Spinning preparation method of molybdenum-rhenium alloy pipe

Abstract

The invention relates to the technical field of molybdenum-rhenium alloy pipe spinning preparation, and discloses a molybdenum-rhenium alloy pipe spinning preparation method which comprises the following steps: preparing raw materials, selecting pure molybdenum powder and rhenium powder, weighing according to 10-30% of rhenium content, placing in a three-dimensional mixer, and vacuumizing and stirring to mix the powder; forming a blank, putting the mixed powder into a rubber mold, and performing cold isostatic pressing and pressure maintaining for 10-30 minutes to obtain the blank, wherein equipment has pressure feedback adjustment, the mold is coated with a high-temperature-resistant release agent, a double-layer structure is adopted, and inner-layer rubber and outer-layer metal are used for reinforcing; sintering treatment is conducted, the blank is placed in a vacuum sintering furnace, the temperature is increased to 1200-1500 DEG C, heat preservation is conducted for 1-3 hours, then heat preservation is conducted for 2-6 hours, a trace amount of hydrogen can be introduced in the later period, and the temperature in the furnace is monitored; and processing the pipe. The raw materials are high in purity and fine in granularity and are uniformly mixed; blank forming and sintering are accurate, and the quality is guaranteed; the pipe machining and spinning precision is high; the post-treatment optimizes the structure, cleans the surface, packages the alloy pipe, ensures the high performance of the alloy pipe, and meets the requirements of high-end fields.

Description

Technical Field

[0001] The invention relates to the technical field of spinning preparation of a molybdenum-rhenium alloy tube, in particular to a spinning preparation method for a molybdenum-rhenium alloy tube. Background Art

[0002] In many high-end fields of modern industry, such as aerospace, nuclear energy, electronics, etc., the demand for high-performance pipes is increasing day by day. Molybdenum-rhenium alloy pipes have become ideal materials for these demanding application scenarios due to the high melting point, high strength, good corrosion resistance of molybdenum, and the excellent improvement of rhenium on alloy toughness and high temperature performance.

[0003] However, the traditional preparation process of molybdenum-rhenium alloy tubes has many limitations and is difficult to meet the high standards of current industrial development. In the early stage of raw material mixing, simple mechanical stirring was mostly used. Due to the fine particle size and certain viscosity of molybdenum powder and rhenium powder, conventional stirring is not only inefficient, but also easily leads to powder agglomeration, resulting in uneven mixing of raw materials, which in turn causes problems such as uneven density and component segregation of the blanks in the subsequent forming process, seriously affecting the mechanical properties and chemical stability of the alloy tube.

[0004] In terms of blank forming, the traditional compression molding process applies uneven pressure and cannot ensure that all parts of the blank reach the ideal relative density. It is easy to have defects such as internal pores and cracks, and it is difficult to demold, which often causes damage to the blank and reduces the product qualification rate.

[0005] The sintering process is even more challenging. The heating rate of ordinary heating equipment is difficult to control accurately, and the temperature fluctuates greatly, which will cause uneven growth of alloy grains and unstable organizational structure of alloy tubes. When used under high temperature and high pressure conditions, deformation, cracking and other failure phenomena are prone to occur. At the same time, the sintering environment lacks effective atmosphere control, and oxidation of the billet cannot be avoided, which greatly reduces the purity and performance of the alloy tube.

[0006] For pipe processing, traditional turning processes have fast tool wear and low processing accuracy, making it difficult to achieve high-precision control of the inner and outer diameters of pipes, and unable to meet the strict requirements of pipe tolerances for precision components such as aircraft engine blade cooling channels and nuclear reactor fuel rod cladding.

[0007] In the spinning process, if there is a lack of precise control of the spinning parameters and real-time monitoring methods, it is easy to cause problems such as uneven wall thickness of the pipe and excessive ovality. In addition, the unreasonable heat distribution during the spinning process will aggravate the residual stress of the pipe and affect its service life.

[0008] In the post-processing process, the pickling is not thorough and there is a lack of effective surface cleaning methods, which results in residual impurities on the surface of the alloy tube, which not only affects the appearance, but also causes corrosion in subsequent use; the packaging is simple and cannot isolate external moisture and oxygen, which causes the alloy tube to oxidize and rust during storage and transportation, further reducing its performance. In summary, an innovative and fully optimized spinning preparation method for molybdenum-rhenium alloy tubes is urgently needed to overcome these difficulties and promote the high-quality development of related industries. Summary of the invention

[0009] 1. Technical issues to be resolved

[0010] In view of the deficiencies in the prior art, the present invention provides a method for spinning a molybdenum-rhenium alloy tube.

[0011] (II) Technical solution

[0012] A spinning preparation method for a molybdenum-rhenium alloy tube comprises the following steps: S1: raw material preparation: selecting molybdenum powder obtained by plasma atomization method, the particle size of which is normally distributed and concentrated in the range of 5-20 μm, and rhenium powder with a purity of not less than 99.9% obtained by electron beam melting and crushing treatment, the particle size of which is 3-15 μm, and weighing the powder according to the mass fraction of rhenium content of 10%-30%; placing the weighed powder in a three-dimensional mixer, the stirring blade inside the mixer is a double-layer spiral structure, the outer blade is responsible for quickly breaking up large agglomerates, and the inner blade is responsible for fine mixing, vacuuming to 0.05-0.2 Pa, and stirring at a speed of 200-600 rpm for 2-6 hours;

[0013] S2: Blank forming: The mixed powder is loaded into a rubber mold. The rubber mold is made of fluororubber and formed by cold isostatic pressing. The pressure is 200-400MPa and the holding time is 10-30 minutes. The pressure feedback adjustment system of the cold isostatic pressing equipment is composed of a high-precision pressure sensor and an intelligent controller. A release agent is applied to the surface of the mold. The release agent is a high-temperature resistant, volatile and residue-free silicone release agent. The thickness of the application is 0.05-0.1mm. The inner surface of the mold is evenly covered by atomization spraying to obtain a blank with a relative density of not less than 85%;

[0014] S3: Sintering treatment: put the blank into a vacuum sintering furnace. The heating element of the vacuum sintering furnace uses a graphite heating element. First, heat it to 1200-1500℃ at a heating rate of 8-18℃ / min and keep it warm for 1-3 hours. At this stage, use an infrared thermometer to monitor the surface temperature of the blank in real time, and control the deviation from the set temperature within ±2℃; then heat it to 1800-2200℃ at a heating rate of 4-10℃ / min and keep it warm for 2-6 hours. The vacuum degree is maintained at 0.005-0.02Pa during the whole sintering process, and then cool it with the furnace. The sintering furnace is equipped with a temperature monitoring system, and multiple thermocouples are distributed in different positions to monitor the sintering temperature in real time;

[0015] S4: Pipe processing: The sintered blank is turned. The turning tool is a carbide tool. The tool edge is treated with a micro-nano coating. The coating material is TiAlN. The cutting speed is 50-150m / min, the feed rate is 0.1-0.5mm / rev, and the machining allowance is 1-3mm. The blank is processed into a pipe with an outer diameter tolerance within ±0.2mm and an inner diameter tolerance within ±0.1mm. The turning process is cooled by cutting fluid. The cutting fluid is a water-based cutting fluid with good lubrication and cooling properties. The cutting fluid is sprayed into the cutting area through a high-pressure spray system;

[0016] S5: Spinning process: Use strong spinning or flow spinning to install the pipe fittings on the core mold of the spinning machine. The core mold is made of high-strength alloy steel and is nitrided to achieve a surface hardness of HV900-HV1200. The core mold speed is 200-600 rpm, the spinning wheel feed speed is 0.5-2mm / s, and the spinning thinning rate is 20%-60%. The pipe fittings are locally heated during the spinning process. The heating equipment is a high-frequency induction heating device with a heating temperature of 800-1200℃ and an induction heating frequency of 20-60kHz. The device is equipped with an intelligent power regulator to adjust the power in real time according to the material and size of the pipe fittings. The spinning equipment is equipped with a force sensor to monitor the spinning pressure in real time.

[0017] S6: Post-processing process: The molybdenum-rhenium alloy tube after spinning is annealed. The annealing furnace is a vacuum annealing furnace. Graphite felt is used as insulation material in the furnace. The annealing temperature is 1000-1500°C and the insulation time is 1-3 hours. High-purity argon is introduced into the annealing furnace as a protective gas. The argon flow rate is 5-15L / min. The argon flow rate is accurately controlled by a gas mass flow controller. After annealing, it is pickled. The pickling solution is a mixed solution of hydrofluoric acid and nitric acid. The solution is placed in an acid- and alkali-resistant polytetrafluoroethylene container. The concentration of hydrofluoric acid is 3%-8%, and the concentration of nitric acid is 8%-15%. The pickling time is 10-30 minutes. The pickling process is carried out with the assistance of ultrasonic oscillation to remove surface impurities, and finally it is blown dry and packaged.

[0018] Furthermore, in step S1, an ultrasonic vibration device is provided inside the three-dimensional mixer with an ultrasonic frequency of 30-60kHz. During the stirring process, it is turned on for 10-20 minutes every 30-60 minutes. The transducer of the ultrasonic vibration device is made of piezoelectric ceramic material with high energy conversion efficiency, and the vibration head is spherical with a large contact area with the powder.

[0019] Furthermore, in step S2, the cold isostatic pressing mold adopts a double-layer structure, the inner layer is made of rubber, and the outer layer is a metal reinforcement layer. The thickness of the metal reinforcement layer is 5-15mm. The metal reinforcement layer is made of stainless steel and is tightly combined with the inner layer through welding to enhance the compression resistance of the mold. The mold is demolded by hydraulic demolding, and the demolding force is controlled at 10-30kN. The hydraulic demolding system consists of a hydraulic pump, a hydraulic cylinder and a precision overflow valve, which can accurately control the demolding force.

[0020] Furthermore, in step S3, the vacuum sintering furnace is equipped with an atmosphere regulating system, and a trace amount of hydrogen can be introduced in the later stage of sintering, and the hydrogen flow rate is 1-3L / min. The atmosphere regulating system consists of a gas cylinder, a precision flow regulating valve and a gas mixing device, and the reducing property of hydrogen is used to remove trace oxide impurities that may exist inside the blank.

[0021] Furthermore, in step S4, the turning processing equipment adopts a CNC lathe, and the CNC system has an automatic compensation function. The CNC system adopts a Siemens 840D system. When it is detected that the outer diameter or inner diameter tolerance exceeds the set range during the turning process, the cutting parameters are automatically adjusted through the built-in PID algorithm.

[0022] Furthermore, in step S5, the dimensions of the tube are monitored in real time during the spinning process using a laser measuring instrument with a measurement accuracy of ±0.05 mm. The laser measuring instrument uses a helium-neon laser and adjusts the spinning wheel feed speed and core mold rotation speed in real time according to the measurement results.

[0023] Furthermore, in step S6, ultrasonic cleaning is performed after the pickling treatment, the ultrasonic frequency is 20-40kHz, and the cleaning time is 5-15 minutes. The ultrasonic cleaning equipment uses a stainless steel water tank with multiple ultrasonic transducers installed at the bottom in an array distribution to further remove tiny impurities on the surface.

[0024] Furthermore, in step S6, vacuum packaging is used for packaging, and a multi-layer composite aluminum foil bag is used as the packaging material. The multi-layer composite aluminum foil bag consists of a three-layer structure, with an inner layer of polyethylene film, a middle layer of aluminum foil, and an outer layer of nylon woven layer. It has high barrier properties and corrosion resistance, and can effectively isolate external moisture and oxygen. The vacuum packaging equipment uses a vacuum heat sealing machine with a heat sealing temperature of 150-200°C and a heat sealing time of 3-5 seconds.

[0025] (III) Beneficial technical effects

[0026] During the raw material preparation stage, advanced powder making technology is used to ensure the high purity and appropriate particle size of molybdenum powder and rhenium powder. The fine structure and ultrasonic vibration of the three-dimensional mixer are used to make the powder mixing highly uniform, effectively avoiding agglomeration and segregation, laying a solid foundation for subsequent processes and ensuring the stability of the alloy tube composition and consistent performance.

[0027] When the blank is formed, the cold isostatic pressing process is combined with a high-precision pressure feedback system and a special mold to apply pressure evenly, which can stably obtain high-quality blanks with a relative density of not less than 85%. The demoulding is smooth and lossless, greatly improving the product qualification rate.

[0028] The sintering process relies on precise heating rate control, reliable temperature monitoring and atmosphere adjustment to ensure uniform growth of alloy grains, stable organizational structure and high purity of billet, which greatly enhances the alloy tube's ability to resist deformation and cracking under high temperature and high pressure environment.

[0029] In the pipe processing stage, carbide tool coating and optimized cutting parameters, combined with high-pressure spray cooling, significantly improve processing accuracy. The inner and outer diameter tolerances of pipe fittings are strictly controlled, perfectly meeting the needs of high-end precision components.

[0030] During the spinning process, the parameters of the core mold and the spinning wheel are precisely controlled, and the real-time size monitoring and induction heating intelligent temperature control are combined to achieve uniform wall thickness and standard ovality. Reasonable heat distribution reduces residual stress and extends the service life of the alloy tube.

[0031] The post-processing process is also excellent. Vacuum annealing combined with precise argon protection optimizes the internal structure; pickling and ultrasonic cleaning thoroughly remove impurities and improve surface quality; vacuum packaging is matched with high-performance multi-layer composite aluminum foil bags to isolate external corrosion and ensure the long-term storage and transportation performance of the alloy tube, promoting the widespread and reliable application of molybdenum-rhenium alloy tubes in high-end fields in all directions. DETAILED DESCRIPTION

[0032] Embodiment 1:

[0033] Raw materials preparation:

[0034] Molybdenum powder with a purity of 99.95% and a particle size of 8-15 μm obtained by plasma rotating electrode method and rhenium powder with a purity of 99.93% and a particle size of 5-10 μm obtained by air flow pulverization after electron beam refining were selected, and the rhenium content was accurately weighed at 20%. The powder was placed in a three-dimensional mixer, and its stirring blade was an asymmetric double-layer spiral structure, with a large outer pitch for rapid dispersion and a small inner pitch for fine mixing. The powder was evacuated to 0.1 Pa and stirred at 400 rpm for 4 hours, during which 45kHz ultrasonic vibration was turned on for 15 minutes every 45 minutes.

[0035] Blank forming:

[0036] The mixed powder is loaded into the fluororubber mold, and cold isostatic pressing is used with a pressure of 300MPa for 20 minutes. The pressure sensor accuracy of the cold isostatic pressing equipment is ±0.05MPa, and the intelligent controller is calibrated in real time. The mold is coated with 0.08mm organic silicone release agent and sprayed with atomization to obtain a blank with a relative density of 88%. The mold has a double-layer structure, with an inner layer of 10mm fluororubber and an outer layer of 8mm stainless steel reinforcement.

[0037] Sintering treatment:

[0038] The blank is put into the vacuum sintering furnace and heated by the graphite heating element. The temperature is first raised to 1350°C at 12°C / min, and the temperature deviation is ±1.5°C by the infrared thermometer. The temperature is kept for 2 hours. Then the temperature is raised to 2000°C at 6°C / min, and kept for 4 hours. The vacuum degree is 0.01Pa, and the multi-thermocouple monitoring has a deviation of ±3°C. Later, 2L / min of hydrogen is passed, and the gas cylinder and precision flow valve are used for regulation.

[0039] Tube processing:

[0040] The sintered blank was turned with a carbide tool coated with 3μm TiAlN coating, a cutting speed of 100m / min, a feed rate of 0.3mm / rev, a machining allowance of 2mm, and a high-pressure spray of 0.3MPa water-based cutting fluid to obtain pipe fittings with an outer diameter tolerance of ±0.15mm and an inner diameter tolerance of ±0.08mm.

[0041] Spinning process:

[0042] Strong spinning mandrel on pipe fittings, nitrided alloy steel mandrel, surface hardness HV1000, rotation speed 400 rpm, spinning wheel feed 1mm / s, thinning rate 40%, high-frequency induction 40kHz heating to 1000℃, intelligent power regulator temperature control, piezoelectric force sensor (accuracy ±5%) to monitor spinning pressure.

[0043] Post-processing process:

[0044] The spun tube was put into a vacuum annealing furnace, graphite felt was used for insulation, annealing at 1200℃ for 2 hours, and 5-15L / min high-purity argon (mass flow controller) was used for protection. Acid washing was carried out with a mixture of 5% hydrofluoric acid and 12% nitric acid, a polytetrafluoroethylene container, 15kHz ultrasonic oscillation for 20 minutes, and then 30kHz ultrasonic cleaning for 10 minutes, and then vacuum packaging was carried out in a multi-layer composite aluminum foil bag, and heat-sealed at 180℃ for 3 seconds.

[0045] After testing, the density uniformity deviation of the alloy tube is less than 0.4%, the wall thickness uniformity deviation is less than 3%, and the room temperature tensile strength exceeds 800MPa, which meets the requirements of aviation engine hot end components.

[0046] Embodiment 2:

[0047] Raw materials preparation:

[0048] Select 99.92% pure molybdenum powder (particle size 6-18μm, plasma atomization) and 99.94% rhenium powder (particle size 4-12μm, electron beam melting and crushing), and weigh them according to the rhenium content of 25%. The three-dimensional mixer has staggered double-layer paddles, vacuumed to 0.15Pa, stirred at 300 rpm for 5 hours, and ultrasonicated for 10 minutes every 60 minutes, with a frequency of 50kHz.

[0049] Blank forming:

[0050] The mixed powder is put into the fluororubber mold, cold isostatically pressed at 350MPa, and the pressure is maintained for 15 minutes. The pressure sensor is ±0.1MPa. The mold is coated with 0.06mm release agent, and the hydraulic demolding is 20kN. The inner layer of the mold is 8mm fluororubber and the outer layer is 10mm stainless steel.

[0051] Sintering treatment:

[0052] The vacuum sintering furnace was heated up, first at 10°C / min to 1400°C, kept warm for 1.5 hours, then at 8°C / min to 2100°C, kept warm for 3 hours, with a vacuum degree of 0.015Pa and a temperature deviation of ±4°C. Hydrogen was passed at 1.5L / min at a later stage.

[0053] Tube processing:

[0054] Coated carbide tool for turning, cutting speed 80m / min, feed 0.2mm / rev, allowance 1.5mm, 0.4MPa cutting fluid spray, pipe tolerance: outer diameter ±0.18mm, inner diameter ±0.1mm.

[0055] Spinning process:

[0056] Flow spinning, core mold speed 500 rpm, spinner feed 1.5 mm / s, thinning rate 30%, induction heating 50 kHz to 900 ° C, spinning monitoring is the same as Example 1.

[0057] Post-processing process:

[0058] Annealing at 1300°C for 1.5 hours, argon 8-12 L / min, pickling with 6% hydrofluoric acid and 10% nitric acid, ultrasound at 12kHz for 25 minutes and 25kHz for 12 minutes, vacuum packaging parameters are the same as in Example 1.

[0059] The alloy tube has a density deviation of less than 0.5%, a wall thickness deviation of less than 4%, and excellent high-temperature endurance strength, and is suitable for nuclear reactor cooling tubes.

[0060] Comparative Example:

[0061] Traditional preparation method:

[0062] The raw materials are mechanically stirred to mix molybdenum powder (purity 99%, particle size 10-30μm) and rhenium powder (purity 99%, particle size 8-20μm), roughly weighed according to 15% rhenium, without vacuum and ultrasound. Molding 200MPa, ordinary steel mold, demoulding is difficult to damage the blank. The sintering electric furnace heats up randomly, there is no atmosphere control, and the insulation is inaccurate. The turning tool is ordinary, the processing accuracy is low, the spinning lacks real-time monitoring, the pickling is a single acid soaking for a short time, and it is simply packaged after natural drying.

[0063]

[0064]

[0065] Performance test results:

[0066] The alloy tube has uneven density with a deviation of more than 5%, uneven wall thickness of more than 10%, poor mechanical properties, low tensile strength, easy deformation and cracking at high temperature, many surface impurities, and easy oxidation during storage, which is in sharp contrast to the examples.

[0067] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a molybdenum-rhenium alloy tube by spinning, characterized in that: The following steps are involved: S1: Raw material preparation: Molybdenum powder obtained by plasma atomization method, with a normal distribution of particle size concentrated in the range of 5-20μm, and rhenium powder with a purity of not less than 99.9% obtained by electron beam melting and crushing, with a particle size of 3-15μm, weighed according to the mass fraction of rhenium content of 10%-30%; the weighed powder is placed in a three-dimensional mixer, the internal stirring blade of the mixer is a double-layer spiral structure, the outer blade is responsible for quickly breaking up large agglomerates, and the inner blade is finely mixed, evacuated to 0.05-0.2Pa, and stirred at a speed of 200-600 rpm for 2-6 hours; S2: Blank forming: The mixed powder is loaded into a rubber mold. The rubber mold is made of fluororubber and formed by cold isostatic pressing. The pressure is 200-400MPa and the holding time is 10-30 minutes. The pressure feedback adjustment system of the cold isostatic pressing equipment is composed of a high-precision pressure sensor and an intelligent controller. A release agent is applied to the surface of the mold. The release agent is a high-temperature resistant, volatile and residue-free silicone release agent. The thickness of the application is 0.05-0.1mm. The inner surface of the mold is evenly covered by atomization spraying to obtain a blank with a relative density of not less than 85%; S3: Sintering treatment: put the blank into a vacuum sintering furnace. The heating element of the vacuum sintering furnace uses a graphite heating element. First, heat it to 1200-1500℃ at a heating rate of 8-18℃ / min and keep it warm for 1-3 hours. At this stage, use an infrared thermometer to monitor the surface temperature of the blank in real time, and control the deviation from the set temperature within ±2℃; then heat it to 1800-2200℃ at a heating rate of 4-10℃ / min and keep it warm for 2-6 hours. The vacuum degree is maintained at 0.005-0.02Pa during the whole sintering process, and then cool it with the furnace. The sintering furnace is equipped with a temperature monitoring system, and multiple thermocouples are distributed in different positions to monitor the sintering temperature in real time; S4: Pipe processing: The sintered blank is turned. The turning tool is a carbide tool. The tool edge is treated with a micro-nano coating. The coating material is TiAlN. The cutting speed is 50-150m / min, the feed rate is 0.1-0.5mm / rev, and the machining allowance is 1-3mm. The blank is processed into a pipe with an outer diameter tolerance within ±0.2mm and an inner diameter tolerance within ±0.1mm. The turning process is cooled by cutting fluid. The cutting fluid is a water-based cutting fluid with good lubrication and cooling properties. The cutting fluid is sprayed into the cutting area through a high-pressure spray system; S5: Spinning process: Use strong spinning or flow spinning to install the pipe fittings on the core mold of the spinning machine. The core mold is made of high-strength alloy steel and is nitrided to achieve a surface hardness of HV900-HV1200. The core mold speed is 200-600 rpm, the spinning wheel feed speed is 0.5-2mm / s, and the spinning thinning rate is 20%-60%. The pipe fittings are locally heated during the spinning process. The heating equipment is a high-frequency induction heating device with a heating temperature of 800-1200℃ and an induction heating frequency of 20-60kHz. The device is equipped with an intelligent power regulator to adjust the power in real time according to the material and size of the pipe fittings. The spinning equipment is equipped with a force sensor to monitor the spinning pressure in real time. S6: Post-processing process: The molybdenum-rhenium alloy tube after spinning is annealed. The annealing furnace is a vacuum annealing furnace. Graphite felt is used as insulation material in the furnace. The annealing temperature is 1000-1500°C and the insulation time is 1-3 hours. High-purity argon is introduced into the annealing furnace as a protective gas. The argon flow rate is 5-15L / min. The argon flow rate is accurately controlled by a gas mass flow controller. After annealing, it is pickled. The pickling solution is a mixed solution of hydrofluoric acid and nitric acid. The solution is placed in an acid- and alkali-resistant polytetrafluoroethylene container. The concentration of hydrofluoric acid is 3%-8%, and the concentration of nitric acid is 8%-15%. The pickling time is 10-30 minutes. The pickling process is carried out with the assistance of ultrasonic oscillation to remove surface impurities, and finally it is blown dry and packaged.

2. The method for preparing a molybdenum-rhenium alloy tube by spinning according to claim 1, characterized in that: In step S1, an ultrasonic vibration device is installed inside the three-dimensional mixer with an ultrasonic frequency of 30-60kHz. It is turned on for 10-20 minutes every 30-60 minutes during the stirring process. The transducer of the ultrasonic vibration device is made of piezoelectric ceramic material with high energy conversion efficiency. The vibration head is spherical and has a large contact area with the powder.

3. The method for preparing a molybdenum-rhenium alloy tube by spinning according to claim 1, characterized in that: In step S2, the cold isostatic pressing mold adopts a double-layer structure, with an inner layer made of rubber and an outer layer made of a metal reinforcement layer. The thickness of the metal reinforcement layer is 5-15mm. The metal reinforcement layer is made of stainless steel and is tightly combined with the inner layer through welding to enhance the mold's pressure resistance. The mold is demolded by hydraulic demolding, and the demolding force is controlled at 10-30kN. The hydraulic demolding system consists of a hydraulic pump, a hydraulic cylinder and a precision overflow valve, which can accurately control the demolding force.

4. The method for preparing a molybdenum-rhenium alloy tube by spinning according to claim 1, characterized in that: In step S3, the vacuum sintering furnace is equipped with an atmosphere regulating system. A small amount of hydrogen can be introduced in the later stage of sintering. The hydrogen flow rate is 1-3L / min. The atmosphere regulating system consists of a gas cylinder, a precision flow regulating valve and a gas mixing device. The reducing property of hydrogen is used to remove trace oxide impurities that may exist inside the blank.

5. The method for preparing a molybdenum-rhenium alloy tube by spinning according to claim 1, characterized in that: In step S4, the turning processing equipment uses a CNC lathe, and the CNC system has an automatic compensation function. The CNC system uses the Siemens 840D system. When it is detected during the turning process that the outer diameter or inner diameter tolerance exceeds the set range, the cutting parameters are automatically adjusted through the built-in PID algorithm.

6. The method for preparing a molybdenum-rhenium alloy tube by spinning according to claim 1, characterized in that: In step S5, the dimensions of the tube are monitored in real time during the spinning process using a laser measuring instrument with a measurement accuracy of ±0.05 mm. The laser measuring instrument uses a helium-neon laser and adjusts the spinning wheel feed speed and core mold rotation speed in real time based on the measurement results.

7. The method for preparing a molybdenum-rhenium alloy tube by spinning according to claim 1, characterized in that: In step S6, ultrasonic cleaning is performed after the pickling treatment, the ultrasonic frequency is 20-40kHz, and the cleaning time is 5-15 minutes. The ultrasonic cleaning equipment uses a stainless steel water tank with multiple ultrasonic transducers installed at the bottom in an array to further remove tiny impurities on the surface.

8. The method for preparing a molybdenum-rhenium alloy tube by spinning according to claim 1, characterized in that: In step S6, vacuum packaging is used for packaging, and the packaging material is a multi-layer composite aluminum foil bag. The multi-layer composite aluminum foil bag consists of a three-layer structure, with an inner layer of polyethylene film, a middle layer of aluminum foil, and an outer layer of nylon woven layer. It has high barrier properties and corrosion resistance, and can effectively isolate external moisture and oxygen. The vacuum packaging equipment uses a vacuum heat sealing machine with a heat sealing temperature of 150-200°C and a heat sealing time of 3-5 seconds.

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