Method for integrally forming deep-cavity thin-wall component of ni-al alloy
By combining vacuum hot pressing and high-temperature preforming with hot gas expansion forming of Ni/Al laminated foil, the forming problem of NiAl alloy deep cavity thin-walled components was solved, achieving high-precision and high-efficiency forming results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DALIAN JIAOTONG UNIVERSITY
- Filing Date
- 2026-05-29
- Publication Date
- 2026-07-21
AI Technical Summary
Existing technologies make it difficult to form high-performance NiAl alloy deep-cavity thin-walled components using traditional hot forming processes. In particular, the material cannot flow effectively into the depth of the cavity during hot gas expansion forming, resulting in excessive thinning of local thickness and easy cracking.
By employing a Ni/Al laminated foil design, a non-uniform thickness preform of Ni/Ni2Al3/Ni layered structure is formed through vacuum hot pressing. The customized wall thickness distribution and in-situ reaction synthesis of the material are achieved by combining high-temperature preforming and hot gas expansion forming, ultimately obtaining a NiAl alloy deep cavity thin-walled component.
It has achieved high-precision forming of complex-shaped NiAl alloy deep-cavity thin-walled components, avoiding necking and cracking caused by excessive local deformation, and improving forming accuracy and material utilization.
Smart Images
Figure CN122425118A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of forming technology for deep cavity thin-walled components of intermetallic compounds, and in particular to an integrated forming method for NiAl alloy deep cavity thin-walled components. Background Technology
[0002] NiAl alloy is a novel lightweight ultra-high temperature structural material characterized by low density, high operating temperature, high specific strength / stiffness, and excellent oxidation resistance, showing broad application prospects in aerospace, energy, and other fields. With an operating temperature reaching 1000℃, NiAl alloy can fill the gap between high-temperature alloys and high-temperature structural ceramics, making it a highly promising new ultra-high temperature structural material. However, NiAl alloy suffers from high high-temperature strength but poor plasticity, making it difficult to obtain thin-walled components using traditional hot forming processes.
[0003] To address the aforementioned issues, some methods involve alternating stacking of Ni and Al foils followed by hot pressing to obtain a Ni / Al laminated slab of uniform thickness. This slab is then hot-formed and in-situ synthesized to ultimately produce a NiAl alloy plate component. This method first prepares a slab of uniform thickness and then hot-forms the NiAl alloy component. However, for deep-cavity components, the deformation varies greatly across different parts. Using a slab of uniform thickness as the initial blank lacks material pre-allocation to meet the deformation requirements of different areas. During hot-formation, the material cannot effectively flow into the deep cavity, relying solely on the thinning of the top and sidewall materials to meet deformation demands. This leads to excessive thinning in certain areas, making cracking highly likely. The aforementioned methods cannot overcome the forming limits under constant volume constraints, making it difficult to achieve precise forming of high-performance deep-cavity NiAl alloy thin-walled components. Therefore, an integrated forming method for NiAl alloy deep-cavity thin-walled components is urgently needed to solve the aforementioned technical problems. Summary of the Invention
[0004] The purpose of this invention is to provide an integrated forming method for NiAl alloy deep cavity thin-walled components, so as to solve the problems existing in the prior art, which makes it easy to form deep cavity thin-walled components with complex shapes and with high forming accuracy.
[0005] To achieve the above objectives, the present invention provides the following solution: This invention provides an integrated forming method for NiAl alloy deep-cavity thin-walled components, comprising the following steps: S1: Based on the three-dimensional model of the component, design and calculate the initial thickness, size and shape of the Ni / Al laminated foil; S2: Surface treatment of Ni / Al laminated foil; S3: Vacuum hot pressing is performed on Ni / Al laminated foil to obtain a non-uniform thickness preform with a Ni / Ni2Al3 / Ni layered structure; S4: High-temperature preforming of the Ni / Ni2Al3 / Ni layered structure non-uniform thickness preform to obtain a Ni / Ni2Al3 / Ni layered structure preform with customized wall thickness distribution; S5: Place the Ni / Ni2Al3 / Ni layered structure preform in a hot gas expansion forming mold to obtain the corresponding shape under the action of hot gas expansion; S6: Through in-situ reaction synthesis, NiAl alloy deep cavity thin-walled components are finally obtained.
[0006] In some embodiments, the surface treatment method for the Ni / Al laminated foil in step S2 is to polish the surfaces of the Ni foil and Al foil to a bright finish, and then stack the Ni foil and Al foil sequentially to obtain the Ni / Al laminated foil, with the Ni foil placed on the outermost side of the laminated structure. Then, the Ni / Al laminated foil is placed in a cleaning solution for cleaning, and after cleaning, it is dried with cold air.
[0007] In some embodiments, the surfaces of the Ni foil and Al foil are polished with sandpaper. The cleaning process involves immersing the entire Ni / Al laminated foil in an acetone solution for ultrasonic cleaning for 15-20 minutes, rinsing it with water, and then immersing it in an anhydrous ethanol solution for ultrasonic cleaning for 15-30 minutes.
[0008] In some embodiments, the hot pressing process in step S3 is carried out in a vacuum hot press furnace, and graphite sheets or graphite powder are placed on the surface of the Ni / Al laminated foil.
[0009] In some embodiments, the vacuum hot pressing process parameters in step S3 are: temperature 550~640℃, time 2~6h, and pressure 1~20MPa.
[0010] In some implementations, the high-temperature preforming temperature in step S4 is selected as 750~900℃.
[0011] In some implementations, the process parameters for thermal expansion in step S5 are a temperature of 750~900℃ and a pressure of 0.1~20MPa.
[0012] In some embodiments, the process parameters for the in-situ reaction synthesis in step S6 are: temperature 900~1200℃, time 1~4h, and pressure 5~20MPa.
[0013] In some embodiments, in step S3, the Ni / Ni2Al3 / Ni layered non-uniform thickness preform is designed according to the shape and size of the preformed component and the final formed part; in step S4, the Ni / Ni2Al3 / Ni layered preformed component is designed according to the shape and size of the final formed part.
[0014] The present invention achieves the following technical effects compared to the prior art: The integrated forming method for NiAl alloy deep-cavity thin-walled components provided by this invention uses Ni and Al foils as raw materials, which are readily available and inexpensive. Non-uniform thickness preforms can be prepared simply by cutting and stacking Ni / Al foils of different thicknesses, without the need for complex machining, making them easy to manufacture. Combined with the superplastic forming capabilities of Ni / Ni2Al3 / Ni layered structural materials, it is easy to form deep-cavity thin-walled components with complex shapes. Furthermore, after hot gas expansion forming, in-situ reaction synthesis is carried out within the mold, facilitating the production of parts with high dimensional accuracy. Attached Figure Description
[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 This is a schematic diagram of an integrated forming method for NiAl alloy deep cavity thin-walled components in some embodiments of the present invention; Figure 2 for Figure 1 Exploded view of Figure a; Figure 3 This is a schematic diagram of the mold used in the integrated forming method of NiAl alloy deep cavity thin-walled components in some embodiments of the present invention.
[0017] In the diagram: 1-Hot press; 2-Hot press upper base plate; 3-Hot press upper water-cooled plate; 4-Hot press upper heat insulation plate; 5-Hot press upper mold; 6-Hot press lower mold; 7-Hot press lower heat insulation plate; 8-Hot press lower water-cooled plate; 9-Hot press lower base plate; 10-Pre-forming press; 11-Pre-forming upper base plate; 12-Pre-forming upper water-cooled plate; 13-Pre-forming upper heat insulation plate; 14-Pre-forming upper mold; 15- 16-Pre-forming lower mold; 17-Pre-forming lower heat insulation plate; 18-Pre-forming lower water cooling plate; 19-Pre-forming lower base plate; 20-Pressure control system; 21-Air expansion press; 22-Air expansion upper base plate; 23-Air expansion upper heat insulation plate; 24-Air expansion upper mold; 25-Air expansion lower mold; 26-Air expansion lower heat insulation plate; 27-Air expansion lower water cooling plate; 28-Air expansion lower base plate. Detailed Implementation
[0018] 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.
[0019] The purpose of this invention is to provide an integrated forming method for NiAl alloy deep cavity thin-walled components, so as to solve the problems existing in the prior art, which makes it easy to form deep cavity thin-walled components with complex shapes and with high forming accuracy.
[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0021] Example 1 like Figures 1-2 As shown, the present invention provides an integrated forming method for NiAl alloy deep cavity thin-walled components, comprising the following steps: wherein, step S1 corresponds to Figure 1 In Figure a, steps S2-S3 correspond to Figure 1 In Figure b, step S4 corresponds to Figure 1 In diagram c, steps S5-S6 correspond to... Figure 1 The finished product is shown in diagram d. Figure 1 Figure e in the diagram.
[0022] S1: Based on the three-dimensional model of the component, design and calculate the initial thickness, size and shape of the Ni / Al laminated foil; S2: Surface treatment of Ni / Al laminated foil; S3: Vacuum hot pressing is performed on Ni / Al laminated foil to obtain a non-uniform thickness preform with a Ni / Ni2Al3 / Ni layered structure; S4: High-temperature preforming of the Ni / Ni2Al3 / Ni layered structure non-uniform thickness preform to obtain a Ni / Ni2Al3 / Ni layered structure preform with customized wall thickness distribution; S5: Place the Ni / Ni2Al3 / Ni layered structure preform in a hot gas expansion forming mold to obtain the corresponding shape under the action of hot gas expansion; S6: Through in-situ reaction synthesis, NiAl alloy deep cavity thin-walled components are finally obtained.
[0023] This embodiment uses Ni foil and Al foil as raw materials, which are readily available and inexpensive. Non-uniform thickness preforms can be prepared simply by cutting and stacking Ni / Al foils of different thicknesses, without complex machining, making them easy to manufacture. Combined with the superplastic forming capabilities of Ni / Ni2Al3 / Ni layered structure materials, it is easy to form complex deep-cavity thin-walled components. Furthermore, after hot gas expansion forming, in-situ reaction synthesis is carried out within the mold, making it easy to produce parts with high dimensional accuracy. A step-by-step forming strategy of high-temperature preforming and hot gas expansion final forming is adopted, distributing the total deformation over two stages to avoid necking and cracking problems caused by excessive local deformation during single forming. The high-temperature preforming stage can achieve preliminary material flow and distribution under no mold constraint or simple mold constraint, obtaining a preformed component close to the final shape, reducing the mold complexity and forming pressure of the final forming stage. The hot gas expansion final forming stage is carried out within a closed mold, with uniform gas pressure distribution, enabling the formation of components with complex curved surfaces, good shape replicability, and no obvious springback deformation. The in-situ reaction takes place directly within the hot gas expansion forming mold, eliminating the need to transfer components and avoiding positioning errors caused by secondary clamping. This ensures the dimensional accuracy of the components. During the reaction, the components fit tightly into the mold cavity, eliminating tiny gaps generated during the forming process and further improving the dimensional accuracy and surface quality of the components.
[0024] In some embodiments, the surface treatment method for the Ni / Al laminated foil in step S2 involves polishing the surfaces of the Ni and Al foils until they are bright, stacking the Ni and Al foils sequentially to obtain the Ni / Al laminated foil, with the Ni foil placed on the outermost side of the laminated structure. The Ni / Al laminated foil is then immersed in a cleaning solution for cleaning, followed by cold air drying. The Ni and Al foils naturally form a dense oxide film (NiO, Al2O3) in the air. Al2O3 has a melting point as high as 2054℃ and is completely stable at hot-pressing temperatures, physically blocking the atomic diffusion and metallurgical bonding of Ni and Al. Mechanical polishing removes the original oxide film, exposing fresh, active metal surfaces, allowing Ni and Al atoms to directly contact and diffuse rapidly during hot pressing, reducing the activation energy of the interfacial reaction and shortening the hot-pressing time. The polished surface forms a uniform micro-uneven structure, effectively increasing the actual contact area between the Ni / Al layers and generating a mechanical interlocking effect. During hot pressing, the more ductile Al layer embeds itself into the microscopic pits of the Ni layer, forming a composite interface of mechanical interlocking and metallurgical bonding, resulting in high interfacial shear strength. The Ni foil, located on the outermost layer, exhibits significantly lower high-temperature reactivity with the mold steel compared to the Al foil, preventing adhesion between the blank and the mold during hot pressing. This eliminates the need for a release agent and avoids interfacial contamination introduced by release agents. Grinding generates a large amount of metal shavings and residual grinding paste. If these impurities remain at the interface, they form hard inclusions, becoming crack initiation points during forming and leading to component failure. Using a suitable cleaning solution can thoroughly dissolve and remove residual oil, grinding paste, and metal shavings, ensuring interface cleanliness. Cold air drying is performed at room temperature to avoid secondary oxidation, while the rapid airflow ensures uniform evaporation of moisture in a short time, leaving no water stains. If hot air drying is used, a new oxide film will rapidly form on the Al foil surface at high temperatures, negating the effect of grinding; furthermore, hot air drying can lead to uneven moisture evaporation and water stains.
[0025] In this embodiment, several Ni foils and several Al foils are stacked alternately, with the outermost layer being Ni foil. The thickness ratio of the Ni foil to the Al foil is designed and calculated as follows: N=n·N A (1) Where: N represents the number of atoms, n represents the amount of substance, N A Represents Avogadro's constant m = n·M (2) Where: m represents mass, n represents amount of substance, and M represents molar mass of substance. h= (3) Where: h represents height, m represents mass, ρ represents density, and S represents cross-sectional area; and ρ is also known. Ni =8.902g / cm 3 MNi =58.69 g / mol; ρ Al =2.70 g / cm3; M Al =26.98g / cm 3； By N Ni :N Al =1:1; According to formulas (1), (2), and (3), we can obtain: h Ni :h Al ≈1:1.5.
[0026] In some embodiments, the surfaces of the Ni and Al foils are polished with sandpaper. The cleaning process involves immersing the entire Ni / Al laminated foil in an acetone solution for ultrasonic cleaning for 15-20 minutes, rinsing with water, and then immersing it in an anhydrous ethanol solution for ultrasonic cleaning for 15-30 minutes. For different needs, the surface roughness can be precisely controlled by selecting sandpaper with different grits. All metal shavings generated during polishing are trapped in the lamination gaps. During overall ultrasonic cleaning, the cavitation effect of the ultrasound generates shock waves that penetrate deep into the micron-level interlayer gaps, thoroughly shaking off and removing shavings and dust, resulting in extremely low interlayer impurity content. If single-sheet cleaning is used before stacking, fingerprints, dust, fibers, and other impurities are inevitably introduced during the operation. This process completes the polishing and stacking of all foils first, followed by a single overall cleaning, and then direct hot pressing, avoiding the possibility of secondary contamination. Furthermore, multiple layers of foil structures can be cleaned at once, significantly improving cleaning efficiency compared to cleaning single foils each time. Acetone is a highly polar organic solvent with a strong dissolving ability for organic substances such as rolling oil, rust-preventive oil, and polishing paste on the surface of commercial foils. Combined with the cavitation effect of ultrasound, it can remove organic oil stains within 15 minutes. After dissolving the oil stains, acetone forms a suspension containing impurities. Water can wash away these suspended impurities and residual acetone, preventing them from redepositing on the foil surface during subsequent ethanol cleaning. Anhydrous ethanol is completely miscible with water, displacing moisture on the foil surface and between layers, preventing thermal oxidation and interfacial porosity caused by residual moisture. Ethanol can also dissolve small amounts of polar inorganic salt impurities that acetone cannot remove, achieving final cleaning. Furthermore, ethanol evaporates quickly, carrying away a large amount of heat during evaporation, lowering the foil surface temperature and effectively preventing secondary oxidation during the drying process.
[0027] In some embodiments, the hot pressing process in step S3 is carried out in a vacuum hot press furnace, and graphite sheets or sprayed graphite powder are placed on the surface of the Ni / Al laminated foil to ensure that the material does not stick to the mold during hot pressing. At the hot pressing temperature of the Ni / Al laminate, graphite does not undergo any detectable chemical reaction with Ni or Al, blocking the cross-interface diffusion of metal atoms. Graphite exists only on the upper and lower outer surfaces of the blank and does not penetrate into the internal interlayer of the Ni / Al laminate, completely unaffecting the cleanliness of the internal Ni / Al interface and the quality of metallurgical bonding. The graphite residue after hot pressing is very easy to remove: graphite sheets can be directly peeled off, and sprayed graphite powder can be completely removed by wiping with alcohol or lightly sanding with sandpaper, leaving no residue. Even if there is a trace amount of graphite residue, it will react with trace amounts of oxygen to generate gas and be discharged during the subsequent higher-temperature in-situ reaction stage, and will not form harmful inclusions in the final NiAl alloy.
[0028] In some embodiments, the vacuum hot pressing process parameters in step S3 are: temperature 550~640℃, time 2~6h, and pressure 1~20MPa. Preferably, the temperature is 620℃, the time is 4h, and the pressure is 20MPa. After hot pressing, the pressure is released, and the Ni / Ni2Al3 / Ni layered non-uniform thickness preform is taken out after cooling to room temperature in the furnace.
[0029] In some embodiments, the high-temperature preforming temperature in step S4 is selected as 750~900℃. The preferred preforming temperature is 800℃, to obtain a Ni / Ni2Al3 / Ni layered structure preform with a customized wall thickness distribution. The preform is then cooled in the furnace or slowly cooled to room temperature in the mold, and finally removed from the mold.
[0030] In some embodiments, the process parameters for hot air expansion in step S5 are a temperature of 750~900℃ and a pressure of 0.1~20MPa. The preferred hot air expansion forming temperature is 820℃ and the pressure is 15MPa.
[0031] In S4 and S5, within this temperature range, the Ni layer and Ni2Al3 layer enter a superplastic deformation state: the fine-grained structure of the Ni2Al3 layer exhibits significant high-temperature plasticity above 750℃, and the Ni layer and Ni2Al3 layer as a whole exhibit excellent high-temperature superplasticity with high elongation, enabling large deformation without cracking to be formed under low pressure.
[0032] In some embodiments, the process parameters for in-situ reaction synthesis in step S6 are: temperature 900~1200℃, time 1~4h, and pressure 5~20MPa. Preferably, the in-situ reaction synthesis parameters are: temperature 1000℃, time 2h, and pressure 20MPa. This ultimately yields a NiAl alloy deep-cavity thin-walled component, which is then cooled to room temperature in the furnace before being removed from the mold.
[0033] In some embodiments, in step S3, the Ni / Ni2Al3 / Ni layered non-uniform thickness preform is designed according to the shape and size of the preformed component and the final formed part; in step S4, the Ni / Ni2Al3 / Ni layered preform is designed according to the shape and size of the final formed part. The non-uniform thickness preform simultaneously matches the requirements of both the preforming and final forming stages, rather than just the final part. Material is precisely pre-allocated throughout the entire process, and the initial thickness is accurately calculated based on the sum of deformations at each part in both the preforming and final forming stages. By actively utilizing the law of constant volume, the material is pre-positioned to the required final location, rather than relying on long-distance material flow during forming. Combined with the subsequent two forming processes, the limiting bulging ratio can be significantly improved, enabling the forming of ultra-deep cavity thin-walled curved surface components. The non-uniform thickness preform can be prepared simply by cutting Ni / Al foils of different thicknesses and stacking them according to the design, without the need for complex machining or welding. It has high thickness accuracy and can achieve arbitrarily complex thickness distribution designs, including continuously varying thicknesses and locally abrupt thicknesses, offering extremely high design freedom. Preformed components are not simply approximate shapes, but rather optimal intermediate shapes precisely calculated based on the shape and dimensions of the final formed part. Their sole purpose is to create the most ideal deformation conditions for the final forming stage, evenly distributing the total deformation across both the preforming and final forming stages. This ensures that the maximum deformation in each stage is controlled within the material's safe forming limit, preventing necking and cracking caused by localized deformation exceeding the limit during one-step forming. Through the design of the preformed shape, material flow is actively guided to areas difficult to deform, such as the top of deep cavities and corners, reducing strain in these areas during final forming. This results in a more uniform stress-strain distribution during the final forming stage, avoiding cracks and uneven deformation caused by stress concentration.
[0034] Example 2 like Figure 3 As shown in the figure, this embodiment illustrates the mold usage process of the integrated forming method for NiAl alloy deep cavity thin-walled components: The hot pressing mold in step S3 includes a lower hot pressing base plate 9, an upper hot pressing base plate 2, a lower hot pressing mold 6, an upper hot pressing mold 5, an upper hot pressing heat insulation plate 4, a lower hot pressing heat insulation plate 7, an upper hot pressing water-cooling plate 3, a lower hot pressing water-cooling plate 8, and a hot pressing press 1; the lower hot pressing base plate 9 and the upper hot pressing base plate 2 are arranged between the lower hot pressing base plate 9 and the upper hot pressing base plate 2, the upper hot pressing base plate 2 is connected to the upper hot pressing water-cooling plate 3, the lower hot pressing base plate 9 is connected to the lower hot pressing water-cooling plate 8, and a heat insulation plate is arranged between the upper hot pressing water-cooling plate 3 and the lower hot pressing water-cooling plate 8. The upper heat insulation plate 4 and the lower heat insulation plate 7 are pressed together. The upper water-cooled plate 3 is connected to the upper heat insulation plate 4, and the lower water-cooled plate 8 is connected to the lower heat insulation plate 7. The upper heat insulation plate 4 and the lower heat insulation plate 7 are arranged between the upper heat insulation plate 4 and the lower heat insulation plate 7. The upper heat insulation plate 4 is connected to the upper heat insulation plate 5, and the lower heat insulation plate 7 is connected to the lower heat insulation plate 6. The hot pressing press 1 is arranged on the upper part of the hot pressing base plate 2. During the hot pressing process, several Ni foils and several Al foils that are alternately stacked gradually combine into one.
[0035] The preforming mold in step S4 includes a preforming lower base plate 18, a preforming upper base plate 11, a preforming lower mold 15, a preforming upper mold 14, a preforming upper heat insulation plate 13, a preforming lower heat insulation plate 16, a preforming upper water-cooled plate 12, a preforming lower water-cooled plate 17, and a preforming press 10. The preforming lower water-cooled plate 17 and the preforming upper water-cooled plate 12 are arranged between the preforming lower base plate 18 and the preforming upper base plate 11. The preforming upper base plate 11 is connected to the preforming upper water-cooled plate 12, and the preforming lower base plate 18 is connected to the preforming lower water-cooled plate 17. The preforming upper heat insulation plate 13 and the preforming lower heat insulation plate 16 are arranged between the preforming upper water-cooled plate 12 and the preforming lower water-cooled plate 17. The preformed upper water-cooled plate 12 is connected to the preformed upper heat insulation plate 13, and the preformed lower water-cooled plate 17 is connected to the preformed lower heat insulation plate 16. The preformed upper heat insulation plate 13 and the preformed lower heat insulation plate 16 are arranged between the preformed upper heat insulation plate 13 and the preformed lower heat insulation plate 16. The preformed upper heat insulation plate 13 is connected to the preformed upper mold 14, and the preformed lower heat insulation plate 16 is connected to the preformed lower mold 15. The preformed press 10 is arranged on the upper part of the preformed upper base plate 11. During the preformation process, the Ni / Ni2Al3 / Ni layered structure non-uniform thickness preform is preformed at high temperature through the preformed mold to obtain a Ni / Ni2Al3 / Ni layered structure preformed component with customized wall thickness distribution.
[0036] In step S5, the hot air expansion forming mold includes a lower air expansion base plate 28, an upper air expansion base plate 21, a lower air expansion mold 25, an upper air expansion mold 24, an upper air expansion heat insulation plate 23, a lower air expansion heat insulation plate 26, an upper air expansion water-cooled plate 22, a lower air expansion water-cooled plate 27, and an air expansion press 20. The lower air expansion water-cooled plate 27 and the upper air expansion water-cooled plate 22 are arranged between the lower air expansion base plate 28 and the upper air expansion base plate 21. The upper air expansion base plate 21 is connected to the upper air expansion water-cooled plate 22, and the lower air expansion base plate 28 is connected to the lower air expansion water-cooled plate 27. An upper air-expanded heat insulation plate 23 and a lower air-expanded heat insulation plate 26 are arranged between the cold plate 22 and the lower air-expanded water-cooled plate 27. The upper air-expanded water-cooled plate 22 is connected to the upper air-expanded heat insulation plate 23, and the lower air-expanded water-cooled plate 27 is connected to the lower air-expanded heat insulation plate 26. An upper air-expanded mold 24 and a lower air-expanded mold 25 are arranged between the upper air-expanded heat insulation plate 23 and the lower air-expanded heat insulation plate 26. The upper air-expanded heat insulation plate 23 is connected to the upper air-expanded mold 24, and the lower air-expanded heat insulation plate 26 is connected to the lower air-expanded mold 25. An air-expanding press 20 is arranged on the upper part of the upper air-expanded base plate 21. The upper air-expanded mold 24 has vertical and horizontal channels that are connected to each other. The horizontal channel is connected to the high-pressure air source of the pressurization control system 19. The pressurization control system 19 is used to control the gas expansion pressure.
[0037] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.
Claims
1. An integrated forming method for a NiAl alloy deep-cavity thin-walled component, characterized in that: Includes the following steps: S1: Based on the three-dimensional model of the component, design and calculate the initial thickness, size and shape of the Ni / Al laminated foil; S2: Surface treatment of Ni / Al laminated foil; S3: Vacuum hot pressing is performed on Ni / Al laminated foil to obtain a non-uniform thickness preform with a Ni / Ni2Al3 / Ni layered structure; S4: High-temperature preforming of the Ni / Ni2Al3 / Ni layered structure non-uniform thickness preform to obtain a Ni / Ni2Al3 / Ni layered structure preform with customized wall thickness distribution; S5: Place the Ni / Ni2Al3 / Ni layered structure preform in a hot gas expansion forming mold to obtain the corresponding shape under the action of hot gas expansion; S6: Through in-situ reaction synthesis, NiAl alloy deep cavity thin-walled components are finally obtained.
2. The integrated forming method for NiAl alloy deep cavity thin-walled components according to claim 1, characterized in that: The surface treatment method for the Ni / Al laminated foil in step S2 is to polish the surfaces of the Ni foil and Al foil to a bright finish, and stack the Ni foil and Al foil sequentially to obtain the Ni / Al laminated foil, with the Ni foil placed on the outermost side of the laminated structure. Then, the Ni / Al laminated foil is placed in a cleaning solution for cleaning, and after cleaning, it is dried with cold air.
3. The integrated forming method for NiAl alloy deep cavity thin-walled components according to claim 2, characterized in that: The surfaces of Ni and Al foils are polished with sandpaper. The cleaning process involves immersing the entire Ni / Al laminated foil in an acetone solution for ultrasonic cleaning for 15-20 minutes, rinsing it with water, and then immersing it in anhydrous ethanol solution for ultrasonic cleaning for 15-30 minutes.
4. The integrated forming method for NiAl alloy deep cavity thin-walled components according to claim 1, characterized in that: In step S3, the hot pressing process is carried out in a vacuum hot press furnace.
5. The integrated forming method for NiAl alloy deep cavity thin-walled components according to claim 1, characterized in that: In step S3, before hot pressing, graphite sheets are placed on the surface of the Ni / Al laminated foil or graphite powder is sprayed onto it.
6. The integrated forming method for NiAl alloy deep cavity thin-walled components according to claim 1, characterized in that: In step S3, the vacuum hot pressing process parameters are: temperature 550~640℃, time 2~6h, and pressure 1~20MPa.
7. The integrated forming method for NiAl alloy deep cavity thin-walled components according to claim 1, characterized in that: In step S4, the high-temperature preforming temperature is selected as 750~900℃.
8. The integrated forming method for NiAl alloy deep cavity thin-walled components according to claim 1, characterized in that: The process parameters for thermal expansion in step S5 are: temperature 750~900℃ and air pressure 0.1~20MPa.
9. The integrated forming method for NiAl alloy deep cavity thin-walled components according to claim 1, characterized in that: The process parameters for the in-situ reaction synthesis in step S6 are: temperature 900~1200℃, time 1~4h, and pressure 5~20MPa.
10. The integrated forming method for NiAl alloy deep cavity thin-walled components according to claim 1, characterized in that: In step S3, the Ni / Ni2Al3 / Ni layered structure non-uniform thickness preform is designed according to the shape and size of the preformed component and the final formed part; in step S4, the Ni / Ni2Al3 / Ni layered structure preformed component is designed according to the shape and size of the final formed part.