High-temperature vacuum spin forming method and device for complex components of difficult-to-deform metals

Abstract

This application belongs to the field of spin forming, and specifically discloses a high-temperature vacuum spin forming method and device for complex components of difficult-to-deform metals. The method specifically involves placing a split support internal mold inside the tube blank, then heating one end of the tube blank to the vacuum spin forming temperature in a vacuum environment and performing forward spin thinning forming. After reaching the forming requirements, stop. Finally, heat the other end of the tube blank to the vacuum spin forming temperature and perform reverse spin thinning forming. After reaching the forming requirements, stop. In this way, a complex component with inner ring ribs is manufactured, and an oxide layer is avoided from forming on the inner and outer surfaces of the complex component. This application can avoid the formation of an oxide layer on the inner and outer surfaces of the complex component with inner ring ribs. At the same time, the segmented spin forming can avoid the problem that the material undergoes abnormal grain growth due to being at high temperature for a long time, thereby affecting the mechanical properties. Moreover, the entire component can be formed in one heat treatment, the forming process is simple, and the mold loading and unloading are easy.

Description

Technical Field

[0001] The present application belongs to the field of spin forming, and more specifically, to a high-temperature vacuum spin forming method and device for complex metal components that are difficult to deform. Background Art

[0002] With the construction and development of major national projects such as aerospace, transportation, and weapons and equipment, higher requirements are placed on the high-quality forming of key components. High-reliability precision manufacturing under the integrated coordinated control of component materials, structures, and performance is the inevitable way to meet this demand. Titanium alloys have significant advantages such as low density, high specific strength, heat resistance, and corrosion resistance. As a new type of lightweight and high-strength structural material, they are widely used in aerospace, weapons industry, and other fields. However, titanium alloys have low room temperature plasticity and high deformation resistance. They are difficult to deform materials and are mostly plastically formed in high temperature ranges. Although the plasticity requirements are met at high temperatures, oxidation defects are also brought about. In particular, surface oxidation after multiple deformations will affect the mechanical properties and surface quality of the components. Stainless steel and special steel are widely used in the fields of weapons and equipment and transportation. These metals are also plastically formed in high temperature ranges, and the surface oxidation phenomenon is serious. Therefore, the selection of forming processes for difficult-to-deform metals under high temperature conditions and the methods and equipment to prevent oxidation are extremely critical.

[0003] Spin forming is a typical continuous local plastic forming process, which has significant advantages in labor-saving plastic forming of thin-walled rotating body components, and has high flexibility, high material utilization and high efficiency. The characteristics of spin forming can meet the labor-saving and good forming of difficult-to-deform metal pipes. However, the spin forming process in the prior art has a serious surface oxidation problem, especially for complex components with inner ring ribs, the oxide layer on the inner surface is difficult to remove through post-processing, which seriously affects its subsequent application.

[0004] CN115889554A discloses a room-temperature spinning forming method for a thin-walled cylinder of a 1200 MPa grade Ti-4Mo-3Cr-1Fe titanium alloy. This method uses room-temperature forming to avoid oxidation problems. The selected blank wall thickness is 8 mm, and double-stage solution treatment and stress relief treatment are carried out successively. It is difficult to ensure the applicability of this method to thick-walled pipes. Most difficult-to-deform metals still use hot forming. CN109108139A discloses a spinning forming method for a titanium-based alloy material based on composite heating. The key point of this method is to ensure the self-temperature range of the titanium alloy billet during the spinning forming process. First, induction coil heating is carried out, and then the billet behind the spinning wheel is thermally insulated with a flame gun. During this forming process, both the billet and the mold are in direct contact with the air, and are greatly affected by the external temperature. Moreover, the heating effect of the flame gun is difficult to accurately control and the heat penetration cannot be guaranteed. The direct contact with the air also makes it difficult to avoid the formation of an oxide layer. CN112718429A discloses a method for reducing oxidation defects during the hot spinning forming process of a titanium-based alloy. This method uses a coating to form an oxygen isolation layer to block the oxygen absorption path of the titanium alloy, and finally removes the surface coating. However, the spinning forming process involves multiple passes and the spinning wheel moves along a variable trajectory. Therefore, it may not be possible to achieve full coverage, and the oxygen isolation layer may be damaged or fall off during the spinning process. Summary of the Invention

[0005] In view of the defects of the prior art, the present application provides a high-temperature vacuum spinning forming method and device for complex components of difficult-to-deform metals, aiming to solve the problems that when difficult-to-deform and easy-to-oxidize metals are formed at high temperatures, oxide layers will be formed on the inner and outer surfaces of the pipe fittings, resulting in low forming quality, high processing costs, and great difficulty in subsequent processing.

[0006] According to one aspect of the present application, a high-temperature vacuum spinning forming method for complex components of difficult-to-deform metals is provided. Specifically: Place the split support inner mold inside the pipe blank, then heat one end of the pipe blank to the vacuum spinning temperature in a vacuum environment and perform forward spinning and thickness reduction forming. Stop when the forming requirements are met. Finally, heat the other end of the pipe blank to the vacuum spinning temperature and perform reverse spinning and thickness reduction forming. Stop when the forming requirements are met. In this way, a complex component with inner ring ribs is manufactured, and oxide layers are avoided from being formed on the inner and outer surfaces of the complex component.

[0007] Through the above technical solution conceived by the present application, compared with the prior art, since the present application proposes to perform spinning forming in a vacuum environment, it can avoid the formation of oxide layers on the inner and outer surfaces of complex components with inner ring ribs. At the same time, by using segmented spinning forming, it can avoid the phenomenon of abnormal grain growth of the pipe blank when it is at high temperature for a long time, thus affecting the mechanical properties.

[0008] As a further preference, the material of the tube blank is titanium alloy, stainless steel or superalloy. When the material of the tube blank is titanium alloy, the vacuum spinning temperature is 820°C to 980°C; when the material of the tube blank is stainless steel, the vacuum spinning temperature is 900°C to 1050°C; when the material of the tube blank is superalloy, the vacuum spinning temperature is 950°C to 1100°C.

[0009] As a further preference, in forward spinning and thickness reduction forming, the spindle speed is 250 r / min to 300 r / min, the roller feed speed is 220 mm / min to 250 mm / min, the feed ratio is 0.73 mm / r to 1 mm / r, and the thickness reduction rate is 11.1% to 18.2%.

[0010] As a further preference, in reverse spinning and thickness reduction forming, the spindle speed is 250 r / min to 280 r / min, the roller feed speed is 180 mm / min to 230 mm / min, the feed ratio is 0.64 mm / r to 0.92 mm / r, and the thickness reduction rate is 11.1% to 18.2%.

[0011] According to another aspect of the present application, a device for implementing the above-mentioned high-temperature vacuum spinning forming method is provided, including a vacuum chamber unit, a spinning unit and an induction heating unit, wherein: the vacuum chamber unit is used to form a vacuum chamber to ensure that high-temperature spinning is carried out in a vacuum environment; the spinning unit is placed inside the vacuum chamber, and it includes a chuck assembly, two sets of roller assemblies and a tailstock assembly. The chuck assembly is arranged at the bottom of the vacuum chamber and is used to fix the tube blank and drive it to rotate; the two sets of roller assemblies are symmetrically arranged on the left and right sides of the vacuum chamber and are used to spin and deform the tube blank; the tailstock assembly is arranged at the top of the vacuum chamber and includes a first hydraulic cylinder, a tailstock seat, a mandrel and a split support inner mold. The first hydraulic cylinder is connected to the mandrel through the tailstock seat, and the split support inner mold is wrapped outside the mandrel; the induction heating unit is arranged between the two sets of roller assemblies and is used to heat the tube blank to make it reach the vacuum spinning temperature.

[0012] As a further preference, the vacuum chamber unit includes a workbench, a support seat, a housing and a vacuum pump. Above the workbench, a chuck assembly and a roller assembly are fixed, and at the same time, the workbench is connected to the support seat below; the housing covers above the workbench, and a hatch and a vacuum pump interface are arranged on the housing. The vacuum pump is connected to the vacuum pump interface and is used to evacuate the cavity space formed by the housing and the workbench to form a vacuum chamber.

[0013] As a further preference, the spinning wheel assembly includes a spinning wheel slide table, a second hydraulic cylinder, a radial carriage, a spinning wheel seat and a spinning wheel. The spinning wheel slide table includes a first guide rail fixed on the workbench and a first slider that moves up and down along the first guide rail. The first slider is connected to the second hydraulic cylinder to move up and down along the first guide rail under the drive of the second hydraulic cylinder. Meanwhile, a hole is opened in the middle of the first slider for the radial carriage to pass through. The radial carriage passes through the slider and is connected to the spinning wheel seat to drive the spinning wheel seat to move left and right in the horizontal direction. The spinning wheel is fixed to the bottom of the spinning wheel seat.

[0014] As a further preference, the chuck assembly includes a top block, a chuck, a chuck flange and a chuck rotating shaft. The top block is arranged above the chuck and is used to insert into the tube blank for fixing it. The chuck is arranged above the workbench and is fixed through the chuck flange under the workbench. The chuck rotating shaft passes through the chuck flange and is connected to the chuck to drive the chuck to rotate.

[0015] As a further preference, the induction heating unit includes a linear slide table, a bracket, a servo motor, an induction coil and an infrared thermometer. The linear slide table includes a second guide rail fixed on the workbench through the bracket and a second slider that moves up and down along the second guide rail. The second slider is connected to the servo motor to move up and down along the second guide rail under the drive of the servo motor. The induction coil is connected to the second slider and passes through the tube blank to heat the tube blank. The infrared thermometer is arranged on the second slider and is used to detect the temperature of the tube blank.

[0016] As a further preference, the first hydraulic cylinder and the second hydraulic cylinder are arranged outside the vacuum chamber and extend into the vacuum chamber through the housing. Meanwhile, a first sealing ring is arranged between the first hydraulic cylinder and the second hydraulic cylinder and the housing to achieve dynamic sealing.

[0017] Generally speaking, compared with the prior art by the above technical solutions conceived in this application, the following technical advantages are mainly possessed:

[0018] 1. This application proposes a process of spin forming in a vacuum environment for hollow thin-walled complex components with inner ring ribs made of difficult-to-deform metals. By means of segmented forward spinning thinning and reverse spinning thinning, a hollow thin-walled component with an external stepped structure and internal inner ring ribs is formed. It can avoid the formation of oxide layers on the inner and outer surfaces of complex components with inner ring ribs, which not only avoids the influence of the oxide layer on the surface forming quality but also avoids the problem of difficult subsequent machining treatment. At the same time, segmented spin forming can avoid the problem that the material undergoes abnormal grain growth at high temperature for a long time, thus affecting the mechanical properties. Moreover, the forming process of first forward spinning and then reverse spinning can form the entire component in one heat treatment. The forming process is simple, the mold loading and unloading are easy, and it has the advantages of good formability, good mechanical properties, low preparation cost and high material utilization rate.

[0019] 2. In particular, the present application optimizes the vacuum spinning parameters, which can ensure high wall thickness uniformity of difficult-to-deform metals during the spinning process, full filling of internal ribs, and avoid problems such as poor control of metal flow caused by wheel stockpiling and necking down, thereby improving the forming quality of the inner and outer surfaces and ensuring the qualified rate of products;

[0020] 3. The high-temperature vacuum spinning forming device provided by the present application can ensure that high-temperature spinning is carried out in a vacuum environment by setting a vacuum chamber, blocking the direct contact between the tube blank and the external environment. At the same time, by optimizing the specific structure of the spinning unit, such components can be integrally near-net formed in one firing. The forming process is simple, mold loading and unloading are easy, greatly reducing the forming load and processing cost, improving the material utilization rate and the overall deformation uniformity of the components, being applicable to the forming of various difficult-to-deform metals, and the prepared products have broad application prospects and benefits in the fields of military, aerospace, transportation, etc. Description of the Drawings

[0021] Figure 1 is a schematic diagram of the internal structure of the high-temperature vacuum spinning forming device provided by the embodiment of the present application;

[0022] Figure 2 is a sectional view of the high-temperature vacuum spinning forming device provided by the embodiment of the present application;

[0023] Figure 3 is a schematic diagram of the overall structure of the high-temperature vacuum spinning forming device provided by the embodiment of the present application, where (a) is the front view and (b) is the rear view;

[0024] Figure 4 is a schematic diagram of the structure of the induction heating unit in the high-temperature vacuum spinning forming device provided by the embodiment of the present application;

[0025] Figure 5 is a schematic diagram of the sealing structure in the high-temperature vacuum spinning forming device provided by the embodiment of the present application;

[0026] Figure 6 is a processing flow chart of the high-temperature vacuum spinning forming method provided by the embodiment of the present application, where (a) is the initial tube blank, (b) is the tube blank after forward spinning and thinning, and (c) is the final tube blank after reverse spinning and thinning;

[0027] Figure 7 is a schematic diagram of the top block, split support inner mold and mandrel in the high-temperature vacuum spinning device provided by the embodiment of the present application, where (a) is a sectional view of the top block, (b) is a sectional view of the split support inner mold, (c) is a top view of the split support inner mold, and (d) is a sectional view of the mandrel.

[0028] In all the drawings, the same reference numerals are used to denote the same elements or structures, where: 1 - housing, 2 - hatch, 3 - vacuum pump interface, 4 - workbench, 5 - support base, 6 - chuck, 7 - spinning wheel, 8 - spinning wheel base, 9 - spinning wheel slide, 10 - tailstock, 11 - mandrel, 12 - induction heating unit, 13 - tube blank, 14 - servo motor, 15 - linear slide, 16 - infrared thermometer, 17 - induction coil, 18 - bracket, 19 - top block, 20 - radial carriage, 21 - split support internal mold, 22 - first hydraulic cylinder, 23 - first sealing ring, 24 - fifth sealing ring, 25 - third sealing ring, 26 - fourth sealing ring, 27 - second sealing ring, 28 - chuck rotating shaft, 29 - chuck flange, 30 - second hydraulic cylinder. Detailed implementation mode

[0029] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0030] The embodiment of the present application provides a high-temperature vacuum spinning forming method for difficult-to-deform metal complex components, specifically: placing the split support internal mold 21 inside the tube blank 13, then heating one end of the tube blank 13 to the vacuum spinning temperature in a vacuum environment and performing forward spinning and thickness reduction forming, stopping after meeting the requirements of wall thickness reduction and inner ring rib forming, and finally heating the other end of the tube blank 13 to the vacuum spinning temperature and performing reverse spinning and thickness reduction forming, stopping after meeting the requirements of wall thickness reduction and inner ring rib forming, so as to manufacture a complex component with inner ring ribs and avoid the formation of oxide layers on the inner and outer surfaces of the complex component.

[0031] Figure 6 It is a processing flow chart of the high-temperature vacuum spinning forming method provided by the embodiment of the present application, where (a) is a schematic structural diagram of the initial tube blank, the initial length of the initial tube blank is L0, the inner diameter of the initial tube blank is D0, the outer diameter of the fixed end is D1, and the outer diameter of the free end is D2; (b) is a schematic structural diagram of the tube blank after forward spinning and thickness reduction, the length of the thickness reduction part is L1, the length of the tube blank after thickness reduction is L2, and the diameter of the inner ring rib is D3; (c) is a schematic structural diagram of the final tube blank after reverse spinning and thickness reduction, and the length of the tube blank after thickness reduction is L3.

[0032] Considering that the hot spinning temperature of refractory metals is generally above 850°C, and there are obvious differences in thermoplasticity even with a difference of dozens of degrees. When the temperature is too low, the deformation plasticity is poor, the resistance is large, and thin-walled parts are prone to fracture. When the temperature is too high, the structure will be overburned and the grains will grow abnormally, resulting in poor component performance. Therefore, hot spinning of refractory metals requires not only high temperature but also stability. The lack of either of the two factors will affect the spinning formability of refractory metals. At the same time, some alloys also have the characteristics of slow heating and fast cooling. By placing the tube blank 13 in a vacuum environment, the present application can avoid the problem of unstable temperature of refractory metals caused by too fast heat dissipation due to air convection. At the same time, the segmented spinning forming method can further improve the temperature stability and meet the requirements of high temperature and stability. On the other hand, during the hot spinning process of refractory and easily oxidized metals, oxide layers of varying degrees will appear under the influence of high temperature and forming time. The surface oxide layer will affect the fluidity of the metal, and forming defects such as scale, interlayer, and folding are likely to occur. The present application proposes to perform spinning forming in a vacuum environment, blocking the direct contact between the tube blank and the external environment, and enabling all-round non-oxidation forming, which greatly guarantees the high-quality forming of complex components. And it is not limited to the component sizes and materials mentioned in the present invention, but can also be applied to the forming of other rotary components such as round plates, bar materials, etc., as well as other refractory materials and high-temperature and easily oxidized materials (such as titanium-based alloys, stainless steels, superalloys, etc.). Compared with the prior art, the high-temperature spinning process is in a vacuum environment, without oxidation behavior, which can greatly avoid the formation of oxide layers on the inner and outer surfaces, avoiding both the influence of the oxide layer on the surface forming quality and the problem of difficult machining of the subsequent oxide layer due to the complex internal cavity. At the same time, the segmented spinning forming can avoid the phenomenon of abnormal grain growth of the material when it is at high temperature for a long time, thus affecting the mechanical properties. And the forming process of first forward spinning and then reverse spinning can form the entire component in one heat treatment. This process method has the characteristics of good formability, good mechanical properties, low die cost, and high material utilization rate.

[0033] Furthermore, the material of the tube blank is titanium alloy, stainless steel or superalloy. By spinning in a vacuum environment, the spinning process window can be expanded. When the material of the tube blank is titanium alloy, the vacuum spinning temperature is 820°C to 980°C. When the material of the tube blank is stainless steel, the vacuum spinning temperature is 900°C to 1050°C. When the material of the tube blank is superalloy, the vacuum spinning temperature is 950°C to 1100°C. Among them, the low spinning temperature values of the three alloys are 20°C to 30°C lower than those in the non-vacuum environment, and the high temperature values are 30°C to 50°C higher than those in the non-vacuum environment. This is because there is no interference from the oxide layer in the vacuum environment, and the oxide layer will increase the surface deformation resistance. Therefore, in the absence of the oxide layer, the deformation temperature can be reduced by ~20°C to obtain a finer and more uniform structure. The higher the temperature in the non-vacuum environment, the more serious the oxide layer, which will affect the forming quality. Therefore, in the vacuum environment, the high temperature value can be further increased by ~30°C, and the forming load can be reduced. In short, spinning forming in a vacuum environment can expand the deformation process window of each alloy and provide greater stability guarantee for alloy forming.

[0034] Furthermore, in forward spinning and thinning forming, the spindle speed is 250 r / min to 300 r / min, the roller feed speed is 220 mm / min to 250 mm / min, the feed ratio is 0.73 mm / r to 1 mm / r, and the thinning rate is 11.1% to 18.2%. In reverse spinning and thinning forming, the spindle speed is 250 r / min to 280 r / min, the roller feed speed is 180 mm / min to 230 mm / min, the feed ratio is 0.64 mm / r to 0.92 mm / r, and the thinning rate is 11.1% to 18.2%. The spinning speed, roller feed speed and thinning rate provided by this application are optimized parameters in a vacuum environment, which can ensure high wall thickness uniformity of difficult-to-deform metals during spinning, full filling of internal ribs, and avoid poor control of metal flow caused by roller stockpiling and necking down, thereby improving the forming quality of the inner and outer surfaces and ensuring the qualification rate of products.

[0035] According to another aspect of this application, such as Figure 1 、 2A high-temperature vacuum spinning forming device for realizing the above method is provided, the device comprises a vacuum cavity unit, a spinning unit and an induction heating unit 12, wherein: the vacuum cavity unit is used to form a vacuum cavity to ensure that the high-temperature spinning is performed in a vacuum environment; the spinning unit is placed inside the vacuum cavity, and comprises a chuck assembly, two sets of spinning wheel assemblies and a tail top assembly, the chuck assembly is arranged at the bottom of the vacuum cavity, and is used to fix the tube blank and drive it to rotate; the two sets of spinning wheel assemblies are symmetrically arranged on the left and right sides of the vacuum cavity, and are used to spin the tube blank; the tail top assembly is arranged at the top of the vacuum cavity The induction heating unit 12 is arranged between the two groups of spinning wheel assemblies, and is used for heating the tube blank to reach the vacuum spinning temperature.

[0036] Because the outer wall of the complex component prepared in this application has a stepped structure, and there are multiple inner ring ribs (such as Figure 6 As shown in (c), the straight wall inside and the inner ring rib structure mean that the mandrel must be supported during the forming process, and the mandrel mold must be easily removed after the forming process. Therefore, the internal support mold matched with it in the spinning forming process proposed in this application is as follows Figure 7 shown. Figure 7 (a) is a top block 19, the outer diameter of one end of the top block 19 is D0, which is consistent with the inner diameter D0 of the tube blank 13, and can be inserted into the tube blank 13. The outer diameter of the other end of the top block 19 is consistent with the outer diameter of the fixed end of the tube blank 13, which is D1. The tube blank 13 and the top block 19 can be clamped by the chuck 6 and driven to rotate together; Figure 7 (b) and (c) are split support inner molds 21, whose outer surface has rib grooves, and whose outer diameter is consistent with the inner diameter of the tube blank 13, which is D0, and whose inner diameter is consistent with Figure 7The outer diameter of the mandrel shown in Figure (d) is uniformly D4. The support inner die is wire cut into 8 parts for easy demoulding. The four-lobe front end marked 1 has a positioning structure corresponding to the positioning groove at the front end of the ejector block 19, which is convenient for mold installation. Before forming, the ejector block 19 extends into one end of the tube blank 13. The ejector block 19 and the tube blank 13 are clamped together by the chuck 6. The split support inner die 21 is placed into the tube blank 13 and then supported by the mandrel 11 to complete the mold installation. After forming, first withdraw the mandrel 11, then slide the 4-lobe molds marked 1 along the positioning groove towards the center of the tube blank 13 and take them out, and then take out the remaining 4 lobes to complete the demoulding. The whole set of molds is designed to be convenient and easy to operate, solving the problem that it is difficult to take out the mold after the inner ring rib is formed. In this application, by covering the outer side of the mandrel 11 with the split support inner die 21, this type of component can be integrally near-net formed in one heat treatment. The forming process is simple, mold installation and demoulding are easy, greatly reducing the forming load and processing cost, improving the material utilization rate and the overall deformation uniformity of the component, being applicable to the forming of various difficult-to-deform metals, and the prepared products have broad application prospects and benefits in the fields of military, aerospace, transportation, etc.

[0037] Furthermore, as Figure 3 shown, the vacuum chamber unit includes a workbench 4, a support base 5, a housing 1, and a vacuum pump. Above the workbench 4, a chuck assembly and a roller assembly are fixed. At the same time, its lower part is connected to the support base 5. The housing 1 covers above the workbench 4 to form a vacuum chamber. The tailstock assembly is fixed above the housing 1. At the same time, a vacuum pump interface 3 and a hatch 2 are provided on the housing 1. The vacuum pump is connected to the vacuum pump interface and is used to evacuate the cavity space formed by the housing 1 and the workbench 4 to form a vacuum chamber. The hatch 2 is used to replace and take out the formed complex component and replace it with a new tube blank 13. In a preferred embodiment, the vacuum chamber unit is also equipped with an oxygen analyzer, and the oxygen content in the vacuum chamber can be detected through the oxygen analyzer.

[0038] Furthermore, the roller assembly includes a roller slide 9, a second hydraulic cylinder 30, a radial carriage 20, a roller seat 8, and a roller 7. The roller slide 9 includes a first guide rail fixed on the workbench 4 and a first slider moving up and down along the first guide rail. The first slider is connected to the second hydraulic cylinder 30 to move up and down along the first guide rail under the drive of the second hydraulic cylinder 30. At the same time, a hole is opened in the middle of the first slider for the radial carriage 20 to pass through. The radial carriage 20 passes through the slider and is connected to the roller seat 8, and is used to drive the roller seat 8 to move left and right in the horizontal direction. The roller 7 is fixed at the bottom of the roller seat 8.

[0039] Furthermore, the chuck assembly includes an ejector block 19, a chuck 6, a chuck flange 29, and a chuck rotating shaft 28. The ejector block 19 is arranged above the chuck 6 and is used to insert into the tube blank 13 to fix it. The chuck 6 is arranged above the workbench 4 and is fixed by the chuck flange 29 below the workbench 4. The chuck rotating shaft 28 passes through the chuck flange 29 and is connected to the chuck 6 to drive the chuck 6 to rotate.

[0040] Further, as Figure 4 shown, the induction heating unit 12 includes a linear slide 15, a bracket 18, a servo motor 14, an induction coil 17, and an infrared thermometer 16. The linear slide 15 includes a second guide rail fixed to the workbench 4 through the bracket 18 and a second slider that moves up and down along the second guide rail. The second slider is connected to the servo motor 14 to move up and down along the second guide rail under the drive of the servo motor 14. The induction coil 17 is connected to the second slider and passes through the tube blank 13 to perform real-time heating and heat compensation on the tube blank 13. The infrared thermometer 16 is arranged on the second slider, so as to be able to follow along with the induction coil 17 in real time to detect the temperature of the tube blank 13 and give feedback.

[0041] Further, as Figure 5 shown, in order to ensure the sealing performance of the vacuum chamber, the present application optimizes the sealing structure in the high-temperature vacuum spinning forming device. The first hydraulic cylinder 22 and the second hydraulic cylinder 30 are arranged outside the vacuum chamber and pass through the housing 1 and extend into the vacuum chamber. At the same time, a first sealing ring 23 is arranged between the first hydraulic cylinder 22 and the second hydraulic cylinder 30 and the housing to achieve dynamic sealing. A second sealing ring 27 is arranged between the chuck flange 29 and the chuck rotating shaft 28 to achieve dynamic sealing. In addition, in order to further ensure the sealing performance, a third sealing ring 25 is arranged between the housing 1 and the workbench 4, and a fourth sealing ring 26 is arranged between the workbench 4 and the chuck flange to achieve static sealing. In a preferred embodiment of the present invention, the upper part of the housing 1 is open, and the first hydraulic cylinder 22 and the second hydraulic cylinder 30 are fixed by arranging a sealing plate. The sealing plate is nested at the opening of the housing 1 and is fixedly connected to the top of the first guide rail. A fifth sealing ring 24 is arranged between the sealing plate and the housing 1 to achieve static sealing. The materials of the first sealing ring 23, the second sealing ring 27, the third sealing ring 25, the fourth sealing ring 26, and the fifth sealing ring 24 are preferably fluororubber sealing rings suitable for the vacuum environment, which have the characteristics of heat resistance, anti-aging, excellent physical properties, and small air permeability. The present application adopts dynamic sealing and static sealing to achieve the sealing of the vacuum chamber. At the same time, in cooperation with the movable induction heating unit, it can realize heating and heat preservation of different parts, providing a guarantee for the temperature control of vacuum spinning forming, and thus ensuring the controllability of the formed structure.

[0042] Further, the high-temperature vacuum spinning forming device further includes a control unit, which is used for performing spinning wheel hydraulic servo digital control, tube blank heating temperature and position servo control, and detecting the positions of the equipment movement mechanisms, the temperature of the tube blank and the vacuum environment, the speed of the spinning wheel, the pressure, etc. The control system can complete functions such as programming of processing programs, parameter setting, machine detection, and adjustment.

[0043] Furthermore, the spinning unit also includes a lubrication component, which uses vacuum grease to lubricate the spinning wheel slide 9 and the chuck rotating shaft 28.

[0044] The technical solution provided in this application is further explained below based on specific implementation.

[0045] Example 1

[0046] Step 1: Prepare the titanium alloy tube blank used for spinning forming, and obtain the Ti-6Al-4V titanium alloy tube blank with D0=100mm, D1=116mm, D2=130mm, and L0=280mm through mechanical processing. The roughness of the inner and outer surfaces of the tube blank is Ra1.6.

[0047] Step 2: Check the spinning tooling, open the hatch 2, install the spinning wheel 7 required for forming, check the fixing bolts and surface quality of the spinning wheel 7; start the tail top seat 10 to move downward, install the mandrel 11 required for spinning, and return the tail top seat 10; install the induction coil 17 and the infrared thermometer 16 on the linear slide 15 respectively.

[0048] Step 3: Install the spun titanium alloy tube blank, start the chuck control system, loosen the jaws, vertically place the prepared top block 19 into the jaws, spray lubricant on the part of the top block that extends into the titanium alloy tube blank, then put the titanium alloy tube blank on the top block 19, and the jaws clamp the titanium alloy tube blank and the top block 19 at the same time.

[0049] Step 4: Input the spinning process parameter program. Input the programmed spinning process program into the control system. Cover the induction coil 17 on the outside of the titanium alloy tube blank. Adjust the position of the infrared thermometer 16. Move the tail top seat 10 downward to extend the mandrel 11 into the tube blank 13 and contact with the top block 19. Detect the axial and radial movement of the spinning wheel 7 and the follow-up of the induction coil 17 and the infrared thermometer 16.

[0050] Step 5: Spray lubricant and preheat the mold, move the tail top seat 10 upward, separate the mandrel 11 from the titanium alloy tube, spray molybdenum disulfide oil or water-based graphite lubricant on the inner wall of the tube 13, and then put the petal support inner mold 21 into the tube 13 respectively, and spray lubricant on the surface of the mandrel 11 appropriately. The mandrel 11 moves downward to support the top block 19, and then the rotary wheel 7 is preheated with a flame spray gun, and the preheating temperature is between 200℃ and 300℃.

[0051] Step 6: Vacuum oxygen-free environment, close hatch 2, start the vacuum pump to evacuate the vacuum chamber, observe the real-time detection values ​​of the barometer and oxygen meter, and stop when the corresponding standards are reached. The air pressure in the vacuum chamber is 10 -1 Near Pa;

[0052] Step 7: First preheat the upper end of the tube blank, then heat and form the end tube blank. After reaching the required test vacuum environment, start the induction heating power supply and at the same time start the chuck rotation control system. Use the induction heating coil 17 to uniformly heat the tube blank 13 in rotation. The infrared thermometer 16 continuously detects the temperature of the titanium alloy tube. After reaching 300 °C, lower the induction coil 17 to heat the lower end tube blank 13. The induction coil 17 is fixed on the linear slide 15 and can move axially along the linear slide 15, but the roller 7 will not touch the induction coil 17 during radial feed. The infrared thermometer 16 continuously detects the temperature of the titanium alloy tube blank. The infrared thermometer 16 and the induction coil 17 can move axially in synchronization, so as to ensure that the temperature of the blank in the front area of the roller 7 reaches the spinning deformation temperature of 850 °C.

[0053] Step 8: The segmented heating can not only preheat the internal mold, but also prevent the unformed end from being under high-temperature heating all the time, which affects the tissue morphology. Therefore, first preheat the upper end and then heat the lower end. When the lower end reaches the deformation temperature, the deformation starts.

[0054] Step 9: The first pass is forward spinning and thickness reduction forming. The spindle speed is 250 r / min, the roller feed speed is 220 mm / min, the feed per revolution is 0.88 mm / r, and the thickness reduction rate is 13.3%. At the start of spinning, the roller 7 contacts the tube blank 13. Since the mold temperature is lower than the tube blank temperature, heat transfer will cause the temperature of the tube blank to drop and the temperature of the mold to rise. At this time, the induction coil 17 will replenish heat to the titanium alloy tube blank to ensure that the spinning temperature is the preset forming temperature.

[0055] Step 10: The second pass is forward spinning and thickness reduction forming. The roller 7 first moves radially away from the tube blank according to the preset trajectory, and then axially moves to the starting point to start the second pass of spinning. The spindle speed is 250 r / min, the roller feed speed is 220 mm / min, the feed per revolution is 0.88 mm / r, and the thickness reduction rate is 15.4%. This pass is longer than the previous pass. At the second pass, the mold temperature has stabilized, and the deformation of the tube blank will also generate heat. Therefore, the heating power is different from the initial value. The infrared thermometer and the induction heating system are a closed-loop system. When the temperature measured by the infrared thermometer 16 is lower than the vacuum spinning temperature, it will feedback to the induction heating power supply to increase the power for heating. When the measured temperature reaches or is higher than the spinning temperature, the power of the power supply will be reduced, so as to achieve the purpose of stabilizing the temperature of the tube blank.

[0056] Step 11: Forward spinning and thinning forming in the third and fourth passes. The spinning wheel 7 first moves radially away from the tube blank 13 along the preset trajectory, axially moves to the starting point to start the third-pass spinning. The spindle speed is 250 r / min, the feeding speed of the spinning wheel is 220 mm / min, the feed per revolution is 0.88 mm / r, and the thinning rate is 18.2%. For the fourth-pass spinning, the spindle speed is 250 r / min, the feeding speed of the spinning wheel is 250 mm / min, the feed per revolution is 1.0 mm / r, and the thinning rate is 11.1%. At this time, the spinning of the lower half section is completed, and the inner ring ribs and wall thickness meet the requirements, and the spinning forming of the upper half section begins.

[0057] Step 12: The spinning wheel retracts, the induction heating coil moves upward, and the upper end of the tube blank starts to be heated, and the heating temperature reaches 850 °C.

[0058] Step 13: Reverse spinning and thinning forming of the upper end tube blank. The spinning wheel 7 first moves radially away from the tube blank along the preset trajectory, axially moves to the starting point at the upper end of the tube blank to start the fifth-pass reverse spinning. The spindle speed is 250 r / min, the feeding speed of the spinning wheel is 180 mm / min, the feed per revolution is 0.72 mm / r, and the thinning rate is 13.3%. For the sixth-pass reverse spinning, the spindle speed is 250 r / min, the feeding speed of the spinning wheel is 180 mm / min, the feed per revolution is 0.72 mm / r, and the thinning rate is 15.4%. For the seventh-pass reverse spinning, the spindle speed is 250 r / min, the feeding speed of the spinning wheel is 180 mm / min, the feed per revolution is 0.72 mm / r, and the thinning rate is 18.2%. For the eighth-pass reverse spinning, the spindle speed is 250 r / min, the feeding speed of the spinning wheel is 230 mm / min, the feed per revolution is 0.92 mm / r, and the thinning rate is 11.1%. Since the reverse spinning deformation resistance is larger than that of the forward spinning, the feed per revolution is a little smaller to meet the deformation requirements of the component, and the spinning forming is stopped.

[0059] Step 14: Turn off the induction heating power supply to stop the coil heating function. The spinning wheel moves axially upward, feeds a certain distance at the upper end of the tube blank to hold the tube blank, the tailstock drives the mandrel to move upward, the mandrel is demolded, the induction coil is removed, and cooling inert gas is filled to cool the tube blank.

[0060] Step 15: When the temperature drops below 150 °C, turn off the cooling gas and the vacuum pump system, inflate and release the pressure until the pressure is restored, open the hatch, and take out the split inner support die and the tube blank. The forming of the component is completed.

[0061] Example 2

[0062] Only the spinning temperature in Step 7 and Step 12 is 820 °C, the spindle speed in Step 9, Step 10, and Step 11 is 300 r / min, the feeding speed of the spinning wheel is 230 mm / min, the spindle speed in Step 13 is 280 r / min, the feeding speed of the spinning wheel is 200 mm / min, and the rest is the same as in Example 1.

[0063] Example 3

[0064] Only the spinning temperature in Steps 7 and 12 is 980°C, the spindle speed in Steps 9, 10, and 11 is 270 r / min, the roller feed rate is 250 mm / min, the spindle speed in Step 13 is 270 r / min, and the roller feed rate is 230 mm / min. The rest is the same as in Example 1.

[0065] Example 4

[0066] Only the tube blank material in Step 1 is selected as stainless steel, the spinning temperature in Steps 7 and 12 is 900°C, the spindle speed in Steps 9, 10, and 11 is 250 r / min, the roller feed rate is 220 mm / min, the spindle speed in Step 13 is 250 r / min, and the roller feed rate is 180 mm / min. The rest is the same as in Example 1.

[0067] Example 5

[0068] Only the tube blank material in Step 1 is selected as stainless steel, the spinning temperature in Steps 7 and 12 is 980°C, the spindle speed in Steps 9, 10, and 11 is 270 r / min, the roller feed rate is 240 mm / min, the spindle speed in Step 13 is 270 r / min, and the roller feed rate is 210 mm / min. The rest is the same as in Example 1.

[0069] Example 6

[0070] Only the tube blank material in Step 1 is selected as stainless steel, the spinning temperature in Steps 7 and 12 is 1050°C, the spindle speed in Steps 9, 10, and 11 is 260 r / min, the roller feed rate is 250 mm / min, the spindle speed in Step 13 is 260 r / min, and the roller feed rate is 230 mm / min. The rest is the same as in Example 1.

[0071] Example 7

[0072] Only the tube blank material in Step 1 is selected as superalloy, the spinning temperature in Steps 7 and 12 is 950°C, the spindle speed in Steps 9, 10, and 11 is 260 r / min, the roller feed rate is 220 mm / min, the spindle speed in Step 13 is 260 r / min, and the roller feed rate is 200 mm / min. The rest is the same as in Example 1.

[0073] Example 8

[0074] Only the tube blank material in Step 1 is selected as superalloy, the spinning temperature in Steps 7 and 12 is 1030 °C, the spindle speed in Steps 9, 10, and 11 is 290 r / min, the roller feed speed is 250 mm / min, the spindle speed in Step 13 is 290 r / min, and the roller feed speed is 230 mm / min. The rest is the same as in Example 1.

[0075] Example 9

[0076] Only the tube blank material in Step 1 is selected as superalloy, the spinning temperature in Steps 7 and 12 is 1100 °C, the spindle speed in Steps 9, 10, and 11 is 270 r / min, the roller feed speed is 250 mm / min, the spindle speed in Step 13 is 270 r / min, and the roller feed speed is 230 mm / min. The rest is the same as in Example 1.

[0077] The method and device provided by the present application are not only applicable to the spinning forming of metal tubes, but also applicable to the forming of other rotary components such as circular plates, bar materials, etc.; for materials, it is also applicable to difficult-to-deform and high-temperature oxidation-prone metal materials such as titanium-based alloys, stainless steels, and superalloys; the process is not limited to power spinning and thinning, and is also applicable to various spinning processes such as conventional spinning, necking, and shearing.

[0078] In the description of the present application, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0079] In addition, the reference to "one embodiment" throughout this specification; the phrase "in one embodiment" and similar language indicate that the specific features, structures, or characteristics described in connection with that embodiment are included in at least one embodiment of the present application. Thus, the appearances of the phrase "in one embodiment;" throughout this specification and similar language may or may not all refer to the same embodiment.

[0080] Those skilled in the art can easily understand that the above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A high temperature vacuum spinning method for complex metal components that are difficult to deform, characterized in that: The high-temperature vacuum spinning forming method specifically comprises: placing a split support inner mold (21) inside a tube blank (13), then heating one end of the tube blank (13) to a vacuum spinning temperature in a vacuum environment and performing forward spinning thinning forming, and stopping when the forming requirements are met; finally, heating the other end of the tube blank (13) to a vacuum spinning temperature and performing reverse spinning thinning forming, and stopping when the forming requirements are met, thereby obtaining a complex component with an inner ring rib and preventing the formation of an oxide layer on the inner and outer surfaces of the complex component; the spindle speed in the forward spinning thinning forming is 2 50r / min~300r / min, the rotary wheel feed speed is 220mm / min~250mm / min, the feed ratio is 0.73mm / r~1mm / r, and the thinning rate is 11.1%~18.2%; the spindle speed in the reverse spinning thinning forming is 250r / min~280r / min, the rotary wheel feed speed is 180mm / min~230mm / min, the feed ratio is 0.64mm / r~0.92mm / r, and the thinning rate is 11.1%~18.2%, among which: When the material of the tube blank (13) is titanium alloy, stainless steel or high-temperature alloy, when the material of the tube blank (13) is titanium alloy, the vacuum spinning temperature is 820°C to 980°C, when the material of the tube blank (13) is stainless steel, the vacuum spinning temperature is 900°C to 1050°C, and when the material of the tube blank (13) is high-temperature alloy, the vacuum spinning temperature is 950°C to 1100°C.

2. A device for implementing the high temperature vacuum spinning forming method of difficult-to-deform metal complex components as claimed in claim 1, characterized in that: The device comprises a vacuum cavity unit, a spinning unit and an induction heating unit (12), wherein: the vacuum cavity unit is used to form a vacuum cavity to ensure that high-temperature spinning is performed in a vacuum environment; the spinning unit is placed inside the vacuum cavity, and comprises a chuck assembly, two groups of spinning wheel assemblies and a tail top assembly, wherein the chuck assembly is arranged at the bottom of the vacuum cavity and is used to fix the tube blank and drive it to rotate; the two groups of spinning wheel assemblies are symmetrically arranged on the left and right sides of the vacuum cavity and are used to spin and deform the tube blank; the tail top assembly is arranged at the top of the vacuum cavity and comprises a first hydraulic cylinder (22), a tail top seat (10), a mandrel (11) and a split support inner mold (21), wherein the first hydraulic cylinder (22) is connected to the mandrel (11) through the tail top seat (10), and the split support inner mold (21) is covered on the outside of the mandrel (11); the induction heating unit (12) is arranged between the two groups of spinning wheel assemblies and is used to heat the tube blank to reach the vacuum spinning temperature.

3. The device according to claim 2, characterized in that The vacuum chamber unit comprises a workbench (4), a support seat (5), a shell (1) and a vacuum pump; a chuck assembly and a rotary wheel assembly are fixed above the workbench (4), and the bottom of the workbench is connected to the support seat (5); the shell (1) is arranged above the workbench (4); a hatch (2) and a vacuum pump interface (3) are arranged on the shell (1); the vacuum pump is connected to the vacuum pump interface (3) and is used to evacuate the cavity space formed by the shell (1) and the workbench (4) to form a vacuum chamber.

4. The device according to claim 3, characterized in that The rotary wheel assembly comprises a rotary wheel slide (9), a second hydraulic cylinder (30), a radial slide (20), a rotary wheel seat (8) and a rotary wheel (7); the rotary wheel slide (9) comprises a first guide rail fixed on a workbench (4) and a first slider moving up and down along the first guide rail; the first slider is connected to the second hydraulic cylinder (30) so as to move up and down along the first guide rail under the drive of the second hydraulic cylinder (30); and the first slider has a middle opening for passing the radial slide (20); the radial slide (20) passes through the slider and is connected to the rotary wheel seat (8) so as to drive the rotary wheel seat (8) to move left and right in a horizontal direction; and the rotary wheel (7) is fixed to the bottom of the rotary wheel seat (8).

5. The device according to claim 2, characterized in that The chuck assembly comprises a top block (19), a chuck (6), a chuck flange (29) and a chuck rotating shaft (28); the top block (19) is arranged above the chuck (6) and is used to insert a tube blank (13) to fix it; the chuck (6) is arranged above the workbench (4) and is fixed by the chuck flange (29) below the workbench (4); the chuck rotating shaft (28) passes through the chuck flange (29) and is connected to the chuck (6) to drive the chuck (6) to rotate.

6. The device according to claim 2, characterized in that The induction heating unit (12) comprises a linear slide (15), a bracket (18), a servo motor (14), an induction coil (17) and an infrared thermometer (16); the linear slide (15) comprises a second guide rail fixed to a workbench (4) via the bracket (18) and a second slider moving up and down along the second guide rail; the second slider is connected to the servo motor (14) so ​​as to move up and down along the second guide rail under the drive of the servo motor (14); the induction coil (17) is connected to the second slider and passes through the tube blank (13) so as to heat the tube blank (13); the infrared thermometer (16) is arranged on the second slider and is used to detect the temperature of the tube blank (13).

7. The device according to claim 4, characterized in that The first hydraulic cylinder (22) and the second hydraulic cylinder (30) are arranged outside the vacuum chamber and extend through the housing (1) into the interior of the vacuum chamber, and a first sealing ring (23) is arranged between the first hydraulic cylinder (22) and the second hydraulic cylinder (30) and the housing (1) to achieve dynamic sealing.

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