Low-oxygen molybdenum-niobium alloy target material and preparation method thereof

Abstract

The invention relates to the technical field of alloy target material preparation, in particular to a low-oxygen molybdenum-niobium alloy target material and a preparation method thereof. According to the technical scheme, the low-oxygen molybdenum-niobium alloy target material comprises the composition proportion of the low-oxygen molybdenum-niobium alloy target material and the preparation method of the low-oxygen molybdenum-niobium alloy target material. According to the preparation method, the carbon nano tube with high specific surface area and activity is adopted to replace traditional carbon black, strong deoxidation elements of titanium and aluminum are added, a multi-stage and synergistic reduction environment is formed in the sintering process, the carbon nano tube can provide rich reaction sites and preferentially react with an oxide layer on the surface of niobium powder, and therefore the oxidation layer on the surface of the niobium powder is reduced; titanium and aluminum are further combined with oxygen dissolved in a matrix to form a stable compound, so that the removal depth of oxygen impurities and the overall deoxidation efficiency are remarkably improved, the overall oxygen content of the target material can be reduced to a lower level, and brittle phase and impurity precipitation caused by oxygen is effectively reduced, so that the mechanical property of the target material is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of alloy target material preparation, and particularly relates to a low-oxygen molybdenum-niobium alloy target material and a preparation method thereof. BACKGROUND

[0002] As a cathode source in sputtering, impurities in the solid and oxygen and water in the pores are the main pollution sources of the deposited film, in order to reduce the pores in the solid of the target material and improve the performance of the film, it is generally required that the sputtering target material has high compactness.

[0003] The existing low-oxygen molybdenum-niobium alloy target material and the preparation method thereof have a single and limited deoxidation mechanism, usually only rely on the reduction reaction of micron-sized carbon powder and oxygen in the alloy, are limited by the particle size and dispersion uniformity of the carbon powder, and are difficult to achieve deep and thorough removal of oxygen impurities, the reaction activity and contact efficiency of the conventional carbon powder are insufficient in the sintering process, which easily leads to incomplete deoxidation, and finally there are still a large amount of oxygen elements remaining in the target material, the oxygen impurities not only form brittle oxide inclusions with alloy elements, affecting the toughness of the material, but also cause particle splashing in the subsequent sputtering process due to gas release, which seriously reduces the uniformity and performance consistency of the film.

[0004] In view of the above problems, the present application uses high specific surface area and active carbon nanotubes to replace traditional carbon black, and combines the addition of strong deoxidizing elements titanium and aluminum, to form a multi-stage and cooperative reduction environment in the sintering process, the carbon nanotubes can provide abundant reaction sites and preferentially react with the oxide layer on the surface of the niobium powder, and the titanium and aluminum further combine with the oxygen dissolved in the matrix to form stable compounds, which significantly improves the removal depth and overall deoxidation efficiency of oxygen impurities, can reduce the overall oxygen content of the target material to a lower level, effectively reduces the precipitation of brittle phases and impurities caused by oxygen, and improves the mechanical properties of the target material. SUMMARY

[0005] In order to overcome the problems of the existing low-oxygen molybdenum-niobium alloy target material and the preparation method thereof, the deoxidation mechanism is single and limited, usually only relies on the reduction reaction of micron-sized carbon powder and oxygen in the alloy, is limited by the particle size and dispersion uniformity of the carbon powder, and is difficult to achieve deep and thorough removal of oxygen impurities, the reaction activity and contact efficiency of the conventional carbon powder are insufficient in the sintering process, which easily leads to incomplete deoxidation, and finally there are still a large amount of oxygen elements remaining in the target material, the oxygen impurities not only form brittle oxide inclusions with alloy elements, affecting the toughness of the material, but also cause particle splashing in the subsequent sputtering process due to gas release, which seriously reduces the uniformity and performance consistency of the film.

[0006] The technical solution of the present invention is as follows: a low-oxygen molybdenum-niobium alloy target material, comprising the following components measured by weight percentage: 70% to 85% molybdenum powder, 10% to 20% niobium powder, 0.05% to 0.15% carbon nanotubes, 0.5% to 2.0% rare earth oxides, 2% to 5% titanium powder, and the balance being aluminum powder, wherein the sum of the mass percentages of the above components is 100%.

[0007] A method for preparing a low-oxygen molybdenum-niobium alloy target includes the following steps: S11: Specialized treatments are applied to molybdenum powder, niobium powder, carbon nanotubes, rare earth oxides, titanium powder, and aluminum powder, including reduction, hydrogenation deoxidation, dispersion, drying, and passivation layer removal. S12: A graded mixing strategy is adopted. First, niobium powder is coated with nano-slurry, then it is dry-mixed and wet-milled with titanium-aluminum pre-alloyed powder and some molybdenum powder, and finally it is mixed with the remaining molybdenum powder in a long-term three-dimensional oscillating mixing process. S13: Combining bidirectional molding and cold isostatic pressing technologies, green bodies are formed under precisely controlled pressure and holding pressure procedures, followed by preheating treatment to remove organic matter and enhance the strength of the green body; S14: Through a precise temperature and atmosphere control process of "low-temperature vacuum degassing - medium-temperature hydrogen reduction - high-vacuum high-temperature sintering - liquid-phase assistance - high-temperature solid solution", deep deoxidation, porosity elimination and complete densification of the alloy are achieved; S15: The sintered billet undergoes surface cleaning and non-destructive testing, and hot isostatic pressing (HIP) is performed as needed. It is then encapsulated in a vacuum-sealed package and subjected to high-temperature forging and hot rolling to initially obtain the required plate / bar shape. S16: The semi-finished product is precision machined to its final dimensions using wire cutting and CNC machine tools, followed by vacuum annealing to relieve stress, and the sputtered surface is precision polished to a mirror finish, while the non-sputtered surface is sandblasted. S17: Comprehensively characterize the finished product by using methods such as chemical composition analysis, metallographic observation, density measurement, mechanical property testing, texture analysis, or sputtering simulation, and establish a complete traceable quality file; S18: After final cleaning and inspection in a Class 100 cleanroom, the target material is vacuum-packed with argon, placed in a custom antistatic foam liner, then packed into a special protective transport box, labeled, and stored in a constant temperature and humidity environment.

[0008] Preferably, the refined pretreatment of raw materials includes the following steps: S21: Place molybdenum powder with a Fisher particle size of 1.5~3.0μm and a purity ≥3N8 in a tubular reduction furnace, introduce dry hydrogen gas with a dew point below -60℃, heat to 800℃ at a rate of 5℃ / min, hold at that temperature for 2 hours, then cool with the furnace to below 150℃, switch to argon protection to cool to room temperature, remove and immediately transfer to an argon-filled glove box for later use; S22: Put the niobium powder with oxygen content ≤1000 ppm into a vacuum reaction kettle, vacuumize to 5 × 10~4 Pa, then introduce high-purity hydrogen to a pressure of 0.1 MPa, heat to 500 ℃ at a rate of 3 ℃ / min and keep for 4 hours to fully hydrogenate the niobium powder; S23: Transfer the hydrogenated niobium powder to a vacuum dehydrogenation furnace, vacuumize to 1 × 10~4 Pa, heat to 650 ℃ at a rate of 2 ℃ / min, keep for 6 hours to remove hydrogen, and place the dehydrogenated niobium powder block in a high-energy planetary ball mill, mill for 2 hours at a speed of 300 r / min under argon protection, sieve through a 400-mesh sieve to obtain active niobium powder with uniform particle size distribution; S24: Put the multi-walled carbon nanotubes into anhydrous ethanol solution containing 1 wt% polyvinylpyrrolidone, and use an ultrasonic cell disruptor to ultrasonically disperse for 1 hour at a power of 600 W to form a stable suspension; S25: Put the nano or powder into a vacuum drying oven, dry at 120 ℃ under 1 × 10~4 Pa for 12 hours to completely remove the physically adsorbed water; S26: Soak the titanium powder and aluminum powder in dilute hydrofluoric acid for 30 seconds respectively, rinse with deionized water to neutralization, then wash with anhydrous ethanol for three times, and finally dry in a vacuum oven at 80 ℃ for 2 hours; S27: Put all the pretreated raw material powders into sealed tanks filled with high-purity argon, label with composition and pretreatment date, and wait for use.

[0009] As preferred, when performing multi-scale powder precision mixing and homogenization, the following steps are included: S31: In the argon-filled glove box, mix the dispersed carbon nanotube suspension with the metered anhydrous ethanol, use a mechanical stirrer to stir at a speed of 500 r / min, and slowly add the dried rare earth oxide nano powder, continue stirring for 1 hour to form a uniform slurry; S32: Pour the pretreated active niobium powder into a high-speed shear mixer, under argon atmosphere, shear stir at 2000 r / min, and use a spray device to uniformly spray the above nano slurry onto the niobium powder, continue for 40 minutes to make the nano materials wrapped on the surface of the niobium powder; S33: Weigh the titanium powder and aluminum powder according to the proportion, put them into a three-dimensional mixer, mix under argon protection for 4 hours, put the mixed powder into a graphite mold, heat to 800 ℃ at a rate of 10 ℃ / min in a vacuum hot pressing furnace, apply a pressure of 20 MPa, keep for 30 minutes, and then break and sieve after cooling in the furnace to obtain pre-alloyed powder; ​​​S34: The surface-wrapped niobium powder, titanium-aluminum pre-alloyed powder, and two-thirds of the total amount of pretreated molybdenum powder are poured into a V-shaped mixer under argon protection, and continuously mixed at a speed of 15 revolutions per minute for 12 hours; S35: The dry mixed powder is transferred to a planetary ball mill tank, and an appropriate amount of anhydrous ethanol is added as a process control agent, with a ball-to-powder ratio of 2:1, and ball-milled at a speed of 150 revolutions per minute for 8 hours under argon protection; S36: The ball-milled slurry is poured into a vacuum filtration device to separate the solvent, and the obtained wet filter cake is placed in a vacuum drying oven and dried at 80°C and -0.095 MPa for 6 hours. The dried agglomerates are gently crushed and passed through a 200-mesh vibrating screen; S37: The sieved powder and the remaining one-third of the molybdenum powder are placed in a large three-dimensional oscillating mixer under argon protection, and mixed for 24 hours in a three-dimensional space motion mode to obtain a final mixed powder with highly uniform chemical composition and particle size distribution.

[0010] As preferred, when performing high-density green body near-net shaping, the following steps are included: S41: A high-strength carbide negative mold is used, the inner wall of the mold cavity is uniformly sprayed with boron nitride release agent and dried, and the final mixed powder is poured into the mold cavity in three times, and after each pouring, a powder leveler is used to flatten it; S42: The mold containing the powder is placed on a servo electric press, and first pre-pressed at a pressure of 10 MPa for 30 seconds to preliminarily position the powder, and then bidirectional synchronous pressing is performed, the upper and lower punches move towards each other at a constant speed of 1 mm / min, and the pressure is finally stabilized at 300 MPa, and the pressure is maintained for 5 minutes; S43: The molded green body is carefully removed from the mold, and vacuum packaged with a flexible rubber sleeve, and the packaged green body is placed in a cold isostatic pressing cylinder, and water is used as the pressure transmission medium, and the pressure is uniformly increased to 400 MPa within 5 minutes, and after maintaining the pressure for 30 minutes, the pressure is slowly released; S44: The diameter and thickness of the CIPed green body are measured using a high-precision digital caliper, the data is recorded, and the green body density is calculated by weighing the green body on an analytical balance, and the green body density is required to be above 65% of the theoretical density; S45: Under a strong light side lamp, the surface of the green body is observed with the naked eye for cracks, delamination, or obvious uneven areas, and an industrial endoscope is used to randomly check the side wall of the green body to check for internal macroscopic defects; S46: The green body that passes the inspection is placed in a tube furnace with argon-4% hydrogen mixed gas, and slowly heated to 600°C at a rate of 1°C / min, and held for 2 hours to remove possible trace amounts of organic matter and moisture, and to give the green body certain strength; S47: After preheating, the green body is cooled to room temperature in an argon environment, and its surface state is checked again. A molybdenum-niobium alloy pad plate of the same material is placed flat at the bottom.

[0011] As preferred, when performing the multi-stage process control sintering, the following steps are included: S51: Put the prepared green body together with the pad plate into the constant temperature zone of the high-temperature vacuum sintering furnace, close the furnace door, start the mechanical pump and Roots pump, and vacuum the furnace chamber to 5× Pa, and maintain static for 1 hour at this vacuum degree, and detect the leakage rate; S52: Increase the furnace temperature from room temperature to 800℃ at a rate of 3℃ / min, and always maintain the vacuum degree not worse than 5× Pa during the temperature rising process, and keep the temperature at 800℃ for 1 hour to fully remove the gas adsorbed on the surface of the powder particles; S53: Introduce high-purity hydrogen into the furnace chamber, adjust the pressure to +5kPa, continue to increase the temperature to 1300℃ at a rate of 5℃ / min, and keep the temperature at this temperature for 4 hours. At this stage, the carbon nanotubes, titanium, and aluminum react with the oxygen in the powder; S54: Close the hydrogen, reopen the vacuum system, quickly switch the atmosphere in the furnace back to high vacuum, and increase the temperature from 1300℃ to 1850℃ at a rate of 8℃ / min; S55: Keep the temperature at 1850℃ for 2 hours. At this time, the addition of aluminum may produce a small amount of transient liquid phase, which promotes mass transfer and pore filling. After the holding period, continue to increase the temperature to the final sintering temperature of 2050℃ at a rate of 10℃ / min; S56: Keep the temperature at the target temperature of 2050℃ for 8 hours. During the holding period, the vacuum degree must be maintained at 5× Pa or better; S57: After the holding period, stop heating and start the program-controlled cooling. In the temperature range from 2050℃ to 1500℃, the cooling rate is controlled to be not more than 5℃ / min; in the temperature range from 1500℃ to 800℃, the cooling rate is not more than 10℃ / min; below 800℃, the furnace can be naturally cooled, and the high vacuum is maintained throughout the process.

[0012] As preferred, when performing the sintered body post-processing and processing, the following steps are included: S61: When the furnace temperature cools down to below 80℃, refill high-purity argon to normal pressure in the furnace, open the furnace door to take out the sintered body, and use a silicon carbide grinding machine to remove the adhesion layer or oxidation color that may be generated on the surface of the sintered body due to contact with the pad plate; S62: Perform ultrasonic flaw detection on the cleaned sintered body to check whether there are unsintered pores or cracks inside, take samples to test the density, oxygen content, and microhardness, and evaluate whether the sintering is up to standard; S63: For the target material with super-high density requirements, the sintered blank is loaded into a low-carbon steel jacket, vacuumed and welded, and then placed into a hot isostatic pressing device. The temperature is raised to 1350°C at a rate of 10°C / min in an argon medium, and a 150 MPa isostatic pressure is applied. The temperature and pressure are maintained for 4 hours; S64: For the blank that needs subsequent forging or rolling, a stainless steel plate is used to make a sealed jacket. The sintered blank is placed into the jacket, vacuumed to 1× Pa, and then the exhaust pipe is sealed using argon arc welding; S65: The packaged blank is placed into a resistance heating furnace and heated to 1250°C under argon protection for 2 hours to ensure uniform heat penetration. Then it is quickly transferred to a quick forging machine for multi-pass axial upsetting and elongation, with a total forging ratio of ≥3; S66: The plate blank after forging and breaking down is heated to 1150°C again and subjected to multi-pass rolling on a four-high reversible hot rolling mill, with a deformation of 15%-20% per pass. The final rolling is performed to obtain the desired thickness of the plate; S67: The outer stainless steel jacket is completely removed by machining. The exposed alloy plate is surface milled or ground to remove the oxide scale and surface defects, resulting in a semi-finished plate / rod with a smooth surface and regular dimensions.

[0013] As a preferred, during the final machining and heat treatment of the target material, the following steps are included: S71: According to the customer's drawing requirements, the semi-finished plate is cut into a specified shape of the target blank using a slow wire spark discharge cutting machine, leaving a 0.5mm machining allowance on one side; S72: The target blank is clamped on a numerical control vertical machining center, and diamond or carbide tools are used to mill, turn, etc. to process it to the final required accurate size and shape and position tolerance; S73: The machined target is placed in a high-vacuum annealing furnace, vacuumed to 1× Pa, heated to 1000°C at a rate of 8°C / min, and held for 3 hours. Then it is slowly cooled to below 500°C at a rate not exceeding 5°C / min, and then cooled in the furnace; S74: The sputtering surface of the target is mechanically polished using diamond polishing paste of different mesh sizes in sequence, and finally polished with a cloth and silica polishing liquid to achieve a mirror finish; S75: The polished target is placed in acetone, anhydrous ethanol, and deionized water in sequence, and subjected to ultrasonic cleaning for 15 minutes each. After cleaning, it is immediately moved into a vacuum drying oven and dried at 80°C for 2 hours; S76: The key dimensions of the target are re-measured using a three-coordinate measuring instrument, the sputtering surface roughness is detected using a white light interferometer, and the conductivity uniformity is spot-checked using an eddy current conductivity meter; S77: Sandblast the non-sputtering surface of the target to enhance the welding bond with the backing plate, and use a laser marking machine to engrave the product batch number, material composition and production date markings on the non-working area of ​​the target.

[0014] As a preferred approach, the following steps are included when conducting full-process quality inspection and data analysis: S81: Inductively coupled plasma mass spectrometry and an oxygen, nitrogen, and hydrogen analyzer are used to sample the finished target material and accurately determine the elemental content of Mo, Nb, Ti, Al, or Y / La, as well as the content of oxygen, nitrogen, and carbon impurities; S82: Metallographic samples are cut along the longitudinal and transverse directions of the target material, and after mounting, polishing, and etching, their microstructure is observed under a metallographic microscope and a scanning electron microscope to evaluate the grain size, second phase distribution, and porosity; S83: Using the Archimedes displacement method, the bulk density of the target material is measured on an analytical balance with an accuracy of 0.0001g. The relative density relative to the theoretical density is calculated. Combined with image analysis software, the porosity in the metallographic images is quantitatively analyzed. S84: On a universal testing machine, standard tensile specimens cut from a target are subjected to room temperature tensile tests to obtain tensile strength, yield strength, and elongation data. Vickers hardness is tested in different regions using a microhardness tester. S85: X-ray diffraction was used to perform phase analysis and macroscopic texture determination on the sputtered surface of the target material, and X-ray stress analyzer was used to measure the magnitude and distribution of residual stress on the target material surface; S86: Mount the target sample on a small magnetron sputtering stage in the laboratory, perform short-time sputtering under standard process parameters, and observe the compactness and surface morphology of the deposited film using scanning electron microscopy to evaluate the sputtering stability of the target. S87: Input the original data, spectra and analysis reports of all the above-mentioned test items, along with the key process parameters in the production process, into the database to generate a unique quality file for this batch of target materials.

[0015] Preferably, the following steps are included in the cleaning, packaging, storage, and transportation: S91: All qualified target materials that pass the inspection are transferred to the ISO Class 5 cleanroom via a material transfer chamber for subsequent operations; S92: In a cleanroom, the surface of the target material is purged with filtered, dry nitrogen gas, followed by a thorough purging of the target material with an ionization air gun to eliminate any static electricity and fine dust that may have accumulated on the surface; S93: Under cleanroom lighting and wearing clean gloves, the operator performs a 360-degree visual inspection of the sputtered surface of the target material to confirm that there are no scratches, dents, or stains, and uses a portable surface cleanliness monitor to scan key areas; S94: Place the target material into a transparent vacuum packaging bag made of multi-layer composite material, use a special vacuum sealing machine to extract the air from the bag and heat seal it to form the first seal protection; S95: Place sufficient blue silica gel indicator desiccant into the vacuum bag after the first sealing, then fill the bag with high-purity argon gas until it is slightly bulging, and then seal the opening again; S96: Based on the target shape, use a CNC cutting machine to process high-density antistatic polyethylene foam to create a perfectly fitting liner. Place an argon-filled vacuum bag into the cavity of the foam liner. S97: Place the foam padding containing the target material into a dedicated high-strength plastic transport box or aluminum box, and place a temperature and humidity recording card inside the box.

[0016] The beneficial effects of this invention are: 1. Existing low-oxygen molybdenum-niobium alloy targets and their preparation methods have relatively simple and limited deoxidation mechanisms, typically relying solely on the reduction reaction between micron-sized carbon powder and oxygen in the alloy. Limited by the particle size and dispersion uniformity of the carbon powder, it is difficult to achieve deep and thorough removal of oxygen impurities. Conventional carbon powders have insufficient reactivity and contact efficiency during sintering, easily leading to incomplete deoxidation. Ultimately, a significant amount of oxygen remains inside the target material. Oxygen impurities not only form brittle oxide inclusions with alloying elements, affecting the material's toughness, but also cause particle splashing during subsequent sputtering due to gas release, severely reducing the uniformity and performance of the thin film. Consistency: This solution replaces traditional carbon black with high specific surface area and activity carbon nanotubes, and combines them with the addition of strong deoxidizing elements titanium and aluminum. During sintering, a multi-level and synergistic reduction environment is formed. Carbon nanotubes can provide abundant reaction sites and preferentially react with the oxide layer on the surface of niobium powder, while titanium and aluminum further combine with oxygen dissolved in the matrix to form stable compounds. This significantly improves the removal depth of oxygen impurities and the overall deoxidation efficiency, and can reduce the overall oxygen content of the target material to a lower level. This effectively reduces the precipitation of brittle phases and impurities caused by oxygen, thereby improving the mechanical properties of the target material. 2. Existing low-oxygen molybdenum-niobium alloy targets and their preparation methods suffer from insufficient densification and microstructure control. They primarily focus on increasing density through high-temperature sintering, but lack precise control over grain growth, pore migration, and closure during sintering. This often results in increased overall target density but internal issues such as localized pore clusters or uneven grain size, directly leading to increased etching rate differences in different areas during sputtering, decreased discharge stability, and consequently affecting the repeatability of the coating process and the reliability of the film quality. This solution addresses these issues at the raw material stage… By using hydrogenation deoxidation to activate niobium powder, nano-slurry encapsulation, and titanium-aluminum pre-alloying, the physicochemical state of the raw materials is optimized in advance. During the sintering stage, a multi-stage precise temperature and atmosphere control program is designed, including low-temperature degassing, medium-temperature reduction, high-temperature liquid phase assistance, and final solid solution densification. In particular, the introduction of a controllable instantaneous liquid phase in the critical temperature range effectively promotes material migration and effective pore filling. This enables active control of grain growth kinetics and densification process during sintering, thereby obtaining an ideal microstructure with fine and uniform grains, extremely low porosity, and diffuse distribution. Attached Figure Description

[0017] Figure 1 The diagram shown is a schematic flowchart of a method for preparing a low-oxygen molybdenum-niobium alloy target according to the present invention. Figure 2 The diagram shown is a schematic of the raw material fine pretreatment process for a low-oxygen molybdenum-niobium alloy target preparation method according to the present invention. Figure 3 The diagram shows a multi-scale powder precision mixing and homogenization process of a low-oxygen molybdenum-niobium alloy target preparation method according to the present invention. Figure 4 The diagram shown is a near-net-shape forming process of a high-density billet in a low-oxygen molybdenum-niobium alloy target preparation method according to the present invention. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Please see Figures 1-4 The present invention provides an embodiment of a low-oxygen molybdenum-niobium alloy target material, comprising the following components measured by weight percentage: 70% to 85% molybdenum powder, 10% to 20% niobium powder, 0.05% to 0.15% carbon nanotubes, 0.5% to 2.0% rare earth oxides, 2% to 5% titanium powder, and the balance being aluminum powder, wherein the sum of the mass percentages of the above components is 100%.

[0020] A method for preparing a low-oxygen molybdenum-niobium alloy target includes the following steps: S11: Specialized treatments are applied to molybdenum powder, niobium powder, carbon nanotubes, rare earth oxides, titanium powder, and aluminum powder, including reduction, hydrogenation deoxidation, dispersion, drying, and passivation layer removal. S12: A graded mixing strategy is adopted. First, niobium powder is coated with nano-slurry, then it is dry-mixed and wet-milled with titanium-aluminum pre-alloyed powder and some molybdenum powder, and finally it is mixed with the remaining molybdenum powder in a long-term three-dimensional oscillating mixing process. S13: Combining bidirectional molding and cold isostatic pressing technologies, green bodies are formed under precisely controlled pressure and holding pressure procedures, followed by preheating treatment to remove organic matter and enhance the strength of the green body; S14: Through a precise temperature and atmosphere control process of "low-temperature vacuum degassing - medium-temperature hydrogen reduction - high-vacuum high-temperature sintering - liquid-phase assistance - high-temperature solid solution", deep deoxidation, porosity elimination and complete densification of the alloy are achieved; S15: The sintered billet undergoes surface cleaning and non-destructive testing, and hot isostatic pressing (HIP) is performed as needed. It is then encapsulated in a vacuum-sealed package and subjected to high-temperature forging and hot rolling to initially obtain the required plate / bar shape. S16: The semi-finished product is precision machined to its final dimensions using wire cutting and CNC machine tools, followed by vacuum annealing to relieve stress, and the sputtered surface is precision polished to a mirror finish, while the non-sputtered surface is sandblasted. S17: Comprehensively characterize the finished product by using methods such as chemical composition analysis, metallographic observation, density measurement, mechanical property testing, texture analysis, or sputtering simulation, and establish a complete traceable quality file; S18: After final cleaning and inspection in a Class 100 cleanroom, the target material is vacuum-packed with argon, placed in a custom antistatic foam liner, then packed into a special protective transport box, labeled, and stored in a constant temperature and humidity environment.

[0021] Preferably, the refined pretreatment of raw materials includes the following steps: S21: Place molybdenum powder with a Fisher particle size of 1.5~3.0μm and a purity ≥3N8 in a tubular reduction furnace, introduce dry hydrogen gas with a dew point below -60℃, heat to 800℃ at a rate of 5℃ / min, hold at that temperature for 2 hours, then cool with the furnace to below 150℃, switch to argon protection to cool to room temperature, remove and immediately transfer to an argon-filled glove box for later use; S22: Niobium powder with an oxygen content ≤1000ppm is loaded into a vacuum reactor and evacuated to 5× After Pa, high-purity hydrogen gas is introduced to a pressure of 0.1 MPa, and the temperature is raised to 500°C at a rate of 3°C / min and held for 4 hours to fully hydrogenate the niobium powder; S23: Transfer the hydrogenated niobium powder to a vacuum dehydrogenation furnace and evacuate to 1× Pa was heated to 650℃ at a rate of 2℃ / min and held for 6 hours to remove hydrogen. The dehydrogenated niobium powder was then placed in a high-energy planetary ball mill and ball-milled at 300 rpm for 2 hours under argon protection. The powder was then passed through a 400-mesh sieve to obtain active niobium powder with uniform particle size distribution. S24: Multi-walled carbon nanotubes were placed in an anhydrous ethanol solution containing 1 wt% polyvinylpyrrolidone and ultrasonically dispersed for 1 hour using an ultrasonic cell disruptor at a power of 600W to form a stable suspension; S25: Nanoparticles or The powder was placed in a vacuum drying oven at 120℃ and 1× Drying under Pa conditions for 12 hours completely removes physically adsorbed water; S26: Immerse titanium powder and aluminum powder separately in dilute hydrofluoric acid for 30 seconds, rinse quickly with deionized water until neutral, then wash three times with anhydrous ethanol, and finally dry in a vacuum oven at 80℃ for 2 hours; S27: Place all pretreated raw material powders into sealed containers filled with high-purity argon gas, label them with the composition and pretreatment date, and set them aside for use.

[0022] Preferably, the process of precision mixing and homogenization of multi-scale powders includes the following steps: S31: In an argon-filled glove box, the dispersed carbon nanotube suspension is mixed with a metered amount of anhydrous ethanol, and stirred at 500 rpm using a mechanical stirrer. At the same time, the dried rare earth oxide nanoparticles are slowly added, and the mixture is stirred continuously for 1 hour to form a uniform slurry. S32: Pour the pretreated active niobium powder into a high-speed shear mixer. Under an argon atmosphere, while shearing and stirring at 2000 rpm, use a spraying device to evenly spray the above nano-slurry onto the niobium powder. Continue the operation for 40 minutes to coat the niobium powder surface with nanomaterials. S33: Weigh titanium powder and aluminum powder according to the ratio, place them in a three-dimensional mixer, mix for 4 hours under argon protection, load the mixed powder into a graphite mold, heat to 800℃ at 10℃ / min in a vacuum hot press furnace, apply a pressure of 20MPa, hold for 30 minutes, cool with the furnace, crush and sieve to obtain pre-alloyed powder; S34: Niobium powder coated with nanomaterials, titanium-aluminum pre-alloyed powder, and two-thirds of the total amount of pretreated molybdenum powder are poured into a V-type mixer and continuously mixed at a speed of 15 rpm for 12 hours under argon protection; S35: Transfer the above dry-mixed powder to a planetary ball mill jar, add an appropriate amount of anhydrous ethanol as a process control agent, the ball-to-powder ratio is 2:1, and ball mill at 150 rpm for 8 hours under argon protection; S36: Pour the ball-milled slurry into a vacuum filter to separate the solvent. Place the resulting wet filter cake in a vacuum drying oven and dry it at 80℃ and -0.095MPa for 6 hours. Gently crush the dried agglomerates and pass them through a 200-mesh vibrating sieve. S37: The sieved powder and the remaining one-third of the molybdenum powder are put into a large three-dimensional oscillating mixer and mixed for 24 hours in a three-dimensional spatial motion mode under argon protection to obtain a final mixed powder with highly uniform chemical composition and particle size distribution.

[0023] Preferably, the near-net-shape forming of a high-density preform includes the following steps: S41: Use a high-strength hard alloy female mold, uniformly spray boron nitride release agent onto the inner wall of the mold cavity and dry it, then pour the final mixed powder into the mold cavity in three batches, and use a powder leveler to smooth it after each pour; S42: Place the mold containing powder on a servo electric press, pre-press it with 10MPa pressure for 30 seconds to initially position the powder, and then perform bidirectional synchronous pressing. The upper and lower punches move towards each other at a constant speed of 1mm / min. The pressure eventually stabilizes at 300MPa and is held for 5 minutes. S43: Carefully remove the molded green preform from the mold, vacuum seal it with a flexible rubber sleeve, place the sealed green preform into a cold isostatic pressing cylinder, use water as the pressure transmission medium, uniformly increase the pressure to 400MPa within 5 minutes, hold the pressure for 30 minutes, and then slowly release the pressure; S44: Use a high-precision digital caliper to measure the diameter and thickness of the green billet after CIP, record the data, weigh the green billet using an analytical balance, and calculate its density. The green billet density should reach more than 65% of the theoretical density. S45: Under strong side-spot lighting, visually inspect the surface of the green billet for cracks, delamination, or obvious uneven areas. Use an industrial endoscope to randomly inspect the sidewalls of the green billet to check for macroscopic defects inside. S46: Place the inspected and qualified green billets into a tube furnace filled with an argon-4% hydrogen mixture, and slowly heat them to 600°C at a rate of 1°C / min, holding them at that temperature for 2 hours to remove any remaining trace amounts of organic matter and moisture, and to impart a certain strength to the green billets; S47: Cool the preheated billet to room temperature in an argon atmosphere, check its surface condition again, and place a molybdenum-niobium alloy pad of the same material flat on its bottom.

[0024] Preferably, the multi-stage controlled sintering process includes the following steps: S51: Place the prepared green billet along with the backing plate into the constant temperature zone of the high-temperature vacuum sintering furnace, close the furnace door, and start the mechanical pump and Roots pump to evacuate the vacuum level in the furnace to 5× The pressure was set at Pa, and the system was statically maintained under this vacuum for 1 hour to detect the leakage rate. S52: Increase the furnace temperature from room temperature to 800°C at a rate of 3°C / min, while maintaining a vacuum level of not less than 5× throughout the heating process. Pa, kept at 800℃ for 1 hour to fully remove the gas adsorbed on the surface of the powder particles; S53: High-purity hydrogen gas is introduced into the furnace, the pressure is adjusted to +5 kPa, and the temperature is increased to 1300℃ at a rate of 5℃ / min. The temperature is then maintained at this temperature for 4 hours. During this stage, carbon nanotubes, titanium, aluminum and oxygen in the powder undergo a reduction reaction. S54: Turn off the hydrogen gas, restart the vacuum system, quickly switch the furnace atmosphere back to high vacuum, and raise the temperature from 1300℃ to 1850℃ at a rate of 8℃ / minute; S55: Hold at 1850℃ for 2 hours. During this time, the addition of aluminum may generate a small amount of transient liquid phase, which promotes material transport and pore filling. After holding, continue to heat at a rate of 10℃ / min to the final sintering temperature of 2050℃. S56: Hold at the target temperature of 2050℃ for 8 hours. During the holding period, the vacuum level must be maintained at 5× Pa or better; S57: After the heat preservation is completed, stop heating and start the program to control cooling. In the range of 2050℃ to 1500℃, control the cooling rate to not exceed 5℃ / minute; in the range of 1500℃ to 800℃, the cooling rate to not exceed 10℃ / minute; below 800℃, it can be naturally cooled with the furnace, and high vacuum is maintained throughout the process.

[0025] Preferably, the post-processing and finishing of the sintered billet includes the following steps: S61: When the furnace temperature cools down to below 80°C, backfill the furnace with high-purity argon gas to atmospheric pressure, open the furnace door and take out the sintered billet. Use a silicon carbide grinding wheel to remove the adhesion layer or oxide color that may have formed on the surface of the sintered billet due to contact with the pad plate. S62: Perform ultrasonic testing on the cleaned sintered billet to check for unsintered pores or cracks. Take samples to test its density, oxygen content, and microhardness to assess whether the sintering meets the standards. S63: For targets requiring ultra-high density, the sintered billet is placed in a low-carbon steel sleeve, vacuumed and welded, and then placed in a hot isostatic pressing (HIP) equipment. In an argon medium, the temperature is raised to 1350°C at a rate of 10°C / min, while an isostatic pressure of 150 MPa is applied, and the temperature and pressure are maintained for 4 hours. S64: For billets requiring subsequent forging or rolling, a sealed sheath made of stainless steel plate is used. The sintered billet is placed in the sheath and vacuumed to 1× After Pa, the extraction pipe is sealed using argon arc welding; S65: Place the packaged blank into a resistance heating furnace, heat it to 1250℃ under argon protection and hold it at that temperature for 2 hours to ensure uniform and thorough heating. Then quickly transfer it to a high-speed forging mill and perform multiple upsetting and drawing along the axial direction, with a total forging ratio ≥3. S66: The forged slab is reheated to 1150℃ and rolled in multiple passes on a four-high reversible hot rolling mill. The deformation in each pass is controlled at 15%-20%, and finally rolled into a plate of the required thickness. S67: The outer stainless steel sheath is completely removed by machining. The exposed alloy sheet is then milled or ground to remove oxide scale and surface defects, resulting in a smooth, dimensionally regular semi-finished sheet / bar.

[0026] Preferably, the finishing and heat treatment of the target material includes the following steps: S71: According to the customer's drawings, use a slow wire EDM machine to cut the semi-finished sheet into target blanks of the specified shape, leaving a finishing allowance of 0.5mm on each side; S72: The target blank is clamped on a CNC vertical machining center, and machined to the final required precise dimensions and geometric tolerances through milling, turning and other processes using diamond or carbide tools; S73: Place the finished target material into a high-vacuum annealing furnace and evacuate to 1× Pa, heated to 1000℃ at 8℃ / min, held at that temperature for 3 hours, then slowly cooled to below 500℃ at a rate not exceeding 5℃ / min, and subsequently cooled in the furnace; S74: The sputtering surface of the target material is mechanically polished using diamond polishing paste of different mesh sizes in sequence, and finally fine polished with a cloth and silica polishing liquid to achieve a mirror finish on the sputtering surface; S75: After polishing, the target material is placed in acetone, anhydrous ethanol, and deionized water in sequence for ultrasonic cleaning for 15 minutes each. After cleaning, it is immediately transferred to a vacuum drying oven and dried at 80°C for 2 hours. S76: Use a coordinate measuring machine to remeasure the key dimensions of the target material, use a white light interferometer to detect the surface roughness of the sputtered surface, and use an eddy current conductivity meter to check the uniformity of conductivity. S77: Sandblast the non-sputtering surface of the target to enhance the welding bond with the backing plate, and use a laser marking machine to engrave the product batch number, material composition and production date markings on the non-working area of ​​the target.

[0027] As a preferred approach, the following steps are included when conducting full-process quality inspection and data analysis: S81: Inductively coupled plasma mass spectrometry and an oxygen, nitrogen, and hydrogen analyzer are used to sample the finished target material and accurately determine the elemental content of Mo, Nb, Ti, Al, or Y / La, as well as the content of oxygen, nitrogen, and carbon impurities; S82: Metallographic samples are cut along the longitudinal and transverse directions of the target material, and after mounting, polishing, and etching, their microstructure is observed under a metallographic microscope and a scanning electron microscope to evaluate the grain size, second phase distribution, and porosity; S83: Using the Archimedes displacement method, the bulk density of the target material is measured on an analytical balance with an accuracy of 0.0001g. The relative density relative to the theoretical density is calculated. Combined with image analysis software, the porosity in the metallographic images is quantitatively analyzed. S84: On a universal testing machine, standard tensile specimens cut from a target are subjected to room temperature tensile tests to obtain tensile strength, yield strength, and elongation data. Vickers hardness is tested in different regions using a microhardness tester. S85: X-ray diffraction was used to perform phase analysis and macroscopic texture determination on the sputtered surface of the target material, and X-ray stress analyzer was used to measure the magnitude and distribution of residual stress on the target material surface; S86: Mount the target sample on a small magnetron sputtering stage in the laboratory, perform short-time sputtering under standard process parameters, and observe the compactness and surface morphology of the deposited film using scanning electron microscopy to evaluate the sputtering stability of the target. S87: Input the original data, spectra and analysis reports of all the above-mentioned test items, along with the key process parameters in the production process, into the database to generate a unique quality file for this batch of target materials.

[0028] Preferably, the following steps are included in the cleaning, packaging, storage, and transportation: S91: All qualified target materials that pass the inspection are transferred to the ISO Class 5 cleanroom via a material transfer chamber for subsequent operations; S92: In a cleanroom, the surface of the target material is purged with filtered, dry nitrogen gas, followed by a thorough purging of the target material with an ionization air gun to eliminate any static electricity and fine dust that may have accumulated on the surface; S93: Under cleanroom lighting and wearing clean gloves, the operator performs a 360-degree visual inspection of the sputtered surface of the target material to confirm that there are no scratches, dents, or stains, and uses a portable surface cleanliness monitor to scan key areas; S94: Place the target material into a transparent vacuum packaging bag made of multi-layer composite material, use a special vacuum sealing machine to extract the air from the bag and heat seal it to form the first seal protection; S95: Place sufficient blue silica gel indicator desiccant into the vacuum bag after the first sealing, then fill the bag with high-purity argon gas until it is slightly bulging, and then seal the opening again; S96: Based on the target shape, use a CNC cutting machine to process high-density antistatic polyethylene foam to create a perfectly fitting liner. Place an argon-filled vacuum bag into the cavity of the foam liner. S97: Place the foam padding containing the target material into a dedicated high-strength plastic transport box or aluminum box, and place a temperature and humidity recording card inside the box.

[0029] Example 1 This embodiment demonstrates the specific application of the above-described low-oxygen molybdenum-niobium alloy target preparation scheme. Following the method described, a molybdenum-niobium alloy target with a niobium content of 15% is prepared. First, each component raw material is accurately weighed, wherein molybdenum powder accounts for 78.85%, niobium powder accounts for 15%, carbon nanotubes account for 0.1%, rare earth yttrium oxide accounts for 1.5%, titanium powder accounts for 4%, and aluminum powder accounts for the remainder, ensuring that the sum of the mass percentages of each component is one hundred.

[0030] High-purity molybdenum powder with a Fisher particle size of approximately 2.5 micrometers was placed in a tubular reduction furnace for hydrogen reduction treatment to remove the surface oxide layer and activate the powder. Niobium powder with an oxygen content of approximately 800 ppm underwent hydrogenation-dehydrogenation cycle treatment, followed by high-energy ball milling and sieving to obtain highly active niobium powder with uniform particle size. Carbon nanotubes were ultrasonically dispersed in ethanol containing a dispersant to form a stable suspension. Nano-yttrium oxide powder was subjected to long-term vacuum drying to completely remove water. Titanium powder and aluminum powder were soaked and washed with dilute acid to remove the surface passivation layer and then dried. All pretreated powders were transferred to an argon-filled environment for storage and future use.

[0031] In the powder mixing and homogenization stage, under an inert atmosphere, the well-dispersed carbon nanotube suspension is mixed and stirred with dry nano-yttrium oxide powder to prepare a uniform nano-slurry. The slurry is then sprayed onto the surface of active niobium powder using a high-speed shear mixing device. Meanwhile, titanium powder and aluminum powder are three-dimensionally mixed and then vacuum hot-pressed for pre-alloying treatment, followed by crushing into pre-alloyed powder. The niobium powder and titanium-aluminum pre-alloyed powder coated with nanomaterials are then dry-mixed with most of the pre-treated molybdenum powder for an extended period of time. Subsequently, the mixture is transferred to a planetary ball mill jar, where a process control agent is added for wet ball milling to further refine and homogenize the powder. The ball-milled slurry is then vacuum-filtered, dried, and sieved before being finally mixed with the remaining molybdenum powder in a large three-dimensional oscillating mixer to obtain a composite powder with extremely uniform composition and particle size distribution.

[0032] Next comes the blank forming process. The final mixed powder is filled into a cemented carbide mold coated with a release agent and subjected to bidirectional synchronous molding using a servo electric press to obtain the initial green blank. This green blank is then encapsulated in a flexible material and subjected to cold isostatic pressing to eliminate density gradients and further increase the green blank density. The dimensions and weight of the formed blank are measured, the green blank density is calculated, and its surface and internal quality are inspected visually and endoscopically. Qualified green blanks are then subjected to low-temperature preheating treatment in a weakly reducing atmosphere to remove residual organic matter and enhance the strength of the blank. After treatment, the blank is cooled and placed on a special pad for sintering.

[0033] Sintering is the core densification and deoxidation process. The green blank is placed in a high-temperature vacuum sintering furnace. First, a high vacuum extraction and leak detection are performed. Then, the temperature program is started, and a high vacuum is maintained in the low-temperature stage to fully remove the gas adsorbed on the powder surface. After entering the intermediate temperature stage, the atmosphere is switched to a slightly positive pressure hydrogen atmosphere. In this environment, carbon nanotubes, titanium, aluminum and other materials undergo a full reduction reaction with oxygen in the raw materials to achieve deep deoxidation. Then, the temperature is switched back to high vacuum and the temperature continues to rise. The temperature is held in a specific high-temperature range, and the instantaneous liquid phase generated by aluminum promotes material migration and pore filling. Finally, the temperature is raised to the highest sintering temperature and held for a long time to achieve complete solid solution and densification of the alloy. The entire heating and high-temperature holding process maintains an extremely high vacuum. After sintering, a strictly controlled programmed cooling system is implemented to ensure the material's microstructure and properties.

[0034] The post-processing steps for the sintered billet then proceed. After the furnace temperature cools, the sintered billet is removed, its surface is cleaned, and ultrasonic flaw detection and sampling are performed to evaluate its density, oxygen content, and basic properties. To meet the ultra-high density requirements, the sintered billet underwent hot isostatic pressing (HIP) strengthening treatment in this case. It was encapsulated in a low-carbon steel sheath and treated in a high-temperature, high-pressure argon atmosphere to eliminate any residual micro-closed pores. For billets requiring further hot working, they were encapsulated in a vacuum-sealed stainless steel sheath. After heating the sheathed billet, it was subjected to multi-directional forging on a high-speed forging mill to break up the as-cast structure and optimize the grain structure. The forged slab was then hot-rolled multiple times to form a plate of the required thickness. Finally, the outer sheath was removed by machining, and the surface of the alloy plate was preliminarily cleaned to obtain a semi-finished product.

[0035] After obtaining the semi-finished product, the target material enters the precision machining stage. According to the final drawing dimensions required by the customer, the plate is cut into target blanks using a slow wire EDM machine, leaving a precision machining allowance. On a CNC machining center, the blanks are milled and turned using superhard tools to precisely machine to all final dimensions and geometric tolerances. The precision-machined target material is placed in a high-vacuum annealing furnace for stress-relief annealing to eliminate the internal stress introduced by machining and prevent subsequent deformation. After annealing, the sputtering working surface of the target material undergoes a series of mechanical polishing and final fine polishing to achieve a mirror finish. The non-sputtering surface is sandblasted to increase the surface area and improve the welding bond with the backing plate. The finished target material undergoes rigorous ultrasonic cleaning and vacuum drying to ensure absolute surface cleanliness.

[0036] Finished sputtering targets undergo comprehensive quality testing. Samples are taken for chemical composition analysis to accurately determine the content of major elements and impurities such as oxygen, nitrogen, and carbon. Metallographic samples are prepared and observed under optical and scanning electron microscopes to analyze grain size, second-phase distribution, and micropore structure. The Archimedes displacement method is used to accurately measure the bulk density and calculate the relative density. Standard tensile specimens are processed for room temperature mechanical property testing, and Vickers hardness is measured at multiple points. X-ray diffraction is used to analyze the phase composition and macroscopic texture of the sputtering surface and measure surface residual stress. Finally, short-time sputtering tests are conducted in a simulated sputtering environment to observe the morphology of the deposited film and evaluate the sputtering stability of the target. All test data and analysis reports are entered into a database to form a complete and traceable quality archive.

[0037] All qualified targets eventually enter the packaging process. In a Class 100 cleanroom environment, the targets are purged with filtered dry gas and an ion gun to remove dust and static electricity. The sputtering surface is visually inspected from all angles under cleanroom lighting, and surface cleanliness is checked by instruments. The targets are then placed in vacuum-sealed bags made of multi-layer composite materials, vacuumed, and heat-sealed. After placing an indicator desiccant inside the bag, high-purity argon gas is introduced and the bag is sealed a second time. Based on the shape of the targets, a perfectly fitting shock-resistant and anti-static foam liner is made using a CNC cutting machine. The vacuum-packed targets are then embedded in the foam liner. Finally, the targets with the liner are placed in a dedicated high-strength protective transport box. A temperature and humidity recording card is placed inside the box, and a label containing product information is affixed to the outside. The boxes are then stored in a temperature- and humidity-controlled warehouse, awaiting shipment.

[0038] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A low-oxygen molybdenum-niobium alloy target; characterized in that: It includes the following components by weight percentage: 70% to 85% molybdenum powder, 10% to 20% niobium powder, 0.05% to 0.15% carbon nanotubes, 0.5% to 2.0% rare earth oxides, 2% to 5% titanium powder, and the balance being aluminum powder. The sum of the mass percentages of the above components is 100%.

2. The low-oxygen molybdenum-niobium alloy target material according to claim 1, characterized in that: A method for preparing a low-oxygen molybdenum-niobium alloy target includes the following steps: S11: Specialized treatments are applied to molybdenum powder, niobium powder, carbon nanotubes, rare earth oxides, titanium powder, and aluminum powder, including reduction, hydrogenation deoxidation, dispersion, drying, and passivation layer removal. S12: A graded mixing strategy is adopted. First, niobium powder is coated with nano-slurry, then it is dry-mixed and wet-milled with titanium-aluminum pre-alloyed powder and some molybdenum powder, and finally it is mixed with the remaining molybdenum powder in a long-term three-dimensional oscillating mixing process. S13: Combining bidirectional molding and cold isostatic pressing technologies, green bodies are formed under precisely controlled pressure and holding pressure procedures, followed by preheating treatment to remove organic matter and enhance the strength of the green body; S14: Through a precise temperature and atmosphere control process of "low-temperature vacuum degassing - medium-temperature hydrogen reduction - high-vacuum high-temperature sintering - liquid-phase assistance - high-temperature solid solution", deep deoxidation, porosity elimination and complete densification of the alloy are achieved; S15: The sintered billet undergoes surface cleaning and non-destructive testing, and hot isostatic pressing (HIP) is performed as needed. It is then encapsulated in a vacuum-sealed package and subjected to high-temperature forging and hot rolling to initially obtain the required plate / bar shape. S16: The semi-finished product is precision machined to its final dimensions using wire cutting and CNC machine tools, followed by vacuum annealing to relieve stress, and the sputtered surface is precision polished to a mirror finish, while the non-sputtered surface is sandblasted. S17: Comprehensively characterize the finished product by using methods such as chemical composition analysis, metallographic observation, density measurement, mechanical property testing, texture analysis, or sputtering simulation, and establish a complete traceable quality file; S18: After final cleaning and inspection in a Class 100 cleanroom, the target material is vacuum-packed with argon, placed in a custom antistatic foam liner, then packed into a special protective transport box, labeled, and stored in a constant temperature and humidity environment.

3. The method for preparing a low-oxygen molybdenum-niobium alloy target according to claim 2, characterized in that: The following steps are included in the fine pretreatment of raw materials: S21: Place molybdenum powder with a Fisher particle size of 1.5~3.0μm and a purity ≥3N8 in a tubular reduction furnace, introduce dry hydrogen gas with a dew point below -60℃, heat to 800℃ at a rate of 5℃ / min, hold at that temperature for 2 hours, then cool with the furnace to below 150℃, switch to argon protection to cool to room temperature, remove and immediately transfer to an argon-filled glove box for later use; S22: Niobium powder with an oxygen content ≤1000ppm is loaded into a vacuum reactor and evacuated to 5× After Pa, high-purity hydrogen gas is introduced to a pressure of 0.1 MPa, and the temperature is raised to 500°C at a rate of 3°C / min and held for 4 hours to fully hydrogenate the niobium powder; S23: Transfer the hydrogenated niobium powder to a vacuum dehydrogenation furnace and evacuate to 1× Pa was heated to 650℃ at a rate of 2℃ / min and held for 6 hours to remove hydrogen. The dehydrogenated niobium powder was then placed in a high-energy planetary ball mill and ball-milled at 300 rpm for 2 hours under argon protection. The powder was then passed through a 400-mesh sieve to obtain active niobium powder with uniform particle size distribution. S24: Multi-walled carbon nanotubes were placed in an anhydrous ethanol solution containing 1 wt% polyvinylpyrrolidone and ultrasonically dispersed for 1 hour using an ultrasonic cell disruptor at a power of 600W to form a stable suspension; S25: Nanoparticles or The powder was placed in a vacuum drying oven at 120℃ and 1× Drying under Pa conditions for 12 hours completely removes physically adsorbed water; S26: Immerse titanium powder and aluminum powder separately in dilute hydrofluoric acid for 30 seconds, rinse quickly with deionized water until neutral, then wash three times with anhydrous ethanol, and finally dry in a vacuum oven at 80℃ for 2 hours; S27: Place all pretreated raw material powders into sealed containers filled with high-purity argon gas, label them with the composition and pretreatment date, and set them aside for use.

4. The method for preparing a low-oxygen molybdenum-niobium alloy target according to claim 2, characterized in that: The process of precision mixing and homogenization of multi-scale powders includes the following steps: S31: In an argon-filled glove box, the dispersed carbon nanotube suspension is mixed with a metered amount of anhydrous ethanol, and stirred at 500 rpm using a mechanical stirrer. At the same time, the dried rare earth oxide nanoparticles are slowly added, and the mixture is stirred continuously for 1 hour to form a uniform slurry. S32: Pour the pretreated active niobium powder into a high-speed shear mixer. Under an argon atmosphere, while shearing and stirring at 2000 rpm, use a spraying device to evenly spray the above nano-slurry onto the niobium powder. Continue the operation for 40 minutes to coat the niobium powder surface with nanomaterials. S33: Weigh titanium powder and aluminum powder according to the ratio, place them in a three-dimensional mixer, mix for 4 hours under argon protection, load the mixed powder into a graphite mold, heat to 800℃ at 10℃ / min in a vacuum hot press furnace, apply a pressure of 20MPa, hold for 30 minutes, cool with the furnace, crush and sieve to obtain pre-alloyed powder; S34: Niobium powder coated with nanomaterials, titanium-aluminum pre-alloyed powder, and two-thirds of the total amount of pretreated molybdenum powder are poured into a V-type mixer and continuously mixed at a speed of 15 rpm for 12 hours under argon protection; S35: Transfer the above dry-mixed powder to a planetary ball mill jar, add an appropriate amount of anhydrous ethanol as a process control agent, the ball-to-powder ratio is 2:1, and ball mill at 150 rpm for 8 hours under argon protection; S36: Pour the ball-milled slurry into a vacuum filter to separate the solvent. Place the resulting wet filter cake in a vacuum drying oven and dry it at 80℃ and -0.095MPa for 6 hours. Gently crush the dried agglomerates and pass them through a 200-mesh vibrating sieve. S37: The sieved powder and the remaining one-third of the molybdenum powder are put into a large three-dimensional oscillating mixer and mixed for 24 hours in a three-dimensional spatial motion mode under argon protection to obtain a final mixed powder with highly uniform chemical composition and particle size distribution.

5. The method for preparing a low-oxygen molybdenum-niobium alloy target according to claim 2, characterized in that: The near-net-shape forming of high-density preforms includes the following steps: S41: Use a high-strength hard alloy female mold, uniformly spray boron nitride release agent onto the inner wall of the mold cavity and dry it, then pour the final mixed powder into the mold cavity in three batches, and use a powder leveler to smooth it after each pour; S42: Place the mold containing powder on a servo electric press, pre-press it with 10MPa pressure for 30 seconds to initially position the powder, and then perform bidirectional synchronous pressing. The upper and lower punches move towards each other at a constant speed of 1mm / min. The pressure eventually stabilizes at 300MPa and is held for 5 minutes. S43: Carefully remove the molded green preform from the mold, vacuum seal it with a flexible rubber sleeve, place the sealed green preform into a cold isostatic pressing cylinder, use water as the pressure transmission medium, uniformly increase the pressure to 400MPa within 5 minutes, hold the pressure for 30 minutes, and then slowly release the pressure; S44: Use a high-precision digital caliper to measure the diameter and thickness of the green billet after CIP, record the data, weigh the green billet using an analytical balance, and calculate its density. The green billet density should reach more than 65% of the theoretical density. S45: Under strong side-spot lighting, visually inspect the surface of the green billet for cracks, delamination, or obvious uneven areas. Use an industrial endoscope to randomly inspect the sidewalls of the green billet to check for macroscopic defects inside. S46: Place the inspected and qualified green billets into a tube furnace filled with an argon-4% hydrogen mixture, and slowly heat them to 600°C at a rate of 1°C / min, holding them at that temperature for 2 hours to remove any remaining trace amounts of organic matter and moisture, and to impart a certain strength to the green billets; S47: Cool the preheated billet to room temperature in an argon atmosphere, check its surface condition again, and place a molybdenum-niobium alloy pad of the same material flat on its bottom.

6. The method for preparing a low-oxygen molybdenum-niobium alloy target according to claim 2, characterized in that: The multi-stage controlled sintering process includes the following steps: S51: Place the prepared green billet along with the backing plate into the constant temperature zone of the high-temperature vacuum sintering furnace, close the furnace door, and start the mechanical pump and Roots pump to evacuate the vacuum level in the furnace to 5× The pressure was set at Pa, and the system was statically maintained under this vacuum for 1 hour to detect the leakage rate. S52: Increase the furnace temperature from room temperature to 800°C at a rate of 3°C / min, while maintaining a vacuum level of not less than 5× throughout the heating process. Pa, kept at 800℃ for 1 hour to fully remove the gas adsorbed on the surface of the powder particles; S53: High-purity hydrogen gas is introduced into the furnace, the pressure is adjusted to +5 kPa, and the temperature is increased to 1300℃ at a rate of 5℃ / min. The temperature is then maintained at this temperature for 4 hours. During this stage, carbon nanotubes, titanium, aluminum and oxygen in the powder undergo a reduction reaction. S54: Turn off the hydrogen gas, restart the vacuum system, quickly switch the furnace atmosphere back to high vacuum, and raise the temperature from 1300℃ to 1850℃ at a rate of 8℃ / minute; S55: Hold at 1850℃ for 2 hours. During this time, the addition of aluminum may generate a small amount of transient liquid phase, which promotes material transport and pore filling. After holding, continue to heat at a rate of 10℃ / min to the final sintering temperature of 2050℃. S56: Hold at the target temperature of 2050℃ for 8 hours. During the holding period, the vacuum level must be maintained at 5× Pa or better; S57: After the heat preservation is completed, stop heating and start the program to control cooling. In the range of 2050℃ to 1500℃, control the cooling rate to not exceed 5℃ / minute; in the range of 1500℃ to 800℃, the cooling rate to not exceed 10℃ / minute; below 800℃, it can be naturally cooled with the furnace, and high vacuum is maintained throughout the process.

7. The method for preparing a low-oxygen molybdenum-niobium alloy target according to claim 2, characterized in that: The post-processing and finishing of sintered billets includes the following steps: S61: When the furnace temperature cools down to below 80°C, backfill the furnace with high-purity argon gas to atmospheric pressure, open the furnace door and take out the sintered billet. Use a silicon carbide grinding wheel to remove the adhesion layer or oxide color that may have formed on the surface of the sintered billet due to contact with the pad plate. S62: Perform ultrasonic testing on the cleaned sintered billet to check for unsintered pores or cracks. Take samples to test its density, oxygen content, and microhardness to assess whether the sintering meets the standards. S63: For targets requiring ultra-high density, the sintered billet is placed in a low-carbon steel sleeve, vacuumed and welded, and then placed in a hot isostatic pressing (HIP) equipment. In an argon medium, the temperature is raised to 1350°C at a rate of 10°C / min, while an isostatic pressure of 150 MPa is applied, and the temperature and pressure are maintained for 4 hours. S64: For billets requiring subsequent forging or rolling, a sealed sheath made of stainless steel plate is used. The sintered billet is placed in the sheath and vacuumed to 1× After Pa, the extraction pipe is sealed using argon arc welding; S65: Place the packaged blank into a resistance heating furnace, heat it to 1250℃ under argon protection and hold it at that temperature for 2 hours to ensure uniform and thorough heating. Then quickly transfer it to a high-speed forging mill and perform multiple upsetting and drawing along the axial direction, with a total forging ratio ≥3. S66: The forged slab is reheated to 1150℃ and rolled in multiple passes on a four-high reversible hot rolling mill. The deformation in each pass is controlled at 15%-20%, and finally rolled into a plate of the required thickness. S67: The outer stainless steel sheath is completely removed by machining. The exposed alloy sheet is then milled or ground to remove oxide scale and surface defects, resulting in a smooth, dimensionally regular semi-finished sheet / bar.

8. The method for preparing a low-oxygen molybdenum-niobium alloy target according to claim 2, characterized in that: The finishing and heat treatment of the target material includes the following steps: S71: According to the customer's drawings, use a slow wire EDM machine to cut the semi-finished sheet into target blanks of the specified shape, leaving a finishing allowance of 0.5mm on each side; S72: The target blank is clamped on a CNC vertical machining center, and machined to the final required precise dimensions and geometric tolerances through milling, turning and other processes using diamond or carbide tools; S73: Place the finished target material into a high-vacuum annealing furnace and evacuate to 1× Pa, heated to 1000℃ at 8℃ / min, held at that temperature for 3 hours, then slowly cooled to below 500℃ at a rate not exceeding 5℃ / min, and subsequently cooled in the furnace; S74: The sputtering surface of the target material is mechanically polished using diamond polishing paste of different mesh sizes in sequence, and finally fine polished with a cloth and silica polishing liquid to achieve a mirror finish on the sputtering surface; S75: After polishing, the target material is placed in acetone, anhydrous ethanol, and deionized water in sequence for ultrasonic cleaning for 15 minutes each. After cleaning, it is immediately transferred to a vacuum drying oven and dried at 80°C for 2 hours. S76: Use a coordinate measuring machine to remeasure the key dimensions of the target material, use a white light interferometer to detect the surface roughness of the sputtered surface, and use an eddy current conductivity meter to check the uniformity of conductivity. S77: Sandblast the non-sputtering surface of the target to enhance the welding bond with the backing plate, and use a laser marking machine to engrave the product batch number, material composition and production date markings on the non-working area of ​​the target.

9. The method for preparing a low-oxygen molybdenum-niobium alloy target according to claim 2, characterized in that: The process of conducting full-process quality inspection and data analysis includes the following steps: S81: Inductively coupled plasma mass spectrometry and an oxygen, nitrogen, and hydrogen analyzer are used to sample the finished target material and accurately determine the elemental content of Mo, Nb, Ti, Al, or Y / La, as well as the content of oxygen, nitrogen, and carbon impurities; S82: Metallographic samples are cut along the longitudinal and transverse directions of the target material, and after mounting, polishing, and etching, their microstructure is observed under a metallographic microscope and a scanning electron microscope to evaluate the grain size, second phase distribution, and porosity; S83: The Archimedes displacement method is used to measure the bulk density of the target material on an analytical balance with an accuracy of 0.0001g, and the relative density relative to the theoretical density is calculated. With the help of image analysis software, the porosity in the metallographic images is quantitatively analyzed. S84: On a universal testing machine, standard tensile specimens cut from a target are subjected to room temperature tensile tests to obtain tensile strength, yield strength, and elongation data. Vickers hardness is tested in different regions using a microhardness tester. S85: X-ray diffraction was used to perform phase analysis and macroscopic texture determination on the sputtered surface of the target material, and X-ray stress analyzer was used to measure the magnitude and distribution of residual stress on the target material surface; S86: Mount the target sample on a small magnetron sputtering stage in the laboratory, perform short-time sputtering under standard process parameters, and observe the compactness and surface morphology of the deposited film using scanning electron microscopy to evaluate the sputtering stability of the target. S87: Input the original data, spectra and analysis reports of all the above-mentioned test items, along with the key process parameters in the production process, into the database to generate a unique quality file for this batch of target materials.

10. The method for preparing a low-oxygen molybdenum-niobium alloy target according to claim 2, characterized in that: The following steps are included when cleaning, packaging, storing, and transporting the goods: S91: All qualified target materials that pass the inspection are transferred to the ISO Class 5 cleanroom via a material transfer chamber for subsequent operations; S92: In a cleanroom, the surface of the target material is purged with filtered, dry nitrogen gas, followed by a thorough purging of the target material with an ionization air gun to eliminate any static electricity and fine dust that may have accumulated on the surface; S93: Under cleanroom lighting and wearing clean gloves, the operator performs a 360-degree visual inspection of the sputtered surface of the target material to confirm that there are no scratches, dents, or stains, and uses a portable surface cleanliness monitor to scan key areas; S94: Place the target material into a transparent vacuum packaging bag made of multi-layer composite material, use a special vacuum sealing machine to extract the air from the bag and heat seal it to form the first seal protection; S95: Place sufficient blue silica gel indicator desiccant into the vacuum bag after the first sealing, then fill the bag with high-purity argon gas until it is slightly bulging, and then seal the opening again; S96: Based on the target shape, use a CNC cutting machine to process high-density antistatic polyethylene foam to create a perfectly fitting liner. Place an argon-filled vacuum bag into the cavity of the foam liner. S97: Place the foam padding containing the target material into a dedicated high-strength plastic transport box or aluminum box, and place a temperature and humidity recording card inside the box.

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