Aluminum-vanadium-niobium-chromium intermediate alloy as well as preparation method and application thereof

Abstract

The invention provides an aluminum-vanadium-niobium-chromium intermediate alloy as well as a preparation method and application thereof. The aluminum-vanadium-niobium-chromium intermediate alloy comprises the following components in percentage by mass: 15%-22% of V, 1%-7% of Nb, 5%-11% of Cr and the balance of Al and inevitable impurities. The preparation method of the aluminum-vanadium-niobium-chromium intermediate alloy comprises the following steps: firstly, respectively preparing three binary intermediate alloys, namely primary alloys, by utilizing an aluminothermic reduction method; then, the primary alloy is refined through vacuum induction melting, and a secondary alloy is obtained; and finally, the secondary alloy and metal aluminum are subjected to vacuum induction melting, and the aluminum-vanadium-niobium-chromium intermediate alloy is prepared. The aluminum-vanadium-niobium-chromium intermediate alloy has the advantages of being uniform in component, low in element segregation and low in impurity content, and has very good application prospects and large-scale industrial popularization potential in the field of titanium alloy production through the additive manufacturing technology.

Description

Technical Field

[0001] The invention relates to alloy technology, and in particular to an aluminum-vanadium-niobium-chromium master alloy, a preparation method and use thereof. Background Art

[0002] Titanium alloys have excellent properties, such as high specific strength, excellent corrosion resistance and high temperature resistance, so they are widely used in aerospace, mechanical chemical industry, metallurgy, energy and military fields. The development of comprehensive high-performance titanium alloys with independent intellectual property rights has attracted more and more attention from various countries. With the advancement of science and technology, the requirements for titanium alloy parts are gradually increasing. In recent years, additive manufacturing technology has begun to be widely used in the production of titanium alloy parts. Additive manufacturing has the characteristics of integrated design and manufacturing, high processing precision, short cycle, and excellent physical and chemical properties of products. Therefore, it is widely used in rail transportation, aerospace, biomedical materials and other fields.

[0003] Alloy elements such as aluminum, vanadium, niobium, and chromium are the main alloying components of titanium alloys. They are usually added to titanium alloys in the form of intermediate alloys to provide intermediate alloy raw materials for the production of high-precision, small-batch, customized, and highly complex titanium alloy parts using additive manufacturing technology. At present, most titanium alloy intermediate alloys use binary alloys. In order to meet the performance requirements during use, several binary alloys need to be added, which can easily cause unstable product performance and bring difficulties to the intermediate process of titanium alloy production. This problem can be effectively solved by using quaternary alloys as intermediate alloys. At the same time, the components of the quaternary alloy can be adjusted according to requirements, which is simple to operate and facilitates the preparation of titanium alloys. The development of this project has very long-term significance.

[0004] At present, additive manufacturing technology mostly uses laser powder deposition technology, which requires the material to be in powder form initially. However, the common vanadium-aluminum binary alloy has a vanadium content below 30% and cannot be powdered, which limits the types and properties of additively manufactured titanium alloys.

[0005] At present, the preparation method of quaternary and above alloys is usually an aluminothermic method outside the furnace, that is, the oxides of the required alloying elements are mixed with metal aluminum and then prepared by aluminothermic reduction method. For example, CN201810626955.6 discloses a molybdenum-aluminum-niobium-chromium-vanadium-tin-zirconium master alloy and its preparation method. The preparation process is: using aluminum as a reducing agent, using molybdenum trioxide, chromium trioxide, niobium pentoxide, vanadium pentoxide, tin dioxide, and chromium dioxide as oxidants, mixing the materials evenly, and then smelting them by aluminothermic method outside the furnace to obtain a molybdenum-aluminum-chromium-niobium-vanadium-tin-zirconium master alloy. This method has the advantages of simple equipment, convenient operation, and low investment. The disadvantages are that the uniformity of the alloy is poor, the segregation of elements inside the alloy is large, and the impurity elements such as oxygen, nitrogen and other gas impurities cannot be controlled, which will have an adverse effect on the final quality of the titanium alloy; at the same time, when the alloy is smelted by aluminothermic method outside the furnace, the reaction is more violent (especially the multi-element alloy reaction), and the order of the reaction of oxides and metal aluminum will cause the splashing of the raw materials of the later reaction, resulting in a decrease in the reaction rate of the raw materials, thereby increasing the production cost. Summary of the invention

[0006] The purpose of the present invention is to propose an aluminum-vanadium-niobium-chromium master alloy to address the problems that the existing quaternary and higher alloys have poor uniformity, large element segregation inside the alloy, and impurity elements such as oxygen, nitrogen and other gas impurities cannot be controlled, which will have an adverse effect on the final quality of the titanium alloy when used in the preparation of titanium alloys. The aluminum-vanadium-niobium-chromium master alloy has the advantages of uniform composition, low element segregation and low impurity content, and has very good application prospects and large-scale industrial promotion potential in the field of additive manufacturing technology for producing titanium alloys.

[0007] It should be noted that, in the present invention, unless otherwise specified, the specific meaning of "including" in relation to composition limitations and descriptions includes both open-ended "including", "comprising", etc. and similar meanings, as well as closed-ended "composed of", "composed of", etc. and similar meanings.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is: an aluminum-vanadium-niobium-chromium master alloy, including the following components in mass percentage: V: 15%-22%, Nb: 1%-7%, Cr: 5%-11%, Al balance and inevitable impurities.

[0009] Furthermore, the aluminum-vanadium-niobium-chromium master alloy includes components with the following mass percentages: V 17%-20%, Nb 2%-5%, Cr 5%-10%, Al balance and inevitable impurities.

[0010] Furthermore, the aluminum-vanadium-niobium-chromium master alloy includes components whose mass percentages are more preferably as follows: V 19%, Nb 3%, Cr 8%, Al balance and inevitable impurities.

[0011] Furthermore, the total content of impurities is not higher than 0.3%.

[0012] Furthermore, the impurities include but are not limited to one or more of Fe, Si, O, N, C and S.

[0013] Furthermore, the impurities include Fe: 0.10% Max, Si: 0.10% Max, O: 0.02% Max, N: 0.02% Max, C: 0.015% Max, and S: 0.01% Max. Furthermore, the melting point of the aluminum-vanadium-niobium-chromium master alloy is 1520-1540°C.

[0014] Furthermore, the density of the aluminum-vanadium-niobium-chromium master alloy is 3.25-3.30 g / cm 3 .

[0015] Furthermore, the particle size of the aluminum-vanadium-niobium-chromium master alloy is less than 0.1 mm.

[0016] Another object of the present invention is to disclose a method for preparing an aluminum-vanadium-niobium-chromium master alloy, comprising the following steps:

[0017] Step 1, after vanadium pentoxide and metal aluminum powder are evenly mixed, they are added into a reaction crucible, ignited for reaction, the reaction temperature is 2230-2270°C, the reaction time is 35-45s, and a vanadium aluminum primary alloy is prepared by aluminothermic reduction reaction;

[0018] Step 2, after uniformly mixing niobium pentoxide, potassium perchlorate and metal aluminum powder, adding the mixture into a reaction crucible, igniting the reaction, the reaction temperature is 2250-2350° C., the reaction time is 35-45 seconds, and the niobium aluminum primary alloy is prepared by aluminothermic reduction reaction;

[0019] Step 3, after uniformly mixing chromium trioxide, potassium perchlorate and metal aluminum powder, adding them into a reaction crucible, igniting the reaction, the reaction temperature is 2325-2375° C., the reaction time is 50-70 seconds, and the chromium-aluminum primary alloy is prepared by aluminothermic reduction reaction;

[0020] Step 4, vacuum induction melting the vanadium-aluminum primary alloy, the niobium-aluminum primary alloy, and the chromium-aluminum primary alloy, respectively, for the purpose of refining the alloy prepared by the aluminothermic reduction method; the melting temperature is 1550° C.-1700° C., the vacuum degree is 3-5 Pa, and after the charge is melted, it is short-term boiling and refining at a high temperature of 1650-1750° C. for 5-10 minutes, and the alloy is cast in a water-cooled copper crucible under vacuum conditions to obtain a vanadium-aluminum secondary alloy, a niobium-aluminum secondary alloy, and a chromium-aluminum secondary alloy, respectively; maintaining a boiling state after the materials are fully melted is conducive to uniform mixing between the materials, and can also avoid the situation where some materials with higher melting points are not melted;

[0021] Step 5: After the vanadium-aluminum secondary alloy, the niobium-aluminum secondary alloy and the chromium-aluminum secondary alloy are cooled (cooled to room temperature), they are taken out and placed in a crucible in the order of metal aluminum particles → niobium-aluminum secondary alloy → chromium-aluminum secondary alloy → vanadium-aluminum secondary alloy (from bottom to top), and vacuum induction melting is performed again; the melting temperature is 1550°C-1600°C, the vacuum degree is 3-5 Pa, and after the charge is melted, it is short-term boiled and refined at a temperature of 1570-1630°C for 5-15 minutes, and the alloy is cast in a water-cooled copper crucible under vacuum conditions to prepare an aluminum-vanadium-niobium-chromium intermediate alloy.

[0022] Furthermore, the raw materials selected in the present invention are: vanadium pentoxide (V2O5), niobium pentoxide (Nb2O5), chromium trioxide (Cr2O3), potassium perchlorate (KClO4), metal aluminum powder and metal aluminum particles. The vanadium pentoxide is ≥99.5%, the niobium pentoxide is ≥99.4%, the chromium trioxide is ≥99.0%, the potassium perchlorate is ≥99.2%, and the metal aluminum powder / particles is ≥99.7%.

[0023] Furthermore, the particle size of the metal aluminum powder is 0.3-3 mm.

[0024] Furthermore, the particle size of the metal aluminum particles is 10-20 mm.

[0025] Aluminum powder is used during the aluminothermic reduction reaction (i.e., when preparing the primary alloy in steps 1, 2, and 3). The powdered material has a larger specific surface area and a more complete reaction, which can effectively improve the reaction efficiency. Aluminum particles are used instead of aluminum powder during vacuum melting (step 5) to prepare the final alloy. The primary reason is that aluminum powder has poor induction. The vacuum melting furnace generates an induced current between the electromagnetic eddy current and the material, which is converted from electrical energy to thermal energy to melt the material. In theory, the larger the volume of a single material, the better the induction. Therefore, aluminum particles are better than aluminum powder. Secondly, the bulk density of aluminum powder is lower, that is, the weight of the same volume of aluminum powder is lower than that of aluminum particles. The reason is that there are more voids inside the aluminum powder. Using aluminum powder will take up too much crucible space and reduce production.

[0026] Furthermore, before preparing the aluminum-vanadium-niobium-chromium master alloy, the raw materials are dried in a constant temperature drying room at 55-70°C for 20-28 hours to ensure that the reaction materials are dry and have a certain initial temperature. The raw materials include but are not limited to vanadium pentoxide (V2O5), niobium pentoxide (Nb2O5), chromium trioxide (Cr2O3), potassium perchlorate (KClO4), metal aluminum powder and metal aluminum particles.

[0027] Furthermore, the mass ratio of vanadium pentoxide to metallic aluminum powder in step 1 is 1.010-1.060:1.

[0028] Furthermore, the mass ratio of vanadium pentoxide to metallic aluminum powder in step 1 is preferably 1.044:1.

[0029] Furthermore, the mass ratio of niobium pentoxide, potassium perchlorate and metallic aluminum powder in step 2 is 1.545-1.650:0.125-0.135:1.

[0030] Furthermore, the mass ratio of niobium pentoxide, potassium perchlorate and metallic aluminum powder in step 2 is preferably 1.550:0.127:1.

[0031] Furthermore, the mass ratio of chromium trioxide, potassium perchlorate and metallic aluminum powder in step 3 is 1.480-1.605:0.100-0.120:1.

[0032] Furthermore, the mass ratio of chromium trioxide, potassium perchlorate and metallic aluminum powder in step 3 is preferably 1.535:0.104:1.

[0033] Furthermore, the reactions of step 1, step 2 and step 3 do not require heating, and the ignition agents used are metal magnesium powder (Mg), metal aluminum powder (Al) and calcium peroxide (CaO2). When used, each mixture is easily ignited by the combustion of the mixed powder of magnesium powder, aluminum powder and calcium peroxide as a side reaction, and the heat generated triggers the main reaction.

[0034] Furthermore, the mass ratio of calcium peroxide:metal aluminum powder:metal magnesium powder in the ignition agent is 3.5-4.5:3.5-4.5:1, preferably 4:4:1.

[0035] Furthermore, in order to make full use of the slag Al2O3 produced by the reaction, the furnace lining (reaction crucible) of the reaction device in step 1, step 2 and step 3 is made of slag Al2O3, which can effectively reduce the introduction of impurities and help to further reduce the content of impurities in the alloy, thereby saving costs and achieving the purpose of recycling raw materials.

[0036] The vanadium-aluminum primary alloy, niobium-aluminum primary alloy, and chromium-aluminum primary alloy (all binary alloys) prepared by the aluminothermic reduction method (steps 1, 2, and 3) have a slight oxide layer on the surface that can be polished away. After polishing, the alloy is silvery bright and has good surface quality, but its internal impurity elements cannot meet the requirements for titanium alloy smelting addition. At this time, vacuum induction melting is required to refine the three primary alloys (step 4). Through the unique smelting conditions of vacuum induction melting, the impurity elements inside the alloy are enriched and removed to ensure that the alloy ingot with accurate chemical composition and high purity is smelted.

[0037] Furthermore, in step 4, the vanadium-aluminum secondary alloy, the niobium-aluminum secondary alloy and the chromium-aluminum secondary alloy are taken out after they are cooled. At this time, the vanadium-aluminum secondary alloy, the niobium-aluminum secondary alloy and the chromium-aluminum secondary alloy are purer inside and the quality of the alloy is improved.

[0038] Furthermore, in step 5, the mass ratio of the vanadium-aluminum secondary alloy, the niobium-aluminum secondary alloy, the chromium-aluminum secondary alloy and the metallic aluminum particles is 0.510-0.690:0.085-0.095:0.160-0.280:1.

[0039] Furthermore, in step 5, the mass ratio of the vanadium-aluminum secondary alloy, the niobium-aluminum secondary alloy, the chromium-aluminum secondary alloy and the metallic aluminum particles is preferably 0.595:0.091:0.220:1.

[0040] Furthermore, in step 5, the vacuum induction melting is carried out; the starting power of the vacuum induction melting process is 20-30kW, and after 10-15 minutes, the power is adjusted to 70-80kW; after 4-5 minutes, the power is adjusted to 100-120kW; after 15-20 minutes, the power is adjusted to 130-140kW, and the power is maintained until the charge is melted; the power is kept unchanged, and the alloy is refined, and short-term boiling refining is carried out at a temperature of 1625-1675°C for 5-15 minutes; after the refining is complete, the power is gradually reduced to 80-100kW, and the alloy is cast in a water-cooled copper crucible when the melt temperature is 1550-1600°C to prepare an aluminum vanadium niobium chromium master alloy.

[0041] Furthermore, the vacuum melting temperature in step 5 is preferably 1585° C.; the boiling time is preferably 7-8 minutes; and the melting power is preferably 140 kW.

[0042] Furthermore, when the vacuum furnace in step 5 is used for smelting, a corundum crucible is used to load the charge; in order to control the content of impurity elements in the alloy, the purity of the corundum crucible is ≥99%.

[0043] Furthermore, the aluminum-vanadium-niobium-chromium master alloy obtained in step 5 is crushed to a D95 of less than 1-6 mm using a crusher; and then the alloy pieces are crushed to less than 0.1 mm using a powder making machine. In particular, nitrogen is used for protection during the powder making process using the powder making machine. The AlVNbCr master alloy is used for the preparation of titanium alloys for additive manufacturing. The raw materials required for additive manufacturing are in powder form, and the final material size is between 50 μm and 100 μm, so the AlVNbCr is crushed to less than 0.1 mm.

[0044] Another object of the present invention is to disclose the use of an aluminum-vanadium-niobium-chromium master alloy in the field of titanium alloy additive manufacturing.

[0045] The aluminum-vanadium-niobium-chromium master alloy of the present invention is a multi-element master alloy, which mainly provides raw materials for titanium alloys used in additive manufacturing. Due to the special processing technology of additive manufacturing technology, all materials used need to be processed into powder. In addition to the problem that vanadium-aluminum alloys cannot be powdered when the vanadium content is less than 30%, the use of binary alloys to produce titanium alloys inevitably requires the use of pure aluminum, and pure aluminum cannot be used for additive alloy manufacturing; at the same time, the more types of raw materials, the greater the difference in melting point and density between the raw materials, the greater the difficulty of additive manufacturing, and the more defects in the finished titanium alloy parts produced. The aluminum-vanadium-niobium-chromium master alloy of the present invention provides as many alloy elements as possible under the condition that the vanadium element can still be powdered when it is less than 30%, reduces the types of raw material alloys required, reduces the difficulty of additive manufacturing technology, and reduces the defects such as segregation inside the finished titanium alloy parts.

[0046] In the aluminum-vanadium-niobium-chromium master alloy material of the present invention, the role of Al in the titanium alloy is to stabilize the α phase, play a good solid solution strengthening role, promote the precipitation of the α phase during heat treatment and enhance the aging strengthening effect; V and Cr elements are respectively isomorphous β stabilizing elements and eutectoid β stabilizing elements, and both alloy elements exist in the β phase in the form of substitutional solid solution, producing a solid solution strengthening effect, and the V element can significantly increase the hardenability and organizational stability of the titanium alloy; Nb element is a β titanium alloy stabilizing element, which can reduce the β phase transformation temperature, produce a higher strengthening effect on the titanium alloy, and improve the hot working performance, processing plasticity and fracture toughness of the titanium alloy.

[0047] For titanium alloys, if the Al content is too high, compound phases such as Ti3Al or TiAl may be formed at the grain boundaries, seriously damaging the alloy performance; the Nb element has a serious tendency to segregate, and its excessive content will also affect the service life and performance of the alloy; and if the Cr content is too high, it is easy to form brittle compounds such as TiCr2 inside the alloy, affecting the fracture performance of the titanium alloy and posing a hidden danger to the safety of the component.

[0048] Therefore, the contents of alloying elements such as Al, V, Nb, Cr, etc. in the aluminum-vanadium-niobium-chromium master alloy of the present invention are specially formulated to meet the specifications of additively manufactured titanium alloys, simplify the additively manufactured titanium alloy preparation process, and reduce production costs. Any change that is not within the range of the element composition and content of the present invention will have a greater impact on the composition or process of the final titanium alloy product.

[0049] The preparation method of the aluminum-vanadium-niobium-chromium master alloy of the present invention comprises the following steps: first, a binary master alloy, i.e., a primary alloy, is prepared by aluminothermic reduction method; then, the primary alloy is refined by vacuum induction melting to obtain a secondary alloy; finally, the secondary alloy and metal aluminum are subjected to vacuum induction melting to obtain an aluminum-vanadium-niobium-chromium master alloy. Compared with the prior art, the present invention has the following advantages:

[0050] 1) It is convenient for the preparation of titanium alloy. The melting point of the aluminum-vanadium-niobium-chromium master alloy of the present invention is about 1540-1560°C, and the melting point of sponge titanium is between 1660°C and 1668°C. The melting points of the two are close. Therefore, when the aluminum-vanadium-niobium-chromium master alloy of the present invention is used to prepare titanium alloy parts using additive manufacturing technology, the two are more likely to reach a similar melting state at the same processing temperature, and the raw material combination effect is better;

[0051] 2) The aluminum-vanadium-niobium-chromium master alloy of the present invention has good uniformity. The aluminum-vanadium-niobium-chromium master alloy produced by the present invention is uniformly alloyed, and when used as a raw material for additive manufacturing of titanium alloys, element segregation is not likely to occur inside the finished product parts;

[0052] 3) The aluminum-vanadium-niobium-chromium master alloy of the present invention has high purity. Compared with the existing one-step aluminothermic reduction reaction (out-of-furnace method, the impurity content of the prepared alloy is high and cannot meet the requirements of titanium alloy processing for additive manufacturing), the present invention adopts a two-step method (aluminothermic reduction reaction + vacuum induction melting) to smelt a master alloy with accurate chemical composition and high purity, the alloy ingot composition is more accurate, and the content of impurity elements such as oxygen and nitrogen is lower;

[0053] 4) The aluminum-vanadium-niobium-chromium master alloy of the present invention has low production cost. The traditional method is to directly use the aluminothermic reduction method to smelt multi-element alloys by mixing metal oxides and metal aluminum. The reaction is violent and the materials are very likely to react incompletely, resulting in material waste and increased production costs. The present invention uses the aluminothermic method to prepare various binary alloys (vanadium-aluminum alloy, niobium-aluminum alloy, chromium-aluminum alloy), and then uses the various binary alloys for vacuum induction melting to produce quaternary master alloys. The operation is simple and controllable, the materials react completely, and the production cost is low.

[0054] 5) The aluminum-vanadium-niobium-chromium master alloy of the present invention is easily broken. The aluminum-vanadium-niobium-chromium master alloy of the present invention is a metallic compound containing a variety of alloy elements, and has the characteristics of good brittleness and easy breakage.

[0055] 6) The aluminum-vanadium-niobium-chromium intermediate alloy of the present invention has good stability. The raw materials used in additive manufacturing are mostly in powder form. The current vanadium-aluminum binary alloy cannot be powdered when the vanadium content is lower than 30%, which limits the types and properties of titanium alloys used in additive manufacturing. The aluminum-vanadium-niobium-chromium quaternary intermediate alloy prepared by the present invention through appropriate element ratios and specific preparation methods can also be powdered when the vanadium content is lower than 30%. When the aluminum-vanadium-niobium-chromium intermediate alloy of the present invention is processed into a powder with a particle size of less than 0.1 mm, the oxygen and nitrogen contents inside it are still at a relatively low level, indicating that the alloy has good stability, which is conducive to maintaining the excellent performance of the final alloy product.

[0056] In summary, the present invention prepares an aluminum vanadium niobium chromium intermediate alloy with low cost, high yield, uniform composition, low element segregation and low impurity content through aluminothermic reduction method + vacuum induction refining method + vacuum induction melting method, which has very good application prospects and large-scale industrial promotion potential in the field of titanium alloy production by additive manufacturing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 This is the production process flow chart of aluminum-vanadium-niobium-chromium master alloy. DETAILED DESCRIPTION

[0058] The present invention is further described below with reference to the examples. The description of the technical features described below is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:

[0059] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0060] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints numerical values ​​A and B.

[0061] In the present specification, a numerical range expressed using "above" or "below" means a numerical range including the number.

[0062] In this specification, the word "may" means both performing a certain process and not performing a certain process.

[0063] In this specification, the use of "optional" or "optional" indicates that certain substances, components, execution steps, application conditions and other factors are used or not used.

[0064] In this specification, when "normal temperature" or "room temperature" is used, the temperature may be 15-25°C.

[0065] In this manual, the reagents or instruments used without indicating the manufacturer are all conventional products that can be obtained through commercial purchase.

[0066] Embodiment 1:

[0067] The first step is to produce the primary alloy by aluminothermic reduction reaction method:

[0068] The production of primary alloy is carried out according to the following steps: furnace building, furnace firing, material drying, material batching, material mixing, furnace loading, reaction, cooling, furnace dismantling, finishing, crushing, sampling and analysis.

[0069] Preparation of primary alloy by aluminothermic method:

[0070] 1. The crucible is made of aluminum oxide refractory material and sintered in a natural gas sintering furnace for 7 hours, with the sintering temperature increasing from 30°C to 600°C; after sintering, keep warm for 2 hours;

[0071] 2. Dry vanadium pentoxide, niobium pentoxide, chromium trioxide, potassium perchlorate and aluminum powder at a temperature of 60°C for 24 hours;

[0072] 3. Calculate the alloy mass ratio in the aluminothermic smelting process: vanadium pentoxide to aluminum powder is 1.044:1, niobium pentoxide, potassium perchlorate to aluminum powder is 1.550:0.127:1, chromium trioxide, potassium perchlorate to aluminum powder is 1.535:0.104:1;

[0073] 4. Put the mixture of vanadium pentoxide and aluminum powder, niobium pentoxide, potassium perchlorate and aluminum powder, chromium trioxide, potassium perchlorate and aluminum powder into special mixing tanks, put them into mixers and mix them at a rate of 10r / min for 20 minutes. Mixing requirements: All raw materials must be fully mixed to ensure full contact between the raw materials;

[0074] 5. The mixed vanadium pentoxide and aluminum powder, niobium pentoxide, potassium perchlorate and aluminum powder, chromium trioxide, potassium perchlorate and aluminum powder are placed in a preheated alumina crucible, ignited for reaction, cooled for 36 hours and then taken out of the furnace to obtain a vanadium aluminum primary alloy, a niobium aluminum primary alloy and a chromium aluminum primary alloy;

[0075] 6. Finishing and crushing: Use a grinding wheel machine to remove the oxide film on the surface of the alloy ingot; use a crusher to crush it to a particle size of 0-50mm, and remove impurities such as iron through magnetic separation and manual selection;

[0076] In the second step, vacuum induction melting is used to produce secondary alloys:

[0077] 7. Feeding: respectively feeding the vanadium-aluminum primary alloy, the niobium-aluminum primary alloy and the chromium-aluminum primary alloy into the vacuum induction melting crucible;

[0078] 8. Vacuuming: Start the mechanical pump, turn on the compound vacuum gauge, and turn on the Roots pump when the vacuum degree is lower than 700 Pa. When the compound vacuum gauge shows that the vacuum degree is less than 10 Pa, start to supply 30kW of electricity to dry the material, and stop vacuuming after 10 minutes;

[0079] 9. Adjust the power to 80kW for heating, and adjust the power to 120kW after 10 minutes. When light is seen coming out from the bottom of the material, adjust the power to 160kW and continue smelting until the alloy is completely melted;

[0080] 10. After all the alloy is melted, adjust the power to 180kW, turn on the vacuum pump, evacuate to below 10 Pa, and refine at 1700℃ for 10 minutes to remove gas impurities in the melt;

[0081] 11. After refining, adjust the power to 120kW, let the molten pool slowly cool down to the pouring temperature, and pour the alloy liquid into the water-cooled copper mold;

[0082] 12. After pouring, fill the furnace with argon gas, continue air cooling for 1 hour, and take out of the furnace after cooling for 180 minutes to obtain vanadium aluminum secondary alloy, niobium aluminum secondary alloy and chromium aluminum secondary alloy respectively;

[0083] The third step is to produce the target alloy using vacuum induction melting:

[0084] Vacuum Induction Melting Batching

[0085] The components of the secondary alloy prepared by the aluminothermic method + vacuum induction melting method were analyzed and the vacuum induction melting formula was calculated. The specific ratio was: 23.75 kg of vanadium-aluminum secondary alloy, 2.88 kg of niobium-aluminum secondary alloy, 7.57 kg of chromium-aluminum secondary alloy, and 35.81 kg of metallic aluminum particles.

[0086] Vacuum Induction Melting

[0087] 13. Feeding: sequentially feed aluminum metal particles, niobium aluminum secondary alloy, chromium aluminum secondary alloy, and vanadium aluminum secondary alloy into the vacuum induction melting crucible;

[0088] 14. Vacuuming: Start the mechanical pump, turn on the compound vacuum gauge, and start the Roots pump when the vacuum degree is lower than 700 Pa. When the compound vacuum gauge shows that the vacuum degree is less than 10 Pa, start to supply 30kW of electricity to dry the material, and stop vacuuming after 10 minutes;

[0089] 15. Adjust the power to 80kW for heating, and adjust the power to 120kW after 5 minutes. When light is seen coming out from the bottom of the material, adjust the power to 140kW and continue smelting until the alloy is completely melted;

[0090] 16. After all the alloy is melted, keep the power at 140kW, turn on the vacuum pump, evacuate to below 10 Pa, and refine at 1600℃ for 10 minutes to remove gas impurities in the melt;

[0091] 17. After refining, adjust the power to 100kW, let the molten pool slowly cool down to the pouring temperature, and pour the alloy liquid into the water-cooled copper mold;

[0092] 18. After pouring, fill the furnace with argon gas and continue air cooling for 1 hour. After cooling for 180 minutes, take the furnace out of the furnace to obtain aluminum-vanadium-niobium-chromium master alloy.

[0093] The aluminum-vanadium-niobium-chromium master alloy prepared in this embodiment is subjected to a comprehensive sample chemical composition analysis, and the results are shown in Table 1. The aluminum-vanadium-niobium-chromium master alloy prepared in this embodiment has a melting point of 1539°C and a density of 3.29 g / cm 3 .

[0094] Embodiment 2:

[0095] The first step is to produce the primary alloy by aluminothermic reduction reaction method:

[0096] The production of primary alloy is carried out according to the following steps: furnace building, furnace firing, material drying, material batching, material mixing, furnace loading, reaction, cooling, furnace dismantling, finishing, crushing, sampling and analysis.

[0097] Preparation of primary alloy by aluminothermic method:

[0098] 1. The crucible is made of aluminum oxide refractory material and sintered in a natural gas sintering furnace for 7 hours, with the sintering temperature increasing from 30°C to 600°C; after sintering, keep warm for 2 hours;

[0099] 2. Dry vanadium pentoxide, niobium pentoxide, chromium trioxide, potassium perchlorate and aluminum powder at a temperature of 60°C for 24 hours;

[0100] 3. Calculate the alloy mass ratio in the aluminothermic smelting process: the mass ratio of vanadium pentoxide to aluminum powder is 1.044:1, the mass ratio of niobium pentoxide, potassium perchlorate and aluminum powder is 1.550:0.127:1, and the mass ratio of chromium trioxide, potassium perchlorate and aluminum powder is 1.535:0.104:1;

[0101] 4. Put the mixture of vanadium pentoxide and aluminum powder, niobium pentoxide, potassium perchlorate and aluminum powder, chromium trioxide, potassium perchlorate and aluminum powder into special mixing tanks, put them into mixers and mix them at a rate of 10r / min for 20 minutes. Mixing requirements: All raw materials must be fully mixed to ensure full contact between the raw materials;

[0102] 5. The mixed vanadium pentoxide and aluminum powder, niobium pentoxide, potassium perchlorate and aluminum powder, chromium trioxide, potassium perchlorate and aluminum powder are placed in a preheated alumina crucible, ignited for reaction, cooled for 36 hours and then taken out of the furnace to obtain a vanadium aluminum primary alloy, a niobium aluminum primary alloy and a chromium aluminum primary alloy;

[0103] 6. Finishing and crushing: Use a grinding wheel machine to remove the oxide film on the surface of the alloy ingot; use a crusher to crush it to a particle size of 0-50mm, and remove impurities such as iron through magnetic separation and manual selection;

[0104] In the second step, vacuum induction melting is used to produce secondary alloys:

[0105] 7. Feeding: respectively feeding the vanadium-aluminum primary alloy, the niobium-aluminum primary alloy and the chromium-aluminum primary alloy into the vacuum induction melting crucible;

[0106] 8. Vacuuming: Start the mechanical pump, turn on the compound vacuum gauge, and turn on the Roots pump when the vacuum degree is lower than 700 Pa. When the compound vacuum gauge shows that the vacuum degree is less than 10 Pa, start to supply 30kW of electricity to dry the material, and stop vacuuming after 10 minutes;

[0107] 9. Adjust the power to 80kW for heating, and adjust the power to 120kW after 10 minutes. When light is seen coming out from the bottom of the material, adjust the power to 160kW and continue smelting until the alloy is completely melted;

[0108] 10. After all the alloy is melted, adjust the power to 180kW, turn on the vacuum pump, evacuate to below 10 Pa, and refine at 1700℃ for 10 minutes to remove gas impurities in the melt;

[0109] 11. After refining, adjust the power to 120kW, let the molten pool slowly cool down to the pouring temperature, and pour the alloy liquid into the water-cooled copper mold;

[0110] 12. After pouring, fill the furnace with argon gas, continue air cooling for 1 hour, and take out of the furnace after cooling for 180 minutes to obtain vanadium aluminum secondary alloy, niobium aluminum secondary alloy and chromium aluminum secondary alloy respectively;

[0111] The third step is to produce the target alloy using vacuum induction melting:

[0112] Vacuum Induction Melting Batching

[0113] The vacuum induction melting formula was calculated based on the analyzed components of the secondary alloy prepared by the aluminothermic method + vacuum induction melting method. The specific ratio was: 23.54 kg of vanadium-aluminum secondary alloy, 2.84 kg of niobium-aluminum secondary alloy, 7.57 kg of chromium-aluminum secondary alloy, and 36.05 kg of metallic aluminum particles.

[0114] Vacuum Induction Melting

[0115] 13. Feeding: sequentially feed aluminum metal particles, niobium aluminum secondary alloy, chromium aluminum secondary alloy, and vanadium aluminum secondary alloy into the vacuum induction melting crucible;

[0116] 14. Vacuuming: Start the mechanical pump, turn on the compound vacuum gauge, and start the Roots pump when the vacuum degree is lower than 700 Pa. When the compound vacuum gauge shows that the vacuum degree is less than 10 Pa, start to supply 30kW of electricity to dry the material, and stop vacuuming after 10 minutes;

[0117] 15. Adjust the power to 80kW for heating, and adjust the power to 120kW after 5 minutes. When light is seen coming out from the bottom of the material, adjust the power to 140kW and continue smelting until the alloy is completely melted;

[0118] 16. After all the alloy is melted, keep the power at 140kW, turn on the vacuum pump, evacuate to below 10 Pa, and refine at 1600℃ for 10 minutes to remove gas impurities in the melt;

[0119] 17. After refining, adjust the power to 100kW, let the molten pool slowly cool down to the pouring temperature, and pour the alloy liquid into the water-cooled copper mold;

[0120] 18. After pouring, fill the furnace with argon gas and continue air cooling for 1 hour. After cooling for 180 minutes, take the furnace out of the furnace to obtain aluminum-vanadium-niobium-chromium master alloy.

[0121] The aluminum-vanadium-niobium-chromium master alloy prepared in this embodiment is subjected to a comprehensive chemical composition analysis, and the results are shown in Table 1. The aluminum-vanadium-niobium-chromium master alloy prepared in this embodiment has a melting point of 1535°C and a density of 3.28 g / cm 3 .

[0122] Embodiment 3:

[0123] The first step is to produce the primary alloy by aluminothermic reduction reaction method:

[0124] The production of primary alloy is carried out according to the following steps: furnace building, furnace firing, material drying, material batching, material mixing, furnace loading, reaction, cooling, furnace dismantling, finishing, crushing, sampling and analysis.

[0125] Preparation of primary alloy by aluminothermic method:

[0126] 1. The crucible is made of aluminum oxide refractory material and sintered in a natural gas sintering furnace for 7 hours, with the sintering temperature increasing from 30°C to 600°C; after sintering, keep warm for 2 hours;

[0127] 2. Dry vanadium pentoxide, niobium pentoxide, chromium trioxide, potassium perchlorate and aluminum powder at a temperature of 60°C for 24 hours;

[0128] 3. Calculate the alloy mass ratio in the aluminothermic smelting process: the mass ratio of vanadium pentoxide to aluminum powder is 1.044:1, the mass ratio of niobium pentoxide, potassium perchlorate and aluminum powder is 1.550:0.127:1; the mass ratio of chromium trioxide, potassium perchlorate and aluminum powder is 1.535:0.104:1;

[0129] 4. Put the mixture of vanadium pentoxide and aluminum powder, niobium pentoxide, potassium perchlorate and aluminum powder, chromium trioxide, potassium perchlorate and aluminum powder into special mixing tanks, put them into mixers and mix them at a rate of 10r / min for 20 minutes. Mixing requirements: All raw materials must be fully mixed to ensure full contact between the raw materials;

[0130] 5. The mixed vanadium pentoxide and aluminum powder, niobium pentoxide, potassium perchlorate and aluminum powder, chromium trioxide, potassium perchlorate and aluminum powder are placed in a preheated alumina crucible, ignited for reaction, cooled for 36 hours and then taken out of the furnace to obtain a vanadium aluminum primary alloy, a niobium aluminum primary alloy and a chromium aluminum primary alloy;

[0131] 6. Finishing and crushing: Use a grinding wheel machine to remove the oxide film on the surface of the alloy ingot; use a crusher to crush it to a particle size of 0-50mm, and remove impurities such as iron through magnetic separation and manual selection;

[0132] In the second step, vacuum induction melting is used to produce secondary alloys:

[0133] 7. Feeding: respectively feeding the vanadium-aluminum primary alloy, the niobium-aluminum primary alloy and the chromium-aluminum primary alloy into the vacuum induction melting crucible;

[0134] 8. Vacuuming: Start the mechanical pump, turn on the compound vacuum gauge, and turn on the Roots pump when the vacuum degree is lower than 700 Pa. When the compound vacuum gauge shows that the vacuum degree is less than 10 Pa, start to supply 30kW of electricity to dry the material, and stop vacuuming after 10 minutes;

[0135] 9. Adjust the power to 80kW for heating, and adjust the power to 120kW after 10 minutes. When light is seen coming out from the bottom of the material, adjust the power to 160kW and continue smelting until the alloy is completely melted;

[0136] 10. After all the alloy is melted, adjust the power to 180kW, turn on the vacuum pump, evacuate to below 10 Pa, and refine at 1700℃ for 10 minutes to remove gas impurities in the melt;

[0137] 11. After refining, adjust the power to 120kW, let the molten pool slowly cool down to the pouring temperature, and pour the alloy liquid into the water-cooled copper mold;

[0138] 12. After pouring, fill the furnace with argon gas, continue air cooling for 1 hour, and take out of the furnace after cooling for 180 minutes to obtain vanadium aluminum secondary alloy, niobium aluminum secondary alloy and chromium aluminum secondary alloy respectively;

[0139] The third step is to produce the target alloy using vacuum induction melting:

[0140] Vacuum Induction Melting Batching

[0141] The vacuum induction melting formula was calculated based on the analyzed components of the secondary alloy prepared by the aluminothermic method + vacuum induction melting method. The specific ratio was: 24.18 kg of vanadium-aluminum secondary alloy, 2.84 kg of niobium-aluminum secondary alloy, 7.47 kg of chromium-aluminum secondary alloy, and 35.51 kg of metallic aluminum particles.

[0142] Vacuum Induction Melting

[0143] 13. Feeding: sequentially feed aluminum metal particles, niobium aluminum secondary alloy, chromium aluminum secondary alloy, and vanadium aluminum secondary alloy into the vacuum induction melting crucible;

[0144] 14. Vacuuming: Start the mechanical pump, turn on the compound vacuum gauge, and start the Roots pump when the vacuum degree is lower than 700 Pa. When the compound vacuum gauge shows that the vacuum degree is less than 10 Pa, start to supply 30kW of electricity to dry the material, and stop vacuuming after 10 minutes;

[0145] 15. Adjust the power to 80kW for heating, and adjust the power to 120kW after 5 minutes. When light is seen coming out from the bottom of the material, adjust the power to 140kW and continue smelting until the alloy is completely melted;

[0146] 16. After all the alloy is melted, keep the power at 140kW, turn on the vacuum pump, evacuate to below 10 Pa, and refine at 1600℃ for 10 minutes to remove gas impurities in the melt;

[0147] 17. After refining, adjust the power to 100kW, let the molten pool slowly cool down to the pouring temperature, and pour the alloy liquid into the water-cooled copper mold;

[0148] 18. After pouring, fill the furnace with argon gas and continue air cooling for 1 hour. After cooling for 180 minutes, take the furnace out of the furnace to obtain aluminum-vanadium-niobium-chromium master alloy.

[0149] The aluminum-vanadium-niobium-chromium master alloy prepared in this embodiment is subjected to a comprehensive chemical composition analysis, and the results are shown in Table 1. The aluminum-vanadium-niobium-chromium master alloy prepared in this embodiment has a melting point of 1528°C and a density of 3.27 g / cm 3 .

[0150] The chemical composition of the comprehensive samples of the aluminum-vanadium-niobium-chromium master alloy in Examples 1-3 of the present invention is shown in Table 1.

[0151] Table 1. Main element composition of intermediate alloy in each example

[0152]

[0153] Chemical composition analysis was performed on 6 different locations of the aluminum-vanadium-niobium-chromium master alloy (cylinder) prepared in Examples 1-3. The results are shown in Tables 2, 3 and 4.

[0154] Table 2. Chemical composition of different positions of aluminum-vanadium-niobium-chromium master alloy in Example 1

[0155]

[0156] Table 3. Chemical composition of different positions of aluminum-vanadium-niobium-chromium master alloy in Example 2

[0157]

[0158]

[0159] Table 4. Chemical composition of different positions of aluminum-vanadium-niobium-chromium master alloy in Example 3

[0160]

[0161] It can be seen from Tables 2-4 that the aluminum-vanadium-niobium-chromium master alloys prepared in Examples 1-3 have uniform and stable compositions without segregation.

[0162] After comprehensive sampling of the aluminum-vanadium-niobium-chromium master alloy processed into powder (first crushed to D95 of 1-6 mm using a jaw crusher, then crushed to less than 0.1 mm using a disc mill, and nitrogen protection was filled during the preparation process), the test results are shown in Table 5.

[0163] Table 5. Chemical element composition of intermediate alloy after powder making in each embodiment

[0164]

[0165] It can be seen from Table 5 that the oxygen and nitrogen contents of the aluminum-vanadium-niobium-chromium master alloys prepared in Examples 1-3 after being prepared into powder are slightly higher than those of the semi-finished products, but are still at a relatively low level, which can ensure their advantage of good stability.

[0166] There are slight differences in the internal elements of the secondary alloys used in each example, which have a slight impact on the internal element values ​​of the final alloy, but can ensure that the element ratio is within the preferred ratio range. It can be seen from the above examples that the aluminum-vanadium-niobium-chromium master alloy provided by the present invention has a stable composition and a low impurity content.

[0167] Comparative Example

[0168] Using vanadium pentoxide, niobium pentoxide, chromium trioxide, potassium perchlorate and aluminum powder that are exactly the same as those in the example standards, an aluminum-vanadium-niobium-chromium master alloy is prepared by a one-step method. The crucible and ignition agent used are the same as those used to prepare each primary alloy. The mass ratio of vanadium pentoxide, niobium pentoxide, chromium trioxide, potassium perchlorate and aluminum powder is 0.333:0.043:0.204:0.204:1, and an aluminum-vanadium-niobium-chromium master alloy is prepared by aluminothermic reduction method. The results of comprehensive sample testing, chemical composition testing at different positions in the alloy ingot and chemical element testing after powdering are shown in the following table:

[0169] Table 6. Main element composition of comparative master alloy

[0170]

[0171] Table 7. Chemical composition of different positions of comparative aluminum-vanadium-niobium-chromium master alloy

[0172]

[0173] Table 8. Chemical element composition of the master alloy after powder making

[0174]

[0175] Comparing the detection data of each element in the comparative example with that in Example 1, it can be seen that the alloy elements in the comparative example are far from the optimal range, and the segregation data of alloy elements in different positions are far different. After being processed into finished products, the oxygen and nitrogen values ​​are greatly increased, and the quality of the alloy is seriously reduced. Therefore, compared with the one-step method to directly prepare the aluminum-vanadium-niobium-chromium master alloy, the master alloy prepared by the two-step method is more excellent.

[0176] It should be understood that the innovative point of the present invention, which is different from the prior art preparation method, is that the intermediate alloy is prepared by a two-step method. The two-step method is to prepare a primary alloy by aluminothermic reduction reaction + vacuum induction melting to prepare the target alloy, while the one-step method is to directly prepare the target alloy by aluminothermic reduction reaction. CN201810626955.6 mentioned in "Background Technology" is a one-step method for preparing multi-element intermediate alloys. There are essential differences between the two preparation methods, so the mass ratio of the comparative raw materials cannot be the same as that of the embodiment, and it can only be ensured that the raw materials used in the two preparation methods are the same or the standards are consistent to achieve the minimum variables. Each embodiment prepares the target alloy with the most preferred material ratio, so there are only slight differences in the results, and the overall trend remains consistent. The comparative example can be compared with Example 1, and similarly, it can also be compared with Example 2 or 3, and the conclusions are consistent.

[0177] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An aluminum-vanadium-niobium-chromium master alloy, characterized in that: The invention comprises the following components in mass percentage: V: 15%-22%, Nb: 1%-7%, Cr: 5%-11%, Al balance and inevitable impurities.

2. A method for preparing the aluminum-vanadium-niobium-chromium master alloy according to claim 1, characterized in that: The following steps are involved: Step 1, after vanadium pentoxide and metal aluminum powder are evenly mixed, they are added into a reaction crucible, ignited for reaction, the reaction temperature is 2230-2270°C, the reaction time is 35-45s, and a vanadium aluminum primary alloy is prepared by aluminothermic reduction reaction; Step 2, after uniformly mixing niobium pentoxide, potassium perchlorate and metal aluminum powder, adding the mixture into a reaction crucible, igniting the reaction, the reaction temperature is 2250-2350° C., the reaction time is 35-45 seconds, and the niobium aluminum primary alloy is prepared by aluminothermic reduction reaction; Step 3, after uniformly mixing chromium trioxide, potassium perchlorate and metal aluminum powder, adding them into a reaction crucible, igniting the reaction, the reaction temperature is 2325-2375° C., the reaction time is 50-70 seconds, and the chromium-aluminum primary alloy is prepared by aluminothermic reduction reaction; Step 4, vacuum induction melting the vanadium-aluminum primary alloy, the niobium-aluminum primary alloy, and the chromium-aluminum primary alloy, respectively, at a melting temperature of 1550° C.-1700° C. and a vacuum degree of 3-5 Pa, and after the charge is melted, short-term boiling refining is performed at a high temperature of 1650-1750° C. for 5-10 minutes, and the alloy is cast in a water-cooled copper crucible under vacuum conditions to obtain a vanadium-aluminum secondary alloy, a niobium-aluminum secondary alloy, and a chromium-aluminum secondary alloy, respectively; Step 5: After the vanadium-aluminum secondary alloy, the niobium-aluminum secondary alloy and the chromium-aluminum secondary alloy are cooled, they are taken out and the metal aluminum particles → the niobium-aluminum secondary alloy → the chromium-aluminum secondary alloy → the vanadium-aluminum secondary alloy are placed in a crucible in the order of the metal aluminum particles → the niobium-aluminum secondary alloy → the chromium-aluminum secondary alloy, and vacuum induction melting is performed again; the melting temperature is 1550°C-1600°C, the vacuum degree is 3-5 Pa, and after the charge is melted, it is short-term boiling and refined at a temperature of 1570-1630°C for 5-15 minutes, and the alloy is cast in a water-cooled copper crucible under vacuum conditions to prepare an aluminum-vanadium-niobium-chromium intermediate alloy.

3. The method for preparing the aluminum-vanadium-niobium-chromium master alloy according to claim 2, characterized in that: The particle size of the metal aluminum powder is 0.3-3 mm; and / or the particle size of the metal aluminum particles is 10-20 mm; And / or, before preparing the aluminum-vanadium-niobium-chromium master alloy, the raw materials are dried in a constant temperature drying room at 55-70° C. for 24-28 hours.

4. The method for preparing the aluminum-vanadium-niobium-chromium master alloy according to claim 2, characterized in that: The mass ratio of vanadium pentoxide to metallic aluminum powder in step 1 is 1.010-1.060:1; And / or, the mass ratio of niobium pentoxide, potassium perchlorate and metallic aluminum powder in step 2 is 1.545-1.650:0.125-0.135:1; And / or, the mass ratio of chromium trioxide, potassium perchlorate and metallic aluminum powder in step 3 is 1.480-1.605:0.100-0.120:

1.

5. The method for preparing the aluminum-vanadium-niobium-chromium master alloy according to claim 2, characterized in that: The reactions of step 1, step 2 and step 3 do not require heating, and the ignition agents used are metal magnesium powder Mg, metal aluminum powder Al and calcium peroxide CaO2.

6. The method for preparing the aluminum-vanadium-niobium-chromium master alloy according to claim 2, characterized in that: The furnace linings of the reaction devices in step 1, step 2 and step 3 are made of slag Al2O3.

7. The method for preparing the aluminum-vanadium-niobium-chromium master alloy according to claim 2, characterized in that: In step 5, the mass ratio of the vanadium-aluminum secondary alloy, the niobium-aluminum secondary alloy, the chromium-aluminum secondary alloy and the metallic aluminum particles is 0.510-0.690:0.085-0.095:0.160-0.280:

1.

8. The method for preparing the aluminum-vanadium-niobium-chromium master alloy according to claim 2, characterized in that: The vacuum induction melting in step 5; the starting power of the vacuum induction melting process is 20-30kW, after 10-15 minutes, the power is adjusted to 70-80kW; after 4-5 minutes, the power is adjusted to 100-120kW; after 15-20 minutes, the power is adjusted to 130-140kW, and this power is maintained until the charge is melted; keeping the power unchanged, the alloy is refined, and short-term boiling refining is performed at a temperature of 1625-1675°C for 5-15 minutes; after the refining is complete, the power is gradually reduced to 80-100kW, and when the melt temperature is 1550-1600°C, the alloy is cast in a water-cooled copper crucible to prepare an aluminum vanadium niobium chromium master alloy.

9. The method for preparing the aluminum-vanadium-niobium-chromium master alloy according to claim 2, characterized in that: The aluminum-vanadium-niobium-chromium intermediate alloy obtained in step 5 is crushed to less than 6 mm using a crusher; and then the alloy pieces are crushed to less than 0.1 mm using a powder making machine under nitrogen protection conditions.

10. Use of the aluminum-vanadium-niobium-chromium master alloy according to claim 1 in the field of titanium alloy additive manufacturing.

Images