Method and system for improving bonding capacity of titanium-based material in superplastic forming / diffusion bonding

Abstract

The invention discloses a method and a system for improving the bonding capacity of a titanium-based material in superplastic forming / diffusion bonding, and belongs to the field of titanium alloy material heat treatment and hot working. In order to solve the problem that in the prior art, the connection quality is reduced due to hydrogen dissipation in the high-temperature SPF / DB process of titanium hydride alloy, hydrogen is mixed into an inert gas pressure source, the environmental hydrogen partial pressure is increased to inhibit hydrogen element loss, and therefore the diffusion connection capacity is improved. The method comprises the specific steps that a titanium alloy plate is subjected to hydrogen treatment, cleaned and sprayed with a separant, then the titanium alloy plate is placed in a mold to be vacuumized, argon-hydrogen mixed gas is introduced to serve as a pressure source, and forming and connecting are completed through rapid heating and pressure maintaining; and after the process is finished, carrying out vacuum annealing in a dehydrogenation temperature range to remove hydrogen elements, and introducing argon to accelerate cooling. The hydrogen element can be effectively reserved to improve the joint quality, meanwhile, the dehydrogenation step is simplified, and the method is suitable for the field of titanium-based material hot working, especially the technical field of titanium hydride alloy superplastic forming / diffusion bonding.

Description

Technical Field

[0001] The present invention belongs to the field of heat treatment and thermal processing of titanium-based materials, and in particular relates to a method for improving the diffusion bonding ability and joint quality of titanium-based materials in a superplastic process / diffusion bonding. Background Art

[0002] Superplastic forming / diffusion bonding (SPF / DB) is a near-zero-residue forming technology that completes both bonding and forming within a single process window, enabling the manufacture of hollow or hybrid hollow and solid structures. This technology can integrate complex thin-walled parts and offers unique advantages in improving structural integrity and load-bearing efficiency. However, the long processing time and high temperatures of this process can easily cause the microstructure of titanium-based materials to grow, resulting in grain coarsening and significantly reducing the mechanical properties of the component.

[0003] The pressure source in the SPF / DB process is a key factor in achieving material forming and connection. Its functions include driving the deformation of superplastic materials and promoting atomic diffusion and bonding. Common types of pressure sources include gas pressure, mechanical pressure, and vacuum-assisted pressure. These pressure sources are used together in most cases to cope with the preparation of complex surface structures. Therefore, the processing environment of SPF / DB is generally a vacuum or inert gas environment. However, at high temperatures, SPF / DB will cause the hydrogen in the titanium-based material to continuously escape and be lost due to being in an inert gas and vacuum environment for a long time. Although spraying glass lubricant on the surface of the specimen can prevent and isolate some of the hydrogen from overflowing, the glass lubricator is extremely difficult to remove after processing and is not suitable for forming components with internal structures. In addition, existing studies mostly attribute the decline in mechanical properties of titanium alloys after SPF / DB to grain coarsening, and the main factors for grain coarsening are excessively high forming temperature and excessively long holding time; the rapid loss of hydrogen elements in hydrogenated titanium-based materials in SPF / DB will cause the material's low-temperature superplasticity and hydrogen-promoted diffusion bonding properties to be greatly weakened or even disappear, resulting in higher temperatures and longer holding times required for SPF / DB. Obviously, it is extremely disadvantageous if the loss of hydrogen elements is not restricted.

[0004] Therefore, the above-mentioned technical blind spots put the existing SPF / DB process into a dilemma. Summary of the Invention

[0005] The purpose of the present invention is to improve the diffusion bonding ability 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 characteristics of hydrogen removal in a high-temperature environment can be greatly suppressed, and ultimately the diffusion bonding ability of the hydrogenated titanium alloy can be improved.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a method for improving the bonding ability 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, and the target hydrogen content is obtained by controlling the temperature, time and hydrogen pressure;

[0009] Step S2: Place a mask on the hydrogenated plate and spray a boron nitride separator on the non-connected area;

[0010] Step S3: Place the sprayed plate into the superplastic forming mold and compact and seal it, then connect the vacuum equipment and evacuate to 10 -1 ~10 -5 Pa;

[0011] Step S4, introducing a mixed gas of argon and hydrogen;

[0012] Step S5: heating to a superplastic forming temperature at a rate of ≥25°C / min, and performing superplastic forming and diffusion bonding using the mixed gas as a pressure source;

[0013] Step S6: cooling to a dehydrogenation temperature range of above 600°C and below the forming temperature, evacuating and keeping warm for 2 to 5 hours;

[0014] Step S7: High-purity argon gas is introduced between the mold and the plate to provide a medium to accelerate the cooling of the component.

[0015] Furthermore, the above pretreatment is specifically as follows: grinding the titanium alloy plate to 800#, immersing it in anhydrous ethanol, ultrasonically cleaning it, and then drying it.

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

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

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

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

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

[0021] The method for improving the connection ability of titanium-based materials in superplastic forming / diffusion bonding described in the present invention can be embedded in a storage device of a computer. Therefore, the present invention also provides a system for improving the connection ability of titanium-based materials in superplastic forming / diffusion bonding, and the system includes a storage device, which is used to execute the above-mentioned method and steps for improving the connection ability of titanium-based materials in superplastic forming / diffusion bonding.

[0022] Furthermore, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, executes any one of the above-mentioned methods for improving the connection ability of titanium-based materials in superplastic forming / diffusion bonding.

[0023] Furthermore, the present invention also provides a computer device, which includes a memory and a processor, wherein a computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes any one of the above-mentioned methods for improving the connection ability of titanium-based materials in superplastic forming / diffusion bonding.

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

[0025] 1. The present invention provides a method for improving the bonding ability of titanium-based materials during superplastic forming / diffusion bonding. This method is used to suppress the escape of hydrogen from titanium-based materials during superplastic forming / diffusion bonding (SPF / DB). Because the pressure source of SPF / DB is an inert gas and a vacuum environment, the high temperature and zero hydrogen partial pressure (negative hydrogen partial pressure) cause the hydrogen in the hydrogenated material to continuously lose, thus preventing good diffusion bonding. The present invention increases the hydrogen partial pressure by mixing a certain amount of hydrogen into the inert gas pressure source to retain the hydrogen in the alloy, thereby improving the quality of diffusion bonding.

[0026] Furthermore, compared with the conventional process, the present invention is innovative in that it not only involves mixing in a certain amount of hydrogen, but also includes the following elements:

[0027] (1) Control the loading time: Use vacuum equipment to pump the vacuum degree to 10 -1 Pa~10 -5 Hydrogen can be injected only after pa to prevent residual impurities such as oxygen and nitrogen from hindering diffusion connection, resulting in the formation of oxides or pores at the interface, reducing the connection strength and density. If there is residual oxygen in the environment, water vapor or other compounds may be formed, leading to local oxidation or contamination.

[0028] (2) Controlling hydrogen partial pressure accuracy: limiting the amount of hydrogen added to the critical hydrogen embrittlement threshold (1-5%), breaking through the two extreme limitations of traditional processes: "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 simultaneously improved.

[0031] 2. The present invention provides a method for removing hydrogen from a component by vacuum annealing and heat preservation within a dehydrogenation temperature range after superplastic forming / diffusion bonding of a hydrogenated titanium alloy, without the need for heating again after forming to remove hydrogen.

[0032] 3. This invention aims to improve the problem of weakened mechanical properties of titanium-based materials after SPF / DB. By utilizing the temporary alloying effect of hydrogen, hydrogen is infiltrated into the titanium alloy through a hot hydrogen process, thereby reducing peak stress and inhibiting grain growth during the SPF / DB process.

[0033] The invention is applicable to the field of thermal processing of titanium-based materials, in particular to the technical field of superplastic forming / diffusion bonding of hydrogenated titanium alloys. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

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

[0036] Figure 2 Schematic diagram of the hydrogenated Ti65 titanium alloy superplastic forming / diffusion bonding equipment of the present invention;

[0037] Figure 3 This is the component morphology after hydrogenation of Ti65 titanium alloy SPF / DB according to the present invention;

[0038] Figure 4 The weld of hydrogenated Ti65 titanium alloy after SPF / DB is described in the present invention, wherein Figure 4 (a) is the weld under ordinary inert gas pressure source, Figure 4 (b) is the weld under the mixed gas (99%Ar +1%H2) pressure source. DETAILED DESCRIPTION

[0039] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details that obscure the description of the present application.

[0040] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. The following embodiments will help those skilled in the art further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that those skilled in the art may make various changes and improvements without departing from the scope of the present invention, and these are all within the scope of protection 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, with the purpose of improving the process of diffusion bonding ability of hydrogenated titanium alloys in superplastic forming / diffusion bonding. By mixing a certain amount of hydrogen into the inert gas providing the pressure source, the characteristics of hydrogen removal in a high-temperature environment can be greatly suppressed, thereby ultimately improving the diffusion bonding ability of the hydrogenated titanium alloy.

[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, and the target hydrogen content is obtained by controlling the temperature, time and hydrogen pressure;

[0044] Step S2: Place a mask on the hydrogenated plate and spray a boron nitride separator on the non-connected area;

[0045] Step S3: Place the sprayed plate into the superplastic forming mold and compact and seal it, then connect the vacuum equipment and evacuate to 10 -1 ~10 -5 Pa;

[0046] Step S4, introducing a mixed gas of argon and hydrogen;

[0047] Step S5: heating to a superplastic forming temperature at a rate of ≥25°C / min, and performing superplastic forming and diffusion bonding using the mixed gas as a pressure source;

[0048] Step S6: cooling to a dehydrogenation temperature range of above 600°C and below the forming temperature, evacuating and keeping warm for 2 to 5 hours;

[0049] Step S7: High-purity argon gas is introduced between the mold and the plate to provide a medium to accelerate the cooling of the component.

[0050] In the field of metal processing, superplastic forming / diffusion bonding (SPF / DB) technology has extremely stringent environmental requirements and usually has to be carried out in a vacuum or inert gas environment. However, under the high-temperature SPF / DB process, titanium alloys face a difficult problem - the hydrogen element in the hydrogenated titanium alloy will continue to escape in the zero hydrogen pressure or negative hydrogen pressure environment created by the inert gas or vacuum. Although spraying glass lubricant on the surface of the sample can block hydrogen leakage to a certain extent, this method has serious defects. On the one hand, the glass lubricant is extremely difficult to remove after processing, and on the other hand, it is completely unsuitable for formed components with complex internal structures.

[0051] In view of the characteristic of hydrogen escaping from titanium hydride alloy at high temperature, this embodiment makes innovative adjustments to the loading gas pressure in the SPF / DB process and cleverly mixes in an appropriate amount of hydrogen to accurately balance the hydrogen partial pressure in the environment. That is, by mixing a certain amount of hydrogen into the loading gas pressure during the SPF / DB process to balance the hydrogen partial pressure in the environment, a hydrogen storage balance equation for titanium alloy is provided. This innovative approach injects reverse power into the hydrogen storage balance equation of titanium alloys, deeply intervening in principle and effectively suppressing hydrogen loss in titanium alloys at high temperatures. This completely breaks the dilemma of traditional methods that rely solely on adding hydrogen, which is difficult to achieve, and opens up a new path for SPF / DB processing of titanium alloys.

[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 titanium-based materials that are difficult to deform and diffuse (such as TiAl alloy, Ti2AlNb and TC4 titanium alloy, etc.), which is mainly reflected in the following aspects:

[0053] 1. Reduce the diffusion bonding temperature:

[0054] This embodiment uses hydrogen as an interstitial atom, significantly reducing the α→β phase transition temperature of the titanium alloy and promoting the formation of the high-temperature β phase. The β phase has a higher diffusion coefficient and plastic deformation capacity, enabling good diffusion bonding at lower temperatures (such as 700°C), avoiding grain coarsening caused by high temperatures.

[0055] 2. Enhanced atomic interdiffusion:

[0056] The diffusion rate of hydrogen in titanium alloys is much higher than that of other alloying elements (such as Al, V, etc.). Its presence can promote grain boundary diffusion and volume diffusion, and improve the mobility of interface atoms.

[0057] 3. Improve plastic deformation ability

[0058] The introduction of hydrogen can reduce the material's flow stress and Young's modulus, improve high-temperature plasticity, and make the material more susceptible to creep and interfacial contact during the joining process, promoting pore closure. For example, when hydrogenated TC4 titanium alloy is diffusion-bonded at 840°C, the interfacial void closure rate is significantly improved.

[0059] 4. Optimize interface bonding quality:

[0060] Hydrogenation treatment can reduce interfacial residual stress and avoid the formation of brittle intermetallic compounds.

[0061] 5. Promote 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 connection interface.

[0063] Although hydrogenation treatment can significantly improve diffusion bonding performance, it should be noted that the hydrogen content in this embodiment needs to be precisely controlled (0.1-0.5wt%). 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 high-efficiency diffusion bonding of titanium-based materials, and has important applications in aerospace, nuclear industry and other fields.

[0065] Embodiment 2: This embodiment specifically describes a method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding proposed in the above embodiment 1.

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

[0067] Specifically:

[0068] The titanium alloy plate is polished to 800#, immersed in anhydrous ethanol for ultrasonic cleaning and then dried, and then placed in a vacuum hydrogen furnace for hydrogenation. The required hydrogenation amount is obtained by controlling reasonable time, temperature and hydrogen pressure (for example, heating to 700℃ and keeping warm for 1h).

[0069] Step S2: Place a mask on the hydrogenated plate and spray a boron nitride separator on the non-connected area;

[0070] Specifically:

[0071] Before superplastic forming / diffusion bonding, the hydrogenated sheet is placed in anhydrous ethanol for ultrasonic cleaning again. After drying, a mask is laid and a boron nitride isolation agent is sprayed to protect the interface area that does not need diffusion bonding.

[0072] Step S3: Place the sprayed plate into the superplastic forming mold and compact and seal it, then connect the vacuum equipment and evacuate to 10 -1 ~10 -5 Pa;

[0073] Specifically:

[0074] Next, put the hydrogenated sheet into the superplastic forming mold. The mold compacts the sheet to ensure that there is no air leakage. The pressure source pipeline should be connected to the vacuum equipment. The vacuum degree should be 10 at room temperature. -1 Pa~10 -5 pa.

[0075] Step S4, introducing a mixed gas of argon and hydrogen;

[0076] Specifically:

[0077] When the vacuum degree reaches the vacuum degree required in step S3 above, a mixed gas of argon and hydrogen is introduced;

[0078] Furthermore, argon is used as the pressure supply gas of SPF, and its volume proportion is not less than 95% to balance the atmospheric pressure and prevent air backflow; hydrogen accounts for 1% to 5% of the volume.

[0079] Furthermore, when the vacuum gauge shows 0.05MPa, stop inflating because the gas will expand due to heat, so a margin must be left.

[0080] Step S5: heating to a superplastic forming temperature at a rate of ≥25°C / min, and performing superplastic forming and diffusion bonding using the mixed gas as a pressure source;

[0081] Specifically:

[0082] After completing the above step S4, the temperature is rapidly increased. After reaching the superplastic forming temperature, superplastic forming / diffusion bonding is performed using the mixed gas as a pressure source.

[0083] Furthermore, in this embodiment, the heating rate is set to be ≥25° C. / min, so as to retain the hydrogen in the hydrogenated titanium alloy as much as possible.

[0084] Step S6: cooling to a dehydrogenation temperature range of above 600°C and below the forming temperature, evacuating and keeping warm for 2 to 5 hours;

[0085] Specifically:

[0086] After the SPF / DB process is completed, the temperature is lowered by 50 to 200 ° C (in actual application, it should still be higher than 600 ° C, which is the dehydrogenation temperature of titanium alloy), and the vacuum degree is still drawn to 10 through the gas supply pipeline. -3 Pa and keep warm for 2 to 5 hours. This step is to remove hydrogen elements in the component.

[0087] Step S7: High-purity argon gas is introduced between the mold and the plate to provide a medium to accelerate the cooling of the component.

[0088] Specifically:

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

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

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

[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 perform vacuum treatment on the upper and lower molds;

[0094] The gas mixing system is used to mix the hydrogen in the hydrogen generator and the argon in the argon bottle in proportion, and when the vacuum degree of the upper and lower molds reaches the requirement, the mixed argon + hydrogen is introduced.

[0095] Implementation method five. This implementation method adds a computer to the system for improving the connection ability of hydrogenated titanium alloys in superplastic forming / diffusion bonding as described in the above implementation method four. The computer is provided with a storage device, and the storage device is embedded with a method for improving the connection ability of titanium-based materials in superplastic forming / diffusion bonding as described in any one of the above embodiments.

[0096] Furthermore, this embodiment also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it executes a method for improving the connection ability of titanium-based materials in superplastic forming / diffusion bonding as described in any one of the above embodiments.

[0097] Furthermore, this embodiment also provides a computer device, which includes a memory and a processor, wherein 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 connection ability of titanium-based materials in superplastic forming / diffusion bonding as described in any one of the above embodiments.

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

[0099] Implementation Method 6: Combination Figure 3 and Figure 4 This embodiment is described. This embodiment provides a specific application description of a method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding based on the above embodiment.

[0100] Specifically:

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

[0102] Step S1: Two Ti65 titanium alloy plates with a thickness of 2 mm and a size of 50 mm × 50 mm were polished to 800#, cleaned and dried using ultrasound, and then placed in a hydrogen furnace for hydrogenation. The temperature was raised to 700°C and kept for 1 hour to prepare a hydrogenated Ti65 titanium alloy with a content of 0.3 wt% H, as shown in FIG. Figure 3 As shown;

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

[0104] Step S3, start heating, heat to 850℃ at a heating rate of 25℃ / min, and keep warm for 10 minutes. 3MPa mixed gas is introduced into the upper mold to provide bulging pressure, and 1MPa mixed gas is introduced into the lower mold to provide supporting back pressure. When the upper and lower pressure difference is 2MPa, the sheet metal deforms downward.

[0105] Step S4: After keeping the temperature and pressure for 1 hour, the temperature is quickly lowered to 700°C after the sheet is completely attached to the mold. The lower mold is first evacuated to a vacuum degree of about 100Pa, and then the upper mold is evacuated to finally make the vacuum degree between the upper and lower molds reach 5×10 -3 Near Pa.

[0106] Step S5: at 650°C and 5×10 -3 Pa vacuum conditions to remove hydrogen elements for 3 hours, after dehydrogenation is completed, the temperature begins to drop, and an appropriate amount of argon is introduced into the cavity between the mold and the sheet so that the vacuum gauge displays a pressure of 0.08 MPa. This step is to provide cooling medium to accelerate the cooling process.

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

[0108] After 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, the present invention provides a method for controlling hydrogen partial pressure to optimize the interfacial properties of superplastic forming / diffusion bonding (SPF / DB) of titanium-based materials. The core of this method is to address the problem of decreased diffusion bonding quality caused by hydrogen escape from titanium-based materials under high temperature and low hydrogen partial pressure conditions by collaboratively controlling the hydrogen environment through multiple parameters. The specific technical solution includes the following innovative features:

[0110] 1. Dynamic Control Mechanism of Hydrogen Partial Pressure In the SPF / DB process, a technical approach combining vacuum pretreatment with gradient hydrogen partial pressure loading is adopted:

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

[0112] Gradient hydrogen partial pressure loading stage: After the vacuum environment is established, the present invention quantitatively introduces hydrogen into the inert gas (argon). By strictly limiting the mixing ratio of hydrogen volume proportion (1% to 5%) and argon volume proportion (≥95%), a micro hydrogen partial pressure environment is formed, which not only suppresses the escape of hydrogen elements inside the material, but also avoids the risk of hydrogen embrittlement.

[0113] 2. Principle of synergistic enhancement of hydrogen environment: The core difference between this invention and conventional inert gas environment lies in that, through the timing coordination of vacuum pretreatment and hydrogen partial pressure loading, it not only retains the high purity advantage of the vacuum environment, but also realizes the regulation of interfacial hydrogen concentration through trace hydrogen supplementation; by utilizing the surface activation effect of hydrogen, it promotes the diffusion of titanium atoms while suppressing hydrogen escape, thereby achieving dual strengthening of interfacial metallurgical bonding.

[0114] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0115] The foregoing description is merely an embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of the claims.

Claims

1. A method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding, characterized in that: The method is: S1. After the surface of the titanium alloy plate is pretreated, it is placed in a vacuum hydrogen furnace for hydrogen treatment, and the target hydrogen content is obtained by controlling the temperature, time and hydrogen pressure; S2. Lay a mask plate on the hydrogenated plate and spray a boron nitride isolation agent on the non-connected area; S3, put the sprayed plate into the superplastic forming mold and compact and seal it, connect the vacuum equipment and evacuate to 10 -1 ~10 - 5 Pa; S4, introducing a mixed gas of argon and hydrogen; S5. Raise the temperature to the superplastic forming temperature at a rate of ≥25°C / min, and use the mixed gas as a pressure source to perform superplastic forming and diffusion bonding; S6. Cool down to a dehydrogenation temperature range above 600°C and below the forming temperature, evacuate and keep warm for 2 to 5 hours; S7. High-purity argon gas is introduced between the mold and the plate to provide a medium to accelerate the cooling of the component.

2. A method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding according to claim 1, characterized in that: The pretreatment is as follows: the titanium alloy plate is polished to 800#, immersed in anhydrous ethanol for ultrasonic cleaning and then dried.

3. The method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding according to claim 2, characterized in that: The volume proportion of hydrogen in the mixed gas in S4 is 1% to 5%.

4. The method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding according to claim 3, characterized in that: The volume proportion of argon in the mixed gas in S4 is ≥95%.

5. 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 to 5 MPa.

6. The method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding according to claim 1, characterized in that: The dehydrogenation temperature in S6 is 600~750℃ and the vacuum degree is ≤10 -3 Pa.

7. The method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding according to claim 1, characterized in that: After the insulation in S6 is completed, it directly enters the cooling stage without the need for additional heating and dehydrogenation.

8. A system for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding, characterized in that: The system includes a storage device, which is used to execute the method and steps described in claim 1.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, which, when executed by a processor, executes the method for improving the bonding ability of titanium-based materials in superplastic forming / diffusion bonding according to any one of claims 1 to 7.

10. A computer device, characterized in that: The device includes a memory and a processor, wherein a computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes the method for improving the connection ability of titanium-based materials in superplastic forming / diffusion bonding as described in any one of claims 1 to 7.

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