Titanium alloy hollow beam-shaped part and thermal forming method and forming die thereof

Abstract

The invention relates to a titanium alloy hollow beam-shaped part and a hot forming method and a forming die thereof, and belongs to the technical field of titanium alloy forming methods. The forming method comprises the following steps: respectively carrying out hot-press forming on a bottom plate blank and a rib plate blank to obtain a bottom plate and a rib plate; the supporting block is arranged in the bottom plate, then the rib plate is arranged on the supporting block, the two ends of the supporting block are subjected to edge sealing welding through the blocking piece, the blocking piece is connected with the bottom plate and the rib plate, and the air pipe is connected to the blocking piece; the bottom plate and the rib plate which are subjected to edge sealing and welding are placed in a mold, diffusion bonding is conducted under heating and pressurizing, and metallurgical bonding is achieved at the joint of the bottom plate and the rib plate; and subsequent machining is conducted, and the hollow beam-shaped part is manufactured. The problems of welding seam performance weak areas and complex welding deformation generated by a traditional tailor-welding method are effectively solved, meanwhile, the defects that due to overall mechanical cold machining, material waste is large, and thin-walled parts are prone to deformation are overcome, and high-quality and high-efficiency near-net forming of the titanium alloy hollow beam-shaped parts is achieved.

Description

Technical Field

[0001] This invention relates to the field of titanium alloy forming methods, and in particular to a hollow beam-shaped titanium alloy part, its hot forming method, and forming mold. Background Technology

[0002] Titanium alloy parts possess advantages such as high strength, low density, good high-temperature resistance, and corrosion resistance, and are widely used in various fields. With continuous development, the requirements for lightweight structural components are becoming increasingly stringent, leading to the widespread application of high-strength, lightweight hollow structural components made of titanium alloys.

[0003] The hollow structural component includes a hollow beam-shaped component, which consists of a V-shaped base plate and a U-shaped rib plate. The U-shaped rib plate is located above the V-shaped base plate, and the two together form a triangular hollow structure.

[0004] The main methods for fabricating hollow beam-shaped components are mechanical cold working and hot pressing followed by welding. Mechanical cold working requires subtractive processing of the profile, resulting in significant material waste and making the thin-walled workpiece prone to deformation during processing. Hot pressing followed by welding presents weak areas in the weld, complex welding deformation control, difficulty in maintaining quality stability, and low processing efficiency. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a titanium alloy hollow beam-shaped part, its thermoforming method and forming mold, to improve production efficiency and ensure the performance and precision of the parts.

[0006] On one hand, the present invention provides a method for hot forming of hollow beam-shaped titanium alloy parts, comprising the following steps:

[0007] S1: Hot pressing is performed on the base plate blank and the rib plate blank to obtain the base plate and the rib plate respectively; S2: Place the support block in the base plate, then place the rib plate on top, and then use the sealing plate to seal and weld the two ends of the support block so that the sealing plate is connected to the base plate and the rib plate, and connect the air pipe to the sealing plate. S3: Place the bottom plate and rib plate after edge sealing and welding in the mold, and perform diffusion connection under heating and pressure to achieve metallurgical bonding at the junction of the bottom plate and rib plate; S4: Perform subsequent machining to obtain a hollow beam-shaped part.

[0008] Furthermore, the base plate is V-shaped; the ribs are U-shaped.

[0009] Furthermore, in step S1, the hot pressing temperature is 700℃~800℃.

[0010] Furthermore, in step S3, the heating temperature of the diffusion connection is 880℃~950℃.

[0011] Furthermore, before step S2, step S11 is included, in which a release agent is sprayed onto the non-diffusion connection welding area and non-welding area of ​​the base plate, the rib plate, the sealing plate and the support block.

[0012] Furthermore, in step S3, after diffusion connection, inert gas needs to be introduced through a gas tube to ensure that its internal pressure is 0.1~0.4MPa.

[0013] Furthermore, the titanium alloy is TC4 titanium alloy.

[0014] Furthermore, the heating temperature for the diffusion connection is 920℃~950℃.

[0015] On the other hand, the present invention provides a hollow beam-shaped titanium alloy component, which is prepared by the forming method described in the present invention.

[0016] Furthermore, the present invention provides a forming mold for implementing a forming method, comprising an upper mold, a lower mold, and a V-shaped insert; The upper mold is fixedly connected to a fixing block, the fixing block having a trapezoidal cross-section; the V-shaped insert is detachably connected to the fixing block. The lower mold has a groove for the V-shaped insert to be inserted into the fixing block.

[0017] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1. This invention replaces the traditional integral machining or welding process with a manufacturing process that combines "separate hot pressing forming + diffusion bonding". It can effectively avoid the weak weld performance areas and complex welding deformation problems caused by traditional welding methods, while solving the defects of large material waste and easy deformation of thin-walled parts caused by integral cold machining, and realize high-quality, high-efficiency near-net-shape forming of titanium alloy hollow beam-shaped parts.

[0018] 2. The present invention controls the hot pressing forming temperature to be 700~800℃ and the diffusion bonding temperature to be 880~950℃. Within the above temperature range, it can ensure that the titanium alloy (e.g., TC4) undergoes sufficient atomic diffusion to achieve a strong metallurgical bond, and can also effectively suppress excessive grain growth, thereby ensuring the overall mechanical properties of the component while ensuring the connection strength.

[0019] 3. This invention improves forming accuracy and part surface quality by spraying a release agent on non-connecting areas to prevent adhesion between the part and the mold or unintended areas inside the part. After diffusion bonding, inert gas is introduced into the closed cavity and maintained at a certain pressure (0.1~0.4MPa). This internal gas pressure can effectively support the hollow beam-shaped part during subsequent cooling, offsetting the shrinkage stress caused by plastic deformation. This is a key measure to control the overall deformation of the hollow beam-shaped part and ensure the shape and dimensional accuracy of complex hollow cross sections.

[0020] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0021] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0022] Figure 1 This is a schematic diagram of a hollow beam-shaped component structure; Figure 2 This is a schematic diagram of the overall structure of the forming mold; Figure 3 for Figure 2 Left-side schematic diagram of the overall structure of the forming mold; Figure 4 This is a schematic diagram of the base plate forming process; Figure 5 This is a schematic diagram of the mold closing process during the base plate forming process; Figure 6 This is a schematic diagram of the rib forming process; Figure 7 This is a schematic diagram of the mold closing process during rib forming; Figure 8 This is a schematic diagram of the edge sealing welding assembly process; Figure 9 This is a schematic diagram of the diffusion connection process; Figure label: 1. Base plate; 11. Base plate blank; 2. Rib plate; 21. Rib plate blank; 3. Upper mold; 31. Fixing block; 4. V-shaped insert; 5. Lower mold; 51. Groove; 6. Sealing plate; 61. Air pipe; 7. Support block. Detailed Implementation

[0023] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0024] Titanium alloy parts possess advantages such as high strength, low density, good high-temperature resistance, and corrosion resistance, and are widely used in various fields. With continuous development, the requirements for lightweight structural components are becoming increasingly stringent, leading to the widespread application of high-strength, lightweight hollow structural components made of titanium alloys.

[0025] The hollow structural component includes a hollow beam-shaped component, which consists of a V-shaped base plate and a U-shaped rib plate. The U-shaped rib plate is located above the V-shaped base plate, and the two together form a triangular hollow structure.

[0026] The main methods for fabricating hollow beam-shaped components are mechanical cold working and hot pressing followed by welding. Mechanical cold working requires subtractive processing of the profile, resulting in significant material waste and making the thin-walled workpiece prone to deformation during processing. Hot pressing followed by welding presents weak areas in the weld, complex welding deformation control, difficulty in maintaining quality stability, and low processing efficiency.

[0027] Therefore, the present invention provides a hot forming method for hollow beam-shaped titanium alloy parts, comprising the following steps: S1: Hot pressing is performed on the base plate blank and the rib plate blank to obtain the base plate and the rib plate respectively; S2: Place the support block in the base plate, then place the rib plate on top, and then use the sealing plate to seal and weld the two ends of the support block so that the sealing plate is connected to the base plate and the rib plate, and connect the air pipe to the sealing plate. S3: Place the bottom plate and rib plate after edge sealing and welding in the mold, and perform diffusion connection under heating and pressure to achieve metallurgical bonding at the junction of the bottom plate and rib plate; S4: Perform subsequent machining to obtain a hollow beam-shaped part.

[0028] Compared with existing technologies, this invention replaces traditional integral machining or welding processes with a manufacturing process that combines "separate hot pressing forming + diffusion bonding". This effectively avoids the weak weld performance areas and complex welding deformation problems caused by traditional welding methods, while solving the defects of large material waste and easy deformation of thin-walled parts caused by integral cold machining. It achieves high-quality, high-efficiency near-net-shape forming of titanium alloy hollow beam-shaped parts.

[0029] Specifically, the base plate blank is a trapezoidal flat plate, and the base plate is V-shaped; The rib blank is a rectangular flat plate, and the rib is U-shaped.

[0030] It should be noted that the present invention uses a forming mold to prepare a titanium alloy hollow beam-shaped part. The titanium alloy hollow beam-shaped part is composed of a base plate and ribs. In the preparation process, the base plate and ribs need to be prepared separately, and then the base plate and ribs are diffusely connected.

[0031] During the preparation of the base plate, the base plate blank is hot-pressed in a forming mold, resulting in a V-shaped base plate with a variable cross-section. Therefore, during the blanking process, the base plate blank is a trapezoidal flat plate.

[0032] During the preparation of the ribs, the rib blanks are hot-pressed in a forming mold, resulting in U-shaped ribs with consistent cross-sectional dimensions. Therefore, during the blanking process, the base plate blank is a rectangular flat plate.

[0033] Specifically, in step S1, the hot pressing temperature is 700℃~800℃.

[0034] Preferably, in step S1, the hot pressing temperature is 750°C to 800°C.

[0035] It should be noted that during the forming process of the base plate and ribs, the hot pressing temperature is controlled between 700℃ and 800℃, which significantly reduces the variable stress and greatly increases the elongation. This allows for V-shaped and U-shaped bending with less force, reducing the required equipment tonnage and mold stress, while also minimizing the risk of cracking. Furthermore, within this temperature range, the titanium alloy is in a high-temperature creep state, which reduces elastic rebound after forming. This allows the base plate and rib blanks to better conform to the mold surface, resulting in high-precision V-shaped base plates and U-shaped ribs, laying a solid dimensional foundation for subsequent assembly and diffusion connections.

[0036] If the hot pressing temperature is below 700℃, the titanium alloy exhibits high rheological stress and insufficient plasticity, requiring extremely high forming pressure. This makes it highly susceptible to microcracks or fractures at bending points. The forming pressure used in the hot pressing process is 45~60t. If the hot pressing temperature exceeds 800℃, the excessively high temperature results in a long heating time, affecting production efficiency. Furthermore, the higher temperature promotes grain growth in the sheet material, impacting its performance.

[0037] Therefore, the hot pressing temperature can be 700℃, 710℃, 720℃, 730℃, 740℃, 750℃, 760℃, 770℃, 780℃, 790℃ or 800℃.

[0038] In this invention, the support block is elongated, with a triangular cross-section and a variable cross-section. The support block and the V-shaped insert have the same dimensions.

[0039] In step S2, the support block is placed in the V-shaped base plate, with its outer surface in contact with the inner surface of the V-shaped base plate. Then, the U-shaped rib is placed on the support block. At this point, the bottom surface of the U-shaped rib is in contact with the upper surface of the support block, and the side of the U-shaped rib is in contact with the inner surface of the V-shaped base plate. Finally, a sealing plate is placed at each end of the support block. The sealing plate is triangular in shape, with its three sides in contact with the V-shaped base plate and the U-shaped rib, respectively. The sealing plate, the V-shaped base plate, and the U-shaped rib are then connected by welding to form a sealed weldment.

[0040] During the diffusion connection process, the support block can better support the V-shaped base plate and U-shaped rib plate in contact with it, ensuring that the diffusion connection does not produce large deformation. In order to introduce protective gas into the sealed weldment, a gas tube needs to be connected to the sealing plate.

[0041] Specifically, in step S3, the heating temperature for the diffusion connection is 880℃~950℃.

[0042] Preferably, in step S3, the heating temperature for the diffusion connection is 920°C to 950°C.

[0043] It should be noted that in this invention, the diffusion bonding temperature is controlled between 880℃ and 950℃. Within this range, atoms at the interface between the titanium alloy base plate and rib plate gain sufficient energy at high temperatures, allowing them to diffuse across the interface and achieve metallurgical bonding with high strength. Simultaneously, at this temperature, the base plate and rib plate exhibit good plasticity, enabling diffusion bonding to be completed under relatively low applied pressure (10~15t). Most importantly, diffusion bonding within this temperature range allows the bonded area to undergo dynamic recrystallization under thermal (heating and pressure) action, forming a fine, equiaxed (α+β) dual-phase structure. This structure contains no low-melting-point eutectic or brittle intermetallic compounds; therefore, the strength, plasticity, and fatigue performance of the bonded area can approach the levels of the base material (the non-bonded area).

[0044] If the diffusion bonding temperature is below 880℃, the atomic diffusion motive force is insufficient, and the interface is difficult to fully bond. The joint exhibits numerous unbonded micropores and rudimentary interfaces at the microscopic level, resulting in mechanical properties far lower than the parent material. If the diffusion bonding temperature is above 950℃, approaching or exceeding the β-phase transformation point, it leads to drastic grain coarsening in the parent material and severe performance degradation.

[0045] Therefore, the heating temperature of the diffusion connection can be 880℃, 890℃, 900℃, 910℃, 920℃, 930℃, 940℃ or 950℃.

[0046] Specifically, before step S2, step S11 is also included, in which a release agent is sprayed onto the non-diffusion connection welding area and non-welding area of ​​the base plate, the rib plate, the sealing plate and the support block.

[0047] It should be noted that the present invention requires the application of a release agent before diffusion bonding. The spraying location is the non-diffusion bonding welding area and the non-welding area of ​​the base plate, rib plate, sealing plate and support block. This can effectively prevent the bonding of the non-diffusion bonding area and also prevent adhesion to the mold, making it easier to remove after diffusion bonding.

[0048] In this invention, the release agent is a conventional release agent, which is boron nitride.

[0049] The support block in this invention has a triangular cross-section, and its cross-section is variable.

[0050] Specifically, in step S3, after diffusion connection, inert gas needs to be introduced through a gas tube to ensure that its internal pressure is 0.1~0.4MPa.

[0051] It should be noted that titanium alloys have a large thermal shrinkage rate. During cooling, the entire component (especially the thin-walled V-shaped base plate and U-shaped ribs) will tend to shrink inward due to uneven cooling. Therefore, after diffusion bonding, inert gas needs to be introduced into the closed space formed by the V-shaped base plate and U-shaped ribs through a gas pipe to create a pressure of 0.1~0.4MPa. This serves two purposes: firstly, to prevent oxidation of the inner surfaces of the V-shaped base plate and U-shaped ribs, which would affect the diffusion bonding quality; and secondly, to ensure that the V-shaped base plate adheres tightly to the mold, guaranteeing the precision of the V-shaped base plate and U-shaped ribs.

[0052] In this invention, the air pressure needs to be controlled at 0.1~0.4MPa, greater than 0.1MPa, to provide sufficient support to resist the contraction force of the thin-walled titanium alloy part during cooling. If the pressure is too low, the support effect will be insufficient and deformation cannot be effectively prevented. The pressure should not be too high (above 0.4MPa) to avoid exceeding the strength of the weld around the sealing plate, or causing excessive bulging of the component at high temperatures, resulting in reverse deformation.

[0053] Specifically, the titanium alloy is TC4 titanium alloy.

[0054] It should be noted that in this invention, other titanium alloy grades may also be used, but TC4 titanium alloy is preferred.

[0055] The present invention provides a forming mold for implementing the forming method described herein, comprising an upper mold, a lower mold, and a V-shaped insert; the upper mold is fixedly connected to a fixing block; the V-shaped insert and the fixing block are detachably connected; the lower mold has a groove for the V-shaped insert to be inserted into the fixing block.

[0056] In this invention, the forming mold includes three forming states: The first type is the V-shaped base plate hot-press forming state: Mold assembly: The V-shaped insert is fixed to the fixed block in the upper mold with bolts (see...). Figure 2 Threaded holes (not labeled) are made on the upper mold and the V-shaped insert. The V-shaped base plate blank is then placed on the lower mold, above the groove in the lower mold. The molds are closed, and the upper mold moves towards the lower mold, pressing down on the V-shaped base plate blank. The V-shaped base plate blank gradually enters the groove of the lower mold until it fits snugly against the groove. After releasing the pressure, the V-shaped base plate is obtained. At this point, the outer surface of the V-shaped base plate fits against the groove, while the V-shaped insert and fixing block fit against the inner surface of the V-shaped base plate.

[0057] In the hot pressing process of the V-shaped base plate, the V-shaped insert works in conjunction with the lower mold to form the V-shaped base plate. The fixing block has two functions: firstly, it is used to fix the V-shaped insert; secondly, it works with the V-shaped insert to form the V-shaped base plate.

[0058] The second type is the U-shaped rib hot-pressed forming state: Mold assembly: Remove the bolts, separate the V-shaped insert from the fixing block, first place the V-shaped base plate into the groove of the lower mold, then place the V-shaped insert into the V-shaped base plate. The outer surface of the V-shaped base plate fits into the groove of the lower mold, and the V-shaped insert fits into the inner surface of the V-shaped base plate. Next, place the U-shaped rib blank on the lower mold, above the groove. Close the mold, and the upper mold moves towards the lower mold, pressing down on the U-shaped rib blank. The U-shaped rib blank gradually enters the groove of the lower mold until it fits into the groove and the V-shaped insert. After releasing the pressure, the U-shaped rib is obtained.

[0059] In the hot pressing process of U-shaped ribs, the V-shaped inserts serve two purposes: firstly, they provide support, supporting the V-shaped base plate and preventing deformation; secondly, they cooperate with the fixing blocks to form the U-shaped ribs. The fixing blocks, acting as the force exertor, compress the U-shaped rib blank during the forming process.

[0060] The third type is the diffused connection state: Before diffusion bonding, the V-shaped base plate and U-shaped rib plate need to be sealed by welding. The sealing process is as follows: The support block is placed inside the V-shaped base plate, with its outer surface in contact with the inner surface of the V-shaped base plate. Then, the U-shaped rib is placed on the support block. At this point, the bottom surface of the U-shaped rib is in contact with the upper surface of the support block, and the side of the U-shaped rib is in contact with the inner surface of the V-shaped base plate. Finally, a sealing plate is placed at each end of the support block. The sealing plate is triangular in shape, with its three sides in contact with the V-shaped base plate and the U-shaped rib, respectively. The sealing plate, V-shaped base plate, and U-shaped rib are then welded together to form a sealed weldment.

[0061] The mold assembly utilizes a U-shaped rib forming mold, comprising an upper mold and a lower mold. A fixing block is fixed to the upper mold; the V-shaped insert is not included in this process. A V-shaped groove is formed inside the lower mold. The sealing component is placed in the groove of the lower mold, with its outer surface tightly fitting against the groove. The upper mold moves towards the lower mold until the lower surface of the fixing block in the upper mold contacts the U-shaped rib. Pressure is then increased to complete mold closing. At this point, the V-shaped base plate and the U-shaped rib complete a diffusion connection, achieving a metallurgical bond.

[0062] During the diffusion connection process, the main function of the support block is to support the V-shaped base plate and U-shaped ribs, preventing them from deforming during the diffusion connection. The sealing plate, together with the V-shaped base plate and U-shaped ribs, forms a sealed space to prevent oxidation of the V-shaped base plate and U-shaped ribs.

[0063] During the diffusion bonding process, the portion of the V-shaped base plate that is higher than the support block comes into contact with the edge of the U-shaped rib plate. Under the combined action of the lower and upper molds, atomic diffusion is achieved, metallurgical bonding is reached, and the bonding strength is improved.

[0064] It should be noted that in this invention, both the upper mold and the lower mold are flat plates, the thickness of the lower mold is greater than the thickness of the upper mold, and the thickness of the lower mold is greater than the height of the V-shaped base plate.

[0065] In this invention, the forming process using the above-mentioned forming mold is divided into three processes, as follows: Forming the V-shaped base plate: The V-shaped insert is fixed to the fixing block of the upper mold to form a triangle; according to the dimensions of the V-shaped base plate in the hollow beam part, the base plate blank is obtained, which is a trapezoidal flat plate. The base plate blank is placed in the forming mold, the mold is closed and heated, and the V-shaped base plate is obtained with the cooperation of the V-shaped insert, the fixing block and the groove in the lower mold.

[0066] Forming of U-shaped ribs: Remove the V-shaped insert from the fixing block and place it together with the V-shaped base plate into the groove in the lower mold. Based on the dimensions of the U-shaped rib in the hollow beam component, obtain the rib blank, which is a rectangular flat plate. Place the rib blank into the forming mold, close the mold, and heat it. With the cooperation of the V-shaped insert, the fixing block, and the groove in the lower mold, the U-shaped rib is obtained.

[0067] Diffusion connection process: Before the diffusion bonding process, a release agent needs to be sprayed and edge-sealing welded. The spraying locations are the non-diffusion bonding welding areas and non-welding areas of the base plate, ribs, sealing plates, and support blocks. Then, the support block is placed in the base plate, and the ribs are placed on top. The two ends of the support block are then edge-sealed and welded using the sealing plates, connecting the sealing plates to the base plate and ribs. The welded assembly is then placed in a groove within the lower mold. The mold is closed, pressurized, and heated to achieve the connection between the base plate and ribs.

[0068] To more clearly describe the present invention, the following embodiments and comparative examples are provided for further illustration.

[0069] Example 1 A method for hot forming a hollow beam-shaped titanium alloy part includes the following steps: The process part model is obtained by adding process allowances to the three-dimensional model of the hollow beam part using 3D modeling software. The hot pressing forming process of the V-shaped base plate and U-shaped rib plate of the process part is simulated using FormingSuite stamping simulation software to obtain the blank unfolding size of the V-shaped base plate and U-shaped rib plate. The blank is obtained by cutting TC4 titanium alloy sheet by laser cutting or other methods. The edges of the blank are polished and the surface of the blank is cleaned.

[0070] V-shaped base plate hot press mold installation: like Figure 2 and 3 As shown, the forming mold includes an upper mold, a lower mold, and a V-shaped insert; a fixing block is fixedly connected to the upper mold; the fixing block has a U-shaped cross-section; the V-shaped insert has a triangular cross-section and is a variable cross-section. A groove is provided on the fixing block to connect with the V-shaped insert.

[0071] The V-shaped insert is fixed to the fixed block in the upper mold with bolts. After the mold is assembled, it is put into the thermoforming machine. The upper mold is connected and fixed to the upper platform of the thermoforming machine, and the lower mold is connected and fixed to the lower platform of the thermoforming machine. Then the oven door of the thermoforming machine is closed and the equipment is heated.

[0072] V-shaped base plate hot pressing: like Figure 4 and 5As shown, when the mold temperature reaches the hot pressing forming temperature of 730℃, the furnace door of the thermoforming machine is opened, and the upper platform of the thermoforming machine is moved to raise the upper mold to a suitable position. The V-shaped base plate blank is placed into the lower mold, positioned above the groove of the lower mold. The furnace door of the thermoforming machine is closed for heat preservation. After heat preservation for 10 minutes, the furnace door of the thermoforming machine is opened to perform the mold closing process of the upper and lower molds. The mold closing pressure is 50t. After mold closing, the furnace door is closed, and the pressure is maintained for 20 minutes before the equipment pressure is released and the equipment is cooled down. The outer surface of the V-shaped base plate is in contact with the groove of the lower mold, while the V-shaped insert and fixing block are located inside the V-shaped base plate, and the V-shaped insert and fixing block are in contact with the inner surface of the V-shaped base plate.

[0073] U-shaped rib plate mold installation; Disconnect the upper mold from the upper platform of the thermoforming machine. Move the upper platform to separate it from the upper mold. Then, disconnect the V-shaped insert from the upper mold. Move the upper platform to the appropriate position to complete the connection and fixation between the upper mold and the upper platform. First, place the V-shaped base plate into the groove of the lower mold, then place the V-shaped insert into the V-shaped base plate. The outer surface of the V-shaped base plate should fit against the groove of the lower mold, and the V-shaped insert should fit against the inner surface of the V-shaped base plate. Close the thermoforming machine door and allow the equipment to heat up.

[0074] U-shaped ribs are hot-pressed and formed. like Figure 6 and 7 As shown, when the mold temperature reaches the hot pressing forming temperature of 730℃, the furnace door of the hot forming machine is opened, and the U-shaped rib blank is placed into the lower mold, located above the groove of the lower mold. The furnace door of the hot forming machine is closed for heat preservation. After heat preservation for 10 minutes, the furnace door of the hot forming machine is opened to carry out the mold closing process of the upper mold and the lower mold. The U-shaped rib blank is pressed down and gradually enters the groove of the lower mold until the U-shaped rib blank is in contact with the groove and the V-shaped insert. The mold closing pressure is 50t. After mold closing, the furnace door is closed, and the pressure is maintained for 20 minutes before the equipment pressure is released and the part is taken out of the furnace.

[0075] Edge sealing welding: Apply a release agent to the non-diffusion connection welding area and non-welding area of ​​the V-shaped base plate, U-shaped rib plate, sealing plate and support block to prevent diffusion connection from occurring in the non-diffusion connection area.

[0076] like Figure 8As shown, a support block is placed within a V-shaped base plate, with its outer surface in contact with the inner surface of the V-shaped base plate. Then, a U-shaped rib is placed on top of the support block. At this point, the lower surface of the U-shaped rib is in contact with the upper surface of the support block, and the side of the U-shaped rib is in contact with the inner surface of the V-shaped base plate. Finally, a sealing plate is placed at each end of the support block. The sealing plate is triangular in shape, with its three sides in contact with the V-shaped base plate and the U-shaped rib, respectively. The sealing plate, V-shaped base plate, and U-shaped rib are then welded together to form a sealed welded component. An air tube is connected to the notch in the sealing plate.

[0077] Hollow beam-shaped diffuser connection; like Figure 9 As shown, the sealing component is placed into the lower mold, moved and positioned, and then the upper mold is closed. The gas path of the diffusion connection equipment is connected. After the gas path is connected, the mold is installed into the diffusion connection equipment. A small flow of high-purity argon gas is introduced into the cavity inside the sealing component for gas washing. After the gas washing is completed, a vacuum is drawn. Then the equipment is heated.

[0078] Once the mold temperature reaches the closing temperature of 730℃, the mold is closed at a pressure of 10t, and the internal cavity of the weldment is continuously evacuated. When the mold temperature reaches the diffusion bonding temperature of 930℃, the pressure of the diffusion bonding equipment on the mold is increased to 15t, causing diffusion bonding to occur in the diffusion bonding area of ​​the weldment under the mold pressure. After holding the pressure for 120 minutes, high-purity argon gas at a pressure of 0.1MPa is introduced into the internal cavity of the weldment for gas expansion and shaping. After shaping for 30 minutes, the equipment is cooled down. After cooling down to below 300℃, the gas pressure in the internal cavity of the weldment and the pressure of the diffusion bonding equipment are removed, and the weldment is taken out.

[0079] Machining allowance The sealing plate is removed by machining, the support block is taken out, the oxide layer on the surface of the beam-shaped component is cleaned, and then the hollow beam-shaped component is machined to remove the process allowance, thus obtaining the hollow beam-shaped component. Figure 1 ).

[0080] Mechanical property test: Samples are taken from the remaining material, and the room temperature mechanical properties are not less than 90% of the original board material, which meets the requirements of national standard GB / T 3621.

[0081] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for hot forming a hollow beam-shaped titanium alloy part, characterized in that, Includes the following steps: S1: Hot pressing is performed on the base plate blank and the rib plate blank to obtain the base plate and the rib plate respectively; S2: Place the support block in the base plate, then place the rib plate on top, and then use the sealing plate to seal and weld the two ends of the support block so that the sealing plate is connected to the base plate and the rib plate, and connect the air pipe to the sealing plate. S3: Place the bottom plate and rib plate after edge sealing and welding in the mold, and perform diffusion connection under heating and pressure to achieve metallurgical bonding at the junction of the bottom plate and rib plate; S4: Perform subsequent machining to obtain a hollow beam-shaped part.

2. The hot forming method for a hollow beam-shaped titanium alloy part according to claim 1, characterized in that, The base plate is V-shaped; the ribs are U-shaped.

3. The hot forming method for a hollow beam-shaped titanium alloy part according to claim 1, characterized in that, In step S1, the hot pressing temperature is 700℃~800℃.

4. The hot forming method for a hollow beam-shaped titanium alloy part according to claim 1, characterized in that, In step S3, the heating temperature for the diffusion connection is 880℃~950℃.

5. The hot forming method for a hollow beam-shaped titanium alloy part according to claim 1, characterized in that, Before step S2, step S11 is also included, in which a release agent is sprayed onto the non-diffusion connection welding area and non-welding area of ​​the base plate, the rib plate, the sealing plate and the support block.

6. The hot forming method for a hollow beam-shaped titanium alloy part according to claim 1, characterized in that, In step S3, after diffusion connection, inert gas needs to be introduced through a gas tube to ensure that the internal pressure is 0.1~0.4MPa.

7. The hot forming method for a hollow beam-shaped titanium alloy part according to claim 1, characterized in that, The titanium alloy is TC4 titanium alloy.

8. The hot forming method for a hollow beam-shaped titanium alloy part according to claim 4, characterized in that, The heating temperature for the diffusion connection is 920℃~950℃.

9. A hollow beam-shaped component made of titanium alloy, characterized in that, It is prepared by the forming method according to any one of claims 1-8.

10. A forming die for implementing the forming method according to any one of claims 1-8, characterized in that, Includes upper mold, lower mold, and V-shaped insert; The upper mold is fixedly connected to a fixing block, the fixing block having a trapezoidal cross-section; the V-shaped insert is detachably connected to the fixing block. The lower mold has a groove for the V-shaped insert to be inserted into the fixing block.

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