Pressure adaptive coaxial laser assisted stir additive forming apparatus and method

Abstract

The application provides a pressure self-adaptive coaxial laser auxiliary stirring additive forming device and method, center tool heads and side tool heads are arranged in a triangular shape, the center tool head has a center feeding channel, the side wall of the center feeding channel has a spiral groove, a laser generator is arranged above the center feeding channel, a linear isolation feeding pipe is connected to the lower end of the laser generator, the lower end of the linear isolation feeding pipe is close to and higher than the neck of the center feeding channel, an annular spiral space is vertically arranged by the side wall of the center feeding channel and the linear isolation feeding pipe in the center feeding channel, the method steps include driving the center tool head to rotate by a driving mechanism, the center tool head drives the two side tool heads to rotate at a low speed, and a motion execution device is used to move the additive forming device downward in the Z direction to slightly contact the additive platform, the application can not only effectively solve the problem of serious flash on both sides of the additive path and improve the additive path lap forming quality, but also make the material plasticization and the additive path more easily matched.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology, specifically relating to a laser coaxial assisted stirring additive forming device and method. Background Technology

[0002] Metal solid-state additive manufacturing is a technology that heats metal materials to a plastic deformation state, plasticizes the material through frictional stirring, and then achieves additive forming by applying upsetting pressure. Specifically, a stirring additive manufacturing heating device is used to heat and plasticize the filler material, and frictional heat between the stirring tool head and the substrate is used to deposit the material on the substrate surface. By programming the additive deposition trajectory, samples can be stacked layer by layer, enabling efficient and rapid forming of complex parts. Simultaneously, the cyclic forging action of applying upsetting force accompanies the stirring solid-state additive deposition forming, which can mitigate problems such as overheating in the additive region, grain growth, and dissolution of strengthening phases caused by molten material additive forming. This results in formed samples with high microstructure density and good performance. This technology is widely used in the joining and forming of metal materials and defect repair, playing a crucial role in the forming and manufacturing of aerospace and weaponry equipment.

[0003] In the prior art, document CN215432012U discloses a laser-assisted friction stir additive welding fixture, comprising: a tool holder, laser channels spaced apart on the side wall of the tool holder, the side wall of the tool holder between two adjacent laser channels being a frame structure; a housing having a cavity suitable for inserting the tool holder; the tool holder being disposed within the housing in a clearance fit with the housing; a laser head and a push switch being disposed within the housing, the push switch being electrically connected to the laser head; the tool holder and the housing being coaxially arranged, the push switch extending toward the cavity; the tool holder being adapted to rotate relative to the housing, during rotation, a portion of the frame structure being adapted to abut against the push switch, thereby shutting off the laser head; when the frame structure disengages from the push switch, the laser head emits laser light, thereby providing auxiliary heating to the additive material inside the tool holder through the laser channels.

[0004] Although the application of additive manufacturing using induction heating friction stirring heads is increasing, as research and application continue to deepen, this technology has gradually exposed many problems, such as: severe flash on both sides of the additive path, resulting in poor overlap quality; severe wear of the tool head under high temperature, high pressure, and high speed, leading to a short lifespan; metal materials easily sticking to the inside of the tool head, even clogging it; difficulty in matching material plasticization with the additive path, resulting in defects such as excessive material accumulation or insufficient material and porosity; uneven force application in the additive path, buckling deformation of the formed structure, and large internal residual stress. These problems seriously affect the quality of additive manufacturing and urgently need to be solved. Summary of the Invention

[0005] In view of this, the first object of the present invention is to provide a pressure - adaptive laser coaxial assisted friction stir additive manufacturing device that can solve the serious problem of flash on both sides of the additive path and the difficulty in matching material plasticization with the additive path.

[0006] The object of the present invention is achieved by the following technical solutions: A pressure - adaptive laser coaxial assisted friction stir additive manufacturing device, including a friction tool head assembly, characterized in that: the friction tool head assembly includes a central tool head, on both sides of the central tool head are respectively provided with side tool heads, the central tool head is传动连接 with the side tool heads through a reduction gear pair, and the central tool head and the side tool heads are arranged in a "pin" shape; the central tool head is provided with a central feeding channel along the axial direction, the side wall of the central feeding channel has spiral grooves, above the central feeding channel is provided a laser generator, the lower end of the laser generator is connected to a linear isolation feeding pipe, the lower end of the linear isolation feeding pipe is close to and higher than the neck of the central feeding channel, and the annular spiral space is formed by the side wall of the central feeding channel and the linear isolation feeding pipe located in the central feeding channel. The annular spiral space means that the overall space is annular and its inner wall has a spiral channel. Adopting such a solution can not only effectively solve the problem of serious flash on both sides of the additive path, improve the quality of additive path lap forming, but also make it easier to match material plasticization with the additive path.

[0007] To further improve the life of the central tool head and avoid the phenomenon of sticking and blocking during the heating process of metal materials, a lower expansion port is further provided below the neck of the central feeding channel and below the lower expansion port, and an upper expansion port is provided at the top of the central feeding channel; the diameter of the neck is 20 - 40 mm, and the diameter of the neck is 30% - 50% of the diameter of the lower expansion port.

[0008] To further improve the problems of material buckling deformation and relatively large internal residual stress, the friction tool head assembly is installed on an anti - offset load assembly; the anti - offset load assembly includes a structural main body member, the friction tool head assembly is installed on the structural main body member, a balance hydraulic cylinder is provided on the upper part of the structural main body member, the balance hydraulic cylinder includes a horizontally arranged balance cylinder and vertical cylinder push rods connected to both ends of the balance cylinder, the balance cylinder is connected to a mounting plate, and the two cylinder push rods correspond to the two side tool heads and are connected to both sides of the structural main body member.

[0009] Furthermore, a Z - direction mounting through - hole is provided on the structural main body member, the central tool head is installed in the Z - direction mounting through - hole through a bearing, and a driving mechanism is also provided on the structural main body member, and the driving mechanism is传动连接 with the central tool head.

[0010] It should be noted that there are some unclear terms like "传动连接" in the original text which should be accurately translated according to the specific mechanical connection relationship in the context. The above translation is a rough version for reference.Preferably, the material of the linear isolation feeding pipe can be stainless steel, 45# steel, plastic resin materials such as PPEK / PEKK, PET, and PEI.

[0011] Both the upper expansion port and the lower expansion port of the central feeding channel are flared, and the upper part of the linear isolation feeding pipe is a cone that fits with the upper expansion port of the central feeding channel.

[0012] The second object of the present invention is to provide a pressure self - adaptive laser coaxial assisted stirring additive manufacturing method, including the following steps:

[0013] Step (1): After connecting the mounting plate of the above - mentioned additive manufacturing device to the motion execution equipment, level the additive manufacturing device. Then drive the additive manufacturing device to move to the initial position of the additive platform, and start the powder feeder to fill the metal material into the annular spiral channel.

[0014] Step (2): The driving mechanism drives the central tool head to rotate, and the central tool head带动两个旁侧工具头减速旋转 (it seems there is a mistake here, maybe it should be "the central tool head drives two side tool heads to rotate at a reduced speed"). Operate the motion execution equipment to make the additive manufacturing device move downward in the Z - direction until it slightly touches the additive platform.

[0015] Step (3): Start the laser generator, select the spot shape, size and power of the laser generator, and heat the metal material by laser for 1 - 5 minutes.

[0016] Step (4): Drive the anti - offset load component to adjust the initial positions of the central tool head and the side tool heads to be parallel to the additive platform according to the height distribution of the additive platform by the additive manufacturing device; at the same time, make the "pin" - shaped friction tool head assembly generate an axial forging pressure.

[0017] Step (5): The metal material transported by the annular spiral channel generates a frictional effect with the additive base surface until the metal material is in a red - hot state, thermoplastically plasticizing the metal material; under the rotation and upsetting pressure of the friction tool head assembly, the metal material generates deformation heat to further plasticize the material. Then drive the motion execution equipment along the designed trajectory to achieve additive manufacturing of the metal material on the additive base surface.

[0018] Step (6): After completing the additive manufacturing of the previous pass, lift the Z - direction height of the additive manufacturing device, and repeat the above steps to complete the additive manufacturing of the component.

[0019] Among them, the motion execution device in the step (1) can be a three-axis, four-axis or five-axis machine tool, or the end of a six-axis robot. The metal material can be low-melting-point materials such as aluminum alloy and magnesium alloy, or high-melting-point materials such as copper alloy, titanium alloy, nickel-based superalloy, and high-strength steel, or metal composite materials mixed with short fibers, granular fibers or fine ceramic particles. The metal material is powder with a particle size of 50-500 μm or strip-shaped metal filings with a diameter of 0.1-0.5 mm and a length of 1-10 mm.

[0020] In the step (2), the rotational speeds of the central tool head and the side tool heads are 50 rpm to 3000 rpm, and the rotational speed ratio of the central tool head to the side tool heads is 1:1 to 1:20.

[0021] In the step (3), the power of the laser generator is 1-8 KW, the light spot can be a circular or rectangular light spot, and the width or diameter of the light spot is 5-40 mm.

[0022] In the step (4), the hydraulic cylinder of the offset load component provides a pressure of 0.5-10 MPa and a forging pressure of 5-20 kN;

[0023] In the step (5), the traveling speed of the motion execution device is 100 mm / min to 100 mm / min;

[0024] In the step (6), the Z-direction height lift of the additive manufacturing device is 0.1-5 mm. Beneficial effects

[0025] (1) The "pin-shaped" friction tool head assembly of the additive manufacturing device of the present invention applies uniform lateral forming pressure on both sides while performing additive manufacturing, which can greatly improve the flash situation on both sides of the sample formed by a single friction stir tool head and enhance the forming quality of the additive path lap joint;

[0026] [[ID=**23**]] (2) Adopting the solution of the present invention, there is no need to directly heat the central tool head, and the tool head can apply pressure and torque at a lower temperature, which can greatly reduce its wear and improve its service life;

[0027] (3) The present invention uses a high-energy-density laser to heat the metal material, with a high instantaneous heating power and a concentrated area. The heated and plasticized metal material and the heated area of the central tool head are small, with less heat conduction, avoiding the problem of material adhesion and blockage;

[0028] (4) In the solution of the present invention, the feeding method is flexibly adjustable, easy to match with the additive manufacturing speed. At the same time, the laser heating power is controllable, and the material plasticization and the additive path are easier to match, and the formed surface is flat and smooth;

[0029] (5) The solution of the present invention can effectively achieve the balance of the off-load of the tool head caused by the uneven additive base surface and the non-parallelism between the axis of the tool head and the normal of the additive surface under a large upsetting force. At the same time, the "pin" - shaped friction tool head assembly during the forming process can passively adjust the tool head angle according to the undulation of the additive base surface, making the pressure applied by the tool head uniform, thereby meeting the uniform increase of the additive thickness in multiple passes, effectively improving problems such as material buckling deformation and large internal residual stress.

[0030] (6) The structure of the present invention is compact, applicable to various platforms such as machine tools and robots, and is also applicable to the additive forming of various metal materials, especially suitable for the additive forming of complex configurations, with a wide application range. Brief Description of the Drawings

[0031] Figure 1 It is a schematic diagram of the pressure - adaptive laser coaxial assisted stir - additive forming device of the present invention;

[0032] Figure 2 It is a three - dimensional schematic diagram of the central tool head structure;

[0033] Figure 3 It is a schematic diagram of the side tool head structure;

[0034] Figure 4 It is the flash of the additive structure of the traditional device;

[0035] Figure 5 It is the unevenness and material shortage of the additive path of the traditional device;

[0036] Figure 6 It is the surface quality of the additive forming path of the device of the present invention;

[0037] Figure 7 It is the porosity and delamination existing in the additive tissue of the traditional device;

[0038] Figure 8 It is the dense tissue formed by the device of the present invention;

[0039] Figure 9 It is the additive forming method 1 of the device of the present invention;

[0040] Figure 10 It is the additive forming method 2 of the device of the present invention.

[0041] Label Explanation: 1. Balance oil cylinder; 2. Mounting plate; 3. Oil cylinder ejector rod; 4. Laser generator; 5. Motor; 6. Linear isolation feeding pipe; 7. Transmission belt; 8. Pulley; 9. Bearing; 10. Central tool head; 11. Structure main body; 12, 16. Side tool heads; 13, 15. Side gears; 14. Central gear; 17. Powder feeding pipe; 18. Powder feeder; 19. Neck; 20. Spiral groove. Detailed Embodiment

[0042] Embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where like or similar reference numerals designate like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present application and should not be construed as a limitation to the present application. On the contrary, the embodiments of the present application include all variations, modifications, and equivalents that fall within the spirit and scope of the appended claims.

[0043] Embodiment 1: As Figure 1-8 shown, this embodiment first provides a pressure self-adaptive laser coaxial assisted stir additive manufacturing device, which includes a friction tool head assembly, a driving assembly, an anti-offset load assembly, a laser generating assembly, and a feeding assembly. Among them, the friction tool head assembly includes a "pin" shaped tool head assembly. The "pin" shaped tool head assembly is arranged on the offset load assembly. The driving assembly drives the friction tool head assembly. A feeding channel is arranged in the friction tool head assembly, and the feeding assembly is connected to the feeding channel. The laser generating assembly has an auxiliary stirring member coaxially arranged with the feeding channel.

[0044] Specifically, the friction tool head assembly includes a central tool head 10. On both sides of the lower end of the central tool head, a side tool head 12 and a side tool head 16 are respectively arranged. The central tool head is传动连接 with the side tool head through a reduction gear pair, and the central tool head and the side tool head are arranged in a "pin" shape. The "pin" shape arrangement in this embodiment means that the two side tool heads are symmetrically arranged on both sides of the central tool head and the bottom surface of the side tool head is lower than the bottom surface of the central tool head.

[0045] Among them, the central tool head 10 is provided with a central feeding channel along the axial direction. The side wall of the central feeding channel has a spiral groove 20. A laser generator 4 is arranged above the central feeding channel. The lower end of the laser generator 4 is connected to a linear isolation feeding pipe 6. The lower end of the linear isolation feeding pipe 6 is close to and higher than the neck opening 19 of the central feeding channel (the vertical distance between the lower end of the linear isolation feeding pipe 6 and the upper end of the neck opening 19 is 3 mm - 8 mm), and a ring-shaped spiral space is formed by the side wall of the central feeding channel and the linear isolation feeding pipe 6 located in the central feeding channel and arranged vertically.

[0046] It should be noted that there is an unclear expression "传动连接" in the original text, which is tentatively translated as "传动连接" here. It may need to be further clarified according to the actual situation.The anti-eccentric load assembly includes a main structural component 11, which can be a regular or irregular shaped mounting block. In this embodiment, the main structural component is a "┌" shaped mounting block. The anti-eccentric load assembly also includes a balancing hydraulic cylinder disposed above the main structural component. The balancing hydraulic cylinder includes a horizontally arranged balancing cylinder 1 and vertical cylinder push rods 3 connected to both ends of the balancing cylinder 1. The balancing cylinder 1 is fixedly connected to the mounting plate 2, and its center is connected to a hydraulic source. The two vertically arranged cylinder push rods are of the same length, and their lower ends are respectively connected to both sides of the main structural component. In this embodiment, the pressure provided by the hydraulic cylinder is 0.5–10 MPa.

[0047] The friction tool head assembly is mounted on the main structural component of the anti-eccentric load assembly. A Z-direction through hole is provided on the main structural component, and the central tool head is mounted within this hole via bearings 9, with both ends extending beyond the Z-direction through hole. A central gear 14 is mounted on the lower outer wall of the central tool head, and side gears 13 and 15 are mounted on the upper parts of the two side tool heads. The central gear and side gears mesh and drive each other. Mounting holes are provided on both sides of the Z-direction through hole at the bottom of the main structural component, and the two side tool heads are mounted within these holes via bearings. Furthermore, the mounting direction of the two side tool heads is the same as the mounting direction of the two hydraulic cylinder push rods; that is, the two side tool heads and the two hydraulic cylinder push rods are located on opposite sides of the central tool head, with the center line connecting the two side tool heads parallel to the center line connecting the two hydraulic cylinder push rods. During operation, the speed ratio between the central gear and the side gears is 1:1 to 2:10.

[0048] Additionally, the drive assembly includes a motor 5, with a drive pulley mounted on the motor output shaft and a driven pulley mounted on the upper outer wall of the central tool head. A transmission belt 7 is mounted on both the drive and driven pulleys. The motor drives the central tool head to rotate via the belts and pulleys 8.

[0049] In this embodiment, a lower expansion port is provided at the lower part of the central feeding channel and below the neck 19 (i.e. the part with the smallest diameter in the entire feeding channel), and an upper expansion port is provided at the top of the central feeding channel; the diameter of the neck 19 is 30%-50% of the diameter of the lower expansion port.

[0050] Specifically: In this embodiment, the internal diameter of the central feeding channel is 20-60 mm, which can be selected but not limited to 20 mm, 40 mm or 60 mm; the opening angle between the upper and lower flared openings is 30-60°, which can be selected but not limited to 30°, 40°, 50° or 60°; the diameter of the neck opening is 20-40 mm, which can be selected but not limited to 20 mm, 30 mm or 40 mm.

[0051] As another implementation manner in this embodiment, a spiral groove 20 is provided on the inner wall of the central feeding channel (excluding the upper expansion port, the lower expansion port and the neck port). The pitch of the spiral groove 20 is 10 to 50 mm, and can be selected but not limited to 10 mm, 13 mm or 15 mm; the thread can be left-handed or right-handed.

[0052] As another implementation manner in this embodiment, a chamfer is provided on the outer edge of the bottom surface of the side tool head, and the chamfer angle is 45 to 60°, and can be selected but not limited to 45°, 50° or 60°.

[0053] In addition, in this embodiment, both the upper expansion port and the lower expansion port of the central feeding channel are in a horn shape, and the upper part of the linear isolation feeding pipe 6 is a cone that matches the upper expansion port of the central feeding channel. Among them, the material of the linear isolation feeding pipe 6 can be stainless steel, 45# steel, plastic resin materials PPEK / PEKK, PET, PEI, etc. The power of the laser generator 4 is 1 to 8 KW, and the light spot can be a circular or rectangular light spot, and the width or diameter of the light spot is 5 to 40 mm.

[0054] The feeding component includes a powder feeder 18 and a powder feeding pipe 17 connected to the powder feeder. The output end of the powder feeding pipe extends into the upper end of the annular spiral channel.

[0055] When the additive manufacturing device in this embodiment is in use, its mounting plate is connected to a motion execution device. The motion execution device can be a three-axis, four-axis, or five-axis machine tool; or the end of a six-axis robot motion.

[0056] During use, due to the side tool heads designed by the "pin" - shaped friction tool head assembly, the flash problem can be effectively solved. And through the anti - offset load component, it can effectively achieve the balance of the tool head offset caused by the uneven additive base surface and the non - parallelism between the tool head axis and the normal of the additive surface under a large upsetting force. And during the forming process, under the action of the anti - offset load component, the "pin" - shaped combined tool head can adaptively adjust the offset angle of the tool head according to the undulation of the additive base surface, making the pressure applied by the tool head uniform, thereby meeting the requirement of uniform increase in the additive thickness in multiple passes, effectively improving problems such as material buckling deformation and large internal residual stress.

[0057] In this embodiment, after the metal powder enters the annular spiral channel, it falls to the neck under its own gravity and the rotational force (cyclone phenomenon) of the central tool head, and comes into contact with the laser, where it is heated and melted. This embodiment uses a high-energy-density laser to heat the metal powder instead of the central tool head, allowing the tool head to apply pressure and torque at a lower temperature, significantly reducing tool head wear and extending its lifespan. Furthermore, it features high instantaneous heating power, concentrated heating area (at the neck), and a small area for heating and plasticizing the metal material compared to the heated area of ​​the central tool head, resulting in less thermal conductivity and avoiding metal material sticking and blockage. More importantly, it allows for flexible and adjustable feeding, easily matching the additive molding speed. Simultaneously, the controllable laser heating power makes it easier to match material plasticization and the additive path, resulting in a smooth and clean forming surface and better molding performance.

[0058] For specific effects, please see: Figure 4 , 5 This addresses the issues of flash, unevenness in the additive manufacturing path, and material shortages in traditional additive structures. Figure 6 The surface quality of the path obtained using the forming apparatus of this embodiment. See also Figure 7 To address the voids and delamination in additive manufacturing caused by the use of conventional molding equipment, Figure 8 The additive structure obtained using the apparatus of this embodiment is dense and has high molding quality.

[0059] Example 2: This example also provides a pressure-adaptive laser coaxial assisted stirring additive manufacturing method, including the following steps:

[0060] Step (1): After connecting the mounting plate of the additive molding device of Example 1 to the motion execution device, the additive molding device is leveled, and then the additive molding device is driven to move to the initial position of the additive platform. The powder feeder is started to fill the metal material into the annular spiral channel.

[0061] Step (2): Start the motor drive belt to make the center tool head rotate at high speed. The center tool head drives the two side tool heads to rotate at low speed through the reduction gear pair. Operate the motion execution device to move the additive forming device downward in the Z direction until it makes slight contact with the additive platform.

[0062] Step (3): Start the laser generator, select the laser spot shape, size and power according to the additive advance speed, and heat the metal material with laser for 1 to 5 minutes;

[0063] Step (4): Drive the anti-offset load component to adjust the initial positions of the central tool head and the side tool heads to be parallel to the additive manufacturing platform according to the height distribution of the additive manufacturing platform; at the same time, make the friction tool head components arranged in a "pin" shape generate axial forging pressure, so that the central tool head generates a frictional effect on the conveyed metal material and the additive manufacturing base surface until the metal material reaches a red-hot state, generating heat to plasticize the metal material.

[0064] Step (5): Under the action of the rotation and upsetting pressure of the friction tool head components, the metal material generates deformation heat to further plasticize the material, and then drive the motion execution device according to the designed trajectory to achieve additive manufacturing of the metal material on the additive manufacturing base surface.

[0065] Step (6): After completing the additive manufacturing of the previous pass, lift the Z-axis height of the additive manufacturing device, repeat the above steps, and complete the additive manufacturing of the component.

[0066] Among them, the motion execution device in step (1) can be a three-axis, four-axis or five-axis machine tool, or the end of a six-axis robot. The metal material is a low-melting-point material such as aluminum alloy or magnesium alloy, or a high-melting-point material such as copper alloy, titanium alloy, nickel-based superalloy or high-strength steel, or a metal composite material mixed with short fibers, particulate fibers or fine ceramic particles. The metal material is powder with a particle size of 50 - 500 μm or strip-shaped metal turnings with a diameter of 0.1 - 0.5 mm and a length of 1 - 10 mm.

[0067] In step (2), the rotational speeds of the central tool head and the side tool heads are 50 rpm - 3000 rpm, and the speed ratio of the central tool head to the side tool heads is 1:1 - 1:20.

[0068] In step (3), the power of the laser generator is 1 - 8 KW, and the light spot can be a circular or rectangular light spot, with a light spot width or diameter of 5 - 40 mm.

[0069] In step (4), the hydraulic cylinder of the anti-offset load component provides a pressure of 0.5 - 10 MPa and a forging pressure of 5 - 20 kN.

[0070] In step (5), the traveling speed of the motion execution device is 100 mm / min - 100 mm / min.

[0071] In step (6), the lifting height of the Z-axis of the additive manufacturing device is 0.1 - 5 mm.

[0072] Adopting the additive manufacturing method of this embodiment can achieve better forming quality. See Figure 4 、 5 for the flash situation of the traditional additive structure and the situation of uneven additive path and lack of material, while Figure 6The path surface quality obtained by using the forming method of this embodiment. It can be seen that the forming method of this embodiment can effectively solve the flash situation on both sides of the formed sample and improve the additive path lap forming quality.

[0073] See Figure 7 The additive tissue voids and delamination caused by using traditional forming devices and methods Figure 8 The additive tissue obtained by using the device and method of this embodiment has a dense structure and high forming quality. It can be seen that the device of Example 1 and the method of this embodiment can meet the requirements of uniformly increasing the additive thickness in multiple passes, effectively improving problems such as material buckling deformation and large internal residual stresses.

[0074] In addition, two specific examples are provided in this embodiment for illustration:

[0075] Example 1: After installing the additive forming device in Example 1 on the motion execution device, see Figure 9 , complete the leveling of the additive forming device, and then move to the initial position of the additive platform. Start the powder feeder 18 to fill the metal material into the annular spiral channel formed by the central tool head and the linear isolation feeder tube.

[0076] Start the motor 5 of the additive forming device to drive the drive belt 7 to rotate the central tool head 10 at a speed of 200 rpm,带动 the side tool heads 12 and 16 to rotate at a speed of 800 rpm. Then operate the motion execution device to slowly move downward in the Z direction until it slightly touches the additive platform.

[0077] Start the laser generator 4, select the laser generator spot shape as a rectangular spot with a size of 20×10 mm and a power of 5 kW according to the additive forward speed, and laser heat for 1 - 5 minutes.

[0078] Drive the constant force hydraulic anti-offset load component, so that the additive forming device adjusts the central tool head 10, the side tool head 12 and the side tool head 16 according to the height distribution of the additive platform to be parallel to the initial position of the additive platform. At the same time, make the "pin" - shaped combined tool head structure generate an axial forging pressure of more than 10 KN, so that the metal material transported by the annular spiral channel of the central tool head has a frictional effect with the additive base surface until the metal material is in a red - hot state, generating thermoplasticized metal material.

[0079] Under the action of the high - speed rotation and upsetting pressure of the "pin" - shaped friction tool head assembly, the metal material generates deformation heat to further plasticize the material. Then drive the motion execution device according to the designed trajectory, with a trajectory forward speed of 500 mm / min, to achieve additive forming of the metal material on the additive base surface.

[0080] After the additive forming of the previous pass is completed, raise the height of the motion equipment in the Z direction by 2 mm, and repeat the above steps to complete the additive forming of the complex component.

[0081] Example 2: After installing the additive forming device in Example 1 on the motion execution equipment, refer to Figure 10 , complete the leveling of the additive forming device, and then move to the initial position of the additive platform. Start the powder feeder 18 to fill the metal material into the annular spiral channel formed by the central tool head and the linear isolation feeder tube.

[0082] Start the motor 5 of the additive forming device, drive the transmission belt 7 to rotate the central tool head 10 at a speed of 250 rpm,带动 the side tool head 12 and the side tool head 16 to rotate at a speed of 500 rpm. Then operate the motion execution equipment and slowly move downward in the Z direction until it slightly touches the platform.

[0083] Start the laser generator 4, select the laser generator spot shape as a circular spot with a diameter of 20 mm and a power of 10 kW according to the additive forward speed, and laser heat for 3 minutes.

[0084] Drive the constant force hydraulic anti-offset load component, so that the additive forming device adjusts the central tool head 10, the side tool head 12 and 16 according to the height distribution of the platform to be parallel to the additive platform at the initial position. At the same time, make the "pin" - shaped combined tool head structure generate an axial forging pressure of more than 15 KN, so that the metal materials conveyed by the "pin" - shaped combined tool head and the central tool head 10 have a frictional effect with the additive base surface until the metal material is in a red - hot state and plasticizes the metal material by heat.

[0085] Under the action of the high - speed rotation and upsetting pressure of the "pin" - shaped combined tool head, the metal material generates deformation heat to further plasticize the material. Then drive the motion execution equipment according to the designed trajectory with a trajectory forward speed of 300 mm / min to achieve the additive forming of the metal material on the additive base surface.

[0086] After the additive forming of one pass is completed, the equipment moves horizontally by 50 mm, executes the trajectory of the previous pass with a forward speed of 300 mm / min, completes the additive forming of the next pass, and realizes multi - pass additive forming through reciprocating motion.

[0087] After the additive forming of the first - layer material is completed, raise the height of the motion equipment in the Z direction by 3.5 mm, move the additive device to the mid - line position of the two - pass trajectories of the first layer, drive the motion execution equipment with a trajectory forward speed of 300 mm / min. After the additive forming of the previous pass is completed, the equipment moves horizontally by 50 mm, and realizes multi - pass additive forming through reciprocating motion.

[0088] Repeat the steps of additive forming of single - layer materials and offset additive forming of the next - layer materials to complete the additive of the metal material.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that various changes in form and detail can be made to it without departing from the scope defined by the claims of the present invention.

Claims

1. A pressure-adaptive laser coaxial assisted stirring additive manufacturing device, comprising a friction tool head assembly, characterized in that: The friction tool head assembly includes a central tool head, with side tool heads arranged on both sides of the central tool head. The central tool head is in driving connection with the side tool heads through a reduction gear pair, and the central tool head and the side tool heads are arranged in a "pin" shape. The central tool head is provided with a central feeding channel along the axial direction. The sidewall of the central feeding channel has spiral grooves. Above the central feeding channel, there is a laser generator. The lower end of the laser generator is connected to a linear isolation feeding pipe, and the lower end of the linear isolation feeding pipe is close to and higher than the neck of the central feeding channel, forming an annular spiral space jointly arranged vertically by the sidewall of the central feeding channel and the linear isolation feeding pipe located in the central feeding channel. Below the lower part of the central feeding channel and below the neck, there is also a lower expansion port, and at the top of the central feeding channel, there is an upper expansion port. The diameter of the neck is 20 - 40 mm, and the diameter of the neck is 30% - 50% of the diameter of the lower expansion port. The friction tool head assembly is installed on an anti-offset load component. The anti-offset load component includes a structural main body. The friction tool head assembly is installed on the structural main body. An equilibrium hydraulic cylinder is arranged on the upper part of the structural main body. The equilibrium hydraulic cylinder includes a horizontally arranged equilibrium cylinder and vertical cylinder push rods connected to both ends of the equilibrium cylinder. The two cylinder push rods correspond to the two side tool heads and are connected to both sides of the structural main body. There is a Z-direction installation through hole on the structural main body, and the central tool head is installed in the Z-direction installation through hole through a bearing. A driving mechanism is also arranged on the structural main body, and the driving mechanism is in driving connection with the central tool head.

2. The pressure-adaptive laser coaxial assisted stirring additive manufacturing device as described in claim 1, characterized in that: Both the upper expansion port and the lower expansion port of the central feeding channel are in a flared shape, and the upper part of the linear isolation feeding pipe is in a conical shape matching the upper expansion port of the central feeding channel.

3. The pressure-adaptive laser coaxial assisted stirring additive manufacturing device as described in claim 1 or 2, characterized in that: The pitch of the spiral grooves on the sidewall of the central feeding channel is 10 - 50 mm.

4. A pressure-adaptive laser coaxial assisted stirring additive manufacturing method, characterized in that, It includes the following steps: Step (1): After installing the additive manufacturing device according to Claim 1, 2 or 3 on a motion execution device, level the additive manufacturing device. Then drive the additive manufacturing device to move to the initial position of the additive manufacturing platform, and start the powder feeder to fill the metal material into the annular feeding channel. Step (2): The driving mechanism drives the central tool head to rotate, and the central tool head drives the two side tool heads to rotate. Operate the motion execution device to make the additive manufacturing device move downward in the Z direction until it slightly touches the additive manufacturing platform. Step (3): Start the laser generator, select the spot shape, size and power of the laser generator, and heat the metal material by laser for 1 - 5 minutes. Step (4): Drive the anti-offset load component to adjust the initial positions of the central tool head and the side tool heads to be parallel to the additive manufacturing platform according to the height distribution of the additive manufacturing platform. At the same time, make the "pin" shaped friction tool head assembly generate an axial forging pressure. Step (5): The metal material conveyed by the annular feeding channel rubs against the additive substrate until the metal material is red-hot, generating heat to plasticize the metal material. Under the rotation and upsetting pressure of the friction tool head assembly, the metal material generates deformation heat to further plasticize the material, and then drives the motion execution device according to the design trajectory to realize the additive forming of the metal material on the additive substrate. Step (6): After completing the previous additive molding, raise the Z-axis height of the additive molding device and repeat the above steps to complete the additive molding of the component.

5. The pressure-adaptive laser coaxial assisted stirring additive manufacturing method as described in claim 4, characterized in that: In step (1), the metal material is powder with a particle size of 50 to 500 μm or strip-shaped metal scraps with a diameter of 0.1 to 0.5 mm and a length of 1 to 10 mm.

6. The pressure-adaptive laser coaxial assisted stirring additive manufacturing method as described in claim 5, characterized in that: In step (2), the rotational speed of the center tool head and the side tool head is 50 rpm to 3000 rpm, and the rotational speed ratio of the center tool head to the side tool head is 1:1 to 1:

20.

7. The pressure-adaptive laser coaxial assisted stirring additive manufacturing method as described in claim 6, characterized in that: In step (3), the power of the laser generator is 1 to 8KW, and the light spot can be circular or rectangular, with a width or diameter of 5 to 40 mm.

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