A method for hot isostatic pressing joining of a double intermediate layer of nickel-based alloy and niobium-based alloy

Abstract

The present application belongs to the field of nuclear fusion technology, and particularly relates to a method for hot isostatic pressing connection of a double-interlayer nickel-based alloy and a niobium-based alloy. The present application comprises the following steps: machining, jacket making, cleaning, assembling, packaging, leak detection, vacuum pumping, clamping and sealing, and hot isostatic pressing. By adding palladium / palladium-based alloy and molybdenum-based alloy as the double-interlayer, and by controlling the hot isostatic pressing system, reliable metallurgical bonding of the connection interface is achieved, no intermetallic compound is generated, the elements of the connection interface are excessively uniform, and the whole has high high-temperature connection strength. The present application can be used for manufacturing of the connection components of the nickel-based alloy and the niobium-based alloy in the high-temperature fusion reactor, and can meet the comprehensive use performance of the materials.

Description

Technical Field

[0001] This invention belongs to the field of nuclear fusion, specifically relating to a hot isostatic pressing method for joining a nickel-based alloy and a niobium-based alloy with a double intermediate layer. Background Technology

[0002] As a core component of the fourth-generation clean energy system, nuclear energy's structural materials directly impact the safety and economic operation of reactors. In the design of fusion reactor blanket structures, materials must withstand extreme multi-field coupling conditions and complex thermomechanical load cycles. Based on thermodynamic calculations and radiation damage theory, blanket materials must possess low thermal neutron absorption cross-sections and fast neutron activation cross-sections, with low-activation materials preferred to reduce radioactive waste yield. Furthermore, they must maintain high tensile and yield strength within the 773-1273 K temperature range. For the high-temperature conditions of fuel assembly cladding, material selection follows the principle of crystal structure stability; MoNbZr alloys, Nb1Zr alloys, and Mo-Re alloys are currently the optimal choices. For the reactor pressure vessel and primary loop piping system, the γ'-phase strengthened nickel-based superalloy GH3230 is used, exhibiting high creep strength at high temperatures and maintaining a low corrosion rate even in high-temperature halogen environments.

[0003] The bonding technology between nickel-based superalloy GH3230 and niobium-based alloy Nb1Zr is a key technological bottleneck in the structural integration of fourth-generation nuclear reactors. Its core scientific problems stem from the thermodynamic incompatibility and physical property mismatch of the material systems. Interface engineering for bonding Nb-based alloy Nb1Zr and Ni-based alloy GH3230 requires addressing two key issues: thermal stress concentration caused by thermal expansion mismatch and the generation and suppression of brittle interfacial phases (such as Laves phase and σ phase). The difference in the thermal expansion coefficients of the material systems leads to multiple interfacial problems, including thermal cycling stress concentration, geometric constraint effects, and crack propagation tendency. Several intermetallic compounds, such as Ni8Nb, Ni3Nb, and Ni6Nb7, form a continuous brittle layer at the interface, resulting in a sharp decrease in interfacial bonding strength.

[0004] Based on the stringent requirements of fourth-generation nuclear energy systems for material connection reliability, current engineering practices mainly employ three types of solid-state joining technologies: explosive welding technology, which requires materials to meet dynamic plasticity conditions, has a wavy interface structure that easily leads to a porosity greater than 5%, and makes dimensional tolerance control difficult; brazing technology, which results in significant high-temperature strength attenuation of the joint and a thermal fatigue life of only 200-300 cycles; and thermal isostatic pressure diffusion bonding, which eliminates interface porosity through triaxial isostatic pressure, has been verified by X-ray tomography to have a porosity of less than 0.03%, an interface diffusion zone width that can be controlled within 10-50 μm, and enables the mass production of complex components. Summary of the Invention

[0005] In view of this, the present invention provides a hot isostatic pressing method for joining nickel-based alloys and niobium-based alloys with two intermediate layers. By adding two suitable intermediate layers and controlling the hot pressing process, a reliable metallurgical bond is achieved in the joint, with no intermediate phase generated and the elements at the joint interface are extremely uniform. The joint also has high connection strength at high temperatures. It can be used as a component for connecting nickel-based alloys and niobium-based alloys in high-temperature fusion reactors and can meet the comprehensive performance requirements of the materials.

[0006] The technical solution adopted in this invention is as follows:

[0007] This invention provides a hot isostatic pressing method for joining a nickel-based alloy and a niobium-based alloy with two interlayers, comprising the following steps:

[0008] Step 1, Machining: Machin the nickel-based alloy workpiece ③ and the niobium-based alloy workpiece ⑥ to the required dimensions respectively;

[0009] Step 2, Sleeve Fabrication: Process the cover plate ② and the outer sleeve ⑦;

[0010] Step 3, Cleaning: Clean all workpieces;

[0011] Step 4, Assembly: Insert the niobium-based alloy workpiece ⑥, the transition layer sheet ⑤, the transition layer sheet ④, and the nickel-based alloy workpiece ③ into the outer casing ⑦ in sequence;

[0012] Step 5, Packaging: Weld the extraction pipe ① and cover plate ②, and cover plate ② and outer sleeve ⑦ using electron beam welding or argon arc welding. The welding process requires protection with inert gas. When welding cover plate ② and outer sleeve ⑦, outer sleeve ⑦ should be placed in water.

[0013] Step 6, Leak Detection: After welding, perform leak detection on the outer casing. The leak rate should be ≤10%. -9 Pa·m 3 / s;

[0014] Step 7, Vacuuming: Vacuum the casing after leak detection;

[0015] Step 8, Sealing: After baking, heat-seal the vacuum tube ① on the casing, maintaining a vacuum level below 1.0 × 10 throughout the process. -3 Pa;

[0016] Step 9, Hot Isostatic Pressing: Place the sealed sleeve in a hot isostatic pressing furnace for diffusion connection, and use high-purity argon as the pressurizing gas; In step (1), the material of the nickel-based alloy workpiece ③ is GH3230, the material of the transition layer sheet ④ is pure Pd or Pd-based alloy, the material of the transition layer sheet ⑤ is Mo-based alloy, and the material of the niobium-based alloy workpiece ⑥ is Nb1Zr alloy.

[0017] In step 1, the surface roughness Ra is guaranteed to be ≤0.8μm.

[0018] In step 2, the surface must be smooth with a roughness Ra ≤ 1.6 μm.

[0019] In step 3, after degreasing the air extraction pipe ①, cover plate ②, nickel-based alloy workpiece ③, transition layer sheet ④, transition layer sheet ⑤, niobium-based alloy workpiece ⑥, and outer sleeve ⑦, they are ultrasonically cleaned in acetone cleaning solution for 15 minutes. After ultrasonic cleaning, the materials are placed in rust removal solution to remove the surface oxide layer. Then, the material surface is ultrasonically cleaned with alcohol for 15 minutes.

[0020] In step 7, the vacuum level is lower than 2.0 × 10⁻⁶. -3 Heating is only permitted when the pressure reaches 450℃ and the vacuum level is below 2.0 × 10⁻⁶ Pa; when heating to 450℃, the vacuum level must be below 2.0 × 10⁻⁶ Pa. -3 Start heat preservation at Pa, keep warm for 3 hours, then remove from the oven and air cool.

[0021] In step 9, the hot isostatic pressing temperature is 1220-1290℃, the holding time is 3-5h, the pressure is ≥150MPa, and then the furnace is cooled to below 200℃ before being taken out and air-cooled to room temperature.

[0022] The beneficial effects of this invention are as follows:

[0023] (1) The present invention uses a double intermediate layer hot isostatic pressing diffusion bonding method to achieve reliable metallurgical bonding of nickel-based alloys and niobium-based alloys, with good bonding quality;

[0024] (2) The present invention provides a hot isostatic pressing method for joining a nickel-based alloy and a niobium-based alloy with a double intermediate layer. The three connection interfaces of the nickel-based alloy and the niobium-based alloy are free of any defects, the interface elements are uniformly distributed, and the whole has a high high-temperature bonding strength.

[0025] (3) The present invention provides a hot isostatic pressing method for joining nickel-based alloys and niobium-based alloys with a double interlayer, which achieves the formation of no intermetallic compounds at the joining interface by adding a suitable double interlayer and controlling the hot pressing regime.

[0026] (4) The hot isostatic pressing method for connecting nickel-based alloy and niobium-based alloy with a double intermediate layer provided by the present invention is suitable for manufacturing large-area connection components of nickel-based alloy and niobium-based alloy in future fusion reactors and can meet the requirements for high-temperature use. Attached Figure Description

[0027] Figure 1 A schematic diagram showing the order in which niobium-based alloy, Mo-based alloy sheet, Pd / Pd-based alloy sheet, and nickel-based superalloy are placed into the casing.

[0028] Figure 2 This is a schematic diagram of the assembly of the workpiece and the casing;

[0029] Figure 3 This is a schematic diagram of the workpiece after sealing.

[0030] Among them, 1-extraction pipe, 2-cover plate, 3-GH3230 workpiece, 4-Pd / Pd-based alloy sheet, 5-Mo-based alloy sheet, 6-Nb1Zr alloy workpiece, 7-outer sheath. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. Furthermore, unless otherwise specified, methods not specifically describing conditions or steps are conventional methods, and the reagents and materials used are commercially available.

[0033] Example 1

[0034] This invention provides a hot isostatic pressing method for joining a nickel-based alloy and a niobium-based alloy with two interlayers, as described in the reference. Figure 1 The materials for the extraction pipe ① are pure iron / stainless steel, the cover plate ② is pure iron / stainless steel, the workpiece ③ is a nickel-based high-temperature alloy GH3230, the workpiece ④ is pure Pd, the workpiece ⑤ is a TZM molybdenum alloy, the workpiece ⑥ is a niobium-based alloy Nb1Zr alloy, and the outer sheath ⑦ is pure iron / stainless steel. The specific steps include the following:

[0035] Step 1, Machining: Machin the nickel-based high-temperature alloy workpiece ③ and the niobium-based alloy workpiece ⑥ to Φ50×35mm, and finish the surface to ensure that the surface roughness Ra≤0.8μm of the surface to be joined; the thickness of the transition layer sheet ④ is 0.15mm, the thickness of the transition layer sheet ⑤ is 0.15mm, and the surface is polished to ensure that the surface roughness Ra≤0.8μm of the surface to be joined.

[0036] Step 2, Sleeve fabrication: Process the cover plate ② and the outer sleeve ⑦, both with a thickness of 4-5mm. The depth of the outer sleeve ⑦ is 80-85mm. Ensure there are no defects detected by visual inspection or penetration testing, and guarantee a smooth surface with a roughness Ra≤1.6μm.

[0037] Step 3, Cleaning: After degreasing the air extraction pipe ①, cover plate ②, nickel-based high-temperature alloy workpiece ③, transition layer sheet ④, transition layer sheet ⑤, niobium-based alloy workpiece ⑥, and outer sleeve ⑦, place them in acetone cleaning solution for ultrasonic cleaning for 15 minutes. After ultrasonic cleaning, place the materials in rust removal solution to remove the surface oxide layer, and then use alcohol to ultrasonically clean the surface of the materials for 15 minutes.

[0038] Step 4, Assembly: Insert the niobium-based alloy workpiece ⑥, the transition layer sheet ⑤, the transition layer sheet ④, and the nickel-based alloy workpiece ③ into the outer casing ⑦ in sequence;

[0039] Step 5, Packaging: Weld the extraction pipe ① and cover plate ②, and cover plate ② and outer sleeve ⑦ using electron beam welding or argon arc welding. The welding process requires protection with inert gas. When welding cover plate ② and outer sleeve ⑦, outer sleeve ⑦ should be placed in water.

[0040] Step 6, Leak Detection: After welding, perform leak detection on the outer casing. The leak rate should be ≤10%. -9 Pa·m 3 / s;

[0041] Step 7: Vacuuming: Vacuum the casing after leak testing, ensuring the vacuum level is below 2.0 × 10⁻⁶. -3 Heating is only permitted when the pressure reaches 450°C, and the vacuum level must be below 2.0 × 10⁻⁶ Pa. -3 Start heat preservation at Pa, keep warm for 3 hours, then remove from the oven and air cool.

[0042] Step 8, Sealing: After baking, heat-seal the vacuum tube ① on the casing, maintaining a vacuum level below 1.0 × 10 throughout the process. -3 Pa;

[0043] Step 9, Hot Isostatic Pressing: Place the sealed sleeve in a hot isostatic pressing furnace for diffusion connection. High-purity argon is used as the pressurizing gas. The hot isostatic pressing temperature is 1250℃, the holding time is 3h, and the pressure is ≥150MPa. After that, it is cooled to 200℃ with the furnace and then removed from the furnace and air-cooled to room temperature.

[0044] Microstructural analysis of the interface after hot isostatic pressing revealed good interface bonding, no defects, and uniform elemental transition. The tensile strength and yield strength of the connector were 280 MPa and 214 MPa, respectively.

[0045] Example 2

[0046] This invention provides a hot isostatic pressing method for joining a nickel-based alloy and a niobium-based alloy with two interlayers, as described in the reference. Figure 1The materials for the extraction pipe ① are pure iron / stainless steel, the cover plate ② is pure iron / stainless steel, the workpiece ③ is a nickel-based high-temperature alloy GH3230, the workpiece ④ is pure Pd, the workpiece ⑤ is a MoRe alloy, the workpiece ⑥ is a niobium-based alloy Nb1Zr alloy, and the outer sheath ⑦ is pure iron / stainless steel. The specific steps include the following:

[0047] Step 1, Machining: Machin the nickel-based high-temperature alloy workpiece ③ to Φ50×35mm, and finish the surface to ensure that the surface roughness Ra ≤ 0.8μm of the surface to be joined; the niobium-based alloy workpiece ⑥ is filled with powder and compacted by vibration; the thickness of the transition layer sheet ④ is 0.15mm, the thickness of the transition layer sheet ⑤ is 0.15mm, and the surface is polished to ensure that the surface roughness Ra ≤ 0.8μm of the surface to be joined.

[0048] Step 2, Sleeve fabrication: Process the cover plate ② and the outer sleeve ⑦, with a thickness of 4-5mm and a depth of 90-100mm. Ensure there are no visual or penetrant defects, and guarantee a smooth surface with a roughness Ra≤1.6μm.

[0049] Step 3, Cleaning: After degreasing the air extraction pipe ①, cover plate ②, nickel-based high-temperature alloy workpiece ③, transition layer sheet ④, transition layer sheet ⑤, and outer sleeve ⑦, ultrasonically clean them in acetone cleaning solution for 15 minutes. After ultrasonic cleaning, place the materials in rust removal solution to remove the surface oxide layer, and then ultrasonically clean the material surface with alcohol for 15 minutes.

[0050] Step 4, Assembly: The niobium-based alloy workpiece ⑥, the transition layer sheet ⑤, the transition layer sheet ④, and the nickel-based alloy workpiece ③ are sequentially loaded into the outer sleeve ⑦; the niobium-based alloy workpiece ⑥ is filled in powder form, and after filling, it is compacted using an aging instrument to ensure that the height is not less than 50mm.

[0051] Step 5, Encapsulation: Weld the extraction pipe ① and cover plate ②, and cover plate ② and outer sleeve ⑦ using electron beam welding or argon arc welding. The welding process requires protection with inert gas. When welding cover plate ② and outer sleeve ⑦, outer sleeve ⑦ should be placed in water.

[0052] Step 6, Leak Detection: After welding, perform leak detection on the outer casing. The leak rate should be ≤10%. -9 Pa·m 3 / s.

[0053] Step 7: Vacuuming: Vacuum the casing after leak testing, ensuring the vacuum level is below 2.0 × 10⁻⁶. -3 Heating is only permitted when the pressure reaches 450°C, and the vacuum level must be below 2.0 × 10⁻⁶ Pa. -3 Start heat preservation at Pa, keep warm for 3 hours, then remove from the oven and air cool.

[0054] Step 8, Sealing: After baking, heat-seal the vacuum tube ① on the casing, maintaining a vacuum level below 1.0 × 10 throughout the process. -3 Pa.

[0055] Step 9, Hot Isostatic Pressing: Place the sealed sleeve in a hot isostatic pressing furnace for diffusion connection. High-purity argon is used as the pressurizing gas. The hot isostatic pressing temperature is 1250℃, the holding time is 3h, and the pressure is ≥150MPa. After that, it is cooled to 200℃ with the furnace and then removed from the furnace and air-cooled to room temperature.

[0056] Microstructural analysis of the interface after hot isostatic pressing revealed good interfacial bonding, no defects, and uniform elemental transition. The connector has a tensile strength of 350 MPa, a yield strength of 219 MPa, and a tensile strength of 77 MPa at 1123 K.

[0057] Example 3

[0058] This invention provides a hot isostatic pressing method for joining a nickel-based alloy and a niobium-based alloy with two interlayers, as described in the reference. Figure 1 The materials for the extraction pipe ① are pure iron / stainless steel, the cover plate ② is pure iron / stainless steel, the workpiece ③ is a nickel-based high-temperature alloy GH3230, the workpiece ④ is a PdW alloy, the workpiece ⑤ is a MoLa alloy, the workpiece ⑥ is a niobium-based alloy Nb1Zr alloy, and the outer sheath ⑦ is pure iron / stainless steel. The specific steps include the following:

[0059] Step 1, Machining: Machin the nickel-based high-temperature alloy workpiece ③ and the niobium-based alloy workpiece ⑥ to Φ50×35mm, and finish the surface to ensure that the surface roughness Ra≤0.8μm of the surface to be joined; the thickness of the transition layer sheet ④ is 0.15mm, the thickness of the transition layer sheet ⑤ is 0.15mm, and the surface is polished to ensure that the surface roughness Ra≤0.8μm of the surface to be joined.

[0060] Step 2, Sleeve fabrication: Process the cover plate ② and the outer sleeve ⑦, both with a thickness of 4-5mm. The depth of the outer sleeve ⑦ is 80-85mm. Ensure there are no defects detected by visual inspection or penetration testing, and guarantee a smooth surface with a roughness Ra≤1.6μm.

[0061] Step 3, Cleaning: After degreasing the air extraction pipe ①, cover plate ②, nickel-based high-temperature alloy workpiece ③, transition layer sheet ④, transition layer sheet ⑤, niobium-based alloy workpiece ⑥, and outer sleeve ⑦, place them in acetone cleaning solution for ultrasonic cleaning for 15 minutes. After ultrasonic cleaning, place the materials in rust removal solution to remove the surface oxide layer, and then use alcohol to ultrasonically clean the surface of the materials for 15 minutes.

[0062] Step 4, Assembly: Insert the niobium-based alloy workpiece ⑥, the transition layer sheet ⑤, the transition layer sheet ④, and the nickel-based alloy workpiece ③ into the outer casing ⑦ in sequence;

[0063] Step 5, Packaging: Weld the extraction pipe ① and cover plate ②, and cover plate ② and outer sleeve ⑦ using electron beam welding or argon arc welding. The welding process requires protection with inert gas. When welding cover plate ② and outer sleeve ⑦, outer sleeve ⑦ should be placed in water.

[0064] Step 6, Leak Detection: After welding, perform leak detection on the outer casing. The leak rate should be ≤10%. -9 Pa·m 3 / s;

[0065] Step 7: Vacuuming: Vacuum the casing after leak testing, ensuring the vacuum level is below 2.0 × 10⁻⁶. -3 Heating is only permitted when the pressure reaches 450°C, and the vacuum level must be below 2.0 × 10⁻⁶ Pa. -3 Start heat preservation at Pa, keep warm for 3 hours, then remove from the oven and air cool.

[0066] Step 8, Sealing: After baking, heat-seal the vacuum tube ① on the casing, maintaining a vacuum level below 1.0 × 10 throughout the process. -3 Pa;

[0067] Step 9, Hot Isostatic Pressing: Place the sealed sleeve in a hot isostatic pressing furnace for diffusion connection. High-purity argon is used as the pressurizing gas. The hot isostatic pressing temperature is 1250℃, the holding time is 3h, and the pressure is ≥150MPa. After that, it is cooled to 200℃ with the furnace and then removed from the furnace and air-cooled to room temperature.

[0068] Microstructural analysis of the interface after hot isostatic pressing revealed good interface bonding, no defects, and uniform elemental transition. The tensile strength and yield strength of the connector were 280 MPa and 213 MPa, respectively.

[0069] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0070] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for hot isostatic pressing (HIP) joining of a nickel-based alloy and a niobium-based alloy with two interlayers, characterized in that: Includes the following steps: Step (1), Machining: Machining the nickel-based high-temperature alloy workpiece ③ and the niobium-based alloy workpiece ⑥ to the required size respectively. The first type of transition layer sheet ④ and the second type of transition layer sheet ⑤ need to be polished. Step (2), Sleeve fabrication: Process the cover plate ② and the outer sleeve ⑦; Step (3), Cleaning: Clean all workpieces; Step (4), Assembly: The niobium-based alloy workpiece ⑥, the second type of transition layer sheet ⑤, the first type of transition layer sheet ④, and the nickel-based high-temperature alloy workpiece ③ are sequentially installed into the outer casing ⑦; Step (5), encapsulation: The exhaust pipe ① and cover plate ②, and cover plate ② and outer sleeve ⑦ are welded using electron beam welding or argon arc welding. The welding process requires protection with inert gas. When welding cover plate ② and outer sleeve ⑦, outer sleeve ⑦ should be placed in water. Step (6) Leak Detection: After welding is completed, leak detection is performed on the outer casing. The leak rate is ≤10%. 9 Pa·m 3 / s; Step (7), Vacuuming: Vacuum the casing after leak detection; Step (8), sealing: After baking, heat-seal the vacuum tube ① on the casing, maintaining a vacuum level below 1.0×10 throughout the process. 3 Pa; Step (9), Hot Isostatic Pressing: The sealed sleeve is placed in a hot isostatic pressing furnace for diffusion connection, and the pressurizing gas is high-purity argon; In step (1), the material of the nickel-based high-temperature alloy workpiece ③ is GH3230 or other nickel-based alloys, the material of the first transition layer sheet ④ is pure Pd or Pd-based alloys, the material of the second transition layer sheet ⑤ is Mo-based alloys, and the material of the niobium-based alloy workpiece ⑥ is Nb1Zr alloy or other niobium-based alloys.

2. The hot isostatic pressing method for joining a nickel-based alloy and a niobium-based alloy with a double interlayer according to claim 1, characterized in that: In step (1), the surface roughness Ra is guaranteed to be ≤ 0.8μm.

3. The hot isostatic pressing method for joining a nickel-based alloy and a niobium-based alloy with a double interlayer according to claim 1, characterized in that: In step (2), the surface is kept smooth with a roughness Ra ≤ 1.6 μm.

4. The hot isostatic pressing method for joining a nickel-based alloy and a niobium-based alloy with a double interlayer according to claim 1, characterized in that: In step (3), after the air extraction pipe ①, cover plate ②, nickel-based high-temperature alloy workpiece ③, first type of transition layer sheet ④, second type of transition layer sheet ⑤, niobium-based alloy workpiece ⑥, and outer sleeve ⑦ are degreased, they are placed in acetone cleaning solution for ultrasonic cleaning for 15 minutes. After ultrasonic cleaning, the materials are placed in rust removal solution to remove the surface oxide layer. Then, the material surface is ultrasonically cleaned with alcohol for 15 minutes.

5. The hot isostatic pressing method for joining a nickel-based alloy and a niobium-based alloy with a double interlayer according to claim 1, characterized in that: In step (7), the vacuum level is lower than 2.0 × 10⁻⁶. -3 Heating is only permitted when the pressure reaches 450°C, with a vacuum level below 2.0 × 10⁻⁶ Pa. -3 Start heat preservation at Pa, keep warm for 3 hours, then remove from the oven and air cool.

6. The hot isostatic pressing method for joining a nickel-based alloy and a niobium-based alloy with a double interlayer according to claim 1, characterized in that: In step (9), the hot isostatic pressing temperature is 1220~1290℃, the holding time is 3~5h, the pressure is ≥150MPa, and then the furnace is cooled to below 200°C before being taken out and air-cooled to room temperature.

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