Preparation method of tantalum-aluminum alloy

Abstract

The preparation method of the tantalum-aluminum alloy disclosed by the embodiment of the invention comprises the following steps: S1, mixing tantalum oxide, metal aluminum and metal magnesium in an oxygen-free environment to obtain a mixed raw material; s2, heating the mixed raw materials to a reaction temperature, and carrying out a self-propagating reaction; wherein the metal magnesium in the mixed raw material reduces the tantalum oxide to generate metal tantalum and magnesium oxide, and the generated metal tantalum and the metal aluminum in the mixed raw material form a tantalum-aluminum alloy; and S3, magnesium oxide is removed, and the tantalum-aluminum alloy powder is obtained. According to the method, magnesium metal reacts with tantalum oxide to generate tantalum metal, the generated tantalum metal and raw material metal aluminum directly form tantalum-aluminum alloy, then magnesium oxide is removed through an acid solution, and tantalum-aluminum alloy powder is obtained; tantalum and aluminum in the obtained tantalum-aluminum alloy powder are uniformly distributed, and the oxygen content is low; the tantalum-aluminum alloy with different compositions can be prepared according to the composition proportion of the tantalum-aluminum alloy, and the method is simple and easy to operate and has good application prospects in the field of tantalum-aluminum alloy preparation.

Description

Technical Field

[0001] The invention belongs to the technical field of alloy preparation, and in particular relates to a method for preparing a tantalum-aluminum alloy. Background Art

[0002] Tantalum aluminum alloy has the characteristics of high melting point, oxidation resistance, creep resistance, high specific strength, high hardness, corrosion resistance, etc. It has important application value in key fields such as aerospace, electronic information, and medical treatment. As a potential high-temperature metal functional material, it is an ideal material for attenuators and is often used in electronic components. Tantalum aluminum alloy is also often used as an additive for high-temperature titanium alloys because of its similar melting point to titanium. Tantalum can enhance the multi-element composite solid solution effect in high-temperature titanium alloys, effectively inhibit the segregation of high-temperature titanium alloy components, improve the high-temperature strength and temperature resistance of titanium alloys, and improve the performance of titanium alloys.

[0003] At present, the common preparation methods of tantalum-aluminum alloys include aluminothermic self-propagating high-temperature synthesis, powder metallurgy, and induction melting. Among them, the self-propagating high-temperature synthesis method requires the addition of a heat-generating agent. After the heat-generating agent is ignited to initiate the aluminothermic reaction, the reaction can proceed spontaneously. This method generates a large amount of heat while aluminum reduces tantalum oxide to form tantalum. Excess aluminum and the product tantalum form a tantalum-aluminum alloy under high temperature conditions. The generated aluminum oxide combines with a slag-forming agent to form slag. Through slag-gold separation, a tantalum-aluminum alloy with a specific composition is obtained. However, the by-product aluminum oxide of this method needs to be removed by adding a slag-forming agent, and the reaction temperature and the proportion of slag are difficult to control. In addition, the heat released by aluminothermic reduction causes a large amount of aluminum to volatilize, and the product composition is difficult to control, and the product uniformity is poor. In addition, potassium chlorate, a strong oxidant, is often used as a heat-generating agent, which is prone to combustion and explosion, and the process is highly dangerous. The induction melting method uses induction melting to melt aluminum into aluminum liquid, and then adds tantalum particles into the aluminum liquid to prepare tantalum-aluminum alloy. Tantalum mainly forms tantalum-aluminum alloy with aluminum in the form of atomic diffusion. However, this method has extremely high requirements on the atmosphere, otherwise aluminum oxide inclusions are easily formed at high temperatures. In addition, the tantalum content in the tantalum-aluminum alloy is low and the alloy composition is uneven.

[0004] In summary, due to the large differences in physical properties such as density and melting point between tantalum and aluminum, the tantalum-aluminum alloy prepared by existing technology has problems such as high impurity content, component segregation, and poor organizational uniformity. Summary of the invention

[0005] In view of this, an embodiment of the present invention discloses a method for preparing tantalum-aluminum alloy, which does not require the addition of a heat-generating agent and a slag-forming agent. The tantalum-aluminum alloy is prepared by directly reducing tantalum oxide with excess magnesium, by directly utilizing the characteristics that magnesium has stronger reducing properties than aluminum and the generated magnesium oxide is easier to remove than aluminum oxide.

[0006] Some embodiments disclose a method for preparing a tantalum-aluminum alloy, comprising the steps of:

[0007] S1, tantalum oxide, metal aluminum and metal magnesium are mixed in an oxygen-free environment to obtain a mixed raw material;

[0008] S2, the mixed raw materials are heated to a reaction temperature, and a self-propagating reaction occurs; wherein the metal magnesium in the mixed raw materials reduces the tantalum oxide to generate metal tantalum and magnesium oxide, and the generated metal tantalum forms a tantalum-aluminum alloy with the metal aluminum in the mixed raw materials;

[0009] S3. Remove magnesium oxide to obtain tantalum-aluminum alloy powder.

[0010] Furthermore, in the preparation method of tantalum-aluminum alloy disclosed in some embodiments, in the mixed raw material, the molar ratio of metallic magnesium to tantalum oxide is not less than 5, and the ratio of metallic aluminum to tantalum oxide is determined according to the stoichiometric ratio of the product tantalum-aluminum alloy.

[0011] In the preparation method of tantalum-aluminum alloy disclosed in some embodiments, the reaction temperature of generating tantalum-aluminum alloy by self-propagating reaction is set to 800-1500°C.

[0012] Some embodiments disclose a method for preparing tantalum-aluminum alloy, which utilizes an acidic solution washing method to remove magnesium oxide; the acidic solution includes any combination of hydrochloric acid, sulfuric acid, nitric acid or hydrofluoric acid.

[0013] Some embodiments disclose a method for preparing a tantalum-aluminum alloy, wherein the method for removing magnesium oxide comprises: washing with an acidic solution, dissolving with distilled water, allowing to stand and precipitate, and drying to obtain a tantalum-aluminum alloy powder.

[0014] In the preparation method of tantalum aluminum alloy disclosed in some embodiments, the oxygen-free environment is an inert atmosphere environment.

[0015] In the method for preparing tantalum aluminum alloy disclosed in some embodiments, the inert atmosphere is argon.

[0016] In the method for preparing tantalum aluminum alloy disclosed in some embodiments, step S1 also includes compression molding the mixed raw material to obtain a raw material blank.

[0017] The method for preparing tantalum-aluminum alloy disclosed in the embodiment of the present invention utilizes the reaction of metal magnesium with tantalum oxide to generate metal tantalum, and the generated metal tantalum directly forms tantalum-aluminum alloy with raw metal aluminum, and then uses an acidic solution to remove magnesium oxide to obtain tantalum-aluminum alloy powder; no exothermic agent or slag-forming agent is used, and the obtained tantalum-aluminum alloy is a powder, in which tantalum and aluminum are evenly distributed and the oxygen content is low; tantalum-aluminum alloys of different compositions can be prepared according to the composition ratio of the tantalum-aluminum alloy, the method is simple and easy to operate, and has good application prospects in the field of tantalum-aluminum alloy preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Tantalum aluminum alloy SEM-EDS image of Example 1;

[0019] Figure 2 Example 1 Tantalum aluminum alloy XRD pattern;

[0020] Figure 3 SEM-EDS image of tantalum-aluminum alloy of Example 2;

[0021] Figure 4 XRD diagram of tantalum-aluminum alloy of Example 2. DETAILED DESCRIPTION

[0022] The word "embodiment" used herein as an "exemplary" does not necessarily mean that any embodiment described is superior or better than other embodiments. Performance index tests in the embodiments of the present invention are performed using conventional test methods in the art unless otherwise specified. It should be understood that the terms described in the embodiments of the present invention are only used to describe specific implementation methods and are not intended to limit the contents disclosed in the embodiments of the present invention.

[0023] Unless otherwise specified, the technical and scientific terms used herein have the same meanings as commonly understood by ordinary technicians in the technical field to which the embodiments of the present invention belong; other experimental methods and technical means not specifically specified in the embodiments of the present invention refer to experimental methods and technical means commonly used by ordinary technicians in the field.

[0024] The terms "substantially" and "approximately" used herein are used to describe small fluctuations. For example, they can refer to less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. The numerical data represented or presented in the range format herein are used only for convenience and brevity, and should therefore be flexibly interpreted as including not only the values ​​clearly listed as the limits of the range, but also all independent values ​​or sub-ranges contained in the range. For example, the numerical range of "1-5%" should be interpreted as including not only the clearly listed values ​​of 1% to 5%, but also the independent values ​​and sub-ranges within the range shown. Therefore, independent values ​​such as 2%, 3.5% and 4% and sub-ranges such as 1%-3%, 2%-4% and 3%-5% are included in this numerical range. This principle also applies to the range of only one numerical value. In addition, such an interpretation applies regardless of the width of the range or the characteristics described.

[0025] In this document, including in the claims, transitional words such as "comprises," "includes," "with," "having," "containing," "involving," "accommodating," etc. are understood to be open-ended, i.e., meaning "including but not limited to." Only the transitional words "consisting of" and "composed of" are closed transitional words.

[0026] In order to better illustrate the present invention, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that the present invention can be implemented without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the gist of the present invention.

[0027] Under the premise of no conflict, the technical features disclosed in the embodiments of the present invention may be arbitrarily combined, and the resulting technical solutions belong to the contents disclosed in the embodiments of the present invention.

[0028] In some embodiments, the method for preparing the tantalum aluminum alloy disclosed in some embodiments comprises the steps of:

[0029] S1, tantalum oxide, metal aluminum and metal magnesium are mixed in an oxygen-free environment to obtain a mixed raw material; generally, in the mixed raw material, the molar ratio of metal magnesium to tantalum oxide is not less than 5, and the ratio of metal aluminum to tantalum oxide is determined according to the stoichiometric ratio of the product tantalum aluminum alloy;

[0030] Typically, the ratio of metallic aluminum to metallic tantalum in the obtained tantalum-aluminum alloy product is equal to the ratio of metallic aluminum to tantalum oxide in the mixed raw material; typically, the oxygen-free environment is an inert atmosphere environment.

[0031] In some embodiments, the inert atmosphere is argon.

[0032] S2, the mixed raw material is heated to a reaction temperature, and a self-propagating reaction occurs; wherein the metal magnesium in the mixed raw material reduces tantalum oxide to generate metal tantalum and magnesium oxide, and the generated metal tantalum forms a tantalum-aluminum alloy with the metal aluminum in the mixed raw material; in some embodiments, the reaction temperature for the self-propagating reaction to generate the tantalum-aluminum alloy is set to 800-1500° C.; generally, the generated product consists of tantalum-aluminum alloy and magnesium oxide;

[0033] S3, remove magnesium oxide to obtain tantalum-aluminum alloy powder. In some embodiments, magnesium oxide is removed by washing with an acidic solution; the acidic solution includes any combination of hydrochloric acid, sulfuric acid, nitric acid or hydrofluoric acid; the product is usually washed with an acidic solution to dissolve magnesium oxide, and the obtained solution is allowed to settle, and then the supernatant is removed to leave the tantalum-aluminum alloy powder, and the tantalum-aluminum alloy powder is further washed with distilled water, and the target product of tantalum-aluminum alloy powder is obtained after drying;

[0034] Some embodiments disclose a method for preparing tantalum-aluminum alloy, wherein step S1 further comprises compression molding the mixed raw materials to obtain a raw material blank; heating the obtained raw material blank to a reaction temperature to perform a self-propagating reaction; wherein the metal magnesium in the raw material blank reduces tantalum oxide to generate metal tantalum and magnesium oxide, and the generated metal tantalum forms a tantalum-aluminum alloy with the metal aluminum in the raw material blank; the raw material blank is transformed into a product blank composed of tantalum-aluminum alloy and magnesium oxide, and then the product blank is washed with a pickling solution to dissolve the magnesium oxide; after standing and settling, the supernatant is removed to leave the tantalum-aluminum alloy powder, the tantalum-aluminum alloy powder is washed with distilled water, and further dried to obtain the tantalum-aluminum alloy powder.

[0035] The technical details are further illustrated below in conjunction with embodiments.

[0036] Example 1

[0037] In Example 1, the method for preparing tantalum aluminum alloy includes:

[0038] Weigh tantalum pentoxide, metallic aluminum and metallic magnesium in a molar ratio of 1:6:10, place in a mixing tank and mix evenly to obtain a raw material mixture;

[0039] The raw material mixture is pre-pressed in a cylindrical mold with a diameter of 12.5 mm, and the pressed green body is pre-pressed on a tablet press under a pressure of 100 MPa to obtain a raw material green body;

[0040] The raw material blank is placed in a reaction furnace, and the reaction furnace is heated to a reaction temperature of 1000°C to initiate a self-propagating reaction, and the reaction temperature is kept at the reaction temperature for 1 hour to obtain a reaction product;

[0041] The temperature in the reaction furnace was lowered to room temperature, the self-propagating reaction product was dissolved with hydrochloric acid and then allowed to settle, the supernatant was removed and then dissolved with distilled water and allowed to settle, this process was repeated three times, and tantalum-aluminum alloy powder was obtained by freeze drying.

[0042] Figure 1 This is the SEM-EDS image of the tantalum aluminum alloy obtained in Example 1. Figure 2 is the XRD pattern of tantalum aluminum alloy; Figure 1 It can be seen that tantalum and aluminum are evenly distributed in the tantalum-aluminum alloy, and the distribution positions are consistent, forming a tantalum-aluminum alloy; Figure 2 It can be seen that the product obtained in Example 1 is a tantalum-aluminum alloy powder with uniform distribution of tantalum and aluminum, and the oxygen content of the powder is measured to be 0.12%.

[0043] Example 2

[0044] In Example 2, the method for preparing tantalum aluminum alloy includes:

[0045] Weigh tantalum pentoxide, metallic aluminum and metallic magnesium in a molar ratio of 1:6:10, place in a mixing tank and mix evenly to obtain a raw material mixture;

[0046] The raw material mixture is placed in a reaction furnace, and the reaction furnace is heated to a reaction temperature of 1000°C to initiate a self-propagating reaction, and the reaction temperature is kept at the reaction temperature for 1 hour to obtain a reaction product;

[0047] The temperature in the reaction furnace was lowered to room temperature, the self-propagating reaction product was dissolved with hydrochloric acid and then allowed to settle, the supernatant was removed and then dissolved with distilled water and allowed to settle, this process was repeated three times, and tantalum-aluminum alloy powder was obtained by freeze drying.

[0048] Figure 3 This is the SEM-EDS image of the tantalum aluminum alloy obtained in Example 2. Figure 4 is the XRD pattern of tantalum aluminum alloy; Figure 3 It can be seen that the tantalum atoms and aluminum atoms in the tantalum-aluminum alloy are evenly distributed and in the same position, forming a tantalum-aluminum alloy; Figure 4 It can be seen that the product obtained in Example 2 is a tantalum-aluminum alloy powder with uniform distribution of tantalum and aluminum, and the oxygen content of the powder is measured to be 0.38%.

[0049] The method for preparing tantalum-aluminum alloy disclosed in the embodiment of the present invention utilizes the reaction of metal magnesium and tantalum oxide to generate metal tantalum, and the generated metal tantalum directly forms tantalum-aluminum alloy with raw metal aluminum, and then uses an acid solution to remove magnesium oxide to obtain tantalum-aluminum alloy powder; no exothermic agent or slag-forming agent is used, and the obtained tantalum-aluminum alloy is a powder, in which tantalum and aluminum are evenly distributed and the oxygen content is low; tantalum-aluminum alloys of different compositions can be prepared according to the composition ratio of the tantalum-aluminum alloy, the method is simple and easy to operate, and has good application prospects in the field of tantalum-aluminum alloy preparation.

[0050] The technical solutions disclosed in the embodiments of the present invention and the technical details disclosed in the embodiments are merely illustrative of the inventive concept of the present invention and do not constitute a limitation on the technical solutions of the embodiments of the present invention. Any conventional changes, replacements or combinations of the technical details disclosed in the embodiments of the present invention have the same inventive concept as the present invention and are within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a tantalum-aluminum alloy, characterized in that: Includes steps: S1, tantalum oxide, metal aluminum and metal magnesium are mixed in an oxygen-free environment to obtain a mixed raw material; S2, the mixed raw materials are heated to a reaction temperature, and a self-propagating reaction occurs; wherein the metal magnesium in the mixed raw materials reduces the tantalum oxide to generate metal tantalum and magnesium oxide, and the generated metal tantalum forms a tantalum-aluminum alloy with the metal aluminum in the mixed raw materials; S3. Remove magnesium oxide to obtain tantalum-aluminum alloy powder.

2. The method for preparing tantalum-aluminum alloy according to claim 1, characterized in that: In the mixed raw materials, the molar ratio of metallic magnesium to tantalum oxide is not less than 5, and the ratio of metallic aluminum to tantalum oxide is determined according to the stoichiometric ratio of the product tantalum-aluminum alloy.

3. The method for preparing tantalum aluminum alloy according to claim 1, characterized in that: The reaction temperature is set at 800-1500°C.

4. The method for preparing tantalum-aluminum alloy according to claim 1, characterized in that: The magnesium oxide is removed by washing with an acidic solution; the acidic solution includes any combination of hydrochloric acid, sulfuric acid, nitric acid or hydrofluoric acid.

5. The method for preparing tantalum-aluminum alloy according to claim 4, characterized in that: The method for removing magnesium oxide includes: washing with an acidic solution, dissolving with distilled water, allowing to stand for precipitation, and drying to obtain tantalum-aluminum alloy powder.

6. The method for preparing tantalum aluminum alloy according to claim 1, characterized in that: The oxygen-free environment is an inert atmosphere environment.

7. The method for preparing tantalum aluminum alloy according to claim 6, characterized in that: The inert atmosphere was argon.

8. The method for preparing tantalum aluminum alloy according to claim 1, characterized in that: Step S1 also includes molding the mixed raw material to obtain a raw material blank.

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