A local variable temperature forming device and method for a linkage die of a titanium alloy hoop-shaped component

Abstract

The invention discloses a local variable-temperature forming device and method for a titanium alloy hoop-like component linkage die. The limit block and the lower die are respectively fixedly connected to the upper platform and the lower platform of the hydraulic press through T-shaped grooves and clamping mechanisms, and the movement direction of the limit block is ensured. The adjusting block is connected to the insulating backing plate by bolts, and the adjusting block and the insulating backing plate are connected to the limit block by support positioning springs. The local variable-temperature forming device and method for the titanium alloy hoop-like component linkage die solve the problems of large springback and low forming accuracy of large-angle thin-walled bending components of titanium alloy; realize the differential-temperature rapid heating of the titanium alloy forming slab, with a high temperature at the forming part and a low temperature at the non-forming part, and reduce the adverse influence of temperature on the non-forming part on the premise of ensuring the deformation temperature; and realize the forming process of the titanium alloy hoop structure component in one process.

Description

Technical Field

[0001] The present invention relates to the technical field of structural design and application of precision plastic forming of titanium alloy thin-walled components, and particularly provides a local variable-temperature forming device and method for a linkage die of titanium alloy hoop-like components. Background Art

[0002] Titanium alloy thin-walled hoops are important functional components of aero-engines, which play a role in connecting additional structures and the engine body. The part shape consists of a straight section in the middle region and annular sections on both sides. However, due to the low elastic modulus and plastic deformation ability of titanium alloy materials themselves, as well as the high yield strength, the room-temperature deformation springback of its thin-walled components is large, the deformation resistance is high, and the forming accuracy is low. Especially for titanium alloy thin-walled bending components, it is very difficult to achieve precise forming under room-temperature conditions. Existing forming methods usually reduce the deformation resistance of titanium alloy by increasing the forming temperature, eliminate residual stress, improve the deformation ability, and improve the forming quality. Therefore, for titanium alloy thin-walled hoop components, currently, precision manufacturing is usually achieved based on hot forming technology and adopting a two-step stamping and bending forming process.

[0003] However, the traditional hot forming method using a heating furnace requires heating both the die and the formed part simultaneously, resulting in a long part manufacturing cycle, low forming efficiency, and a reduced service life of the forming die due to its long-term operation in a high-temperature environment. At the same time, heating large-size dies also leads to an increase in energy consumption and production costs. Meanwhile, limited by the size of the heating furnace and the hot environment, it is very difficult to apply a forming mechanism with complex multi-directional movements, which makes it necessary to adopt a two-step hot bending forming process for the annular sections on both sides of the titanium alloy thin-walled hoop component. This not only increases the processing technological process but also requires the separate design of two sets of bending dies. In addition, the long-term exposure of titanium alloy in a high-temperature environment also leads to the coarsening of the material microstructure and the reduction of mechanical properties.

[0004] People urgently hope to obtain a local variable-temperature forming device and method for a linkage die of titanium alloy hoop-like components with excellent technical effects. Summary of the Invention

[0005] The purpose of the present invention is to provide a local variable-temperature forming device and method for a linkage die of titanium alloy hoop-like components with excellent technical effects. Aiming at the deficiencies of the traditional hot forming process of titanium alloy hoop-like components for aero-engines, such as many processes, low efficiency, short die life, large influence of part structure on heat, and limitation of the formed part size by the heating furnace size, a local variable-temperature forming device and method for a linkage die of titanium alloy hoop-like components are proposed, so as to achieve the efficient, high-quality, and low-energy-consumption precise forming of titanium alloy hoop-like components.

[0006] The local variable temperature forming device and method for the linkage die of titanium alloy hoop belt components aims at the deficiencies existing in the existing forming technology of titanium alloy thin-walled hoop belt components, and proposes to utilize the Joule heat effect generated by pulse current passing through the metal to realize the rapid heating of the bending part of the forming slab; adopt a transverse linkage die to realize the forming of the annular bending part within one forming cycle, shortening the forming process; adopt the variable thickness auxiliary design of the forming device to reduce the heat generation during the forming process by reducing the current density in the middle section, and weaken the adverse effects of high temperature on the microstructure and mechanical properties of titanium alloy. By comprehensively utilizing the rapid heating advantage of current energy field-assisted hot forming and the method of temperature control by controlling the local current density, as well as the optimized design of the multi-directional linkage die tooling structure and the precise control of the forming loading sequence, this patent has creativity and novelty in the field of precise forming of titanium alloy thin-walled hoop belt components with high efficiency, high quality and low energy consumption.

[0007] The local variable temperature forming device for the linkage die of titanium alloy hoop belt components includes: a hydraulic press, a limit block, an electrode, a power supply, an insulating backing plate, an adjusting block, an upper die, an upper die insulation and heat insulation layer, a core die, a lower die insulation and heat insulation layer, a temperature measuring thermocouple, a lower die, a support positioning spring and an ultra-thin insulating cushion; wherein, the limit block and the lower die are respectively fixedly connected to the upper platform and the lower platform of the hydraulic press through T-shaped grooves and clamping mechanisms, and the movement direction of the limit block is ensured; the adjusting block and the insulating backing plate are connected by bolts, and the adjusting block and the insulating backing plate are connected to the limit block through a support positioning spring, which can provide vertical pressure while playing a positioning role; the upper die insulation and heat insulation layer is connected to the outside of the upper die, the lower die insulation and heat insulation layer is connected to the outside of the lower die, the electrode is connected to the forming slab by bolts or a mechanical clamping mechanism, the positive and negative electrodes of the electrode are respectively connected to both sides of the forming slab, and form a loop with the power supply; the surface of the core die is provided with an insulation and heat insulation layer, which can be an insulation treatment of the surface of the core die or a ceramic sheet or an asbestos gasket with the same shape as the surface of the core die;. The temperature measuring thermocouple is placed in the temperature measuring hole of the lower die, and the ultra-thin insulating cushion is placed on the forming slab, where the ultra-thin is less than 0.2 mm, preventing the slab from folding over and contacting itself, and avoiding short-circuiting a part of the forming slab.

[0008] Preferably, the upper die only moves in the horizontal direction and can rotate around the arc at its tail, avoiding interference and collision with structures such as the core die during the forming process.

[0009] The specific materials of the upper die insulation and heat insulation layer and the lower die insulation and heat insulation layer are alumina or zirconia or ceramic sheets or asbestos gaskets, etc.

[0010] The local variable temperature forming method for the linkage die of titanium alloy hoop belt components is as follows:

[0011] Step 1: Cut and process the forming slab according to the shape and size characteristics of the hoop belt component.

[0012] Step 2: Insulating and heat-insulating coating treatments are respectively carried out on the contact parts of the upper die, lower die, core die and forming slab, and the coating thickness is 5 µm to 800 µm.

[0013] Step 3: Install the limit block, support positioning spring, insulating backing plate, adjusting block, upper die, core die and lower die on the hydraulic press in sequence. The limit block is installed on the upper platform of the hydraulic press, and the limit block, support positioning spring, insulating backing plate and adjusting block are fixedly connected in sequence. The two upper dies are respectively fixed on the side cylinders of the hydraulic press at both ends. The core die is fixed on the other upper platform of the hydraulic press through a connecting rod, and the lower die is fixed on the lower platform of the hydraulic press.

[0014] Step 4: Both ends of the forming slab are fixedly connected to the two electrodes respectively. One side electrode is connected to the positive pole of the power supply, and the other side electrode is connected to the negative pole of the power supply. Then place the forming slab on the lower die according to the position, and the current value range of the power supply is 0 A to 20,000 A.

[0015] Step 5: Start the hydraulic press, the limit block moves downwards, making the adjusting block contact the forming slab, and applying a vertical pressure to the forming slab through the support positioning spring.

[0016] Step 6: The core die moves downwards to close the mold with the lower die, bending the forming slab. Both sides of the forming slab can be vertically lifted, and then place an ultra-thin insulating cushion layer at the bending and overlapping part of the forming slab.

[0017] Step 7: Turn on the power supply to heat up the bending part of the forming slab to reach 600 °C to 900 °C.

[0018] Step 8: The upper die moves towards the center to make the forming slab bend inwards, and the upper die moves to the position at the mold closing place.

[0019] Step 9: The limit block moves downwards, and the forming slab undergoes plastic deformation under the vertical pressure applied to the upper die until the upper die and the lower die are closed.

[0020] Step 10: After power-on and heat preservation for 1 min to 10 min, control the power supply to gradually reduce the current until the current returns to zero, and then turn off the power supply.

[0021] Step 11: The upper platform of the hydraulic press moves upwards, the upper die retracts horizontally, the forming core die and the ultra-thin insulating cushion layer are drawn out laterally, the electrodes are separated from the forming slab, and the formed part is taken out.

[0022] The local variable temperature forming device and method for the linkage die of titanium alloy hoop-like components solve the problems of large springback and low forming accuracy of large-angle thin-walled bending components of titanium alloy; realize the differential temperature rapid heating of the titanium alloy forming slab, with a high temperature at the forming part and a low temperature at the non-forming part, reducing the adverse effect of temperature on the non-forming part while ensuring the deformation temperature; and realize the forming process of titanium alloy hoop structure components in one process. Brief Description of the Drawings

[0023] The present invention will be further described in detail below with reference to the drawings and embodiments:

[0024] Figure 1 FIG. is a schematic diagram of the position of the local variable temperature forming device for the linkage die of titanium alloy hoop-like components and the forming slab during the forming process;

[0025] Figure 2 FIG. is a schematic diagram of the position of the local variable temperature forming device for the linkage die of titanium alloy hoop-like components and the forming slab in the final forming state.

[0026] In the figure: 1. Limit block, 2. Electrode, 3. Power supply, 4. Insulating backing plate, 5. Adjusting block, 6. Forming slab, 7. Upper die, 8. Upper die insulation and heat insulation layer, 9. Core die, 10. Lower die insulation and heat insulation layer, 11. Temperature measuring thermocouple, 12. Lower die, 13. Support and positioning spring, 14. Ultra-thin insulating cushion layer. Specific Embodiments

[0027] Combined with the description of the specific embodiments of the present invention and the drawings, the details of the present invention can be more clearly understood. However, the specific embodiments of the present invention described herein are only for the purpose of explaining the present invention and cannot be understood in any way as a limitation of the present invention. Under the teaching of the present invention, those skilled in the art can conceive any possible deformation based on the present invention, and these should all be regarded as belonging to the scope of the present invention.

[0028] Example 1

[0029] The local variable temperature forming device of the linkage die for titanium alloy hoop belt-like components includes: a hydraulic press, a limit block 1, an electrode 2, a power supply 3, an insulating backing plate 4, an adjusting block 5, an upper die 7, an upper die insulating and heat-insulating layer 8, a core die 9, a lower die insulating and heat-insulating layer 10, a temperature-measuring thermocouple 11, a lower die 12, a support and positioning spring 13, and an ultra-thin insulating cushion 14; among them, the limit block 1 and the lower die 12 are respectively fixedly connected to the upper platform and the lower platform of the hydraulic press through T-shaped grooves and clamping mechanisms, and the movement direction of the limit block 1 is ensured; the adjusting block 5 and the insulating backing plate 4 are connected by bolts, and the adjusting block 5 and the insulating backing plate 4 are connected to the limit block 1 through the support and positioning spring 13, which can provide vertical pressure while playing a positioning role; the upper die insulating and heat-insulating layer 8 is connected to the outside of the upper die 7, and the lower die insulating and heat-insulating layer 10 is connected to the outside of the lower die 12. The electrode 2 and the formed blank 6 are connected by bolts or mechanical clamping mechanisms. The positive and negative poles of the electrode 2 are respectively connected to both sides of the formed blank 6 and form a loop with the power supply 3; the surface of the core die 9 is provided with an insulating and heat-insulating layer, which can be insulating treatment of the surface of the core die or ceramic chips or asbestos gaskets with the same shape as the surface of the core die 9; the temperature-measuring thermocouple 11 is placed in the temperature-measuring hole of the lower die 12, and the ultra-thin insulating cushion 14 is placed on the formed blank 6. Here, the ultra-thin means less than 0.2 mm, preventing the blank from folding over and contacting itself, and avoiding short-circuiting a part of the formed blank.

[0030] Preferably, the upper die 7 only moves in the horizontal direction and can rotate around the arc at its tail, avoiding interference and collision with structures such as the core die during the forming process.

[0031] The specific materials of the upper die insulating and heat-insulating layer 8 and the lower die insulating and heat-insulating layer 10 are alumina or zirconia or ceramic chips or asbestos gaskets, etc.

[0032] The specific steps of the local variable temperature forming method of the linkage die for titanium alloy hoop belt-like components are as follows:

[0033] Step 1: According to the shape and size characteristics of the hoop belt component, use methods such as laser cutting, wire cutting, or water cutting to cut the formed blank 6 into the shape and size to be processed, and polish the edges of the formed blank 6 to remove defects such as burrs and flash.

[0034] Step 2: Perform insulating and heat-insulating coating treatment on the contact parts of the upper die 7, the lower die 12, the core die 9, and the formed blank 6 respectively, and realize uniform distribution of the insulating and heat-insulating coating by adjusting the treatment parameters, and the thickness of each part is similar. The coating thickness is 5 µm to 800 µm.

[0035] Step 3: Install the limit block 1 and the lower die 12 on the upper platform and the lower platform of the hydraulic press respectively. Then, fixedly install the support positioning spring 13, the insulating cushion plate 4, and the adjusting block 5 under the limit block 1 in sequence. The insulating cushion plate 4 and the adjusting block 5 are connected by bolts or mechanically. The support positioning spring 13 plays a role in positioning and controlling the positions of the insulating cushion plate 4 and the adjusting block 5. The upper die 7 is fixedly installed on the side cylinders of the hydraulic press at both ends, enabling it to move horizontally. The core die 9 is fixed on another upper platform of the hydraulic press through a connecting rod, enabling it to move vertically.

[0036] Step 4: Fasten both ends of the formed blank 6 to the two electrodes 2 respectively. One side electrode 2 is connected to the positive pole of the power supply 3, and the other side electrode 2 is connected to the negative pole of the power supply 3, forming a current loop. The power supply 3 remains off during installation. Spray lubricant on both sides of the formed blank 6, and then place the formed blank 6 on the lower die according to the position.

[0037] Step 5: Start the hydraulic press. The limit block 1 moves downward, making the adjusting block 5 contact the formed blank 6, and applying a vertical pressure to the formed blank 6 through the support positioning spring 13 to avoid arcing caused by current passing through.

[0038] Step 6: The core die moves downward to close the die with the lower die, causing the formed blank 6 to undergo plastic deformation and bending, enabling both sides of the formed blank 6 to be vertically lifted along the die surface. Then, place an ultra-thin insulating cushion layer at the bending and overlapping part of the formed blank 6.

[0039] Step 7: Turn on the power supply and gradually increase the current magnitude, causing the temperature of the plastically deformed and bent part of the formed blank 6 to rapidly rise, reaching the forming temperature of 600°C - 900°C.

[0040] Step 8: The upper die 7 moves towards the center, causing the formed blank to bend inward. The upper die 7 moves to the position at the die closing place, ensuring that the bent part of the formed blank can achieve final die fitting.

[0041] Step 9: The limit block 1 moves downward, causing the upper die 7 to deflect downward through the vertical pressure applied on the upper die 7, thereby causing the formed blank 6 to undergo plastic deformation until the upper die 7 and the lower die 12 are closed, completing the forming process.

[0042] Step 10: After power-on and heat preservation for 1 min - 10 min, control the power supply current to gradually decrease until its value is zero, and then turn off the power supply.

[0043] Step 11: The upper platform of the hydraulic press moves upward, and the side cylinders retract, causing the upper die 7 to retract horizontally, and the forming core die 9 and the ultra-thin insulating cushion layer 14 to be withdrawn laterally. The electrode 2 is separated from the formed blank 6, and the formed part is taken out.

[0044] Example 2

[0045] The specific steps of the local variable temperature forming method for the titanium alloy hoop belt component linkage die are as follows:

[0046] Step 1: According to the shape and size characteristics of the hoop belt component, use methods such as laser cutting, wire cutting, or water cutting to cut the forming blank 6 into the shape and size to be processed, and polish the edges of the forming blank 6 to remove defects such as burrs and flash;

[0047] Step 2: Perform insulation and heat insulation coating treatment on the contact parts of the upper die 7, lower die 12, core die 9 and the forming blank 6 respectively. By adjusting the treatment parameters, ensure that the insulation and heat insulation coating is evenly distributed and the thickness of each part is similar, and the coating thickness is 5 µm to 10 µm;

[0048] Step 3: Install the limit block 1 and the lower die 12 on the upper platform and lower platform of the hydraulic press respectively. Then, fixedly install the support positioning spring 13, insulation backing plate 4 and adjusting block 5 under the limit block 1 in sequence. The insulation backing plate 4 and the adjusting block 5 are connected by bolts or mechanically. The support positioning spring 13 plays a role in positioning and controlling the positions of the insulation backing plate 4 and the adjusting block 5. The upper die 7 is fixedly installed on the side cylinders of the hydraulic press at both ends so that it can move horizontally. The core die 9 is fixed on the other upper platform of the hydraulic press through a connecting rod so that it can move vertically;

[0049] Step 4: Fasten both ends of the forming blank 6 to two electrodes 2 respectively. One side electrode 2 is connected to the positive pole of the power supply 3, and the other side electrode 2 is connected to the negative pole of the power supply 3 to form an electric current loop. Keep the power supply 3 closed during installation, spray lubricant on both sides of the forming blank 6, and then place the forming blank 6 in position on the lower die;

[0050] Step 5: Start the hydraulic press, the limit block 1 moves downwards, so that the adjusting block 5 contacts the forming blank 6, and apply a vertical pressure to the forming blank 6 through the support positioning spring 13 to avoid arcing caused by current passing through;

[0051] Step 6: The core die moves downwards to close the mold with the lower die, causing the forming blank 6 to undergo plastic deformation and bending, so that both sides of the forming blank 6 can be vertically lifted along the mold surface. Then, place an ultra-thin insulation cushion layer at the bending and overlapping part of the forming blank 6;

[0052] Step 7: Turn on the power supply and gradually increase the current magnitude, so that the temperature of the plastic deformation and bending part of the forming blank 6 rises rapidly to reach the forming temperature of 600 °C;

[0053] Step 8: The upper die 7 moves towards the center, causing the forming blank to bend inwards. The upper die 7 moves to the position at the mold closing place; ensure that the bending part of the forming blank can achieve final mold fitting;

[0054] Step Nine: The limit block 1 moves downward, causing the upper die 7 to deflect downward under the vertical pressure applied to the upper die 7, thereby plastically deforming the formed slab 6 until the upper die 7 and the lower die 12 are closed to complete the forming process;

[0055] Step Ten: After power-on and heat preservation for 1 min to 2 min, control the power supply current to gradually decrease until its value is zero, and then turn off the power supply;

[0056] Step Eleven: The upper platform of the hydraulic press moves upward, the side cylinders retract, causing the upper die 7 to retract horizontally, the forming core die 9 and the ultra-thin insulating cushion layer 14 to be withdrawn laterally, the electrode 2 to be separated from the formed slab 6, and the formed part to be taken out.

[0057] Example 3

[0058] The specific steps of the local variable temperature forming method for the linked die of titanium alloy hoop belt components are as follows:

[0059] Step One: According to the shape and size characteristics of the hoop belt component, use methods such as laser cutting, wire cutting or water cutting to cut the formed slab 6 into the shape and size to be processed, and polish the edges of the formed slab 6 to remove defects such as burrs and flash;

[0060] Step Two: Conduct insulating and heat-insulating coating treatment on the contact parts of the upper die 7, lower die 12, core die 9 and the formed slab 6 respectively. By adjusting the treatment parameters, make the insulating and heat-insulating coating evenly distributed, and the thickness of each part is similar. The coating thickness is 700 µm to 800 µm;

[0061] Step Three: Install the limit block 1 and the lower die 12 on the upper platform and lower platform of the hydraulic press respectively. Then, fixedly install the support positioning spring 13, insulating cushion plate 4 and adjusting block 5 under the limit block 1 in sequence. The insulating cushion plate 4 and the adjusting block 5 are connected by bolts or mechanically. The support positioning spring 13 plays a role in positioning and controlling the positions of the insulating cushion plate 4 and the adjusting block 5. The upper die 7 is fixedly installed on the side cylinders of the hydraulic press at both ends, enabling it to move horizontally. The core die 9 is fixed on another upper platform of the hydraulic press through a connecting rod, enabling it to move vertically;

[0062] Step Four: Both ends of the formed slab 6 are tightly connected to two electrodes 2 respectively. One side electrode 2 is connected to the positive pole of the power supply 3, and the other side electrode 2 is connected to the negative pole of the power supply 3 to form an electric current loop. The power supply 3 remains closed during installation, and the two sides of the formed slab 6 are sprayed with lubricant, and then the formed slab 6 is placed on the lower die according to the position;

[0063] Step Five: Start the hydraulic press, the limit block 1 moves downward, making the adjusting block 5 contact the formed slab 6, and applying a vertical pressure to the formed slab 6 through the support positioning spring 13 to avoid the phenomenon of sparking caused by current passing through;

[0064] Step Six: The core die moves downward and closes with the lower die, causing the formed slab 6 to undergo plastic deformation and bending, enabling both sides of the formed slab 6 to vertically lift along the die surface. Then, an ultra-thin insulating cushion layer is placed at the bending and overlapping part of the formed slab 6.

[0065] Step Seven: Turn on the power supply and gradually increase the current magnitude, causing the temperature of the plastically deformed and bent part of the formed slab 6 to rapidly rise to the forming temperature of 900 °C.

[0066] Step Eight: The upper die 7 moves towards the center, causing the formed slab to bend inward. The upper die 7 moves to the position at the die closing point; ensure that the bent part of the formed slab can achieve final die fitting.

[0067] Step Nine: The limit block 1 moves downward, causing the upper die 7 to deflect downward through the vertical pressure applied on the upper die 7, thereby causing the formed slab 6 to undergo plastic deformation until the upper die 7 and the lower die 12 are closed, completing the forming process.

[0068] Step Ten: After power-on and heat preservation for 8 - 10 minutes, control the power supply current to gradually decrease until its value is zero, and then turn off the power supply.

[0069] Step Eleven: The upper platform of the hydraulic press moves upward, and the side cylinders retract, causing the upper die 7 to retract horizontally. The forming core die 9 and the ultra-thin insulating cushion layer 14 are drawn out laterally, the electrode 2 is separated from the formed slab 6, and the formed part is taken out.

[0070] Example 4

[0071] The specific steps of the local variable temperature forming method for the titanium alloy hoop belt-like component linkage die are as follows:

[0072] Step One: According to the shape and size characteristics of the hoop belt component, use methods such as laser cutting, wire cutting, or water cutting to cut the formed slab 6 into the shape and size to be processed, and polish the edges of the formed slab 6 to remove defects such as burrs and flash.

[0073] Step Two: Conduct insulating and heat-insulating coating treatments on the contact parts of the upper die 7, lower die 12, core die 9, and the formed slab 6 respectively. By adjusting the treatment parameters, ensure that the insulating and heat-insulating coating is evenly distributed, and the thickness of each part is similar, with the coating thickness in the range of 100 µm - 500 µm.

[0074] Step Three: Install the limit block 1 and the lower die 12 on the upper platform and lower platform of the hydraulic press respectively. Then, fixedly install a support and positioning spring 13, an insulating cushion plate 4, and an adjusting block 5 under the limit block 1 in sequence. The insulating cushion plate 4 and the adjusting block 5 are connected by bolts or mechanically. The support and positioning spring 13 plays a role in positioning and controlling the positions of the insulating cushion plate 4 and the adjusting block 5. The upper die 7 is fixedly installed on the side cylinders of the hydraulic press at both ends, enabling it to move horizontally. The core die 9 is fixed to another upper platform of the hydraulic press through a connecting rod, enabling it to move vertically.

[0075] Step Four: Both ends of the formed slab 6 are fixedly connected to the two electrodes 2 respectively. One side electrode 2 is connected to the positive pole of the power supply 3, and the other side electrode 2 is connected to the negative pole of the power supply 3 to form a current loop. The power supply 3 is kept closed during installation, and lubricant is sprayed on both sides of the formed slab 6. Then, the formed slab 6 is placed on the lower die according to the position.

[0076] Step Five: Start the hydraulic press. The limit block 1 moves downward, making the adjusting block 5 contact the formed slab 6, and applying a vertical pressure to the formed slab 6 through the support positioning spring 13 to avoid arcing caused by current passing through.

[0077] Step Six: The core die moves downward to close the mold with the lower die, causing the formed slab 6 to undergo plastic deformation and bending, enabling both sides of the formed slab 6 to be vertically lifted along the die surface. Then, an ultra-thin insulating cushion layer is placed at the bending and overlapping part of the formed slab 6.

[0078] Step Seven: Turn on the power supply and gradually increase the current magnitude, causing the temperature of the plastically deformed and bent part of the formed slab 6 to rise rapidly, reaching the forming temperature of 700°C - 800°C.

[0079] Step Eight: The upper die 7 moves towards the center, causing the formed slab to bend inward, and the upper die 7 moves to the position at the mold closing point; ensure that the bent part of the formed slab can achieve final mold fitting.

[0080] Step Nine: The limit block 1 moves downward, causing the upper die 7 to deflect downward through the vertical pressure applied on the upper die 7, thereby causing the formed slab 6 to undergo plastic deformation until the upper die 7 and the lower die 12 are closed to complete the forming process.

[0081] Step Ten: After power-on and heat preservation for 5 min - 7 min, control the power supply current to gradually decrease until its value is zero, and then turn off the power supply.

[0082] Step Eleven: The upper platform of the hydraulic press moves upward, and the side cylinder retracts, causing the upper die 7 to retract horizontally, and the forming core die 9 and the ultra-thin insulating cushion layer 14 to be withdrawn laterally. The electrode 2 is separated from the formed slab 6, and the formed part is taken out.

Claims

1. A local variable temperature forming device for a titanium alloy hoop-like component linkage die, characterized in that: The local variable temperature forming device for the linkage die of titanium alloy hoop belt components includes: a hydraulic press, a limit block (1), an electrode (2), a power supply (3), an insulating backing plate (4), an adjusting block (5), an upper die (7), an upper die insulation and heat insulation layer (8), a core die (9), a lower die insulation and heat insulation layer (10), a temperature measuring thermocouple (11), a lower die (12), a support positioning spring (13) and an ultra-thin insulating cushion layer (14); wherein, the limit block (1) and the lower die (12) are respectively fixedly connected to the upper platform and the lower platform of the hydraulic press, the adjusting block (5) is connected to the insulating backing plate (4), and the adjusting block (5), the insulating backing plate (4) and the limit block (1) are connected by the support positioning spring (13), the upper die insulation and heat insulation layer (8) is connected to the outside of the upper die (7), the lower die insulation and heat insulation layer (10) is connected to the outside of the lower die (12), the positive and negative electrodes of the electrode (2) are respectively connected to both sides of the formed blank (6) and form a loop with the power supply (3); the surface of the core die (9) is provided with an insulation and heat insulation layer, the temperature measuring thermocouple (11) is placed in the temperature measuring hole of the lower die (12), and the ultra-thin insulating cushion layer (14) is placed on the formed blank (6); The upper die (7) only moves in the horizontal direction and can rotate around the arc at its tail.

2. A forming method of a local variable temperature forming device for a titanium alloy hoop-like component linkage die as described in claim 1, characterized in that: The specific steps are as follows: Step 1: According to the shape and size characteristics of the hoop belt component, the formed blank (6) is cut and processed. Step 2: Insulation and heat insulation coating treatments are respectively carried out on the contact parts of the upper die (7), the lower die (12), the core die (9) and the formed blank (6), and the coating thickness is in the range of 5μm to 800μm. Step 3: The limit block (1), the support positioning spring (13), the insulating backing plate (4), the adjusting block (5), the upper die (7), the core die (9) and the lower die (12) are sequentially installed on the hydraulic press, wherein the limit block (1) is installed on the upper platform of the hydraulic press, the limit block (1), the support positioning spring (13), the insulating backing plate (4) and the adjusting block (5) are sequentially fixedly connected, the two upper dies (7) are respectively fixed on the side cylinders of the hydraulic press at both ends, the core die (9) is fixed on the other upper platform of the hydraulic press through a connecting rod, and the lower die (12) is fixed on the lower platform of the hydraulic press. Step 4: Both ends of the formed blank (6) are tightly connected to the two electrodes (2) respectively, one side electrode (2) is connected to the positive pole of the power supply (3), the other side electrode (2) is connected to the negative pole of the power supply (3), and the formed blank (6) is placed on the lower die (12) according to the position, and the current value range of the power supply (3) is from 0A to 20000A. Step 5: Start the hydraulic press, the limit block (1) moves downward, so that the adjusting block (5) contacts the formed blank (6), and a vertical pressure is applied to the formed blank (6) through the support positioning spring (13). Step 6: The core die (9) moves downward to close the die with the lower die (12), the formed blank is bent, both sides of the formed blank can be vertically lifted, and then the ultra-thin insulating cushion layer (14) is placed at the bending and overlapping part of the formed blank (6). Step 7: Turn on the power supply (3) to heat the bending part of the formed blank (6) to reach 600°C to 900°C. Step eight: The upper die (7) moves towards the center to bend the formed slab inward, and the upper die (7) moves to the position at the mold closing point; Step nine: The limit block (1) moves downwards, and the formed slab (6) undergoes plastic deformation by applying vertical pressure on the upper die (7) until the upper die (7) and the lower die (12) are closed; Step ten: After power-on and heat preservation for 1 min to 10 min, control the power supply to gradually reduce the current until the current returns to zero, and then turn off the power supply; Step eleven: The upper platform of the hydraulic press moves upwards, the upper die (7) retracts in the horizontal direction, the forming core mold (9) and the ultra-thin insulating cushion layer (14) are withdrawn laterally, the electrode (2) is separated from the formed slab (6), and the formed part is taken out.

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