta-10W have relatively high melting temperatures. For example, pure tantalum melts at 3020 ° C, Ta-40Nb melts at 2705 ° C, Ta-2.5W melts at 3005 ° C, and Ta-10W melts at 3030 ° C. Niobium and niobium-based alloys have similar high melting temperature. Because of this relatively high melting temperature, the aluminothermit reactant may be selected to produce a metal product that forms a volatile (sacrificial) alloy constituent. Volatile (sacrificial) alloy constituents facilitate the liquefaction and coalescence of metal products produced through an aluminothermit reaction into tantalum or niobium alloys by reducing the melting temperature of the alloy. . As used herein, the term “volatile (sacrificial) alloy constituent (s)” refers to a specific constituent of a tantalum or niobium alloy (eg, Ta, Nb, W, Mo, Ti, Zr). , Hf, V, Cr), elements such as copper and iron that are relatively more volatile and therefore easily reduced to unavoidable impurity levels in tantalum or niobium alloys refined using electron beam melting Point to. The precursor reactant (s) used to produce “volatile (sacrificial) alloy constituent (s)” may be referred to as “sacrificial metal oxide (s)”.

  When iron is added as an alloying element to tantalum or niobium, the melting temperature decreases. For example, tantalum containing 5% iron by weight melts at 2500 ° C. compared to 3020 ° C. for pure tantalum. Similarly, copper lowers the melting temperature of tantalum, niobium, tantalum alloys, and niobium alloys. Iron and copper are also readily formed by aluminothermic reduction of iron (III) oxide and copper (II) oxide, respectively, and both aluminothermit reactions generate a large amount of heat, thus increasing the reaction temperature. Iron and copper are also relatively more volatile than tantalum, niobium, tungsten, molybdenum, titanium, zirconium, and hafnium, and are therefore easily removed from tantalum alloy matrix using electron beam melting.

  In various embodiments, the sacrificial metal oxide reactant may include iron (III) oxide powder, copper (II) oxide powder, or both. Other sacrificial metal oxide reactant powders that may be suitable for the purpose of generating reaction heat and generating volatile (sacrificial) elements that reduce the melting temperature of the resulting tantalum-based alloy include, for example, manganese dioxide, nickel oxide ( II), cobalt (II) oxide, chromium oxide, and molybdenum oxide. These additional sacrificial oxides can be reactive in the aluminothermite reaction, but these oxides are responsible for the formation of aluminothermites of tantalum-based or niobium-based alloys in iron (III) oxide and copper (II) oxide. It may be less suitable. This is because the metal components of these additional oxides are relatively less volatile than iron and copper and are therefore not as easily removed as by electron beam refining. However, these additional oxides may alternatively function as non-sacrificial oxides that provide a metal component as an alloy additive to the tantalum-based or niobium-based alloys produced herein.

Like iron (III) oxide and copper (II) oxide, manganese dioxide powder is reduced by aluminum powder while releasing considerable heat of reaction. The sacrificial manganese in the resulting tantalum-based alloy can also be easily removed using electron beam melting. However, the boiling temperature of manganese (2060 ° C.) is significantly lower than the boiling temperatures of copper and iron (2562 ° C. and 2862 ° C., respectively), and thus manganese limits the temperature of the aluminothermite reaction with tantalum pentoxide. May cause improper alloy-slag phase separation. Nickel (II) oxide and cobalt (II) oxide are energetically more intense than iron (III) oxide and copper (II) oxide and do not react with aluminum. Nickel and cobalt metals also tend to form intermetallic compounds with tantalum. Chromium oxide such as Cr ₂ O ₃ can also be used in various embodiments. Molybdenum metal has a significantly lower vapor pressure compared to the vapor pressure of iron and copper; therefore, molybdenum cannot be removed from tantalum alloy matrix as easily as iron and copper during electron beam melting. As described above, it can be used as a precursor oxide that brings molybdenum alloying to a tantalum-based alloy or niobium-based alloy.

  In various embodiments, the reactants may also include an aluminothermite promoter to generate sufficient heat to achieve a reaction temperature that causes alloy formation and slag phase separation. An aluminothermit accelerator is a reactant compound that oxidizes aluminum and generates a large amount of heat of reaction, but does not produce a reduced metal content that coalesces into a tantalum or niobium alloy matrix. Examples of heat promoter reactants include, for example, potassium chlorate and barium peroxide.

  In various embodiments, the reactants may include barium peroxide powder. Barium peroxide reacts with aluminum under aluminothermic reaction conditions to produce barium oxide and aluminum oxide. Barium oxide has a favorable phase relationship with aluminum oxide, and slag containing a mixture of barium oxide and aluminum oxide has a significantly lower melting point temperature than slag containing mostly aluminum oxide. For example, a composition of 32 mol% barium oxide in aluminum oxide has a melting temperature of 1870 ° C. compared to 2072 ° C. for pure aluminum oxide. Thus, slag containing a mixture of barium oxide reaction product and aluminum oxide reaction product will more easily phase separate from liquefied and coalesced tantalum or niobium alloys under aluminothermic reaction conditions, thereby making the monolithic It is easy to form a non-brittle tantalum alloy or niobium alloy regular and a separated slag phase that are completely consolidated at a low temperature. In various embodiments, the reactants may be substantially free of potassium chlorate, meaning that potassium chlorate is present in the reaction mixture below the inevitable impurity level.

A method for producing a tantalum alloy or a niobium alloy includes aluminum metal powder (Al), tantalum pentoxide powder (Ta ₂ O ₅ ), niobium pentoxide powder (Nb ₂ O ₅ ), iron (III) oxide powder (Fe Performing an aluminothermite reaction between reactants comprising at least one of ₂ O ₃ ) and copper (II) oxide powder (CuO) and barium peroxide powder (BaO ₂ ). The aluminothermit reaction can proceed, for example, according to the following chemical equation:
3Ta ₂ O ₅ + 10Al → 6Ta + 5Al ₂ O ₃
3Nb ₂ O ₅ + 10Al → 6Nb + 5Al ₂ O ₃
Fe ₂ O ₃ + 2Al → 2Fe + Al ₂ O ₃
3CuO + 2Al → 3Cu + Al ₂ O ₃
3BaO ₂ + 2Al → 3BaO + Al ₂ O ₃

The product of the aluminothermit reaction includes a slag phase comprising a mixture of aluminum oxide (Al ₂ O ₃ ) and barium oxide (BaO), and a separate, monolithic, fully consolidated, non-brittle tantalum alloy regular or niobium alloy Regulars can be included. The tantalum-based alloy may include niobium, iron, copper, aluminum, and the balance tantalum and unavoidable impurities, and the niobium-based alloy may include tantalum, iron, copper, aluminum, and the balance niobium and unavoidable impurities. Iron, copper, and aluminum can be reduced to inevitable impurity levels by producing a refined tantalum alloy or niobium alloy ingot by electron beam melting of a tantalum alloy or niobium alloy regular.

Methods for producing tantalum alloys include aluminum metal powder (Al), tantalum pentoxide powder (Ta ₂ O ₅ ), tungsten trioxide powder (WO ₃ ), iron (III) oxide powder (Fe ₂ O ₃ ) and An aluminothermit reaction may be performed between the reactants including at least one of the copper (II) oxide powder (CuO) and the barium peroxide powder (BaO ₂ ). The aluminothermit reaction can proceed, for example, according to the following chemical equation:
3Ta ₂ O ₅ + 10Al → 6Ta + 5Al ₂ O ₃
WO ₃ + 2Al → W + Al ₂ O ₃
Fe ₂ O ₃ + 2Al → 2Fe + Al ₂ O ₃
3CuO + 2Al → 3Cu + Al ₂ O ₃
3BaO ₂ + 2Al → 3BaO + Al ₂ O ₃

The product of the aluminothermit reaction may include a slag phase comprising a mixture of aluminum oxide (Al ₂ O ₃ ) and barium oxide (BaO), and a separate, monolithic, fully consolidated, non-brittle tantalum alloy regular. . Tantalum-based alloys can include tungsten, iron, copper, aluminum, and the balance tantalum and unavoidable impurities. Iron, copper, and aluminum can be reduced to unavoidable impurity levels by producing a refined tantalum alloy ingot by electron beam melting a tantalum alloy regular.

Methods for producing tantalum alloys include aluminum metal powder (Al), tungsten metal powder (W), tantalum pentoxide powder (Ta ₂ O ₅ ), iron (III) oxide powder (Fe ₂ O ₃ ) and copper oxide. (II) An aluminothermit reaction may be performed between reactants including at least one of the powders (CuO) and the barium peroxide powder (BaO ₂ ). The aluminothermit reaction can proceed, for example, according to the following chemical equation:
3Ta ₂ O ₅ + 10Al → 6Ta + 5Al ₂ O ₃
W → W
Fe ₂ O ₃ + 2Al → 2Fe + Al ₂ O ₃
3CuO + 2Al → 3Cu + Al ₂ O ₃
3BaO ₂ + 2Al → 3BaO + Al ₂ O ₃

The product of the aluminothermit reaction may include a slag phase comprising a mixture of aluminum oxide (Al ₂ O ₃ ) and barium oxide (BaO), and a separate, monolithic, fully consolidated, non-brittle tantalum alloy regular. . Tantalum-based alloys can include tungsten, iron, copper, aluminum, and the balance tantalum and unavoidable impurities. Iron, copper, and aluminum can be reduced to unavoidable impurity levels by producing a refined tantalum alloy ingot by electron beam melting a tantalum alloy regular.

Methods for producing tantalum alloys include aluminum metal powder (Al), tantalum pentoxide powder (Ta ₂ O ₅ ), molybdenum trioxide powder (MoO ₃ ), iron (III) oxide powder (Fe ₂ O ₃ ) and An aluminothermit reaction may be performed between the reactants including at least one of the copper (II) oxide powder (CuO) and the barium peroxide powder (BaO ₂ ). The aluminothermit reaction can proceed, for example, according to the following chemical equation:
3Ta ₂ O ₅ + 10Al → 6Ta + 5Al ₂ O ₃
MoO ₃ + 2Al → Mo + Al ₂ O ₃
Fe ₂ O ₃ + 2Al → 2Fe + Al ₂ O ₃
3CuO + 2Al → 3Cu + Al ₂ O ₃
3BaO ₂ + 2Al → 3BaO + Al ₂ O ₃

The product of the aluminothermit reaction may include a slag phase comprising a mixture of aluminum oxide (Al ₂ O ₃ ) and barium oxide (BaO), and a separate, monolithic, fully consolidated, non-brittle tantalum alloy regular. . Tantalum-based alloys can include molybdenum, iron, copper, aluminum, and the balance tantalum and unavoidable impurities. Iron, copper, and aluminum can be reduced to unavoidable impurity levels by producing a refined tantalum alloy ingot by electron beam melting a tantalum alloy regular.

Methods for producing a niobium alloy include aluminum metal powder (Al), niobium pentoxide powder (Nb ₂ O ₅ ), molybdenum trioxide powder (MoO ₃ ), iron (III) oxide powder (Fe ₂ O ₃ ) and An aluminothermit reaction may be performed between the reactants including at least one of the copper (II) oxide powder (CuO) and the barium peroxide powder (BaO ₂ ). The aluminothermit reaction can proceed, for example, according to the following chemical equation:
3Nb ₂ O ₅ + 10Al → 6Nb + 5Al ₂ O ₃
MoO ₃ + 2Al → Mo + Al ₂ O ₃
Fe ₂ O ₃ + 2Al → 2Fe + Al ₂ O ₃
3CuO + 2Al → 3Cu + Al ₂ O ₃
3BaO ₂ + 2Al → 3BaO + Al ₂ O ₃

The product of the aluminothermit reaction may include a slag phase comprising a mixture of aluminum oxide (Al ₂ O ₃ ) and barium oxide (BaO), and a separate, monolithic, fully consolidated, non-brittle niobium alloy regular. . Niobium-based alloys can include molybdenum, iron, copper, aluminum, and the balance niobium and unavoidable impurities. Iron, copper, and aluminum can be reduced to unavoidable impurity levels by producing a refined niobium alloy ingot by electron beam melting of a tantalum alloy regular.

Methods for producing niobium alloys include aluminum metal powder (Al), niobium pentoxide powder (Nb ₂ O ₅ ), zirconium dioxide powder (ZrO ₂ ), iron (III) oxide powder (Fe ₂ O ₃ ) and oxidation. An aluminothermit reaction may be performed between reactants including at least one of the copper (II) powder (CuO) and the barium peroxide powder (BaO ₂ ). The aluminothermit reaction can proceed, for example, according to the following chemical equation:
3Nb ₂ O ₅ + 10Al → 6Nb + 5Al ₂ O ₃
3ZrO ₂ + 4Al → 3Zr + 2Al ₂ O ₃
Fe ₂ O ₃ + 2Al → 2Fe + Al ₂ O ₃
3CuO + 2Al → 3Cu + Al ₂ O ₃
3BaO ₂ + 2Al → 3BaO + Al ₂ O ₃

The product of the aluminothermit reaction may include a slag phase comprising a mixture of aluminum oxide (Al ₂ O ₃ ) and barium oxide (BaO), and a separate, monolithic, fully consolidated, non-brittle niobium alloy regular. . Niobium-based alloys can include zirconium, iron, copper, aluminum, and the balance niobium and unavoidable impurities. Iron, copper, and aluminum can be reduced to inevitable impurity levels by producing niobium alloy ingots that are refined by electron beam melting of niobium alloy regulars.

Methods for producing niobium alloys include aluminum metal powder (Al), niobium pentoxide powder (Nb ₂ O ₅ ), titanium dioxide powder (ZrO ₂ ), iron (III) oxide powder (Fe ₂ O ₃ ) and oxidation. An aluminothermit reaction may be performed between reactants including at least one of the copper (II) powder (CuO) and the barium peroxide powder (BaO ₂ ). The aluminothermit reaction can proceed, for example, according to the following chemical equation:
3Nb ₂ O ₅ + 10Al → 6Nb + 5Al ₂ O ₃
3TiO ₂ + 4Al → 3Ti + 2Al ₂ O ₃
Fe ₂ O ₃ + 2Al → 2Fe + Al ₂ O ₃
3CuO + 2Al → 3Cu + Al ₂ O ₃
3BaO ₂ + 2Al → 3BaO + Al ₂ O ₃

The product of the aluminothermit reaction may include a slag phase comprising a mixture of aluminum oxide (Al ₂ O ₃ ) and barium oxide (BaO), and a separate, monolithic, fully consolidated, non-brittle niobium alloy regular. . Niobium-based alloys can include titanium, iron, copper, aluminum, and the balance niobium and unavoidable impurities. Iron, copper, and aluminum can be reduced to inevitable impurity levels by producing niobium alloy ingots that are refined by electron beam melting of niobium alloy regulars.

The methods for producing the niobium alloy include aluminum metal powder (Al), niobium pentoxide powder (Nb ₂ O ₅ ), iron (III) oxide powder (Fe ₂ O ₃ ), and copper (II) oxide powder (CuO). At least one of these, barium peroxide powder (BaO ₂ ), zirconium dioxide powder (ZrO ₂ ), titanium dioxide powder (ZrO ₂ ), hafnium dioxide powder (HfO ₂ ), tantalum pentoxide powder (Ta ₂ O ₅₎ ), And performing an aluminothermit reaction between reactants comprising any combination or partial combination of tungsten trioxide powder (WO ₃ ) and / or tungsten metal. The aluminothermit reaction can proceed, for example, according to the following chemical equation:
3Nb ₂ O ₅ + 10Al → 6Nb + 5Al ₂ O ₃
3ZrO ₂ + 4Al → 3Zr + 2Al ₂ O ₃
3TiO ₂ + 4Al → 3Ti + 2Al ₂ O ₃
3HfO ₂ + 4Al → 3Hf + 2Al ₂ O ₃
3Ta ₂ O ₅ + 10Al → 6Ta + 5Al ₂ O ₃
WO ₃ + 2Al → W + Al ₂ O ₃
W → W
Fe ₂ O ₃ + 2Al → 2Fe + Al ₂ O ₃
3CuO + 2Al → 3Cu + Al ₂ O ₃
3BaO ₂ + 2Al → 3BaO + Al ₂ O ₃

The product of the aluminothermit reaction may include a slag phase comprising a mixture of aluminum oxide (Al ₂ O ₃ ) and barium oxide (BaO), and a separate, monolithic, fully consolidated, non-brittle niobium alloy regular. . Niobium-based alloys can include zirconium, titanium, hafnium, tantalum, tungsten, iron, copper, aluminum, and the balance niobium and unavoidable impurities. Iron, copper, and aluminum can be reduced to inevitable impurity levels by producing niobium alloy ingots that are refined by electron beam melting of niobium alloy regulars.

The aluminothermite reaction mixture used in the method described herein for producing a tantalum alloy or niobium alloy includes an aluminum metal powder, a tantalum pentoxide powder and / or a niobium pentoxide powder, and an alloying element precursor powder. , Sacrificial metal oxide powders, and / or any combination or partial combination of aluminothermite promoter powders. For example, the aluminothermit reaction mixture may be aluminum, tantalum pentoxide (Ta ₂ O ₅ ), niobium pentoxide (Nb ₂ O ₅ ), molybdenum trioxide (MoO ₃ ), titanium dioxide (TiO ₂ ), zirconium dioxide (ZrO ₂ ). ), Hafnium dioxide (HfO ₂ ), vanadium pentoxide (V ₂ O ₅ ), tungsten trioxide (WO ₂ ), chromium oxide (III) (Cr ₂ O ₃ ), iron oxide (III) (Fe ₂ O ₃ ) , Copper (II) oxide (CuO), manganese dioxide (MnO ₂ ), nickel oxide (II) (NiO), cobalt oxide (II) (CoO), and / or barium peroxide (BaO ₂ ) May be included in any combination or partial combination. The metal oxide alloying element precursor powder is chemically reduced by aluminum to the corresponding metal. In addition to or as an alternative to the metal oxide alloying element precursor powder, the aluminothermite reaction mixture contains an alloying element in addition to any acceptable element brought about by the reaction product reduced by the aluminothermite process. Any combination or partial combination of metal powders inert in the resulting aluminothermite process may be included. For example, the aluminothermit reaction mixture may include any combination or partial combination of tungsten powder, molybdenum powder, titanium powder, zirconium powder, hafnium powder, vanadium powder, and / or chromium powder.

The composition and relative amount of reactant powder (and inert powder, if used) can be based on the metal composition of the particular tantalum or niobium alloy target and the stoichiometry of the aluminothermit reaction. For example, to produce a Ta-40Nb alloy target, a Ta: Nb weight ratio of 60:40 based on the weight of the metal can be specified in the reactant feedstock comprising tantalum pentoxide and niobium pentoxide. To produce a Ta-2.5W alloy target, for example, a Ta: W weight ratio of 97.5: 2.5 based on the weight of the metal, including tantalum pentoxide and tungsten metal or tungsten trioxide. It can be specified in the reactant feed. Tantalum metal precursor (Ta ₂ O ₅ ) and the relative metal of a particular alloying element precursor such as, for example, niobium metal precursor (Nb ₂ O ₅ ) or tungsten metal precursor (W or WO ₃ ) The weight ratio can be adjusted to take into account the yield loss to the slag phase, which can reduce the relative amount of metal (eg, Ta, Nb, or W) contained in the regular product.

In embodiments where the targeted alloy composition includes a tantalum-based alloy containing tungsten, such as Ta-2.5W, the tungsten alloy powder is used as an inert tungsten precursor and reduced by an aluminothermit process. Tungsten metal alloying with tantalum metal produced from a tantalum oxide precursor can be provided. Tungsten metal powder is chemically inert under aluminothermic reaction conditions and can remain in the zero (elemental) oxidation state (W ^o ) during the reaction to bring tungsten to the alloy tantalum. It can be called “reactant” or “precursor”. In such embodiments, the tungsten metal precursor contributes nothing to the exotherm during the aluminothermit reaction. Instead, the tungsten metal precursor functions as a heat sink in the reaction mixture, reducing the thermal energy and reaction temperature of the exothermic reaction that can be otherwise utilized. Thus, if there is an excess of tungsten in the initial reaction mixture, it can be an obstacle to reactant conversion yield and alloy-slag phase separation. In various embodiments including a tungsten metal precursor in the reaction mixture, the amount of tungsten can be limited to 7% of the reaction mixture based on the total weight of the metal.

  The relative amount of sacrificial metal oxide powder (eg, iron (III) oxide powder, copper (II) oxide powder, or both) in the original reaction mixture is determined by the metal composition of the specific tantalum alloy or niobium alloy target. Not. This is because metal reaction products (eg, Fe and / or Cu) obtained by an aluminothermit reaction are removed or reduced to unavoidable impurity levels in tantalum or niobium alloy matrix by downstream electron beam melting. Because it can. In practice, the relative amount of sacrificial metal oxide powder reactant is the reduction of the melting temperature of the alloy and the formation of undesirable alloy phases due to the presence of sacrificial alloy constituents in the tantalum or niobium alloy matrix. Determined by balance.

  As described above, the addition of a relatively small amount of iron as an alloy constituent to tantalum or niobium significantly reduces the melting temperature of the alloy. When iron (III) oxide is reduced to aluminothermite by iron, a relatively large amount of heat of reaction is also generated as compared to aluminothermit reduction of other metal oxides to elemental metals. However, at a concentration of 21% by weight or more, iron does not completely dissolve in tantalum, but precipitates from the tantalum base material to form a brittle intermetallic TaFe compound that forms a phase that greatly embrittles the bulk alloy material. Form. In addition, any iron present in the tantalum or niobium alloy regular produced by the aluminothermit reaction method must be removed or reduced as a sacrificial element to the inevitable impurity level by downstream electron beam melting. obtain. Thus, the relative amount of iron (III) oxide powder reactant can be limited to ensure that the resulting tantalum alloy or niobium alloy regular comprises less than 21% by weight of the alloy regular.

  Similar to iron, the addition of a relatively small amount of copper as an alloy constituent to tantalum or niobium reduces the melting temperature of the alloy. The heat of reaction when reducing copper (II) oxide to copper metal is not as great as the heat of reaction when reducing iron (III) oxide to iron. However, unlike iron, copper does not form any harmful intermetallic compounds with tantalum over the entire composition range. Instead, copper and tantalum are essentially immiscible at ambient temperature and form a separate, relatively ductile metal phase. In various embodiments, copper (II) oxide powder may be used as a sacrificial metal oxide reactant instead of or in addition to iron (III) oxide. Considering the specific tantalum alloy or niobium alloy composition to be produced by the aluminothermit reaction method, (1) easy liquefaction and coalescence of tantalum alloy or niobium alloy metal under aluminothermit reaction conditions (2) does not result in the formation of brittle intermetallic phases in the solid tantalum or niobium alloy regular product; (3) facilitates alloy-slag phase separation; and (4) downstream regulars. Electron beam melting of iron results in an iron and / or copper alloy concentration that is easily removed or reduced to unavoidable impurity levels; suitable for iron (III) oxide and copper (II) oxide reactants Combinations can be easily determined.

  Relative amounts of aluminothermit accelerator reactants, such as barium peroxide, can be reduced by metals that are reduced by the aluminothermit process (eg, tantalum, niobium, iron, copper, tungsten, molybdenum, titanium, zirconium, hafnium, vanadium, chromium, Such as manganese, cobalt, nickel, or any combination thereof) and the tungsten metal powder, if present, is determined by the amount of thermal energy required to ensure liquefaction and coalesce into the tantalum or niobium alloy matrix can do. The relative amount of aluminothermite accelerator reactants containing barium peroxide is easier under aluminothermic reaction conditions from tantalum or niobium alloys in which the resulting slag phase containing aluminum oxide and barium oxide reaction products is liquefied and coalesced. It may be based in part on the melting point drop of the slag phase that will cause phase separation.

As described above, the aluminum powder reactant functions as a reducing agent that is oxidized by at least the tantalum pentoxide and / or niobium pentoxide reactant, the sacrificial metal oxide reactant (s), and the aluminothermite accelerator reactant. To do. Similar to iron, if the concentration of aluminum is about 4 to 6% by weight or more, it does not completely dissolve in tantalum, and even in the molten state, it precipitates from the tantalum base material and greatly solidifies the bulk alloy material. A brittle intermetallic Ta ₂ Al compound that forms a brittle phase is formed. Therefore, excess aluminum in the resulting alloy regular product is controlled while controlling the amount of aluminum powder in the initial reaction mixture to ensure that there is a stoichiometrically sufficient amount for the aluminothermit reaction. It can also be important to avoid forming intermetallic Ta ₂ Al compounds. In various embodiments, the amount of aluminum powder in the initial reaction mixture may comprise up to 5.0% excess of the stoichiometric amount based on moles. The amount of aluminum powder in the original reaction mixture may comprise up to 4.0% excess of the stoichiometric amount based on moles. The amount of aluminum powder in the initial reaction mixture may be 0.0% to 5.0% excess of the stoichiometric requirement based on moles, or any subrange included therein, for example 1.0. % To 5.0%, 2.0% to 5.0%, 3.0% to 5.0%, 1.0% to 4.0%, 2.0% to 4.0%, or 3. An excessive amount such as 0% to 4.0% may be contained.

  In various embodiments, the method for producing a tantalum alloy or niobium alloy includes an aluminum metal powder, tantalum pentoxide and / or niobium pentoxide powder, an alloying element precursor powder (eg, tungsten metal, tungsten trioxide, Molybdenum trioxide, titanium dioxide, zirconium dioxide, hafnium dioxide, and / or vanadium pentoxide), at least one sacrificial metal oxide powder (eg, iron (III) oxide and / or copper (II) oxide), and at least one Mixing a reaction mixture containing two aluminothermit promoter powders (eg, barium peroxide) may be included. The reactant powder should be completely dried so that there is no risk of water vapor formation during the aluminothermit reaction. For example, in various embodiments, the water content, determined as loss on ignition (LOI), is 0.5%, 0.4%, 0.3%, or 0.2% for each reactant powder. Can be less. The reactant powder should also be micronized. For example, in various embodiments, the reactant powder may have a particle size distribution (-200 mesh, <74 micrometers, <0.0029 inches) where more than 85 wt.% Passes through a 200 US mesh.

  The reactant powders may be individually weighed and mixed together using standard powder mixing equipment, such as a double cone blender, twin cylindrical (V) blender, or vertical screw mixer. In various embodiments, the reactant powders may be mixed for at least 10 minutes, in some embodiments for at least 20 minutes, to ensure macroscopically homogeneous mixing. After mixing, the reaction mixture can be loaded into a reaction vessel.

  Referring to FIG. 3, the reaction vessel 10 includes a vessel side wall 12 and a vessel bottom 14. The container sidewall 12 and the container bottom 14 may include materials that maintain structural integrity when subjected to the high levels of heat and high temperatures achieved during the aluminothermit reaction. For example, the container sidewall 12 and the container bottom 14 may be fabricated from extruded, compression molded, or isoformed graphite. The container side wall 12 and the container bottom 14 may include coarse, medium, or fine graphite.

  For example, in various embodiments, the reaction vessel sidewall may include coarse or medium grain extruded graphite, and the reaction vessel bottom may include fine-grained isoformed (ie, isostatic press) graphite. . Without intending to be bound by theory, the smaller the particle size of the fine-grained, isoformed graphite, the physical robustness and structure against erosion by the molten aluminothermit reaction product brought to the bottom of the reaction vessel. It is thought that the overall perfection will increase. Fine-grained isoformed graphite also provides a contact surface characterized by reduced porosity, thereby effectively eliminating more molten material than coarser material. Fine-grained isoformed graphite is more expensive than coarse-grained or medium-sized graphite, and therefore, considering the cost, the reaction vessel bottom is fine-grained because the reactant and product loads are placed on the reaction vessel bottom. The reaction vessel side wall may be required to contain a coarser graphite material that is less expensive. Nevertheless, in various embodiments, the reaction vessel sidewall may include fine-grained isoformed graphite. Similarly, the reaction vessel bottom may include a coarser graphite material.

  The thickness of the vessel sidewall and vessel bottom should be sufficient to maintain structural integrity when subjected to the high heat and high temperatures produced during the aluminothermite reduction reaction. In various embodiments, the container sidewall and container bottom may be at least 1 inch thick. The specific outer shape (shape and dimensions) of the reaction vessel is not necessarily limited. However, in various embodiments, the specific profile of the reaction vessel can be determined by the configuration of the downstream electron beam melting furnace input. In such an embodiment, the specific outer shape of the reaction vessel has an outer shape (shape and dimensions) that allows the electron beam melting of the regular directly in an electron beam furnace to produce a refined tantalum alloy or niobium alloy ingot. Having a tantalum alloy or niobium alloy regular may be selected.

  Referring again to FIG. 3, the reaction vessel 10 can be formed by mechanically securing the vessel sidewall 12 and vessel bottom 14 together. Alternatively, the reaction vessel 10 including the vessel sidewall 12 and vessel bottom 14 may be formed as a monolithic, continuous vessel made from a material such as graphite, for example, using compression molding or iso-molding techniques. .

  The reaction vessel 10 is placed on top of the layer of refractory material 18. The layer of refractory material 18 may include a refractory material, such as refractory clay bricks or other ceramic-based materials used in high temperature industrial applications. The layer of refractory material 18 may be placed on top of the elevated concrete slab 22. Alternatively, the layer of refractory material 18 may be placed directly on a suitable floor (eg, concrete) in the plant or factory (not shown).

  The reaction vessel 10 may include at least a layer of magnesium oxide 16 disposed on the vessel bottom 14. The magnesium oxide layer 16 provides a barrier between the container bottom 14 and the reaction mixture 20 disposed on top of the magnesium oxide layer 16 as shown in FIG.

  While not intending to be bound by theory, during development of the method described herein, tantalum alloy regular cracks generated through the aluminothermit reaction may cause the regular to be removed from the graphite reaction vessel. Observed. The observed tantalum alloy regular cracks occurred despite the continued finding that the alloy material itself was relatively ductile. This behavior is due, at least in part, to the hot cracking mechanism that can occur, where the alloy material produced by the aluminothermit reaction causes the graphite reaction during liquefaction, coalescence, solidification, and cooling. It seems to stick to the inner surface of the container. Again, without intending to be bound by theory, hot cracking that may occur is the result of growth and growth of carbides at the interface between the newly formed alloy material and the graphite reaction vessel. It is possible that It was found that when the magnesium oxide layer was applied to the inner bottom surface of the reaction vessel, the observed cracks disappeared.

  In various embodiments, a reaction vessel for producing aluminothermite of a tantalum alloy or niobium alloy may include a layer of magnesium oxide disposed on at least an inner bottom surface of the reaction vessel. The magnesium oxide layer serves as a barrier between the reactant powder mixture and the bottom of the reaction vessel. The magnesium oxide layer may include a layer of magnesium oxide powder disposed on the bottom of the reaction vessel. In various embodiments, refractory grade magnesium oxide powder in a heavy / dead fired state (ie, calcined at a temperature above 1500 ° C. to eliminate reactivity) may be used. The magnesium oxide powder layer may be placed in the reaction vessel immediately before the reaction vessel is charged with the reaction mixture.

  The magnesium oxide layer may be disposed on at least the inner bottom surface of the reaction vessel, but may optionally be applied to the side wall of the reaction vessel. Referring to FIG. 4, a reaction vessel 10 ′ is shown that includes a magnesium oxide layer 16 disposed on the vessel bottom 14 and the vessel sidewall 12.

  In various embodiments, the layer of magnesium oxide may be disposed in the reaction vessel as a thermal spray coating layer applied to the reaction vessel sidewall and / or the bottom of the reaction vessel. A sprayed magnesium oxide coating layer can have advantages such as, for example, increased structural integrity, reduced porosity, and uniform thickness. In various embodiments, the layer of magnesium oxide may be placed in the reaction vessel by applying a coating composition comprising magnesium oxide particles to the sidewalls of the reaction vessel and / or the bottom of the reaction vessel. In various embodiments, the layer of magnesium oxide may be disposed within the reaction vessel by placing a magnesium oxide sheet or wallboard immediately adjacent to the side wall of the reaction vessel and / or the bottom of the reaction vessel.

  Other ceramic materials may be used in place of magnesium oxide to provide a barrier layer in the reaction vessel, but such other materials may not be as effective as magnesium oxide and may be reactive under aluminothermic conditions. . For example, refractory materials such as silicon dioxide and zirconium dioxide can be reduced in the aluminothermit reaction by aluminum metal powder in the reaction mixture to silicon and zirconium, respectively. Similar to magnesium oxide, calcium oxide is inert to the aluminothermit reaction and may therefore be appropriate, but calcium oxide is sensitive to exposure to air.

  In various embodiments, the reactant powder mixture may be loaded into the reaction vessel after the magnesium oxide layer has been placed on the side wall of the reaction vessel and / or on the bottom of the reaction vessel. Loading the reactant powder mixture may include placing the mixture in a reaction vessel on top of an optional magnesium oxide layer located on the inner bottom surface of the reaction vessel (see, eg, FIGS. 2 and 3). Wanna) After loading the reactant powder mixture into the reaction vessel, an ignition line is placed in contact with the reactant powder mixture in the reaction vessel.

  Referring to FIG. 5, an ignition wire 28 immersed in the reactant powder mixture 20 within the reaction vessel 10 is shown. The ignition wire 28 is connected to a current source (power supply device) 24 by a lead wire and a return wire 26.

  In various embodiments, the ignition wire may be immersed directly in the reactant powder mixture in the reaction vessel, as shown in FIG. For example, an ignition wire that is several inches long may be looped as shown in FIG. 5 and immersed in the reactant powder mixture in the reaction vessel for at least 2 inches. Alternatively, the ignition wire comprises an aluminum metal powder and a reducible metal oxide or peroxide, such as tantalum pentoxide, niobium pentoxide, iron (III) oxide, copper (II) oxide, and / or barium peroxide. May be placed inside a plastic starter bag (not shown) containing any one or any combination. The starter bag may be placed directly on top of the reactant powder mixture in the reaction vessel and may be partially or completely immersed in the reactant powder mixture, although this is not necessary. While not intending to be bound by theory, the smaller the volume of reactants in the starter bag, the less the ignition wire is immersed in direct contact with the entire reactant powder mixture in the reaction vessel. It is believed that reaction ignition can provide a reproducible environment. Nevertheless, the ignition wire may be placed in direct contact with the reactant powder mixture by dipping the wire directly into the main reaction mixture, or indirectly through the starter bag.

  The ignition wire may include, for example, tantalum, niobium, a tantalum alloy, or a niobium alloy. Alternatively, the ignition wire may include any refractory metal or alloy that is intended to be present in the targeted alloy composition, such as tungsten, tungsten alloy, niobium, niobium alloy, and the like. In some embodiments, the ignition line may be at least 12 inches long, for example, a comparison of 20 to create a resistive heating element to ignite the reaction mixture and initiate an aluminothermite reaction. Narrow gauges may be included. The ignition wire may be connected to the power supply using a length and gauge, eg, aluminum wire or copper wire, sufficient to pass current through the ignition wire. The connection between the ignition wire and the wire connecting to the power supply may include, for example, a stranded wire connection or a metal butt connector.

  After the ignition wire is placed in contact with the reaction mixture, the reaction vessel may be sealed inside the reaction chamber. Although the specific profile and structure of the reaction chamber is not necessarily important, the reaction chamber physically contains the reaction vessel and provides structural integrity when subjected to the heat and temperature generated during the aluminothermit reaction. Should be maintained. The reaction chamber should also be capable of containing any reaction material that is discharged from the reaction vessel during the reaction. The reaction chamber should also be capable of hermetically sealing the reaction vessel from the ambient environment.

  Referring to FIG. 6, a reaction chamber 30 is shown that includes a lid structure that seals the reaction vessel 10 containing the reactant powder mixture 20. The reaction chamber 30 includes a vacuum port 32 that connects to a vacuum source (not shown) such as a vacuum pump for establishing a vacuum inside the reaction chamber. Lead wires and return wires 26 (connecting ignition wire 28 and power supply 24) are arranged through an electrical port (not shown) in reaction chamber 30. After the reactant powder mixture 20 and the ignition wire 28 are placed in the reaction vessel 10, the reaction vessel 10 is placed inside the reaction chamber 30 by lowering the reaction chamber over the reaction vessel, as indicated by arrow 34. Sealed. The reaction vessel 30 engages with a suitable surface such as, for example, a flat base plate with machined flat ends, or a concrete slab to provide a hermetic seal and vacuum into the reaction vessel through the vacuum port 32. Establish. After the aluminothermit reaction is complete and the resulting reaction product is sufficiently cooled, the vacuum may be stopped and the reaction chamber may be raised as indicated by arrow 34. The raising and lowering of the reaction vessel 30 may be performed using an appropriate plant facility such as a crane or a hoisting device (not shown), for example. The reaction vessel 30 may include any suitable structural material, such as steel.

  It is not always necessary to establish a vacuum for the aluminothermit reaction. However, conducting the reaction under vacuum provides advantages such as negating pressure spikes in the reaction mixture that can drain material from the reaction vessel. Performing the reaction under vacuum can also improve the quality of the tantalum or niobium alloy regular produced by the aluminothermit reaction by reducing nitrogen and oxygen contamination. Establishing a vacuum in the reaction chamber is also insulated and increases the cooling time of the reaction product, further reducing tantalum or niobium alloy regular cracking during solidification and cooling. A reasonable vacuum pressure is suitable inside the reaction chamber. For example, a vacuum pressure of less than 100 millitorr may be used.

  Initiating the aluminothermit reaction may include energizing the ignition wire. The initiation of the aluminothermit reaction may occur after the reaction vessel is sealed inside the reaction chamber and a vacuum is established in the reaction chamber. Energizing the ignition line may include starting the power supply and sending a current of at least 60 amperes through the ignition line. In various embodiments, the ignition wire may be energized at at least 70 amps, at least 80 amps, at least 90 amps, at least 100 amps. In various embodiments, the ignition line may be energized for at least 1 second, or in some embodiments, at least 2 seconds, at least 3 seconds, at least 4 seconds, or at least 5 seconds.

  After initiation, the aluminothermit reaction proceeds very quickly and can be completed within 10 minutes of initiation, or in some embodiments within 5 minutes of initiation. However, the resulting reaction product containing the slag phase and tantalum alloy regular may require 24-48 hours of cooling to reach ambient temperature. After the reaction product reaches an acceptable temperature, such as ambient temperature, the reaction chamber may be refilled with air to remove the vacuum, and the reaction chamber is opened and the reaction product is removed from the reaction vessel. Also good. In various embodiments, the hot reaction product may be gas quenched by refilling the reaction chamber with a gas such as air or argon to accelerate cooling to ambient temperature. Gas refilling may be repeated several times to further accelerate cooling. However, gas quenching should be performed only after the reaction product has solidified, if any. Therefore, to ensure solidification, gas quenching should not be performed until at least 12 hours after the start of the aluminothermit reaction.

As described above, the reaction product of the aluminothermit reaction includes a solidified slag phase and a tantalum alloy or niobium alloy regular. The slag phase may include oxides such as barium oxide and / or aluminum oxide. The tantalum alloy or niobium alloy regular may include an alloying element dissolved in the tantalum matrix or niobium matrix, the alloying element being a precursor reactant (eg, Ta ₂ O ₅ , Nb ₂ O ₅ , MoO ₃ , TiO ₂ , ZrO ₂ , HfO ₂ , V ₂ O ₅ , W, or WO ₃ ), a sacrificial metal oxide reactant (eg, Fe ₂ O ₃ and / or CuO), and excess aluminum.

For example, Table 1 below shows a reaction mixture that can yield a 22.7 kilogram (50.0 pound) tantalum alloy regular containing 2.2 weight percent tungsten, sacrificial iron and copper, and excess aluminum. Show.
In various embodiments, the weight percentages shown in Table 1 are ± 10%, ± 5%, ± 2%, ± 1%, ± 0.5%, ± 0.1%, ± 0.05%, or ± It can vary by 0.01%.

  Additional target product weight may be obtained by scaling the relative amount of reactants and maintaining the relative weight percentage. The resulting tantalum alloy regular containing 2.2 weight percent tungsten is electron beam melted to reduce the copper, aluminum, and iron content of the regular material, 2.5 weight percent tungsten, the balance tantalum and Refined Ta-2.5W alloy ingots containing inevitable impurities can be produced.

  Niobium-containing tantalum-based alloy regulars, tantalum-containing niobium-based alloy regulars, tungsten-containing tantalum-based alloy regulars with different tungsten contents, zirconium-containing niobium-based alloy regulars, titanium-containing niobium-based alloy regulars, molybdenum-containing tantalum-based alloy regulars, or more The amount of an alternative reaction mixture when producing aluminothermit other tantalum or niobium alloy compositions, including highly alloyed compositions, can be determined by the information disclosed herein.

  In various embodiments, the reaction mixture is based on the total weight of the reaction mixture, 55.1% to 57.1% tantalum pentoxide powder; 0% to 3.5% iron (III) oxide powder; % To 3.2% copper (II) oxide powder; 21.5% to 23.5% barium peroxide powder; 14.7% to 16.7% aluminum metal powder; and 0% to 15% Tungsten metal powder may be included. In other embodiments, the reaction mixture is 55.6% to 56.6% tantalum pentoxide powder; 2.0% to 3.0% iron (III) oxide powder, based on the total weight of the reaction mixture. 1.7% to 2.7% copper (II) oxide powder; 22.0% to 23.0% barium peroxide powder; 15.2% to 16.2% aluminum metal powder; 5% to 1.5% tungsten metal powder may be included. In some embodiments, the reaction mixture is 56.0% to 56.2% tantalum pentoxide powder; 2.4% to 2.6% iron (III) oxide based on the total weight of the reaction mixture. 2.1% to 2.3% copper (II) oxide powder; 22.4% to 22.6% barium peroxide powder; 15.6% to 15.8% aluminum metal powder; and 0 .9% to 1.1% tungsten metal powder may be included.

  In various embodiments, the methods described herein can be at least 80% of the original tantalum provided by the tantalum pentoxide reactant, based on the metal weight, and in some embodiments, based on the metal weight. Tantalum alloy regulars can be produced having tantalum yields of at least 85%, at least 90%, at least 93%, or at least 95% of the original tantalum provided by the tantalum pentoxide reactant. In various embodiments, the methods described herein can comprise at least 80 weight percent tantalum, in some embodiments, at least 81%, at least 83%, at least 85%, at least, based on the total weight of the regular. Tantalum alloy regulars containing 87%, or at least 89% tantalum can be produced. In various embodiments, the methods described herein can be at least 1.0 weight percent tungsten, in some embodiments, at least 1.3%, at least 1.5%, based on the total weight of the regular. A tantalum alloy regular comprising at least 1.7%, at least 2.0%, at least 2.1%, or at least 2.2% tungsten.

The aluminothermit method described herein produces an oxide slag phase that can be completely separated from the alloy regular of the metal, thereby facilitating separation and removal of the tantalum or niobium alloy regular from the slag. Become. The tantalum alloy or niobium alloy regular can be cleaned to remove residual slag and then placed directly into an electron beam melting furnace to refine the alloy composition to produce a tantalum alloy or niobium alloy ingot. In this way, the tantalum alloy or niobium alloy regular produced by the present specification can function as a pre-alloyed intermediate product in the production of tantalum or niobium alloy ingots and factory products. . Tantalum alloy or niobium alloy regulars are monolithic, fully consolidated, and non-brittle. The tantalum alloy or niobium alloy regular also includes alloying elements that are completely dissolved in the tantalum matrix or niobium matrix, thereby allowing direct electron beam melting, as well as uniform microstructure, specific alloy composition, and Casting of a tantalum alloy or niobium alloy ingot having alloying elements dispersed completely and uniformly in the tantalum matrix or niobium matrix is facilitated.

Referring back to FIG. 1A, after the tantalum alloy or niobium alloy regular produced by the method described herein is electron beam melted, the resulting tantalum alloy or niobium alloy ingot is forged, rolled, cut, annealed. And may be cleaned to produce factory products such as billets, rods, rods, sheets, wires, etc. of tantalum or niobium alloys.

  The following non-limiting and non-exhaustive examples are intended to further illustrate various non-limiting and non-exhaustive embodiments without limiting the scope of the embodiments described herein. .

Example 1:
A tantalum alloy regular was produced by performing an aluminothermit reaction using the reactant powders and amounts listed in Table 2.

The amount of aluminum metal powder was 4% excess of the stoichiometric amount required to reduce tantalum pentoxide, iron (III) oxide, copper (II) oxide, and barium peroxide according to the following chemical equation.
3Ta ₂ O ₅ + 10Al → 6Ta + 5Al ₂ O ₃
W → W
Fe ₂ O ₃ + 2Al → 2Fe + Al ₂ O ₃
3CuO + 2Al → 3Cu + Al ₂ O ₃
3BaO ₂ + 2Al → 3BaO + Al ₂ O ₃

  The reactant powder was completely dried (<0.2% LOI) and refined (85 wt% -200 mesh). The reactant powders were individually weighed and loaded into a double cone powder blender. The reactant powder was mixed in a blender for at least 20 minutes to obtain a macroscopically homogeneous reaction mixture. The reaction mixture was loaded into the reaction vessel.

  The reaction vessel was cylindrical with an inner height of 12 inches and an inner diameter of 4.25 inches. The reaction vessel was fabricated from an iso-molded fine-grain graphite sheet that forms the bottom of the reaction vessel, and an extruded medium-grain to coarse-grain graphite sheet that forms a cylindrical sidewall. The bottom and side walls were approximately 1 inch thick. The reaction vessel was placed on top of the refractory brick layer and the refractory brick layer was placed on top of the concrete slab. A layer of heavy / dead burned magnesium oxide powder was spread on the bottom inner surface of the reaction vessel and the reaction mixture was loaded on top of the magnesium oxide powder layer. A barrier was formed between the reaction mixture and the graphite bottom of the reaction vessel by the magnesium oxide powder layer.

  A tantalum ignition wire was immersed in the reactant powder mixture in the reaction vessel. The ignition wire was connected to the power supply device by an aluminum wire. The aluminothermite reaction was initiated by sending 100 amps of current from the power supply through the ignition line for 5 seconds. The reaction proceeded very quickly and the reaction product was allowed to cool to ambient temperature over 48 hours. The reaction product contained well-defined separated regular and slag phases. The reaction product was removed from the reaction vessel and weighed to determine total material recovery. Total material recovery was determined to be 3145.6 grams (98% of the original 3205 grams of reactant powder).

  The regular and slag phases were separated and analyzed for chemical composition. Based on the stoichiometry of the chemical reaction, assuming a perfect yield, the regular theoretical alloy composition is 1.2% aluminum, 3.4% iron, 3.4% copper by weight percent. , 1.8% tungsten and the balance tantalum (90.2%). Taking into account that copper is essentially immiscible with tungsten at ambient temperature, the theoretical alloy composition was determined according to ASTM E1508-98 (2008): Standard Guide for Quantitative Analysis by Energy-Dispersive Spectroscopy. Which is generally consistent with the measurements of the actual alloy composition of the regular, made using Scanning Electron Microscopy / Energy Dispersion Spectroscopy (SEM / EDS). SEM / EDS analysis showed the actual alloy composition in weight percent: 3.4% aluminum, 8.4% iron, 2.0% tungsten, balance tantalum and inevitable impurities. The yield of tantalum in the regular was 90% of the original tantalum provided by the tantalum pentoxide reactant (based on metal weight). The slag phase contained approximately 32% barium oxide and 68% aluminum oxide, and a small amount of tantalum, iron and copper containing byproducts, based on moles.

  FIG. 7 is an SEM image of the microstructure of the tantalum alloy regular. The microstructure contained two observable phases: a darker phase labeled “A” in FIG. 7 and a brighter phase labeled “B”. Based on SEM / EDS analysis, phase A is a phase rich in aluminum and iron and phase B is a phase low in aluminum and iron. Both phases (A and B) contain tantalum as the main constituent and also contain dissolved tungsten. SEM / EDS analysis showed no phase containing tungsten as the main constituent. In fact, from SEM / EDS analysis, the tungsten concentration only varied from 0.4% to 3.7% by weight in each distinct phase, and the average tungsten concentration was 2 over the entire SEM / EDS field. It was shown to be 0.0%. This showed that the tungsten metal powder that was inert by the aluminothermit process was completely dissolved in the tantalum metal produced by the aluminothermit reduction of tantalum pentoxide.

  The tantalum alloy regular was monolithic, fully consolidated, non-brittle and free of any cracks. Tantalum alloy regulars can be placed directly into an electron beam melting furnace to reduce aluminum, copper, and iron to unavoidable impurity levels, to dissolve tungsten homogeneously in the tantalum matrix, and Ta-2.5W It was possible to refine tantalum alloy compositions, including establishing tungsten concentrations within the specifications.

Example 2:
A tantalum alloy regular was produced by conducting an aluminothermit reaction with the reactant powders and amounts listed in Table 3.

The amount of aluminum metal powder was 4% excess of the stoichiometric amount required for reduction of tantalum pentoxide, iron (III) oxide, and barium peroxide according to the following chemical equation.
3Ta ₂ O ₅ + 10Al → 6Ta + 5Al ₂ O ₃
W → W
Fe ₂ O ₃ + 2Al → 2Fe + Al ₂ O ₃
3BaO ₂ + 2Al → 3BaO + Al ₂ O ₃

  The reactant powder was completely dried (<0.2% LOI) and refined (85 wt% -200 mesh). The reactant powders were individually weighed and loaded into a double cone powder blender. The reactant powder was mixed in a blender for at least 20 minutes to obtain a macroscopically homogeneous reaction mixture. The reaction mixture was loaded into the reaction vessel.

  The reaction vessel was cylindrical with an inner height of 12 inches and an inner diameter of 4.25 inches. The reaction vessel was fabricated from an iso-molded fine-grain graphite sheet that forms the bottom of the reaction vessel, and an extruded medium-grain to coarse-grain graphite sheet that forms a cylindrical sidewall. The bottom and side walls were approximately 1 inch thick. The reaction vessel was placed on top of the refractory brick layer and the refractory brick layer was placed on top of the concrete slab. A layer of heavy / dead burned magnesium oxide powder was spread on the bottom inner surface of the reaction vessel and the reaction mixture was loaded on top of the magnesium oxide powder layer. A barrier was formed between the reaction mixture and the graphite bottom of the reaction vessel by the magnesium oxide powder layer.

  A tantalum ignition wire was immersed in the reactant powder mixture in the reaction vessel. The ignition wire was connected to the power supply device by an aluminum wire. The aluminothermite reaction was initiated by sending 100 amps of current from the power supply through the ignition line for 5 seconds. The reaction proceeded very quickly and the reaction product was allowed to cool to ambient temperature over 48 hours. The reaction product contained well-defined separated regular and slag phases. The reaction product was removed from the reaction vessel and weighed to determine total material recovery. Total material recovery was determined to be 3216.6 grams (99% of the original 3248 grams of reactant powder).

  The regular and slag phases were separated and analyzed for chemical composition. Based on the stoichiometry of the chemical reaction, assuming a perfect yield, the regular theoretical alloy composition is 1.2% aluminum, 6.8% iron, 1.8% tungsten by weight percent. The remaining tantalum (90.2%) is considered. The slag phase contained approximately 32% barium oxide and 68% aluminum oxide and a small amount of tantalum-containing byproducts and iron-containing byproducts, based on moles. The yield of tantalum in the regular was 88% of the original tantalum provided by the tantalum pentoxide reactant (based on metal weight).

  The tantalum alloy regular was monolithic, fully consolidated, and non-brittle. The tantalum alloy regular is directly put into an electron beam melting furnace to reduce aluminum and iron to unavoidable impurity levels, to dissolve tungsten homogeneously in the tantalum base material, and Ta-2.5W specifications. It was possible to refine the tantalum alloy composition, including establishing a tungsten concentration within the range.

The methods and apparatus for the production of tantalum alloys described herein provide operational and economic advantages over methods using tantalum metal feedstocks. The methods described herein include (1) the need for a relatively expensive virgin sodium reduced tantalum metal; (2) an expensive HDH process; and (3) a powder molded article for electron beam melting. The pressing and sintering operations necessary to produce are unnecessary. Referring to FIGS. 1A and 1B, by using a less expensive tantalum pentoxide feed, by eliminating several unit operations, the flow of the process for producing an ingot and plant product of tantalum alloy shorter Become cheaper. The method described herein is a monolithic and fully solidified material that can be easily isolated from the separated slag phase and can be placed directly into an electron beam melting furnace to refine a tantalum alloy composition. Directly produces bonded non-brittle tantalum alloy regulars. The tantalum alloy regulars produced by the methods described herein also include alloying elements that are completely dissolved in the tantalum matrix, thereby allowing direct electron beam melting as well as uniform microstructures, certain Casting of the tantalum alloy ingot having the alloy composition and the alloying elements completely and uniformly dispersed in the tantalum base material is facilitated.

This specification has been written with reference to various non-limiting and non-exhaustive embodiments. However, one of ordinary skill in the art will recognize that various substitutions, modifications, or combinations of any of the disclosed embodiments (or portions thereof) may be made within the scope of the specification. As such, this specification is intended and understood to support additional embodiments not expressly set forth herein. Such embodiments, for example, combine or modify any of the disclosed steps, components, elements, features, aspects, characteristics, limitations, etc. of the various non-limiting and non-exhaustive embodiments described herein. Or can be obtained by reorganization. As such, Applicant reserves the right to amend the claims to add features as variously described herein during the filing process, and such amendments are subject to 35 USC 112. It complies with the requirements of (a) and 132 (a).
[Aspect of the Invention]
[1]
Tantalum pentoxide powder;
At least one of iron (III) oxide powder and copper (II) oxide powder;
Barium peroxide powder; and
Aluminum metal powder
Performing an aluminothermite reaction using a reaction mixture comprising:
A method for producing a tantalum alloy.
[2]
The reaction mixture includes niobium pentoxide powder, tungsten trioxide powder, molybdenum trioxide powder, chromium (III) oxide powder, hafnium dioxide powder, zirconium dioxide powder, titanium dioxide powder, vanadium pentoxide powder, and tungsten metal powder. The method of [1], further comprising at least one of
[3]
The method of [1], wherein the reaction mixture further comprises at least one of niobium pentoxide powder, tungsten trioxide powder, molybdenum trioxide powder, and tungsten metal powder.
[4]
The method of [1], wherein the reaction mixture further comprises niobium pentoxide powder.
[5]
The method according to [1], wherein the reaction mixture further comprises a tungsten trioxide powder and / or a tungsten metal powder.
[6]
The method of [1], wherein the reaction mixture further comprises molybdenum trioxide powder.
[7]
The method according to [1], wherein the aluminothermit reaction generates a tantalum alloy regular and a separated slag phase.
[8]
The method of [7], further comprising electron beam melting the tantalum alloy regular to produce a tantalum alloy ingot.
[9]
The tantalum alloy ingot is
At least one of niobium, tungsten, and molybdenum; and
Including the balance of tantalum and inevitable impurities,
The method of [8].
[10]
Performing the aluminothermit reaction,
Placing the reaction mixture in the reaction vessel including a magnesium oxide layer located on a bottom surface of the reaction vessel; and
Initiating the aluminothermit reaction,
The method of [1].
[11]
Tantalum pentoxide powder and / or niobium pentoxide powder;
Iron (III) oxide powder and / or copper (II) oxide powder;
Barium peroxide powder;
Aluminum metal powder; and
At least one of tungsten trioxide powder, molybdenum trioxide powder, chromium (III) oxide powder, hafnium dioxide powder, zirconium dioxide powder, titanium dioxide powder, vanadium pentoxide powder, and tungsten metal powder
Performing an aluminothermite reaction using a reaction mixture comprising:
A method for producing tantalum or niobium alloys.
[12]
The reaction mixture is
Tantalum pentoxide powder;
Molybdenum trioxide powder;
Iron (III) oxide powder and / or copper (II) oxide powder;
Barium peroxide powder; and
Aluminum metal powder
The method according to [11], including:
[13]
The reaction mixture is
Niobium pentoxide powder;
Iron (III) oxide powder and / or copper (II) oxide powder;
Barium peroxide powder;
Aluminum metal powder; and
At least one of tungsten trioxide powder, molybdenum trioxide powder, chromium (III) oxide powder, hafnium dioxide powder, zirconium dioxide powder, titanium dioxide powder, vanadium pentoxide powder, and tungsten metal powder
The method according to [11], including:
[14]
The reaction mixture is
Niobium pentoxide powder;
Molybdenum trioxide powder;
Iron (III) oxide powder and / or copper (II) oxide powder;
Barium peroxide powder; and
Aluminum metal powder
[13] The method of [13].
[15]
The reaction mixture is
Niobium pentoxide powder;
Titanium dioxide powder;
Iron (III) oxide powder and / or copper (II) oxide powder;
Barium peroxide powder; and
Aluminum metal powder
[13] The method of [13].
[16]
The reaction mixture is
Niobium pentoxide powder;
Zirconium dioxide powder;
Iron (III) oxide powder and / or copper (II) oxide powder;
Barium peroxide powder; and
Aluminum metal powder
[13] The method of [13].
[17]
The method according to [13], wherein the aluminothermit reaction generates a niobium alloy regular and a separated slag phase.
[18]
The method according to [17], further comprising electron beam melting the niobium alloy regular to produce a niobium alloy ingot.
[19]
The niobium alloy ingot is
At least one of tungsten, molybdenum, hafnium, zirconium, titanium, and vanadium; and
Including the balance niobium and inevitable impurities,
[18] The method.
[20]
The niobium alloy ingot is
At least one of molybdenum, zirconium, and titanium; and
Including the balance niobium and inevitable impurities,
[18] The method.
[21]
Niobium pentoxide powder;
Iron (III) oxide powder and / or copper (II) oxide powder;
Barium peroxide powder;
Aluminum metal powder; and
At least one of tantalum pentoxide powder, tungsten trioxide powder, molybdenum trioxide powder, chromium (III) oxide powder, hafnium dioxide powder, zirconium dioxide powder, titanium dioxide powder, vanadium pentoxide powder, and tungsten metal powder
Performing an aluminothermite reaction using a reaction mixture comprising:
A method for producing a niobium alloy.
[22]
The reaction mixture is
Niobium pentoxide powder;
Tantalum pentoxide powder;
Iron (III) oxide powder and / or copper (II) oxide powder;
Barium peroxide powder; and
Aluminum metal powder
[21] The method of [21].
[23]
The aluminothermit reaction produces a niobium alloy regular and a separated slag phase, and the method further comprises electron beam melting the niobium alloy regular to produce a niobium alloy ingot, the niobium alloy ingot comprising:
At least one of tantalum, molybdenum, zirconium, and titanium; and
The remaining niobium and inevitable impurities
[21] The method of [21].

Claims (12)

Tantalum pentoxide powder;
At least one of iron (III) oxide powder and copper (II) oxide powder;
Barium peroxide powder;
Performing an aluminothermit reaction using a reaction mixture comprising aluminum metal powder; and at least one of hafnium dioxide powder and vanadium pentoxide powder;
A method for producing a tantalum alloy.   The reaction mixture of claim 1, further comprising at least one of niobium pentoxide powder, tungsten trioxide powder, molybdenum trioxide powder, chromium (III) oxide powder, zirconium dioxide powder, and tungsten metal powder. the method of.   The method of claim 1, wherein the reaction mixture further comprises at least one of niobium pentoxide powder, tungsten trioxide powder, molybdenum trioxide powder, and tungsten metal powder.   The method of claim 1, wherein the reaction mixture further comprises niobium pentoxide powder.   The method of claim 1, wherein the reaction mixture further comprises tungsten trioxide powder and / or tungsten metal powder.   The method of claim 1, wherein the reaction mixture further comprises molybdenum trioxide powder.   The method of claim 1, wherein the aluminothermit reaction produces a tantalum alloy regular and a separated slag phase.   The method of claim 7, further comprising electron beam melting the tantalum alloy regular to produce a tantalum alloy ingot. The tantalum alloy ingot is
At least one of niobium, tungsten, and molybdenum; and the balance tantalum and unavoidable impurities,
The method of claim 8. Performing the aluminothermit reaction,
Placing the reaction mixture in the reaction vessel including a magnesium oxide layer located on a bottom surface of the reaction vessel; and initiating the aluminothermit reaction.
The method of claim 1. Tantalum pentoxide powder and / or niobium pentoxide powder;
Iron (III) oxide powder and / or copper (II) oxide powder;
Barium peroxide powder;
Performing an aluminothermit reaction using a reaction mixture comprising aluminum metal powder; and at least one of hafnium dioxide powder and vanadium pentoxide powder;
A method for producing tantalum or niobium alloys. The reaction mixture is
Tantalum pentoxide powder;
Molybdenum trioxide powder;
Iron (III) oxide powder and / or copper (II) oxide powder;
Barium peroxide powder;
The method of claim 11, comprising: an aluminum metal powder; and at least one of a hafnium dioxide powder and a vanadium pentoxide powder.