A continuous laser additive and extrusion forming apparatus and production method for a difficult-to-cast alloy

Abstract

A continuous laser additive and extrusion forming equipment and production method for difficult-to-cast alloy, comprising a laser additive facility, a surface leveling device, an alloy movable block, a traction device, a loop device and an extrusion forming facility, the laser additive facility forms a required metal rod material shape on the top surface of the alloy movable block from different element powders or different alloy powders, the alloy movable block moves downward under the traction of the traction device with the formed metal rod material, the moving speed is synchronous with the speed of the laser additive facility for forming the metal rod material, the laser additive facility continuously forms the metal rod material, under the traction of the alloy movable block and the traction device, the metal rod material enters the loop device, the loop device sends the metal rod material into the extrusion forming facility for extrusion processing to form various profile products. The application has the beneficial effects that the difficult-to-cast alloy is relatively easy to prepare and process, the processing procedure is short, the continuous production can be realized, the processing cost can be reduced, and the product quality is good.

Description

Technical Field

[0001] This invention belongs to the field of metal material forming technology, and particularly relates to continuous laser additive manufacturing and continuous extrusion forming technology. Background Technology

[0002] Casting alloys involves melting different metal components to form a cast billet, which is then further processed. However, when the melting points of the metal components differ significantly, melting them to form a cast billet is difficult. Existing laser additive manufacturing technology has the advantage of producing alloys with large differences in metal melting points. The drawback of existing laser additive manufacturing technology is that the produced alloy parts may exhibit casting defects such as voids, cracks, and coarse grains. To address this, existing technologies employ pressure processing to resolve casting defects such as porosity and cracks in the laser-added alloy parts. A further limitation of existing methods is that they can only produce single pieces and cannot be used for continuous production. Summary of the Invention

[0003] The purpose of this invention is to provide a facility and production method that combines laser continuous additive manufacturing technology with continuous extrusion molding, thereby overcoming the shortcomings of the prior art.

[0004] The technical solution of this invention is: a continuous laser additive extrusion forming equipment for difficult-to-cast alloys, comprising a laser additive manufacturing facility, a looper device, and an extrusion forming facility. The laser additive manufacturing facility includes a laser and optical fiber, a powder feeding system, a powder mixer, and a laser forming device. The laser forming device includes an inert gas protective box, a laser cladding head, a laser coaxial powder nozzle, a molten pool, and a crystallizer. The base plate of the inert gas protective box is fixed on the lifting platform of the elevator. The laser cladding head, the laser coaxial powder nozzle, the molten pool, and the crystallizer are arranged inside the inert gas protective box. The laser cladding head is located at the upper part of the inert gas protective box, the crystallizer is located below the laser cladding head, the molten pool is located in the inner hole of the crystallizer, and the laser coaxial powder nozzle is placed inside the laser cladding head. At the lower edge, the laser is connected to the laser cladding head via an optical fiber. The powder feeding system includes a powder feeding tank, a powder feeding pipeline, and a powder mixer. The powder feeding tank is connected to the powder mixer via the powder feeding pipeline, and the powder mixer is connected to the laser coaxial powder nozzle in the inert gas protection box via a pipeline. The looper is a looper with a spring slide rail. The inlet section of the looper is a vertical section, and the outlet section is a horizontal section. The inlet section and the outlet section are connected by an inclined section. The extrusion forming facility includes a continuous extruder, a cooling device, a guide frame, and a storage device. The continuous extruder, cooling device, guide frame, and storage device are fixed sequentially on the foundation. The laser forming device further includes a surface leveling device, an alloy block, a traction device, and a sealing device.

[0005] The inert gas protection box is a box body with a base plate as the base plate. An opening is formed on the base plate corresponding to the laser cladding head. The diameter of the opening is 103% to 105% of the diameter of the laser additive surface. The opening is sealed by a sealing device, which includes a sealing cylinder and a sealing ring. The sealing cylinder is a sleeve with a flange at one end, composed of two semi-cylindrical sleeves. One of the mating surfaces of the two semi-cylindrical sleeves has a boss, and the other has a groove. The boss and groove mate. A sealing ring groove is formed radially on the inner wall of the sleeve. The sealing ring is a metal ring, consisting of two... The semi-circular rings are arranged in pairs. The outer diameter of the sealing ring is 98% to 100% of the outer diameter of the sealing ring groove, and the inner diameter of the sealing ring is 100% to 102% of the set diameter of the laser additive surface. The sealing ring is placed in the sealing ring groove. Each sealing ring groove contains 2 to 4 layers of sealing rings. The total thickness of the sealing rings in each sealing ring groove is 97% to 99% of the thickness of the groove. The butt joints of two adjacent layers of sealing rings are at 90° to each other. The angle between the butt joints of two adjacent layers of sealing rings and the butt joints of the sealing cylinder is 45°. The flange end of the sealing cylinder is bolted to the base plate opening of the inert gas protection box base plate. The axis of the inner hole of the sealing cylinder coincides with the axis of the base plate opening.

[0006] The surface smoothing device includes a milling cutter, a driven gear, a driving gear, a motor, a turntable motor, a driving gear, a driven gear, a coaxial driven gear, a milling cutter turntable, and turntable balls. The milling cutter turntable is a gear disk with teeth on its outer circumference. A central hole is formed in the center of the gear disk, with a diameter of 103% to 105% of the diameter of the laser additive surface. An annular bearing groove centered on the central hole is provided on the underside of the gear disk. A corresponding groove is formed on the inert gas protection chamber substrate at a location opposite to the annular bearing groove on the underside of the gear disk. The turntable balls are placed within the grooves on the inert gas protection chamber substrate. The rotary table motor is fixedly mounted on the inert gas protection box base plate outside the outer circumference of the milling cutter rotary table. The rotary table drive gear is mounted on the rotary table motor shaft. The coaxial driven gear is mounted on the middle part of the coaxial driven gear shaft via a key. The coaxial driven gear shaft is mounted on the inert gas protection box base plate via a bearing. The coaxial driven gear meshes with the teeth on the outer circumference of the milling cutter rotary table. The rotary table driven gear is mounted on the upper end of the coaxial driven gear shaft via a key. The rotary table driven gear meshes with the rotary table drive gear. The milling cutter motor is fixedly mounted on the milling cutter rotary table. The milling cutter drive gear is connected to the milling cutter motor shaft. The milling cutter driven gear is mounted on the middle part of the milling cutter shaft via a key. The lower end of the milling cutter shaft is mounted on the milling cutter rotary table via a bearing. The milling cutter is mounted on the upper end of the milling cutter shaft via a key.

[0007] The alloy movable block is a long rod, which is composed of two rods with different diameters. The upper diameter of the long rod is 105% - 110% of the set diameter of the laser additive manufacturing surface. The upper part of the long rod is placed in the inner hole of the mold, and the upper end surface of the long rod is located on the molten pool surface. The lower diameter of the long rod is the same as the set diameter of the laser additive manufacturing surface. The lower end of the long rod passes through the central hole of the milling cutter turntable and the substrate opening on the substrate of the inert gas protection box and extends outside the inert gas protection box. The lower end is placed in the pulley groove of the traction wheel of the traction device. The milling cutter of the surface leveling device abuts against the side surface of the lower part of the alloy movable block.

[0008] The traction device consists of a traction wheel and a loose pulley of a loose pulley device with a spring slide rail. The traction wheel is a grooved wheel with a semicircular groove on its outer circumferential surface. The groove surface is treated by sandblasting. The traction wheel is installed on the loose pulley frame. The traction wheel is connected to the motor through a reduction mechanism. The traction wheel corresponds to the loose pulley of the loose pulley device with a spring slide rail. The spring of the loose pulley of the loose pulley device with a spring slide rail is in a compressed state, and the loose pulley is disengaged from the traction wheel. The spring of the loose pulley of the loose pulley device with a spring slide rail is in a released state, and the loose pulley is in a clamped state with the traction wheel.

[0009] The inlet of the loose pulley device is connected to the outlet of the traction device, and the outlet of the loose pulley device is connected to the inlet of the continuous extrusion machine (20).

[0010] For the continuous laser additive manufacturing and extrusion forming equipment for difficult-to-cast alloys according to the present invention, it is characterized in that: the diameter of the set laser additive manufacturing surface is equal to the width of the extrusion wheel groove of the continuous extrusion machine.

[0011] For the continuous laser additive manufacturing and extrusion forming equipment for difficult-to-cast alloys according to the present invention, it is characterized in that: the number of annular bearing grooves under the milling cutter turntable of the surface leveling device is 2 - 6. The distance between the inner wall of the innermost annular bearing groove and the circumference of the central hole of the milling cutter turntable (31) is s, where 5mm < s < 10mm. The distance between the outer wall of the outermost annular bearing groove and the circumference of the outer contour of the milling cutter turntable is d, where 5mm < d < 10mm. The remaining bearing grooves are evenly distributed.

[0012] For the continuous laser additive manufacturing and extrusion forming equipment for difficult-to-cast alloys according to the present invention, it is characterized in that: the diameter of the milling cutter of the surface leveling device is 5 - 20mm.

[0013] For the continuous laser additive manufacturing and extrusion forming equipment for difficult-to-cast alloys according to the present invention, it is characterized in that: the number of seal ring grooves on the inner wall of the sealing cylinder is 1 - 4. The seal ring grooves are evenly distributed along the axial direction of the sealing cylinder, and the distance between adjacent two seal ring grooves is greater than 5mm.

[0014] The present invention discloses a continuous laser additive extrusion forming equipment for difficult-to-cast alloys, characterized in that: there are 1 to 5 traction wheels and sling wheels with spring slide rails, and the traction wheels and sling wheels with spring slide rails correspond one-to-one and are arranged longitudinally directly below the opening of the substrate.

[0015] The present invention discloses a continuous laser additive extrusion forming equipment for difficult-to-cast alloys, characterized in that: a rod limiting frame is fixed below the inert gas protective box substrate, the rod limiting frame consists of 3 to 5 supports and a limiting ring, one end of the support is fixedly connected to the limiting ring, the included angle between the plane of the support and the limiting ring is 45°, the 3 to 5 supports are evenly arranged on the limiting ring, the other end of the support is fixed to the bottom of the inert gas protective box substrate by bolts, the axis of the limiting ring coincides with the axis of the substrate opening on the inert gas protective box substrate, and the inner diameter of the limiting ring is the same as the diameter of the lower section of the alloy block.

[0016] The present invention relates to a continuous laser additive extrusion forming equipment for difficult-to-cast alloys, characterized in that: the sealing ring is a cast iron ring or a stainless steel ring.

[0017] The present invention discloses a continuous laser additive extrusion forming equipment for difficult-to-cast alloys, characterized in that: the groove linear velocity of the extrusion wheel of the continuous extruder is consistent with the average speed of the traction wheel pulling the metal rod material downward, which is 10-700 mm / min.

[0018] The present invention discloses a production method for a continuous laser additive extrusion forming equipment for difficult-to-cast alloys, comprising laser additive manufacturing and continuous extrusion, characterized in that: the laser additive manufacturing includes the following steps:

[0019] Release the spring from the looper wheel of the spring-loaded sliding device, causing the traction wheel and the looper wheel of the spring-loaded sliding device to clamp the lower end of the alloy slider. Start the traction wheel, which pulls the alloy block up and down, placing the top surface of the alloy block in the laser focal plane of the crystallizer. Start the laser additive manufacturing facility to perform additive manufacturing according to the set parameters. Adjust the rotation speed of the traction wheel to move downwards synchronously with the additive manufacturing speed of the laser additive manufacturing facility, keeping the surface of the additive always within the laser focal plane.

[0020] The continuous extrusion process includes the following steps: adjusting the rotational speed of the extrusion rollers of the continuous extruder to match the rotational speed of the traction rollers; the metal rod material of the laser additive manufacturing facility connected to the alloy block is pulled into the looper by the traction rollers, and the looper takes the alloy block and the metal rod material of the laser additive manufacturing facility into the extrusion rollers of the continuous extruder; the extruded product enters the cooling device for cooling, and is then collected by the receiving device via the guide frame.

[0021] The principle of this invention is as follows: A laser additive manufacturing device provides a metal rod blank for continuous extrusion. An opening is made in the substrate of the inert gas protection box of the laser additive manufacturing device, and a sealing device is installed at the opening to ensure the sealing of the inert gas protection box. A traction device uses an alloy lever to pull the metal rod blank out of the inert gas protection box through the opening in the substrate. Before being pulled out of the inert gas protection box, the surface of the metal rod is smoothed by a surface leveling device installed inside the inert gas protection box to remove burrs and other defects from the surface of the metal rod during the laser additive manufacturing process. The sealing device at the opening in the substrate uses a metal sealing ring. When the metal rod passes through the metal sealing ring, the heat of the metal rod causes the metal sealing ring to expand, achieving a sliding seal between the metal sealing ring and the metal rod. The metal rod pulled out of the inert gas protection box is fed into an extrusion molding facility through a looper device for extrusion processing.

[0022] The beneficial effects of this invention are: it makes the preparation and processing of difficult-to-cast alloys relatively easy, the processing steps are short, continuous production is possible, processing costs can be reduced, and the product quality is good. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of a continuous laser additive extrusion forming equipment for difficult-to-cast alloys.

[0024] Figure 1-1 This is a schematic diagram of the surface smoothing device structure of a continuous laser additive extrusion forming equipment for difficult-to-cast alloys.

[0025] Figure 2 This is a schematic diagram of a local structure of the laser additive forming area in a continuous laser additive extrusion forming equipment for difficult-to-cast alloys before production begins.

[0026] Figure 3 This is a schematic diagram of a local structure of the laser additive forming area in a continuous laser additive extrusion forming equipment for difficult-to-cast alloys after production has commenced.

[0027] Figure 4 This is a schematic diagram of the main structure of the sealing device in a continuous laser additive extrusion forming equipment for difficult-to-cast alloys.

[0028] Figure 4-1 yes Figure 4 Side view half section diagram

[0029] Figure 5 This is a schematic diagram of the interface between two adjacent sealing rings in the sealing device of a continuous laser additive extrusion forming equipment for difficult-to-cast alloys.

[0030] Figure 5-1 This is a schematic diagram of the interface between two adjacent sealing rings in the sealing device of a continuous laser additive extrusion forming equipment for difficult-to-cast alloys.

[0031] Figure 6This is a schematic diagram of the traction device structure of a continuous laser additive extrusion forming equipment for difficult-to-cast alloys.

[0032] Figure 6-1 yes Figure 6 A top-down view.

[0033] In the diagram: 1. Inert gas protective chamber; 2. Laser cladding head; 3. Laser beam; 4. Laser coaxial powder nozzle; 5. Molten pool; 6. Inert gas protective chamber substrate; 7. Crystallizer; 8. Metal rod; 9. Milling cutter; 10. Powder feeding hopper one; 11. Powder feeding hopper two; 12. Powder feeding hopper three; 13. Powder feeding hopper four; 14. Powder mixer; 15. Powder feeding system; 16. Laser and optical fiber; 17. Traction wheel; 18. Loose-fitting bracket with spring slide rail; 19. Loose-fitting bracket. 20. Roller, Continuous extrusion press, 21. Cooling device, 22. Guide frame, 23. Storage device, 24. Milling cutter driven gear, 25. Milling cutter driving gear, 26. Milling cutter motor, 27. Turntable motor, 28. Turntable driving gear, 29. Turntable driven gear, 30. Coaxial driven gear, 31. Milling cutter turntable, 32. Turntable bearing ball, 33. Alloy movable block, 34. Sealing cylinder, 35. Sealing ring, 36. Rod material limiting frame, 37. Base plate opening. Detailed Implementation

[0034] The present invention will be further described below with reference to embodiments and accompanying drawings.

[0035] A continuous laser additive extrusion forming equipment for difficult-to-cast alloys includes a laser additive manufacturing facility, a looper surface leveling device, an alloy block 33, a traction device, a sealing device, and an extrusion forming facility. The laser additive manufacturing facility includes a laser and an optical fiber 16, a powder feeding system, a powder mixer 14, and a laser forming device. The laser forming device includes an inert gas protection box 1, a laser cladding head 2, a laser coaxial powder nozzle 4, a molten pool 5, and a crystallizer 7. The base plate 6 of the inert gas protection box 1 is fixed to the lifting platform of the elevator. The laser cladding head 2, the laser coaxial powder nozzle 4, the molten pool 5, and the crystallizer 7 are arranged inside the inert gas protection box. The laser cladding head 2 is located at the upper part of the inert gas protection box, the crystallizer 7 is located below the laser cladding head 2, and the molten pool 5 is located inside the crystallizer 7. In the process, the laser coaxial powder nozzle 4 is placed at the lower edge of the laser cladding head 2. The laser is connected to the laser cladding head 2 through an optical fiber. The powder feeding system includes a powder feeding tank 10-13, a powder feeding pipeline 15, and a powder mixer 14. The powder feeding tank 10-13 is connected to the powder mixer 14 through the powder feeding pipeline 15. The powder mixer 14 is connected to the laser coaxial powder nozzle 4 in the inert gas protection box through a pipeline. The looper is a looper with a spring slide rail. The inlet section of the looper is a vertical section, and the outlet section is a horizontal section. The inlet section and the outlet section are connected by an inclined section. The extrusion molding facility includes a continuous extruder 20, a cooling device 21, a guide frame 22, and a storage device 23. The continuous extruder 20, the cooling device 21, the guide frame 22, and the storage device 23 are fixed sequentially on the foundation.

[0036] The inert gas protection box has a base plate as its substrate 6. The substrate 6 has a substrate opening 37 corresponding to the laser cladding head 2. The diameter of the substrate opening 37 is 103% to 105% of the set diameter of the laser additive surface. The substrate opening 37 is sealed by a sealing device. The sealing device includes a sealing cylinder 34 and a sealing ring 35. The sealing cylinder 34 is a sleeve with a flange at one end, and the sleeve is composed of two semi-cylindrical sleeves. One of the mating surfaces of the two semi-cylindrical sleeves has a boss, and the other... The sleeve is provided with grooves and bosses that mate with each other. Sealing ring grooves are radially formed on the inner wall of the sleeve. There are 1 to 4 sealing ring grooves, evenly distributed along the axial direction of the sealing cylinder. The distance between two adjacent sealing ring grooves is greater than 5 mm. The sealing ring 35 is a metal ring, composed of two opposing semicircular rings. The outer diameter of the sealing ring 35 is 98% to 100% of the outer diameter of the sealing ring groove, and the inner diameter of the sealing ring 35 is 100% to 102% of the set diameter of the laser additive surface. The sealing ring 35 is placed within the sealing ring groove. Each sealing ring... The groove contains 2 to 4 layers of sealing rings 35. The total thickness of the sealing rings 35 in each sealing ring groove is 97% to 99% of the groove thickness. The butt joints of two adjacent layers of sealing rings 35 are at 90° to each other. The included angle between the butt joints of two adjacent layers of sealing rings 35 and the butt joints of the sealing cylinder 34 is 45°. The flange end of the sealing cylinder 34 is bolted to the base plate opening 37 of the inert gas protection box base plate 6. The axis of the inner hole of the sealing cylinder 34 coincides with the axis of the base plate opening 37. A rod limiting frame is fixed below the inert gas protection box base plate 6. 36. The rod material limiting frame 36 consists of 3 to 5 supports and a limiting ring. One end of the support is fixedly connected to the limiting ring. The angle between the plane where the support and the limiting ring are located is 45°. The 3 to 5 supports are evenly arranged on the limiting ring. The other end of the support is fixed to the bottom of the inert gas protection box base plate 6 by bolts. The axis of the limiting ring coincides with the axis of the base plate opening 37 on the inert gas protection box base plate 6. The inner diameter of the limiting ring is the same as the diameter of the lower section of the alloy movable block 33. The sealing ring 35 is a cast iron ring or a stainless steel ring.

[0037] The surface leveling device includes a milling cutter 9, a milling cutter driven gear 24, a milling cutter driving gear 25, a milling cutter motor 26, a turntable motor 27, a turntable driving gear 28, a turntable driven gear 29, a coaxial driven gear 30, a milling cutter turntable 31 and turntable balls 32. The milling cutter turntable 31 is a gear disc with teeth on its outer circumference. A central hole is opened in the central part of the gear disc, and the aperture of the central hole is 103% - 105% of the set laser additive surface diameter. An annular bearing groove centered on the central hole is provided under the gear disc. There are 2 - 6 annular bearing grooves under the milling cutter turntable 31. The distance between the groove wall of the innermost annular bearing groove and the circumference of the central hole of the milling cutter turntable 31 is s, where 5mm < s < 10mm. The distance between the groove wall of the outermost annular bearing groove and the circumference of the outer contour of the milling cutter turntable 31 is d, where 5mm < d < 10mm. The remaining bearing grooves are evenly distributed. Corresponding grooves are opened at the relative positions on the upper surface of the inert gas protection box substrate 6 and the annular bearing grooves under the gear disc. The turntable balls 32 are placed in the grooves on the inert gas protection box substrate 6. The annular bearing grooves under the gear disc of the milling cutter turntable 31 are placed on the balls in the grooves on the inert gas protection box substrate 6. The turntable motor 27 is fixedly installed on the inert gas protection box substrate 6 outside the outer circumference of the milling cutter turntable 31. The turntable driving gear 28 is installed on the shaft of the turntable motor 27. The coaxial driven gear 30 is installed in the middle of the coaxial driven gear shaft by a key. The coaxial driven gear shaft is installed on the inert gas protection box substrate 6 through a bearing. The coaxial driven gear 30 meshes with the teeth on the outer circle of the milling cutter turntable 31. The turntable driven gear 29 is installed at the upper end of the coaxial driven gear shaft by a key. The turntable driven gear 29 meshes with the turntable driving gear 28. The milling cutter motor 26 is fixedly installed on the upper surface of the milling cutter turntable 31. The milling cutter driving gear 25 is connected to the shaft of the milling cutter motor 26. The milling cutter driven gear 24 is installed in the middle of the milling cutter shaft by a key. The lower end of the milling cutter shaft is installed on the upper surface of the milling cutter turntable 31 through a bearing. The milling cutter 9 is installed at the upper end of the milling cutter shaft by a key. The diameter of the milling cutter 9 is 5 - 20mm;

[0038] The alloy movable block 33 is a long rod. The long rod is composed of two segments with different diameters. The diameter of the upper segment of the long rod is 105% - 110% of the set laser additive surface diameter. The upper segment of the long rod is placed in the inner hole of the mold 7. The upper end surface of the long rod is located on the molten pool surface. The diameter of the lower segment of the long rod is the same as the set laser additive surface diameter. The lower end of the long rod passes through the central hole of the milling cutter turntable 31 and the substrate opening 37 on the inert gas protection box substrate 6 and extends outside the inert gas protection box 1. The lower end is placed in the groove of the traction wheel 17 of the traction device. The milling cutter 9 of the surface leveling device abuts against the side surface of the lower segment of the alloy movable block 33;

[0039] The traction device consists of a traction wheel 17 and a looper wheel 19 with a spring-loaded slide rail. The traction wheel 17 is a grooved wheel with a semi-circular groove on its outer circumference. The groove surface is sandblasted. The traction wheel 17 is mounted on the looper frame and is connected to the motor through a reduction mechanism. The traction wheel 17 corresponds to the looper wheel 19 with the spring-loaded slide rail. When the spring of the looper wheel 19 with the spring-loaded slide rail is in a compressed state, the looper wheel 19 is disengaged from the traction wheel 17. When the spring of the looper wheel 19 with the spring-loaded slide rail is in a released state, the looper wheel 19 is clamped to the traction wheel 17. There are 1 to 5 traction wheels 17 and 5 looper wheels 19 with spring-loaded slide rails. The traction wheels 17 and the looper wheels 19 with spring-loaded slide rails are arranged vertically directly below the opening 37 on the base plate.

[0040] The inlet of the looper is connected to the outlet of the traction device, and the outlet of the looper is connected to the inlet of the continuous extruder 20; the groove linear velocity of the extrusion wheel of the continuous extruder 20 is consistent with the average speed of the traction wheel 17 pulling the metal rod 8 downward, which is 10 to 700 mm / min.

[0041] The diameter of the laser additive surface is set to be equal to the width of the extrusion wheel groove of the continuous extruder 20.

[0042] A production method for continuous laser additive extrusion forming equipment for difficult-to-cast alloys, including laser additive manufacturing and continuous extrusion, wherein laser additive manufacturing includes the following steps:

[0043] Release the spring of the looper wheel 19 with the spring slide rail, so that the traction wheel 17 and the looper wheel 19 with the spring slide rail clamp the lower end of the alloy slider 15. Start the traction wheel 17, which pulls the alloy block 33 up and down, so that the top surface of the alloy block 33 is placed in the laser focal plane of the crystallizer. Start the laser additive manufacturing facility to add material according to the set parameters. Adjust the rotation speed of the traction wheel 17 so that it moves downward synchronously with the addition speed of the laser additive manufacturing facility, keeping the surface of the additive always in the laser focal plane.

[0044] The continuous extrusion process includes the following steps: adjusting the rotation speed of the extrusion rollers of the continuous extruder 20 to match the rotation speed of the traction rollers 17; the metal rod material 8, which is added by the laser additive manufacturing facility and connected to the alloy block 33, is pulled into the looper by the traction rollers 17, and the looper then pulls the alloy block 33 and the metal rod material 8 added by the laser additive manufacturing facility into the extrusion rollers of the continuous extruder 20; the extruded product enters the cooling device 21 for cooling, and is then collected by the receiving device 23 via the guide frame 22.

[0045] Example

[0046] This example demonstrates the preparation of TC4 titanium alloy wire using a continuous laser additive extrusion forming equipment for difficult-to-cast alloys. Pure TC4 titanium alloy powder was used as the raw material. TC4 titanium alloy powder with a particle size of 50–100 μm was placed in a powder feeding hopper (10). Since it was a single powder, mixing was unnecessary; the powder was directly fed to the laser processing point inside the inert gas protection chamber (1) using inert gas, with a feeding rate adjusted to 20 g / min. The substrate of the inert gas protection chamber (1) was made of TC4 titanium alloy sheet. Based on the required dimensions and shape of the metal rod to be prepared by laser additive manufacturing, a three-dimensional solid model of the metal rod was constructed using a computer. A layered model with a thickness of 0.5 mm per layer along the Z-axis and the scanning path program for each layer were set. The laser additive manufacturing process parameters were: laser power 1500 W, scanning speed 300 mm / min, laser spot diameter 4 mm, overlap rate 30%, oxygen concentration in the laser additive environment below 50 ppm, and the diameter of the circular cross-section of the laser-added metal rod 12 mm. Alloy live block 33 is a TC4 titanium alloy rod. The thick section of the titanium alloy rod has a diameter of 12.5 mm and a length of 70 mm, while the thin section has a diameter of 12 mm and a length of 80 mm. The total length of the alloy live block is 150 mm. Before starting additive manufacturing, the spring of the looper wheel 19 of the looper device with spring slide rail is compressed to disengage the looper wheel 19 from the traction wheel. Then, the rod limiting frame 36 and the sealing device are removed. The alloy block 33 is inserted into the inert gas protection box 1 from the lower end of the base plate opening 37, with the coarse section on top. The sealing device and the rod limiting frame 36 are then fitted onto the thin section of the alloy block 33. The sealing device and the rod limiting frame 36 are fixed to the underside of the base plate 6 of the inert gas protection box with bolts. Then, the spring of the looper wheel 19 of the looper device with spring slide rail is released. The looper wheel 19 of the looper device with spring slide rail and the traction wheel 17 clamp the lower section of the alloy block 33. The traction wheel 17 is rotated to adjust the upper surface of the coarse section of the alloy block to the laser focus height. The lower surface of the coarse section is 1-2 mm higher than the upper edge of the milling cutter.

[0047] The laser additive manufacturing process is initiated, and the laser beam adds material according to the preset scanning path, completing the first layer of additive manufacturing. Under the action of the traction wheel 17, the alloy block 33 descends by 0.5mm, and the second layer of additive manufacturing continues. The above process is repeated, and the TC4 titanium alloy being added continuously extends downwards, gradually forming the metal rod 8 of the additive manufacturing. Under the traction of the traction wheel 17, the alloy block 33 gradually descends as the thickness of the additive manufacturing increases. The descent speed is matched with the additive manufacturing speed at 20mm / min to ensure that the height of the laser-printed plane remains unchanged. During the descent of the alloy movable block 33 carrying the additive metal rod 8, when the coarse section of the alloy movable block 33 contacts the milling cutter 9 of the surface smoothing device, the milling cutter base disc, driven by the turntable motor 27, is driven by gear sets 28, 29, and 30 to make the milling cutter move horizontally around the rod. The milling cutter 9 performs a surface finishing process on the coarse section of the alloy movable block 33 and the circumferential surface of the metal rod 8. Before the coarse section of the alloy movable block 33 and the metal rod 8 descend to the substrate opening 37, after the circumferential surface is smoothed by the milling cutter 9, the diameter of the coarse section of the alloy movable block 33 and the metal rod 8 reaches 12mm.

[0048] After passing through the feed inlet of the looper, the metal rod is fed into the continuous extruder 20 by the looper. The surface linear velocity of the extrusion roller is matched with the additive speed, and the adjustment tolerance of the looper is 20%. The extruded product enters the cooling device 21 for cooling, and is then collected by the collecting device 23 via the guide frame 22. The collecting device 23 is a take-up reel.

Claims

1. A continuous laser additive manufacturing and extrusion forming equipment for difficult-to-cast alloys, comprising a laser additive manufacturing facility, a looper device, and an extrusion forming facility. The laser additive manufacturing facility includes a laser and an optical fiber (16), a powder feeding system, a powder mixer (14), and a laser forming device. The laser forming device includes an inert gas protection box (1), a laser cladding head (2), a laser coaxial powder nozzle (4), a molten pool (5), and a crystallizer (7). The base plate (6) of the inert gas protection box (1) is fixed on the lifting platform of the elevator. The laser cladding head (2), the laser coaxial powder nozzle (4), the molten pool (5), and the crystallizer (7) are arranged inside the inert gas protection box. The laser cladding head (2) is located at the upper part of the inert gas protection box, the crystallizer (7) is located below the laser cladding head (2), the molten pool (5) is located in the inner hole of the crystallizer (7), and the laser coaxial powder nozzle (4) is placed in the upper part of the inert gas protection box. The lower edge of the laser cladding head (2) is connected to the laser cladding head (2) via an optical fiber. The powder feeding system includes a powder feeding tank (10-13), a powder feeding pipeline (15), and a powder mixer (14). The powder feeding tank (10-13) is connected to the powder mixer (14) via the powder feeding pipeline (15). The powder mixer (14) is connected to the laser coaxial powder nozzle (4) in the inert gas protection box via a pipeline. The looper is a looper with a spring slide rail. The inlet section of the looper is a vertical section, and the outlet section is a horizontal section. The inlet section and the outlet section are connected by an inclined section. The extrusion molding facility includes a continuous extruder (20), a cooling device (21), a guide frame (22), and a storage device (23). The continuous extruder (20), the cooling device (21), the guide frame (22), and the storage device (23) are fixed sequentially on the foundation. The feature is that: The laser forming device further includes a surface leveling device, an alloy movable block (33), a traction device, and a sealing device; The inert gas protection box is a box body with a base plate as the base plate (6). The base plate (6) of the inert gas protection box has a base plate opening (37) corresponding to the laser cladding head (2). The diameter of the base plate opening (37) is 103% to 105% of the set laser additive surface diameter. The base plate opening (37) is sealed by a sealing device. The sealing device includes a sealing cylinder (34) and a sealing ring (35). The sealing cylinder (34) is a sleeve with a flange at one end. The sleeve is composed of two semi-cylindrical sleeves. One of the two semi-cylindrical sleeves has a boss and the other has a groove on the mating surface. The boss and the groove cooperate with each other. A sealing ring groove is opened radially on the inner wall of the sleeve. The sealing ring (35) is a metal ring. The sealing ring (35) is composed of two semi-cylindrical rings facing each other. The sealing ring (35) has an outer diameter that is 98% to 100% of the outer diameter of the sealing ring groove, and an inner diameter that is 100% to 102% of the set laser additive surface diameter. The sealing ring (35) is placed in the sealing ring groove, and each sealing ring groove contains 2 to 4 layers of sealing rings (35). The total thickness of the sealing rings (35) in each sealing ring groove is 97% to 99% of the thickness of the groove. The butt joints of two adjacent layers of sealing rings (35) are at 90° to each other. The angle between the butt joints of two adjacent layers of sealing rings (35) and the butt joints of the sealing cylinder (34) is 45°. The flange end of the sealing cylinder (34) is bolted to the substrate opening (37) of the inert gas protection box substrate (6). The axis of the inner hole of the sealing cylinder (34) coincides with the axis of the substrate opening (37).The surface smoothing device includes a milling cutter (9), a milling cutter driven gear (24), a milling cutter driving gear (25), a milling cutter motor (26), a turntable motor (27), a turntable driving gear (28), a turntable driven gear (29), a coaxial driven gear (30), a milling cutter turntable (31), and turntable balls (32). The milling cutter turntable (31) is a gear disk with teeth on its outer circumference. A central hole is opened in the center of the gear disk. The diameter of the central hole is 103% to 105% of the diameter of the laser additive surface. An annular bearing groove with the central hole as the center is provided on the bottom of the gear disk. A groove corresponding to the annular bearing groove on the bottom of the gear disk is opened on the upper part of the inert gas protection box substrate (6). The turntable balls (32) are placed in the groove on the inert gas protection box substrate (6). The annular bearing groove on the bottom of the gear disk of the milling cutter turntable (31) is placed on the balls in the groove on the inert gas protection box substrate (6). The motor (27) is fixedly mounted on the inert gas protection box base plate (6) outside the outer circumference of the milling cutter turntable (31). The turntable drive gear (28) is mounted on the shaft of the turntable motor (27). The coaxial driven gear (30) is mounted on the middle of the coaxial driven gear shaft by a key. The coaxial driven gear shaft is mounted on the inert gas protection box base plate (6) by bearings. The coaxial driven gear (30) meshes with the teeth on the outer circumference of the milling cutter turntable (31). The turntable driven gear (29) The driven gear (29) is mounted on the upper end of the coaxial driven gear shaft by a key, and the driven gear (28) of the turntable meshes with the driving gear (28) of the turntable. The milling cutter motor (26) is fixedly mounted on the milling cutter turntable (31). The driving gear (25) of the milling cutter is connected to the shaft of the milling cutter motor (26). The driven gear (24) of the milling cutter is mounted on the middle part of the milling cutter shaft by a key. The lower end of the milling cutter shaft is mounted on the milling cutter turntable (31) by a bearing. The milling cutter (9) is mounted on the upper end of the milling cutter shaft by a key. The alloy movable block (33) is a long rod, which consists of two rods with different diameters. The diameter of the upper segment of the long rod is 105% - 110% of the set diameter of the laser additive surface. The upper segment of the long rod is placed in the inner hole of the mold (7), and the upper end surface of the long rod is located on the molten pool surface. The diameter of the lower segment of the long rod is the same as the set diameter of the laser additive surface. The lower end of the long rod passes through the central hole of the milling cutter turntable (31) and the substrate opening (37) on the substrate of the inert gas protection box substrate (6) and extends outside the inert gas protection box (1). The lower end part is placed in the groove of the traction wheel (17) of the traction device. The milling cutter (9) of the surface leveling device abuts against the side surface of the lower segment of the alloy movable block (33); The traction device consists of a traction wheel (17) and a loose pulley (19) of a loose pulley device with a spring slide rail. The traction wheel (17) is a grooved wheel with a semi-circular groove on its outer circumferential surface. The surface of the groove is treated by sand blasting. The traction wheel (17) is installed on the loose pulley frame. The traction wheel (17) is connected to the motor through a speed reduction mechanism. The traction wheel (17) corresponds to the loose pulley (19) of the loose pulley device with a spring slide rail. The spring of the loose pulley (19) of the loose pulley device with a spring slide rail is in a compressed state, and the loose pulley (19) is disengaged from the traction wheel (17). The spring of the loose pulley (19) of the loose pulley device with a spring slide rail is in a released state, and the loose pulley (19) is in a clamped state with the traction wheel (17); The inlet of the loose pulley device is connected to the outlet of the traction device, and the outlet of the loose pulley device is connected to the inlet of the continuous extrusion machine (20).

2. The continuous laser additive manufacturing and extrusion forming equipment for difficult-to-cast alloys according to claim 1, characterized in that: The diameter of the set laser additive surface is equal to the width of the groove of the extrusion wheel of the continuous extrusion machine (20).

3. The continuous laser additive manufacturing and extrusion forming equipment for difficult-to-cast alloys according to claim 2, characterized in that: The number of annular bearing grooves under the milling cutter turntable (31) of the surface leveling device is 2 - 6. The distance between the groove wall of the innermost annular bearing groove and the circumference of the central hole of the milling cutter turntable (31) is s, where 5mm < s < 10mm. The distance between the groove wall of the outermost annular bearing groove and the circumference of the outer contour of the milling cutter turntable (31) is d, where 5mm < d < 10mm. The remaining bearing grooves are evenly distributed.

4. The continuous laser additive manufacturing and extrusion forming equipment for difficult-to-cast alloys according to claim 3, characterized in that: The diameter of the milling cutter (9) of the surface leveling device is 5 - 20mm.

5. The continuous laser additive manufacturing and extrusion forming equipment for difficult-to-cast alloys according to claim 4, characterized in that: The number of sealing ring grooves on the inner wall of the sealing cylinder (34) is 1 - 4. The sealing ring grooves are evenly distributed along the axial direction of the sealing cylinder, and the distance between adjacent two sealing ring grooves is greater than 5mm.

6. The continuous laser additive manufacturing and extrusion forming equipment for difficult-to-cast alloys according to claim 5, characterized in that: The number of the traction wheel (17) and the loose pulley (19) of the loose pulley device with a spring slide rail is each 1 - 5. The traction wheel (17) and the loose pulley (19) of the loose pulley device with a spring slide rail correspond to each other and are arranged longitudinally directly below the substrate opening (37).

7. The continuous laser additive manufacturing and extrusion forming equipment for difficult-to-cast alloys according to claim 6, characterized in that: A rod limiting frame (36) is fixed below the inert gas protection box substrate (6). The rod limiting frame (36) consists of 3 to 5 supports and a limiting ring. One end of the support is fixedly connected to the limiting ring. The angle between the plane where the support and the limiting ring are located is 45°. The 3 to 5 supports are evenly arranged on the limiting ring. The other end of the support is fixed to the bottom of the inert gas protection box substrate (6) by bolts. The axis of the limiting ring coincides with the axis of the substrate opening (37) on the inert gas protection box substrate (6). The inner diameter of the limiting ring is the same as the diameter of the lower section of the alloy movable block (33).

8. The continuous laser additive manufacturing and extrusion forming equipment for difficult-to-cast alloys according to claim 7, characterized in that: The sealing ring (35) is a cast iron ring or a stainless steel ring.

9. The continuous laser additive manufacturing and extrusion forming equipment for difficult-to-cast alloys according to claim 8, characterized in that: The groove linear velocity of the extrusion wheel of the continuous extruder (20) is consistent with the average speed of the traction wheel (17) pulling the metal rod (8) downward, which is 10 to 700 mm / min.

10. A production method of any one of the continuous laser additive manufacturing and extrusion forming equipment for difficult-to-cast alloys as described in claims 1 to 9, comprising laser additive manufacturing and continuous extrusion, characterized in that: The laser additive manufacturing process includes the following steps: Release the spring of the looper wheel (19) of the looper device with spring slide rail, so that the traction wheel (17) and the looper wheel (19) of the looper device with spring slide rail clamp the lower end of the alloy block (33). Start the traction wheel (17), and the traction wheel (17) pulls the alloy block (33) up and down, so that the top surface of the alloy block (33) is placed in the laser focal plane of the crystallizer. Start the laser additive manufacturing facility to add material according to the set parameters. Adjust the rotation speed of the traction wheel (17) so that it moves downward synchronously with the addition speed of the laser additive manufacturing facility, and keep the surface of the additive always in the laser focal plane. The continuous extrusion includes the following steps: adjusting the rotation speed of the extrusion wheel of the continuous extruder (20) to match the rotation speed of the traction wheel (17); the metal rod (8) of the laser additive facility connected to the alloy block (33) is pulled into the looper by the traction wheel (17), and the looper puts the alloy block (33) and the metal rod (8) of the laser additive facility into the extrusion wheel of the continuous extruder (21); the extruded product enters the cooling device for cooling (21), and is collected by the storage device (23) via the guide frame (22).

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