A method of improving the joining capability of titanium-based materials in superplastic forming / diffusion bonding and a system thereof

Abstract

The application relates to a method for improving the connection capability of titanium-based materials in superplastic forming / diffusion bonding and a system thereof, belonging to the field of titanium alloy material heat treatment and hot working. In view of the problem of connection quality decline of hydrogenated titanium alloy in the high-temperature SPF / DB process due to hydrogen escape, hydrogen is mixed in an inert gas pressure source to improve the environmental hydrogen partial pressure to inhibit hydrogen element loss, so that the diffusion bonding capability is improved. The specific steps include: hydrogenation treatment is performed on titanium alloy plates, the plates are cleaned and sprayed with a release agent, then the plates are placed in a mold to perform vacuumization and argon-hydrogen mixed gas is introduced as a pressure source, forming and connection are completed through rapid heating and pressure keeping; after the process is completed, vacuum annealing is performed in a dehydrogenation temperature range to remove hydrogen elements, and argon is introduced to accelerate cooling. The application can effectively retain hydrogen elements to improve joint quality, simultaneously simplify the dehydrogenation step, and is suitable for the field of titanium-based material hot working, especially the field of hydrogenated titanium alloy superplastic forming / diffusion bonding technology.

Description

Technical Field

[0001] This invention belongs to the field of heat treatment and heat processing of titanium-based materials, and specifically relates to a method for improving diffusion bonding capability and joint quality of titanium-based materials in superplastic processes / diffusion bonding. Background Technology

[0002] Superplastic forming / diffusion bonding (SPF / DB) is a near-net-shape forming technology that completes bonding and forming within a single process window, enabling the manufacture of hollow or hybrid hollow-solid structures. This technology allows for the integral fabrication of complex thin-walled parts, offering unique advantages in improving structural integrity and load-bearing efficiency. However, the process is time-consuming and involves high temperatures, which makes the microstructure of titanium-based materials prone to growth, resulting in grain coarsening and a significant reduction in the mechanical properties of the components.

[0003] The pressure source in the SPF / DB process is a key element in achieving material forming and bonding, its function including driving the deformation of superplastic materials and promoting atomic diffusion bonding. Commonly used pressure source types include gas pressure, mechanical pressure, and vacuum-assisted pressure. These pressure sources are often used together in most cases to handle the fabrication of complex surface structures; therefore, the processing environment for SPF / DB is generally a vacuum or inert gas environment. However, at high temperatures, the prolonged exposure to inert gas and vacuum environments in SPF / DB causes continuous hydrogen loss from the titanium-based material. Although spraying glass lubricant onto the sample surface can prevent some hydrogen leakage, the glass lubricant is extremely difficult to remove after processing and is unsuitable for forming components with internal structures. Furthermore, existing studies mostly attribute the decline in mechanical properties of titanium alloys after SPF / DB to grain coarsening, and the most important factors for grain coarsening are excessively high forming temperature and excessively long holding time. The rapid loss of hydrogen in SPF / DB of titanium hydride-based materials will greatly weaken or even eliminate the low-temperature superplasticity and hydrogen-promoted diffusion bonding properties of the material, resulting in higher SPF / DB temperatures and longer holding times. Obviously, it is extremely detrimental not to limit the loss of hydrogen.

[0004] Therefore, the aforementioned technological blind spots have put the existing SPF / DB process in a dilemma. Summary of the Invention

[0005] The purpose of this invention is to improve the diffusion bonding capability of titanium-based materials in superplastic forming / diffusion bonding. By mixing a certain amount of hydrogen into the inert gas that provides the pressure source, the characteristic of hydrogen removal in high-temperature environment can be greatly suppressed, thereby improving the diffusion bonding capability of titanium hydride alloys.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for improving the bonding capability of titanium-based materials in superplastic forming / diffusion bonding, the method comprising the following steps:

[0008] Step S1: After the surface of the titanium alloy plate is pretreated, it is placed in a vacuum hydrogen furnace for hydrogen treatment. The target hydrogen content is obtained by controlling the temperature, time and hydrogen pressure.

[0009] Step S2: Lay the hydrogenated board onto a mask and spray boron nitride release agent onto the non-connection areas;

[0010] Step S3: Place the sprayed sheet into the superplastic forming mold and press and seal it. Connect the vacuum equipment and evacuate to 10°C. -1 ~10 -5 Pa;

[0011] Step S4: Introduce a mixture of argon and hydrogen gas;

[0012] Step S5: Heat to the superplastic forming temperature at a rate of ≥25℃ / min, and use the mixed gas as a pressure source for superplastic forming and diffusion bonding.

[0013] Step S6: Cool down to a dehydrogenation temperature range above 600℃ but below the forming temperature, then vacuum and keep warm for 2-5 hours;

[0014] Step S7: Introduce high-purity argon gas between the mold and the sheet metal to provide a medium for accelerating component cooling.

[0015] Furthermore, the above pretreatment specifically involves: grinding the titanium alloy sheet to 800#, immersing it in anhydrous ethanol for ultrasonic cleaning, and then drying it.

[0016] Furthermore, in step S4 above, the volume percentage of hydrogen in the mixed gas is 1% to 5%.

[0017] Furthermore, in step S4 above, the volume percentage of argon in the mixed gas is ≥95%.

[0018] Furthermore, in step S5 above, the gas pressure difference of the pressure source is 0.1 to 5 MPa.

[0019] Furthermore, in step S6 above, the dehydrogenation temperature is 600–750°C, and the vacuum degree is ≤10. -3 Pa.

[0020] Furthermore, after the heat preservation in step S6 is completed, the cooling stage begins directly, without the need for additional heating for dehydrogenation.

[0021] The method for improving the bonding capability of titanium-based materials in superplastic forming / diffusion bonding described in this invention can be embedded in a computer storage device. Therefore, this invention also provides a system for improving the bonding capability of titanium-based materials in superplastic forming / diffusion bonding, the system including a storage device for executing the above-described method and steps for improving the bonding capability of titanium-based materials in superplastic forming / diffusion bonding.

[0022] Furthermore, the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, performs a method for improving the bonding capability of titanium-based materials in superplastic forming / diffusion bonding as described in any of the preceding claims.

[0023] Furthermore, the present invention also provides a computer device including a memory and a processor, wherein the memory stores a computer program, and when the processor runs the computer program stored in the memory, the processor executes a method for improving the bonding capability of titanium-based materials in superplastic forming / diffusion bonding as described in any of the above claims.

[0024] The beneficial effects of this invention are as follows:

[0025] 1. This invention provides a method for improving the bonding capability of titanium-based materials in superplastic forming / diffusion bonding. This method is used to suppress hydrogen loss during superplastic forming / diffusion bonding (SPF / DB) of titanium-based materials. Since the pressure source for SPF / DB is an inert gas and vacuum environment, this high temperature and zero hydrogen partial pressure (negative hydrogen partial pressure) cause continuous hydrogen loss from the hydrogenated material, thus preventing good diffusion bonding. This invention improves the diffusion bonding quality by mixing a certain amount of hydrogen into the inert gas of the pressure source, thereby increasing the hydrogen partial pressure and retaining hydrogen in the alloy.

[0026] Furthermore, compared with traditional processes, the innovation of this invention lies in the fact that it is not merely about mixing in a certain amount of hydrogen; this invention also incorporates the following elements:

[0027] (1) Control the loading timing: Evacuate the vacuum to 10 using a vacuum device. -1 Pa~10 -5 Hydrogen can only be injected after the process of pa (presumably referring to a specific process or process) to prevent residual oxygen, nitrogen, and other impurities from hindering diffusion and bonding, which could lead to the formation of oxides or pores at the interface, reducing the bonding strength and density. Additionally, if residual oxygen remains in the environment, it may form water vapor or other compounds, leading to localized oxidation or contamination.

[0028] (2) Control the accuracy of hydrogen partial pressure: limit the amount of hydrogen added to within the critical hydrogen embrittlement threshold (1-5%), breaking through the two extreme limitations of the traditional process of "zero hydrogen" or "high hydrogen".

[0029] (3) Process sequence innovation: A three-stage process chain of “vacuum impurity removal → micro-hydrogen loading → vacuum annealing” is adopted to establish a dynamic balance of hydrogen partial pressure;

[0030] (4) Quality assurance system: Through the coupling design of hydrogen loading parameters and vacuum annealing, the connection strength (interface hydrogen concentration optimization) and service reliability (residual hydrogen elimination) are improved simultaneously.

[0031] 2. This invention provides a method for removing hydrogen from titanium hydride alloys after superplastic forming / diffusion bonding by vacuum annealing and holding within the dehydrogenation temperature range, without requiring reheating after forming to remove hydrogen.

[0032] 3. This invention aims to address the issue of weakened mechanical properties in titanium-based materials after SPF / DB (Special Pressure Fiber / Deep Grain Growth). It utilizes the temporary alloying effect of hydrogen, employing a thermal hydrogenation process to infiltrate hydrogen into the titanium alloy. This process reduces peak stress and inhibits grain growth during SPF / DB.

[0033] This invention is applicable to the field of hot working of titanium-based materials, especially to the field of superplastic forming / diffusion bonding technology of titanium hydride alloys. Attached Figure Description

[0034] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 This is a flowchart of a method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding proposed in this invention;

[0036] Figure 2 This is a schematic diagram of the hydrogenated Ti65 titanium alloy superplastic forming / diffusion bonding equipment described in this invention;

[0037] Figure 3 This describes the morphology of the component after SPF / DB hydrogenation of Ti65 titanium alloy as described in this invention;

[0038] Figure 4 This refers to the weld of the hydrogenated Ti65 titanium alloy described in this invention after SPF / DB, wherein... Figure 4 (a) is a weld under a normal inert gas pressure source. Figure 4 (b) is the weld under a mixed gas (99%Ar +1%H2) pressure source. Detailed Implementation

[0039] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of this application with unnecessary detail.

[0040] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

[0041] Implementation Method 1: Combination Figure 1 This embodiment describes a method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding. The purpose is to improve the diffusion bonding ability of titanium hydride alloys in superplastic forming / diffusion bonding. By mixing a certain amount of hydrogen into the inert gas that provides the pressure source, the characteristic of hydrogen removal in high-temperature environment can be greatly suppressed, thereby improving the diffusion bonding ability of titanium hydride alloys.

[0042] like Figure 1 As shown, the method includes the following steps:

[0043] Step S1: After the surface of the titanium alloy plate is pretreated, it is placed in a vacuum hydrogen furnace for hydrogen treatment. The target hydrogen content is obtained by controlling the temperature, time and hydrogen pressure.

[0044] Step S2: Lay the hydrogenated board onto a mask and spray boron nitride release agent onto the non-connection areas;

[0045] Step S3: Place the sprayed sheet into the superplastic forming mold and press and seal it. Connect the vacuum equipment and evacuate to 10°C. -1 ~10 -5 Pa;

[0046] Step S4: Introduce a mixture of argon and hydrogen gas;

[0047] Step S5: Heat to the superplastic forming temperature at a rate of ≥25℃ / min, and use the mixed gas as a pressure source for superplastic forming and diffusion bonding.

[0048] Step S6: Cool down to a dehydrogenation temperature range above 600℃ but below the forming temperature, then vacuum and keep warm for 2-5 hours;

[0049] Step S7: Introduce high-purity argon gas between the mold and the sheet metal to provide a medium for accelerating component cooling.

[0050] In the field of metal processing, superplastic forming / diffusion bonding (SPF / DB) technology has extremely stringent environmental requirements, typically requiring a vacuum or inert gas environment. However, titanium alloys face a thorny problem under high-temperature SPF / DB processes—hydrogen in titanium hydride alloys continuously escapes under the zero-hydrogen pressure or negative-hydrogen pressure environment created by inert gas or vacuum. Although spraying glass lubricant onto the sample surface can prevent hydrogen leakage to some extent, this method has serious drawbacks. On the one hand, glass lubricant is extremely difficult to remove after processing; on the other hand, it is completely unsuitable for forming components with complex internal structures.

[0051] Given the characteristic of titanium hydride alloys releasing hydrogen at high temperatures, this embodiment innovatively adjusts the loading gas pressure in the SPF / DB process, cleverly incorporating an appropriate amount of hydrogen to precisely balance the partial pressure of hydrogen in the environment. Specifically, by mixing a certain amount of hydrogen into the loading gas pressure during the SPF / DB process to balance the partial pressure of hydrogen in the environment, a hydrogen storage balance equation for the titanium alloy is provided. The reverse dynamics of this approach help to suppress hydrogen loss from titanium hydride alloys at high temperatures. This innovative measure injects reverse dynamics into the hydrogen storage balance equation of titanium alloys, deeply intervening in the process from a fundamental perspective. It effectively suppresses hydrogen loss from titanium hydride alloys under high-temperature environments, completely breaking the traditional dilemma that simply adding hydrogen is ineffective, and opening up a new path for the processing of titanium alloys with SPF / DB.

[0052] Furthermore, the hydrogenation treatment (thermal hydrogen treatment, THP) proposed in this embodiment, as a temporary alloying method, has a significant promoting effect on the diffusion bonding of difficult-to-deform and difficult-to-diffuse titanium-based materials (such as TiAl alloys, Ti2AlNb and TC4 titanium alloys, etc.), mainly in the following aspects:

[0053] 1. Reduce diffusion connection temperature:

[0054] This embodiment uses hydrogen as an interstitial atom, which can significantly reduce the α→β phase transformation temperature of titanium alloys and promote the formation of the high-temperature β phase. The β phase has a higher diffusion coefficient and plastic deformation capacity, which allows for good diffusion bonding at lower temperatures (such as 700°C), avoiding grain coarsening caused by high temperatures.

[0055] 2. Enhanced interdiffusion of atoms:

[0056] Hydrogen diffuses much faster in titanium alloys than other alloying elements (such as Al and V). Its presence can promote grain boundary diffusion and volume diffusion, and increase the mobility of interface atoms.

[0057] 3. Improves plastic deformation capacity

[0058] The introduction of hydrogen can reduce the rheological stress and Young's modulus of materials, improve high-temperature plasticity, and make the materials more prone to creep and interfacial contact during the bonding process, thus promoting pore closure. For example, when hydrogenated TC4 titanium alloy is diffusely bonded at 840℃, the interfacial pore closure rate is significantly improved.

[0059] 4. Optimize interface integration quality:

[0060] Hydrogenation can reduce residual stress at the interface and prevent the formation of brittle intermetallic compounds.

[0061] 5. Promotes grain boundary activation and dynamic recrystallization

[0062] Hydrogen segregation at grain boundaries can increase grain boundary activity, promote dynamic recrystallization, refine grains, and thus improve the metallurgical bonding quality of the interface.

[0063] Although hydrogenation can significantly improve diffusion bonding performance, it should be noted that the hydrogen content in this embodiment needs to be precisely controlled (0.1-0.5 wt%). Too high a content will lead to hydrogen embrittlement and residual hydrides. Vacuum annealing is required after bonding to remove residual hydrogen and avoid hydrogen-induced delayed cracking.

[0064] In summary, the hydrogenation treatment proposed in this embodiment provides a feasible solution for low-temperature and efficient diffusion bonding of titanium-based materials, which has important applications in aerospace, nuclear industry and other fields.

[0065] Implementation Method 2: This implementation method provides a detailed description of a method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding, as proposed in Implementation Method 1 above.

[0066] Step S1: After the surface of the titanium alloy plate is pretreated, it is placed in a vacuum hydrogen furnace for hydrogen treatment. The target hydrogen content is obtained by controlling the temperature, time and hydrogen pressure.

[0067] Specifically:

[0068] The titanium alloy sheet is ground to 800#, ultrasonically cleaned in anhydrous ethanol, dried, and then placed in a vacuum hydrogen furnace for hydrogen treatment. The required amount of hydrogen is obtained by controlling the appropriate time, temperature, and hydrogen pressure (e.g., heating to 700°C and holding for 1 hour).

[0069] Step S2: Lay the hydrogenated board onto a mask and spray boron nitride release agent onto the non-connection areas;

[0070] Specifically:

[0071] Before superplastic forming / diffusion bonding, the hydrogenated plate is ultrasonically cleaned again in anhydrous ethanol, dried, and then a mask is laid and a boron nitride release agent is sprayed to protect the interface areas that do not need diffusion bonding from being bonded.

[0072] Step S3: Place the sprayed sheet into the superplastic forming mold and press and seal it. Connect the vacuum equipment and evacuate to 10°C. -1 ~10 -5 Pa;

[0073] Specifically:

[0074] Next, the hydrogenated sheet is placed into a superplastic forming mold. The mold compacts the sheet to ensure no air leakage. The pressure source pipeline is connected to a vacuum device, and a vacuum of 10 is achieved at room temperature. -1 Pa~10 -5 pa.

[0075] Step S4: Introduce a mixture of argon and hydrogen gas;

[0076] Specifically:

[0077] Once the vacuum level reaches the level required in step S3 above, a mixture of argon and hydrogen gas is introduced.

[0078] Furthermore, argon is used as the pressurizing gas for the SPF, and its volume percentage is no less than 95% to balance atmospheric pressure and prevent air backflow; hydrogen has a volume percentage of 1% to 5%.

[0079] Furthermore, stop filling the gas when the vacuum gauge reads 0.05 MPa, because the gas will expand when heated, so a margin needs to be left.

[0080] Step S5: Heat to the superplastic forming temperature at a rate of ≥25℃ / min, and use the mixed gas as a pressure source for superplastic forming and diffusion bonding.

[0081] Specifically:

[0082] After completing step S4 above, the temperature is rapidly increased until the superplastic forming temperature is reached. Then, the mixed gas is used as a pressure source for superplastic forming / diffusion bonding.

[0083] Furthermore, this embodiment specifies a heating rate of ≥25°C / min to retain hydrogen in the titanium hydride alloy as much as possible.

[0084] Step S6: Cool down to a dehydrogenation temperature range above 600℃ but below the forming temperature, then vacuum and keep warm for 2-5 hours;

[0085] Specifically:

[0086] After the SPF / DB process is completed, the temperature is lowered by 50–200°C (in practical applications, it should still be higher than 600°C, as this temperature is the dehydrogenation temperature of titanium alloys), and the vacuum level is still reduced to 10 through the gas supply pipeline. -3 Pa and heat-preservation for 2-5 hours is a step to remove hydrogen from the components.

[0087] Step S7: Introduce high-purity argon gas between the mold and the sheet metal to provide a medium for accelerating component cooling.

[0088] Specifically:

[0089] After step S6 is completed, appropriate high-purity argon gas is introduced into the cavity between the mold and the sheet to provide cooling. This method can provide a medium for rapid cooling to meet the requirements of rapid cooling of components.

[0090] Implementation Method 4: Combination Figure 2 This embodiment describes a system for improving the bonding capability of titanium hydride alloys in superplastic forming / diffusion bonding, used to implement the method for improving the bonding capability of titanium-based materials in superplastic forming / diffusion bonding as described in Embodiment 1 or 2 above. The system is as follows: Figure 2 As shown, the specific structure includes two pressure source assemblies, an upper mold, and a lower mold;

[0091] The upper mold and the lower mold are each equipped with a pressure source assembly;

[0092] The pressure source assembly includes an argon cylinder, a hydrogen generator, a gas mixing system, a vacuum device, and a vacuum gauge;

[0093] The vacuum equipment is used to evacuate the upper and lower molds;

[0094] The gas mixing system is used to mix hydrogen in the hydrogen generator and argon in the argon cylinder in a certain proportion. After the vacuum degree of the upper and lower molds reaches the required level, the mixed argon + hydrogen is introduced.

[0095] Implementation Method 5: This implementation method is based on the system for improving the bonding ability of titanium hydride alloys in superplastic forming / diffusion bonding as described in Implementation Method 4 above, with the addition of a computer. The computer is equipped with a storage device, and the storage device is embedded with a method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding as described in any of the above embodiments.

[0096] Furthermore, this embodiment also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, performs a method for improving the bonding capability of titanium-based materials in superplastic forming / diffusion bonding as described in any of the above embodiments.

[0097] Furthermore, this embodiment also provides a computer device, which includes a memory and a processor. The memory stores a computer program. When the processor runs the computer program stored in the memory, the processor executes a method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding as described in any of the above embodiments.

[0098] This embodiment provides a computer device, the hardware of which is a general-purpose model and not shown in the figure. The system includes a processor and a memory, which can be connected via a bus or other means. The memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs and modules, as well as corresponding program instructions / modules. The processor executes various functional applications and data processing by running the non-transitory software programs, instructions and modules stored in the memory, so as to realize the method and steps of improving the connection capability of titanium hydride alloy in superplastic forming / diffusion bonding in the above method embodiment.

[0099] Implementation Method Six: Combination Figure 3 and Figure 4 This embodiment describes the specific application of a method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding, as proposed in the above embodiments.

[0100] Specifically:

[0101] First, connect the system proposed in Embodiment 4 above for improving the bonding capability of titanium hydride alloys in superplastic forming / diffusion bonding; then, stack two titanium hydride alloy sheets together and perform superplastic forming / diffusion bonding for integrated forming, using a mixture of argon and hydrogen as a pressure source to provide the pressure required for SPF / DB. The specific steps are as follows:

[0102] Step S1: Two Ti65 titanium alloy plates, each 2mm thick and 50mm x 50mm in size, were polished to 800#, ultrasonically cleaned, and dried before being placed in a hydrogen furnace for hydrogen treatment. After heating to 700℃ and holding for 1 hour, a 0.3wt% H hydrogenated Ti65 titanium alloy was prepared. Figure 3 As shown;

[0103] Step S2: Before heating, press the sheet metal tightly with a pressure head to prevent air leakage. Use a vacuum pump to evacuate the cavity between the mold and the sheet metal to achieve a vacuum level of 5×10⁻⁶. -2 Pa, then fill with a mixed gas (99% high-purity Ar and 1% high-purity H2) in a volume ratio to balance the atmospheric pressure. Stop filling when the vacuum gauge shows 0.05 MPa (leaving a margin to account for the thermal expansion of the gas);

[0104] Step S3: Start heating. Heat the material to 850°C at a rate of 25°C / min and hold for 10 minutes. Introduce 3MPa mixed gas into the upper mold to provide expansion pressure and 1MPa mixed gas into the lower mold to provide support back pressure. With a pressure difference of 2MPa, the sheet material deforms downward.

[0105] After step S4, heat preservation and pressure holding for 1 hour, once the sheet material has completely adhered to the mold, rapidly cool to 700℃. First, evacuate the lower mold to a vacuum level of approximately 100Pa, then evacuate the upper mold, ultimately achieving a vacuum level of 5×10⁻⁶ between both molds. -3 Near Pa.

[0106] Step S5, at 650℃ and 5×10 -3 The material is kept at a vacuum level of 0.08 MPa for 3 hours to remove hydrogen. After dehydrogenation, cooling begins. An appropriate amount of argon gas is introduced into the cavity between the mold and the sheet metal to make the vacuum gauge show a pressure of 0.08 MPa. This step is to provide a cooling medium to accelerate the cooling process.

[0107] Finally, we get the following: Figure 4 The weld of hydrogenated Ti65 titanium alloy after SPF / DB is shown, in which Figure 4 (a) is a weld under a normal inert gas pressure source. Figure 4 (b) is a weld under a mixed gas (99% Ar + 1% H2) pressure source.

[0108] After the Figure 4 (a) and Figure 4 (b) By comparison, it can be found that the weld under the mixed gas (99% Ar + 1% H2) pressure source has fewer bubbles and higher connection quality than the weld under the ordinary inert gas pressure source.

[0109] In summary, this invention provides a hydrogen partial pressure control method for optimizing the interface performance of superplastic forming / diffusion bonding (SPF / DB) in titanium-based materials. The core of this method lies in addressing the problem of decreased diffusion bonding quality caused by hydrogen escape from titanium-based materials under high temperature and low hydrogen partial pressure conditions through multi-parameter synergistic control of the hydrogen environment. Specific technical solutions include the following innovations:

[0110] 1. The dynamic control mechanism of hydrogen partial pressure in the SPF / DB process adopts a technical approach that combines vacuum pretreatment with gradient hydrogen partial pressure loading:

[0111] Vacuum pretreatment stage: First, the vacuum level of the reaction chamber is precisely controlled to 10. -1 ~10 -5 Within the Pa range, it ensures the removal of interfering gases such as oxygen and nitrogen, eliminates the obstruction of hydrogen diffusion by the surface oxide layer, prevents the formation of oxides or pores at the interface, and reduces the connection strength and density; it also prevents the formation of water vapor or other compounds if residual oxygen in the environment may lead to local oxidation or pollution.

[0112] Gradient hydrogen partial pressure loading stage: After establishing a vacuum environment, this invention introduces hydrogen into an inert gas (argon) in a quantitative manner. By strictly limiting the mixing ratio of hydrogen volume percentage (1% to 5%) and argon percentage (≥95%), a micro-hydrogen partial pressure environment is formed, which not only inhibits the escape of hydrogen elements from the material, but also avoids the risk of hydrogen embrittlement.

[0113] 2. Synergistic effect principle of hydrogen environment: The core difference between this invention and conventional inert gas environment lies in the timing combination of vacuum pretreatment and hydrogen partial pressure loading. This not only retains the high purity advantage of the vacuum environment, but also achieves interface hydrogen concentration regulation through trace hydrogen supplementation. By utilizing the surface activation effect of hydrogen, it promotes titanium atom diffusion while suppressing hydrogen escape, thus achieving dual strengthening of the interface metallurgical bond.

[0114] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0115] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding, characterized in that, The method is as follows: S1. After surface pretreatment of titanium alloy plates, they are placed in a vacuum hydrogen furnace for hydrogen treatment. The target hydrogen content is obtained by controlling the temperature, time and hydrogen pressure. S2. Lay the hydrogenated sheet material onto a mask and spray boron nitride release agent onto the non-bonding areas to protect the interface areas that do not require diffusion bonding from being bonded. S3. Place the sprayed sheet into the superplastic forming mold and press and seal it. Connect the vacuum equipment to evacuate to 10. -1 ~10 - 5 Pa, to remove oxygen and nitrogen impurities from the gas; S4. Introduce a mixture of argon and hydrogen, wherein the volume percentage of hydrogen is 1% to 5% and the volume percentage of argon is ≥95%. The trace amount of hydrogen in the mixture increases the partial pressure of hydrogen in the environment to suppress the escape of hydrogen elements from the titanium hydride-based material during superplastic forming / diffusion bonding. S5. Heat to the superplastic forming temperature at a rate of ≥25℃ / min, and use the mixed gas as a pressure source for superplastic forming and diffusion bonding. S6. Cool the temperature to a dehydrogenation temperature range above 600℃ but below the forming temperature, and evacuate to a vacuum degree ≤10. -3 Pa and heat preservation for 2~5 hours to remove hydrogen from the components, and after the heat preservation is completed, the cooling stage is directly started without additional heating to remove hydrogen; S7. High-purity argon gas is introduced between the mold and the sheet metal to provide a medium for accelerating component cooling.

2. The method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding according to claim 1, characterized in that, The pretreatment process involves grinding the titanium alloy sheet to 800#, immersing it in anhydrous ethanol for ultrasonic cleaning, and then drying it.

3. The method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding according to claim 1, characterized in that, The gas pressure difference of the pressure source in S5 is 0.1~5MPa.

4. A system for improving the bonding capability of titanium-based materials in superplastic forming / diffusion bonding, characterized in that, The system includes a storage device for performing the method and steps of claim 1.

5. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, performs a method according to any one of claims 1-3 for improving the bonding capability of titanium-based materials in superplastic forming / diffusion bonding.

6. A computer device, characterized in that, The device includes a memory and a processor, wherein the memory stores a computer program, and when the processor runs the computer program stored in the memory, the processor executes a method for improving the bonding capability of titanium-based materials in superplastic forming / diffusion bonding as described in any one of claims 1-3.

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