Refractory metal three-dimensional shaped parts and additive manufacturing method

Abstract

The present application relates to the technical field of refractory metal additive manufacturing, and provides a refractory metal three-dimensional special-shaped part and an additive manufacturing method, the method comprising: precursor preparation, additive manufacturing slurry preparation, additive manufacturing and heat treatment. The present application adopts oxide precursor of refractory metal, which is nano-powder synthesized by wet chemical method, can reduce nano-refractory metal powder, and after printing and heat treatment, can obtain dense refractory metal three-dimensional special-shaped part. The present application can sinter dense metal parts under pressureless condition, ensures excellent performance of refractory metal, does not release gas in the debinding stage, combines two-step debinding method, can completely avoid the introduction of cracks and pores, can prepare different metal oxides by preparing various metal salts, can obtain corresponding metal components under the same process, and can produce non-thin-walled parts, and has the potential of industrial application.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology for refractory metals, and particularly to a three-dimensional irregular part of refractory metal and an additive manufacturing method thereof. Background Technology

[0002] Refractory metals, such as tungsten, molybdenum, niobium, tantalum, vanadium, and zirconium, possess excellent properties such as high melting points and high hardness, and have important applications under many special service conditions. For example, tungsten is widely used in key components of aerospace, electronic, and radiological equipment; molybdenum has significant application potential in semiconductor manufacturing, nuclear energy, and other fields.

[0003] However, due to their high hardness and brittleness, refractory metals are costly and technically challenging to process. The fabrication of irregularly shaped parts requires significant costs and time for custom mold making, and some complex irregularly shaped parts are even impossible to fabricate, severely hindering the further development of refractory metals. Emerging additive manufacturing technologies offer unrestricted freedom in structural fabrication and are gradually changing the way materials are prepared. For example, high-energy beam additive manufacturing plays a crucial role in the fabrication of nickel-based superalloys that are difficult to process using traditional methods.

[0004] However, existing additive manufacturing technologies are almost entirely unsuitable for refractory metals. Selective laser melting and direct energy deposition (DED) introduce unavoidable cracks into the interior of refractory metals; binder jetting produces rough surfaces that often require further processing; and electron beam melting requires extremely harsh working environments and very high equipment costs. Furthermore, since refractory metals often require nanoparticles as raw materials, the powder spreading process in the aforementioned selective laser melting, binder jetting, and electron beam melting technologies is almost impossible to perform. Patent CN 114619042 A proposes a method for preparing three-dimensional tungsten materials using photopolymerization 3D printing. Its basic idea is to use tungsten salts to prepare photopolymerizable gel inks for additive manufacturing. However, this method suffers from an outgassing reaction during preparation, leading to preform cracking, and the final solid content is low, limiting its application to small, thin-walled structures. Additionally, tungsten powder prepared using ammonium metatungstate as a precursor has coarse grains and unsatisfactory performance.

[0005] In summary, there is currently no suitable additive manufacturing technology that can be properly applied to the preparation of three-dimensional irregular parts made of refractory metals. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a refractory metal three-dimensional irregular part and an additive manufacturing method. The method uses the oxide precursor of the refractory metal as the nanopowder synthesized by wet chemical method, which can reduce the nano refractory metal powder. After printing and heat treatment, a dense refractory metal three-dimensional irregular part can be obtained.

[0007] The present invention adopts the following technical solution:

[0008] On one hand, the present invention provides an additive manufacturing method for three-dimensional irregular parts of refractory metals, comprising:

[0009] S1. Preparation of precursor: Dissolve a certain proportion of oxidant, fuel and metal salt in deionized water, and heat the mixture under stirring to obtain an oxide precursor.

[0010] S2. Preparation of additive manufacturing slurry: The oxide precursor, photosensitive resin, photoinitiator and additives in a certain proportion are thoroughly mixed, and the mixture is ball-milled and vacuum-treated to obtain the additive manufacturing slurry.

[0011] S3. Additive manufacturing: The additive manufacturing slurry is placed in the printer, the printing model and parameters are set, and additive manufacturing is carried out to obtain a three-dimensional irregular part oxide precursor blank.

[0012] S4. Heat treatment: The oxide precursor blank of the three-dimensional irregular part is degreased, reduced and sintered in sequence to obtain a dense refractory metal three-dimensional irregular part.

[0013] In addition to any of the possible implementations described above, another implementation is provided, in step S1,

[0014] The oxidant is ammonium nitrate, and its molar ratio is 50%-80%;

[0015] The fuel is one or more of glycine, urea, and citric acid, with a molar ratio of 15%-40%.

[0016] The metal salt is a refractory metal salt with a molar ratio of 1%-10%; the refractory metals include tungsten, molybdenum, niobium, tantalum, vanadium and zirconium.

[0017] In addition to any of the possible implementations described above, another implementation is provided in which the refractory metal salt is one of the following refractory metal salts: ammonium metatungstate, ammonium molybdate, ammonium metaniobate, ammonium metatantalate, etc.

[0018] In addition to any of the possible implementations described above, another implementation is provided in which the heating temperature in step S1 is 200-400℃ and the reaction time is 5-25 min.

[0019] In addition to any of the possible implementations described above, another implementation is provided, in step S2,

[0020] The volume ratio of the oxide precursor in the slurry is 40%-50%;

[0021] The photosensitive resin includes one or more of the following: acrylamide (ACMO), 1,6-hexanediol diacrylate (HDDA), tripropylene glycol diacrylate (TPGDA), trimethylolpropane triacrylate (TPGDA), pentaerythritol tetraacrylate (PPTTA), polyurethane acrylate, epoxy acrylate, and polyester acrylate, with a volume ratio of 40%-50% in the slurry.

[0022] The photoinitiator includes one or more of ethyl 2,4,6-trimethylbenzoylphenylphosphonate (TPO-L), 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO), and 1-hydroxycyclohexylphenyl ketone (184), which account for 1%-5% of the mass of the photosensitive resin.

[0023] The additives include one or more of hydroquinone, tert-butylhydroquinone, tert-butylcatechol, UNIQSPERSE 9450, UNIQJET 9510, Modaflow 2100, EFKA PX 4701, AgiSyn 008, RJ10, and P115, which account for 5-10% of the mass of the photosensitive resin.

[0024] In addition to any of the possible implementations described above, another implementation is provided in which, in step S2, the ball mill rotation speed is 200-400 r / min, the ball milling time is 10-24 hours, and the vacuum degree is not greater than 0.1 MPa.

[0025] In addition to any of the possible implementations described above, another implementation is provided in which, in step S3, the printer is a digital light processing (DLP) printer.

[0026] In addition to any of the possible implementations described above, another implementation is provided in which, in step S4, the three-dimensional irregular part oxide precursor blank is degreased at a certain temperature and inert atmosphere, and then reduced and sintered at a certain temperature and in a reducing atmosphere.

[0027] In addition to any of the possible implementations described above, another implementation is provided, wherein the degreasing stage is divided into two steps. The first step has a heating range of 0℃-700℃, a heating rate of 0.1℃ / min-0.3℃ / min, and a holding range of 100℃-200℃, 300℃-500℃, and 600℃-700℃, with a holding time of 1h-2h for each stage, and the atmosphere is nitrogen or argon. The second step has a heating range of 0℃-800℃, a heating rate of 1℃ / min-2℃ / min, a holding range of 700℃-800℃, and a holding time of 1h-2h, with the atmosphere being air.

[0028] The heating range of the reduction stage is 0℃-1000℃, the heating rate is 5℃ / min-10℃ / min, the holding range is 800℃-1000℃, the holding time is 4h-8h, and the atmosphere is hydrogen.

[0029] The sintering stage is divided into two steps. The first step involves heating from 0℃ to 1600℃ at a rate of 5℃ / min to 10℃ / min in a hydrogen atmosphere. The second step involves heating from 0℃ to 1500℃ at a rate of 5℃ / min to 10℃ / min in a 10-hour holding period in a hydrogen atmosphere.

[0030] On the other hand, the present invention also provides a refractory metal three-dimensional irregular part, which is obtained by the above method.

[0031] The beneficial effects of this invention are as follows:

[0032] 1. Using nano-oxide powder as raw material, fine-grained metal powder can be obtained after reduction. This allows for the application of a two-step sintering method, which can sinter dense metal parts under pressureless conditions, ensuring the excellent properties of refractory metals.

[0033] 2. Using nano-oxides as precursors, they will not decompose and release gas during the degreasing stage. Combined with a two-step degreasing method, the introduction of cracks and pores can be completely avoided.

[0034] 3. It has high versatility and stability. Various metal salts can be used to prepare different metal oxides, and corresponding metal components can be obtained under the same process.

[0035] 4. It is capable of producing non-thin-walled parts and has the potential for industrial application. Attached Figure Description

[0036] Figure 1 The diagram shown is an implementation flowchart of an additive manufacturing method for a refractory metal three-dimensional irregular part according to an embodiment of the present invention.

[0037] Figure 2 The image shown is a physical image of the tungsten lattice prepared in the example.

[0038] Figure 3 The image shown is a microstructure of the three-dimensional irregular metal part prepared in the example. Detailed Implementation

[0039] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the technical features or combinations of technical features described in the following embodiments should not be considered in isolation, but can be combined with each other to achieve better technical effects.

[0040] like Figure 1As shown, an additive manufacturing method for a refractory metal three-dimensional irregular part according to an embodiment of the present invention includes:

[0041] S1. Preparation of precursor: Dissolve a certain proportion of oxidant, fuel and metal salt in deionized water, and heat the mixture under stirring to obtain an oxide precursor.

[0042] S2. Preparation of additive manufacturing slurry: The oxide precursor, photosensitive resin, photoinitiator and additives in a certain proportion are thoroughly mixed, and the mixture is ball-milled and vacuum-treated to obtain the additive manufacturing slurry.

[0043] S3. Additive manufacturing: The additive manufacturing slurry is placed in the printer, the printing model and parameters are set, and additive manufacturing is carried out to obtain a three-dimensional irregular part oxide precursor blank.

[0044] S4. Heat treatment: The oxide precursor blank of the three-dimensional irregular part is degreased, reduced and sintered in sequence to obtain a dense refractory metal three-dimensional irregular part.

[0045] In one specific embodiment, in step S1,

[0046] The oxidant is ammonium nitrate, and its molar ratio is 50%-80%;

[0047] The fuel is one or more of glycine, urea, and citric acid, with a molar ratio of 15%-40%.

[0048] The metal salt is a refractory metal salt with a molar ratio of 1%-10%; the refractory metals include tungsten, molybdenum, niobium, tantalum, vanadium and zirconium.

[0049] In one specific embodiment, the refractory metal salt is one of the following: ammonium metatungstate, ammonium molybdate, ammonium metaniobate, ammonium metatantalate, etc.

[0050] In one specific embodiment, in step S1, the heating temperature is 200-400℃ and the reaction time is 5-25 min.

[0051] Photosensitive resins are unsaturated acrylic monomers containing carbon-carbon double bonds. Photoinitiators can activate these molecules, and when irradiated with ultraviolet light of a specific wavelength, the carbon-carbon double bonds open and link together, linking the monomer molecules into long-chain molecules, i.e., a cross-linking reaction occurs. Macroscopically, this is how liquid resin is transformed into solid plastic.

[0052] There are two types of additives. One is surface modification, which adheres to the surface of the powder, allowing the powder to be evenly dispersed in the organic matter, reducing the viscosity of the system and facilitating printing. The other is light absorption. Since ultraviolet light will cause diffuse reflection when it shines on the powder, the actual cured pattern will not match the designed model. The light absorber can absorb the scattered light and ensure printing accuracy.

[0053] In one specific embodiment, in step S2,

[0054] The volume ratio of the oxide precursor in the slurry is 40%-50%;

[0055] The photosensitive resin includes one or more of the following: acrylamide (ACMO), 1,6-hexanediol diacrylate (HDDA), tripropylene glycol diacrylate (TPGDA), trimethylolpropane triacrylate (TPGDA), pentaerythritol tetraacrylate (PPTTA), polyurethane acrylate, epoxy acrylate, and polyester acrylate, with a volume ratio of 40%-50% in the slurry.

[0056] The photoinitiator includes one or more of ethyl 2,4,6-trimethylbenzoylphenylphosphonate (TPO-L), 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO), and 1-hydroxycyclohexylphenyl ketone (184), which account for 1%-5% of the mass of the photosensitive resin.

[0057] The additives include one or more of hydroquinone, tert-butylhydroquinone, tert-butylcatechol, UNIQSPERSE 9450, UNIQJET 9510, Modaflow 2100, EFKA PX 4701, AgiSyn 008, RJ10, and P115.

[0058] In one specific embodiment, in step S2, the ball mill rotation speed is 200-400 r / min, the ball milling time is 10-24 hours, and the vacuum degree is no greater than 0.1 MPa.

[0059] In one specific embodiment, in step S3, the printer is a digital light processing (DLP) printer.

[0060] In one specific embodiment, in step S4, the three-dimensional irregular part oxide precursor blank is degreased under a certain temperature and inert atmosphere, and then reduced and sintered under a certain temperature and reducing atmosphere.

[0061] In one specific embodiment, the degreasing stage is divided into two steps. The first step involves heating in the range of 0℃-700℃, with a heating rate of 0.1℃ / min-0.3℃ / min, and holding in the ranges of 100℃-200℃, 300℃-500℃, and 600℃-700℃ for 1-2 hours, using nitrogen or argon atmosphere. The second step involves heating in the range of 0℃-800℃, with a heating rate of 1℃ / min-2℃ / min, and holding in the range of 700℃-800℃ for 1-2 hours, using air atmosphere.

[0062] The heating range of the reduction stage is 0℃-1000℃, the heating rate is 5℃ / min-10℃ / min, the holding range is 800℃-1000℃, the holding time is 4h-8h, and the atmosphere is hydrogen.

[0063] The sintering stage is divided into two steps. The first step involves heating from 0℃ to 1600℃ at a rate of 5℃ / min to 10℃ / min in a hydrogen atmosphere. The second step involves heating from 0℃ to 1500℃ at a rate of 5℃ / min to 10℃ / min in a 10-hour holding period in a hydrogen atmosphere.

[0064] Example 1

[0065] An additive manufacturing method for a refractory metal three-dimensional irregular part includes:

[0066] S1. Weigh 40 parts ammonium nitrate, 20 parts glycine, and 5 parts ammonium metatungstate according to the mass ratio, dissolve them in deionized water, heat at 300℃ for 25 minutes with constant stirring, and obtain WO after a vigorous oxidation reaction. 2.7 Powder;

[0067] S2. Weigh 50 parts of the above powder, 20 parts of HDDA, 15 parts of PPTTA, and 10 parts of polyurethane acrylate according to the volume ratio. Add 3% TPO, 5% EFKA PX 4701, 2% hydroquinone, and 3% AgiSyn 008 according to the mass ratio of the resin. Place the mixture in a ball mill jar and vacuum it to 0.1 MPa. Ball mill at 350 r / min for 20 h to obtain a slurry.

[0068] S3. Set the printing model and parameters, and after printing, obtain the oxide blank;

[0069] S4. Place the billet in a tube furnace and heat it to 700°C at 0.3°C / min under a nitrogen atmosphere. Hold it at 300°C, 500°C, and 700°C for 2 hours each. After cooling, heat it to 800°C in air at 2°C / min and hold it for 2 hours. After cooling, heat it to 800°C at 10°C / min under a hydrogen atmosphere and hold it for 4 hours. Then, heat it to 1500°C at 5°C / min and cool it to 1300°C at 5°C / min. Hold it for 10 hours and cool it with the furnace to obtain a dense three-dimensional tungsten metal part.

[0070] The physical image of the prepared tungsten lattice is shown below. Figure 2 As shown, the microstructure of the prepared three-dimensional irregular metal part is illustrated in the figure. Figure 3 As shown, the prepared three-dimensional tungsten metal parts have a density exceeding 90% and a hardness of not less than 7 GPa.

[0071] Example 2

[0072] An additive manufacturing method for a refractory metal three-dimensional irregular part includes:

[0073] S1. Weigh 45 parts ammonium nitrate, 18 parts glycine and 3 parts ammonium molybdate according to the mass ratio, dissolve them in deionized water, heat at 310℃ for 20 minutes with constant stirring, and obtain molybdenum oxide powder after a vigorous oxidation reaction.

[0074] S2. Weigh 50 parts of the above powder, 20 parts of HDDA, 15 parts of PPTTA, and 15 parts of polyurethane acrylate according to the volume ratio. Add 2% TPO, 5% Modaflow 2100, 2% hydroquinone, and 3% AgiSyn 008 according to the mass ratio of the resin. Place the mixture in a ball mill jar and vacuum it to 0.1 MPa. Ball mill at 350 r / min for 20 h to obtain a slurry.

[0075] S3: Set the printing model and parameters. After printing, an oxide blank is obtained. The blank is placed in a tube furnace and heated to 700°C at 0.2°C / min under a nitrogen atmosphere. It is then held at 400°C, 600°C, and 700°C for 2 hours each. After cooling, it is heated to 800°C in air at 2°C / min and held for 2 hours. After cooling, it is heated to 800°C at 10°C / min under a hydrogen atmosphere and held for 4 hours. Then, it is heated to 1350°C at 5°C / min and cooled to 1150°C at 5°C / min, held for 10 hours, and then cooled with the furnace to obtain a dense three-dimensional molybdenum part.

[0076] The prepared three-dimensional tungsten metal parts have a density of over 90% and a hardness of not less than 7 GPa.

[0077] Example 3

[0078] An additive manufacturing method for a refractory metal three-dimensional irregular part includes:

[0079] S1. Weigh 40 parts of ammonium nitrate, 20 parts of glycine and 5 parts of ammonium metatantalate according to the mass ratio, dissolve them in deionized water, heat at 300℃ for 25 minutes with constant stirring, and obtain tantalum pentoxide powder after a vigorous oxidation reaction.

[0080] S2. Weigh 55 parts of the above powder, 20 parts of HDDA, 15 parts of PPTTA, and 10 parts of polyurethane acrylate according to the volume ratio. Add 3% TPO, 5% EFKA PX 4701, 2% hydroquinone, and 3% RJ10 according to the mass ratio of the resin. Place the mixture in a ball mill jar and vacuum it to 0.1 MPa. Ball mill at 350 r / min for 20 h to obtain a slurry.

[0081] S3. Set the printing model and parameters. After printing, an oxide blank is obtained. Place the blank in a tube furnace and heat it to 700℃ at 0.2℃ / min under a nitrogen atmosphere. Hold it at 400℃, 600℃, and 700℃ for 2 hours each. After cooling, heat it to 700℃ in air at 2℃ / min and hold it for 2 hours. After cooling, heat it to 800℃ at 10℃ / min under a hydrogen atmosphere and hold it for 6 hours. Then, heat it to 1480℃ at 5℃ / min and cool it to 1350℃ at 5℃ / min. Hold it for 10 hours and cool it with the furnace to obtain a dense three-dimensional tantalum metal part.

[0082] The prepared three-dimensional tungsten metal parts have a density of over 90% and a hardness of not less than 7 GPa.

[0083] The innovative aspects of this invention are explained as follows:

[0084] 1. Existing metal 3D printing technologies require powder with a certain degree of flowability after each layer is laid and then laser-scanned. However, nanopowders have very poor flowability, so existing technologies use micron-sized powders (nanopowders cannot be used). Metal parts prepared using micron-sized powders have relatively large grain sizes, at the micron level. In contrast, this invention uses a wet chemical method (oxidant, fuel, and metal salt dissolved in deionized water and reacted under heat) to produce nano-metal oxide powders. The refractory metal irregular parts prepared by this invention have nano-sized metal grains, which are much smaller than the metal grain sizes prepared by traditional 3D printing technologies. Therefore, the metal parts prepared by this application have superior quality.

[0085] 2. The heat treatment process of this invention is unique, dividing the heat treatment into three steps: debinding, reduction, and sintering. Traditionally, it is believed that for solid parts or blanks, reduction using reducing agents such as hydrogen (without damaging the parts or blanks) can only reduce the surface of the parts or blanks, not the interior, thus failing to obtain pure metal parts. Through extensive practice, the inventors discovered that the heat treatment process of this invention can completely solve this technical problem, as described below: Nanoparticles are dispersed in adhesive (i.e., photosensitive resin). After exposure, the photosensitive resin transforms from liquid to solid, encapsulating the nanoparticles and forming a blank. During the debinding process, the resin gradually decomposes and volatilizes. As the temperature rises, the resin is completely removed. At this point, the powder particles are loosely bound together by friction, resulting in a very loose blank (with voids). Heating this blank in a hydrogen atmosphere allows hydrogen to fully penetrate the interior of the blank through the pores, causing a reduction reaction that reduces tungsten oxide to pure tungsten. During sintering, the temperature continues to rise, and the contacting tungsten powder begins to change from physical contact to chemical contact, tightly bonding together. At this point, the billet undergoes dimensional shrinkage. Continued holding at temperature sintersects the loose billet into a dense, pure tungsten bulk part. Figure 3It can be seen that the prepared parts are pure tungsten parts and do not contain unreduced tungsten oxide.

[0086] 3. In the embodiments of the present invention, the grain size of tungsten after sintering can be controlled below 700 nm (the grain size of pure tungsten obtained by traditional powder metallurgy process is tens of micrometers to hundreds of micrometers), which is much smaller than that of traditional powder metallurgy process. The density reaches more than 90%, and there is no obvious texture, abnormal grain growth, second phase impurities and grain boundary liquid phase precipitates. The hardness of tungsten can reach about 7 GPa.

[0087] 4. Using nano-oxides as precursors, the powder will not decompose and release gas during the degreasing stage. Combined with the two-step degreasing method, the powder will not release gas during the heating process, thus completely avoiding the introduction of cracks and pores.

[0088] 5. Traditional metal additive manufacturing has three methods: Selective Laser Melting (SLM), Direct Energy Deposition (DED), and Selective Electron Blowing (EBM). SLM and DED-printed tungsten often produce cracks, and EBM is very expensive. This invention uses Direct Laser Melting (DLP) combined with heat treatment, which avoids cracking while also using much cheaper equipment. SLM, DED, and EBM all require equipment costing millions, while DLP is only in the hundreds of thousands range. Furthermore, after DLP printing, the parts can be debonded, reduced, and sintered in an industrial furnace, resulting in high efficiency. It can also produce non-thin-walled parts, showing potential for industrial applications.

[0089] While several embodiments of the present invention have been provided herein, those skilled in the art should understand that modifications can be made to these embodiments without departing from the spirit of the invention. The above embodiments are merely exemplary and should not be construed as limiting the scope of the invention.

Claims

1. An additive manufacturing method for a three-dimensional irregular part of a refractory metal, characterized in that, The method includes: S1. Preparation of precursor: Dissolve a certain proportion of oxidant, fuel and metal salt in deionized water, and heat the mixture under stirring to obtain an oxide precursor. S2. Preparation of additive manufacturing slurry: The oxide precursor, photosensitive resin, photoinitiator and additives in a certain proportion are thoroughly mixed, and the mixture is ball-milled and vacuum-treated to obtain the additive manufacturing slurry. S3. Additive manufacturing: The additive manufacturing slurry is placed in a printer, the printing model and parameters are set, and additive manufacturing is performed to obtain a three-dimensional irregular oxide precursor blank; the printer is a digital light processing printer. S4. Heat treatment: The oxide precursor blank of the three-dimensional irregular part is degreased, reduced and sintered in sequence to obtain a dense refractory metal three-dimensional irregular part. The degreasing stage consists of two steps. The first step involves heating from 0℃ to 700℃ at a rate of 0.1℃ / min to 0.3℃ / min, with holding intervals of 100℃-200℃, 300℃-500℃, and 600℃-700℃, each lasting 1-2 hours in a nitrogen or argon atmosphere. The second step involves heating from 0℃ to 800℃ at a rate of 1℃ / min to 2℃ / min, with holding intervals of 700℃-800℃, lasting 1-2 hours in an air atmosphere. The heating range of the reduction stage is 0℃-1000℃, the heating rate is 5℃ / min-10℃ / min, the holding range is 800℃-1000℃, the holding time is 4h-8h, and the atmosphere is hydrogen. The sintering stage is divided into two steps. The first step involves heating from 0℃ to 1600℃ at a rate of 5℃ / min to 10℃ / min in a hydrogen atmosphere. The second step involves heating from 0℃ to 1500℃ at a rate of 5℃ / min to 10℃ / min in a 10-hour holding period in a hydrogen atmosphere.

2. The additive manufacturing method for refractory metal three-dimensional irregular parts as described in claim 1, characterized in that, In step S1, the oxidant is ammonium nitrate, and its molar ratio is 50%-80%; The fuel is one or more of glycine, urea, and citric acid, with a molar ratio of 15%-40%. The metal salt is a refractory metal salt with a molar ratio of 1%-10%; the refractory metals include tungsten, molybdenum, niobium, tantalum, vanadium and zirconium.

3. The additive manufacturing method for refractory metal three-dimensional irregular parts as described in claim 2, characterized in that, The refractory metal salt is one of the following: ammonium metatungstate, ammonium molybdate, ammonium metaniobate, or ammonium metatantalate.

4. The additive manufacturing method for refractory metal three-dimensional irregular parts as described in claim 1, characterized in that, In step S1, the heating temperature is 200-400℃ and the reaction time is 5-25 min.

5. The additive manufacturing method for refractory metal three-dimensional irregular parts as described in claim 1, characterized in that, In step S2, the volume ratio of the oxide precursor in the slurry is 40%-50%; The photosensitive resin includes one or more of the following: acryloylmorpholine, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, polyurethane acrylate, epoxy acrylate, and polyester acrylate, with a volume ratio of 40%-50% in the slurry. The photoinitiator includes one or more of ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and 1-hydroxycyclohexylphenyl ketone (184), which account for 1%-5% of the mass of the photosensitive resin. The additives include one or more of hydroquinone, tert-butylhydroquinone, tert-butylcatechol, UNIQSPERSE 9450, UNIQJET9510, Modaflow 2100, EFKA PX 4701, AgiSyn 008, RJ10, and P115, which account for 5-10% of the mass of the photosensitive resin.

6. The additive manufacturing method for refractory metal three-dimensional irregular parts as described in claim 1, characterized in that, In step S2, the ball milling speed is 200-400 r / min, the ball milling time is 10-24 hours, and the vacuum degree is not greater than 0.1 MPa.

7. A three-dimensional irregularly shaped part of a refractory metal, characterized in that, The refractory metal three-dimensional irregular part is prepared by the method described in any one of claims 1-6.

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