A laser coaxial wire additive manufacturing device and method based on double magnetic field cooperation

Abstract

The application relates to the field of laser additive manufacturing, and particularly discloses a laser coaxial wire additive manufacturing device and method based on double magnetic field cooperation, which comprises a motion system, a coaxial wire additive manufacturing system, a double magnetic field auxiliary system and a control monitoring system, and is externally provided with a wire feeding mechanism. The double magnetic field auxiliary system is composed of a magnetic pressure induction system and a symmetric sliding magnetic field generation system; the magnetic pressure induction system is arranged around a welding head to generate a vertical magnetic field; the symmetric sliding magnetic field generation system generates a horizontal magnetic field through Helmholtz coils on two sides; the two magnetic field systems are independently adjustable and are orthogonally arranged in space. The device is provided with a high-speed camera to monitor the molten pool state in real time, the magnetic field strength and proportion are dynamically adjusted through a controller and double electromagnetic generators, and accurate control of molten drop transition and molten pool flow is realized. The application improves the quality and stability of coaxial wire additive manufacturing.

Description

Technical Field

[0001] The present invention relates to the technical field of laser additive manufacturing, and in particular to a laser coaxial fuse additive manufacturing device and method based on dual magnetic field collaboration. Background Art

[0002] Laser additive manufacturing technology has been widely used in high-end manufacturing fields such as aerospace, automobile manufacturing, and shipbuilding due to its advantages such as high energy density, small deformation, narrow heat-affected zone, and wide applicability. However, the traditional side wire feeding method has problems such as unstable material deposition position, strong directional dependence, and poor process flexibility, and slight changes in the wire feeding angle will affect the deposition quality. Laser coaxial fuse technology achieves material deposition by feeding the metal wire coaxially with the laser beam, which can improve deposition efficiency and achieve precise control of composition. However, in the high-power laser coaxial fuse additive manufacturing process, the fluid dynamics behavior of the molten pool is complex, the instability problem caused by the surface tension gradient is prominent, and under high-speed deposition conditions, the molten pool depth is difficult to meet the process requirements.

[0003] Single magnetic field-assisted laser welding technology has the following technical defects: First, the intensity and distribution of a single magnetic field are difficult to achieve precise control, resulting in poor stability in the additive manufacturing process; second, the existing magnetic field has a single mode of action, making it difficult to achieve multi-dimensional control of the molten pool flow and unable to effectively increase the molten pool depth. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a laser coaxial fused wire additive manufacturing device and method based on dual magnetic field collaboration, which can effectively solve the problems of uneven weld formation caused by existing side-axis wire feeding, the inability of a single magnetic field to achieve multi-dimensional control, and the inability to effectively increase the depth of the molten pool.

[0005] To achieve the above-mentioned objectives, the present invention proposes a laser coaxial fuse additive manufacturing device based on dual magnetic field collaboration, which includes a motion system, a coaxial fuse additive manufacturing system, a dual magnetic field auxiliary system, and a control and monitoring system, and a wire feeding mechanism is configured on the outside of the device; the motion system is composed of a guide rail system and a bottom support structure; the coaxial fuse additive manufacturing system includes a support mechanism for the welding head; the dual magnetic field auxiliary system is composed of a magnetic pressure induction system and a symmetrical sliding magnetic field generating system; the control and monitoring system is composed of a high-speed camera and a controller.

[0006] Preferably, the guide rail system includes a horizontal X-guide rail and a Y-guide rail perpendicular to the horizontal X-guide rail, and is connected to a gear transmission mechanism to form an XY platform structure that moves in a horizontal plane; the guide rail system controls the vertical movement of the welding head through the Z-guide rail; the guide rail system as a whole is a three-dimensional motion control system.

[0007] Preferably, the support mechanism of the welding head is a trapezoidal metal three-dimensional structure; the support mechanism of the welding head is connected with the gear transmission mechanism of the guide rail system through a mechanical connection assembly, forming a motion system for accurately adjusting the position of the welding head in three-dimensional space.

[0008] Preferably, the coaxial fuse welding head is fixed inside the support mechanism of the welding head, the welding head is connected with an external laser generator, the laser emitter emits a high-power continuous wave laser beam into the welding head; the welding head is provided with a through coaxial protective gas channel, which extends along the axial direction of the welding head, and which delivers protective gas to the working area; the welding head is also provided with an optical system for converting the incident continuous wave laser beam into a Bessel beam with a ring-shaped intensity distribution, the optical system also includes a focusing mirror for focusing the Bessel beam on the workpiece surface; a wire feeding channel is provided on the central axis of the welding head, and a wire feeding mechanism delivers the welding wire vertically through the wire feeding channel; the wire feeding path coincides with the central axis of the welding head, so that the welding wire precisely passes through the central region of the Bessel beam; a wire feeding nozzle is installed below the mounting seat of the welding head.

[0009] Preferably, the magnetic pressure induction system is arranged around the welding head and fixed to the upper outer wall of the wire feeding nozzle, and the magnetic field action region intersects with the axis of the welding head; the magnetic pressure induction system is composed of a magnetic induction coil, a cooling flow guide seat, a ring-shaped magnetic pole assembly and a magnetic shielding layer; the magnetic induction coil is formed by winding insulated copper wires with a rectangular cross-section, and is arranged in a radial multi-layer concentric ring structure, coaxially arranged with the welding head, each layer of coil is concentrically arranged and has the same number of turns, and a magnetic shielding layer is arranged on the outer layer; the magnetic induction coil is installed on the ring-shaped magnetic pole assembly, and the lead-out end of the magnetic induction coil is connected with a double electromagnetic generator, which adjusts and controls the input power of the magnetic induction coil through a power control unit; the cooling flow guide seat is of a ring structure, has a water inlet on the upper part and a cooling water channel inside; the ring-shaped magnetic pole assembly is made of high magnetic permeability soft magnetic material, located at the bottom of the magnetic pressure induction system, coaxial with the magnetic induction coil, and the inner diameter thereof matches the welding head; the ring-shaped magnetic pole assembly has a ring-shaped cooling water channel inside and a water outlet at the bottom, the cooling water channel is connected with the water channel of the cooling flow guide seat, and the water inlet and the water outlet are connected through a water cooler to form a closed-loop cooling system; the ring-shaped magnetic pole assembly is fixed with the cooling flow guide seat through a detachable structure;

[0010] The symmetric sliding type magnetic field generating system is composed of symmetric sliding rail devices on both sides and annular magnetic control symmetric generating devices; the annular magnetic control symmetric generating devices include coil mounting seats and are arranged on both sides of the additive manufacturing working surface, with the coil center axis parallel to the additive manufacturing direction; the coil mounting seat is made of non-magnetic material, and a Helmholtz coil is coaxially arranged in the coil mounting seat, and an insulating gap is formed between the inner wall of the coil mounting seat and the outer wall of the Helmholtz coil; the Helmholtz coil is made of hollow wire, and a spiral refrigeration loop for passing cooling medium is formed inside the Helmholtz coil; the Helmholtz coil has a spiral structure and is arranged in an axial direction, and the axial direction is arranged at a preset angle with the additive manufacturing direction; the spiral refrigeration loop is coaxially arranged with the Helmholtz coil and extends in the spiral direction.

[0011] Preferably, the magnetic induction lines of the magnetic pressure induction system are distributed along the vertical direction, the magnetic induction lines of the symmetric sliding type magnetic field generating system are distributed along the horizontal direction, and the two magnetic fields form an orthogonal magnetic field configuration in the molten pool area.

[0012] Preferably, the orthogonal magnetic field configuration adopts a regional control principle, and a controllable stable composite magnetic field distribution is formed in the molten pool area by adjusting the magnetic pole position and adjusting the excitation parameters; the spatial coupling position of the orthogonal magnetic field is controlled by a magnetic field distribution measurement system; the magnetic field distribution measurement system includes a magnetic field detection device, a position recording and control system; the magnetic field detection device is composed of a three-dimensional Hall sensor array and is installed on the sliding rail device and kept a certain safety distance from the annular magnetic control symmetric generating device; the position recording and control system is provided with a data acquisition unit and also contains a data processing module.

[0013] Preferably, the high-speed camera is fixed on the mounting seat of the welding head by bolt connection, adopts a folding support arm design, the support arms are connected to each other through hinge nodes, bolt fastening points are arranged at key connection positions and non-interference design is adopted; the controller is used for receiving information after the high-speed camera obtains image analysis and generating corresponding control instructions to control the output power and its ratio of the two electromagnetic emissions of the double electromagnetic generator.

[0014] Preferably, the workpiece to be additively manufactured is fixed on the bottom wing type bottom plate, the wing type bottom plate adopts a symmetric double-wing design, each side has an independent adjustment shield plate, each shield plate is provided with a fixed point at four corners, and the wing type bottom plate forms a semi-closed additive manufacturing working space.

[0015] A laser coaxial wire additive manufacturing method based on double magnetic field cooperation of the device, comprising the following steps:

[0016] S1, pretreatment and installation of workpiece: clean the surface of the workpiece to ensure that there is no contamination, fix the workpiece on the wing type bottom plate, adjust the position of the protection plate to form a semi-closed additive manufacturing space, install the welding wire into the wire feeding mechanism, check the operation state of the wire feeding system, and ensure that the welding wire conveying channel is unobstructed;

[0017] S2, spatial layout and parameter setting of magnetic field generating device: first install the Helmholtz coil, make its axis parallel to the additive manufacturing direction, and make the coil center coplanar with the optical axis of the laser welding head, set a reasonable coil spacing according to the coil radius to ensure that a uniform magnetic field is formed in the additive manufacturing area, then install the magnetic pressure sensing system above the welding head, adjust its position to make the generated magnetic field direction perpendicular to the surface of the workpiece;Install a magnetic shielding layer outside the magnetic field generating device, adjust the excitation parameters of the Helmholtz coil and the magnetic pressure sensing system according to the process requirements, form the required strength of the horizontal and vertical magnetic fields, and maintain the orthogonal relationship between the two magnetic fields;

[0018] S3, measurement and calibration of magnetic field spatial distribution: use the magnetic field detection device to scan the three-dimensional magnetic field distribution of the additive manufacturing area, collect and analyze the magnetic field intensity data through the position recording and control system, and accurately adjust the position and angle of the Helmholtz coil according to the measurement results, and install the spiral refrigeration loop at the same time;

[0019] S4, start and control of additive manufacturing process: start each system component in the predetermined order, including the wire feeding mechanism, the protective gas supply, the laser system and the position recording and control system;

[0020] S5, real-time monitoring and parameter optimization: real-time monitoring of the molten pool state by a high-speed camera, analysis of the collected image data by the controller to obtain molten pool shape feature information, based on the analysis results, the system dynamically adjusts the strength of the vertical and horizontal magnetic fields through the double electromagnetic generators, and uses a gradual adjustment method to ensure the stability of the additive manufacturing process, and accurately controls the droplet transfer and molten pool flow;

[0021] S6, additive manufacturing completion and post-processing: after the additive manufacturing is completed, each system is turned off in turn according to the established program, the workpiece is inspected for quality, and the process parameter data including magnetic field strength, laser power and wire feeding speed are recorded.

[0022] Therefore, the present application proposes a laser coaxial wire additive manufacturing device and method based on double magnetic field cooperation, which has the following advantages:

[0023] (1) The present application makes the wire feeding direction always coaxial with the laser beam, overcomes the problem of unstable droplet transport caused by the change of wire feeding angle in traditional lateral wire feeding, and improves the reliability of the welding process.

[0024] (2) The magnetic pressure induction system and the symmetric slip type magnetic field generating system constitute a double magnetic field auxiliary system cooperative system, by adjusting the reasonable double magnetic field ratio, not only increase the depth of the molten pool, solve the technical bottleneck that the traditional single magnetic field is difficult to realize deep melting welding. At the same time, a stronger electromagnetic stirring effect can be generated, promote the heat and mass transfer inside the molten pool, improve the uniformity and stability of the penetration, and the molten pool flow is more uniform.

[0025] The technical solutions of the present application will be further described in detail below by means of the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a laser coaxial wire additive manufacturing device based on double magnetic field cooperation of an embodiment of the present application;

[0027] Figure 2 is a magnetic pressure induction system structure schematic diagram of an embodiment of the present application;

[0028] Figure 3 is a ring-shaped magnetic control symmetric generating device structure schematic diagram of an embodiment of the present application;

[0029] Figure 4 is a schematic diagram of the current direction and size of the orthogonal magnetic field system.

[0030] REFERENCE NUMERALS

[0031] 1, guide rail system; 2, gear transmission mechanism; 3, workpiece; 4, wing type bottom plate; 5, welding wire; 6, welding head; 7, support mechanism; 8, magnetic pressure induction system; 9, magnetic induction coil; 10, cooling flow guide seat; 11, ring-shaped magnetic pole assembly; 12, water inlet; 13, slide rail device; 14, ring-shaped magnetic control symmetric generating device; 15, water outlet; 16, Helmholtz coil; 17, high-speed camera; 18, bolt; 19, support arm; 20, controller; 21, double electromagnetic generator; 22, spiral refrigeration loop; 23, magnetic field detection device; 24, position recording and control system; 25, protection plate; 26, wire feeding mechanism; 27, fixed point; 28, cooler; 29, mounting seat; 30, magnetic shielding layer; 31, wire feeding nozzle. DETAILED DESCRIPTION

[0032] In order to make the technical solutions, advantages and purposes of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely. The described embodiments are part of the embodiments of the present application, not all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application.

[0033] Unless otherwise defined, technical or scientific terms used in the present invention shall have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0034] like Figures 1-4 As shown, the present invention is a laser coaxial fuse additive manufacturing device based on dual magnetic field collaboration, which includes a motion system, a coaxial fuse additive manufacturing system, a dual magnetic field auxiliary system, a control and monitoring system, and a wire feeding mechanism is configured on the outside of the device; the motion system is composed of a guide rail system 1 and a bottom support structure; the coaxial fuse additive manufacturing system includes a support mechanism 7 for the welding head 6; the dual magnetic field auxiliary system is composed of a magnetic pressure induction system 8 and a symmetrical sliding magnetic field generating system; the control and monitoring system is composed of a high-speed camera 17 and a controller 20.

[0035] The guide rail system 1 comprises a horizontal X-rail and a perpendicular Y-rail, connected by a gear transmission mechanism 2 to form an XY platform structure that moves horizontally. The Z-rail enables vertical movement of the welding head 6, forming a three-dimensional motion control system. This system precisely controls the position of the welding head 6 in space, enabling precise positioning in forward, backward, left, right, and up and down directions, tailored to the needs of additive manufacturing.

[0036] The support mechanism 7 for the welding head 6 is a trapezoidal metal three-dimensional structure. It is connected to the gear transmission mechanism 2 of the guide rail system 1 via a mechanical connection component, forming a motion system that precisely adjusts the welding head's position in three dimensions. This system ensures that the welding head 6 can move stably along the guide rails along with the gear transmission mechanism 2. The movement of the gear transmission mechanism 2 ensures that the working position of the welding head 6 is precisely aligned with the surface of the workpiece 3, and cooperates with the guide rail system 1 to achieve precise three-dimensional positioning of the welding head 6.

[0037] The coaxial fuse welding head 6 is fastened to the inner side of the supporting mechanism 7 of the welding head. The welding head 6 is connected to an external laser generator. The laser emitter emits a high-power continuous wave laser beam into the welding head 6. A through coaxial shielding gas channel is provided inside the welding head 6. The coaxial shielding gas channel extends axially along the welding head 6 to transport the shielding gas downward to the working area.

[0038] An optical system is also provided in the welding head 6, which is used to convert the incident continuous wave laser beam into a Bessel beam with a ring-shaped intensity distribution. The optical system also includes a focusing mirror for focusing the Bessel beam on the surface of the workpiece 3, thereby realizing concentric and coaxial additive manufacturing of the welding wire 5 and the laser beam; a wire feeding channel is provided on the central axis of the welding head 6, and the wire feeding mechanism 26 vertically transports the welding wire 5 through the wire feeding channel. The conveying path of the welding wire 5 coincides with the central axis of the welding head 6, so that the welding wire can accurately pass through the central area of ​​the Bessel beam.

[0039] A wire feeder nozzle 31 is installed below the mounting seat of the welding head 6. The magnetic pressure induction system 8 is fixed to the outer wall of the upper part of the wire feeder nozzle 31 and is arranged around the welding head 6. The magnetic field action area intersects the axis of the welding head 6, so that the main magnetic induction intensity reaches the maximum value in the additive manufacturing molten pool area; the magnetic pressure induction system 8 is composed of a magnetic induction coil 9, a cooling flow guide seat 10, a ring-shaped magnetic pole assembly 11 and a magnetic shielding layer 30; the magnetic induction coil 9 is formed by winding an insulated copper wire with a rectangular cross section, and is arranged in a radial multi-layer concentric ring structure, coaxially arranged with the welding head 6, and each layer of coil is concentrically arranged and has the same number of turns. The magnetic shielding layer 30 is arranged on the outer layer, which is used to limit the magnetic field action range and reduce the interference to other parts of the system; the magnetic induction coil 9 is installed on the ring-shaped magnetic pole assembly 11, and the lead-out end of the magnetic induction coil 9 is connected with the double electromagnetic generator 21, and the input power of the magnetic induction coil 9 is adjusted and controlled by the power control unit.

[0040] The cooling flow guide seat 10 is in a ring-shaped structure, has a water inlet 12 at the upper part, and has a cooling water channel inside; the ring-shaped magnetic pole assembly 11 is made of high magnetic permeability soft magnetic material, is located at the bottom of the magnetic pressure induction system 8, is coaxial with the magnetic induction coil 9, and is used for guiding magnetic lines, and the inner diameter thereof is matched with the welding head 6; the ring-shaped magnetic pole assembly 11 has a ring-shaped cooling water channel inside, is provided with a water outlet 15 at the bottom, and the cooling water channel is connected with the water channel of the cooling flow guide seat 10, and the water inlet 12 and the water outlet 15 are connected through the water cooler 28 to form a closed-loop cooling system; the ring-shaped magnetic pole assembly 11 is fixed with the cooling flow guide seat 10 through a detachable structure.

[0041] The symmetrical sliding magnetic field generating system is composed of two symmetrical sliding rail devices 13 and a ring-shaped magnetic control symmetrical generating device 14; the sliding rail device 13 has a linear sliding function and can realize precise positioning and adjustment; the ring-shaped magnetic control symmetrical generating device 14 includes a coil mounting seat 29 and is arranged on both sides of the additive manufacturing working surface, and the coil center axis thereof is parallel to the additive manufacturing direction; the coil mounting seat 29 is made of non-magnetic material, and a Helmholtz coil 16 is coaxially arranged in the coil mounting seat 29; an insulating gap is formed between the inner wall of the coil mounting seat 29 and the outer wall of the Helmholtz coil 16; the Helmholtz coil 16 is made of hollow wire, and a spiral cooling loop 22 for passing cooling medium is formed inside the Helmholtz coil 16; the Helmholtz coil 16 is arranged in a spiral structure and is arranged in an axial direction, and the axial direction is arranged at a preset angle with the additive manufacturing direction; the spiral cooling loop 22 is coaxially arranged with the Helmholtz coil 16 and extends in the spiral direction.

[0042] The magnetic induction lines of the magnetic pressure induction system 8 mainly distribute in the vertical direction, and the magnetic induction lines of the symmetrical sliding magnetic field generating system mainly distribute in the horizontal direction, and the two magnetic fields form an orthogonal magnetic field configuration in the molten pool area.

[0043] The orthogonal magnetic field configuration design makes the magnetic field lines of the two magnetic field systems perpendicular to each other in geometric space, forming a relatively independent magnetic field action area. The orthogonal magnetic field configuration adopts a regional control principle, and a controllable and stable composite magnetic field distribution is formed in the molten pool area by adjusting the magnetic pole position and adjusting the excitation parameters.

[0044] The spatial coupling position of the orthogonal magnetic field is controlled by a magnetic field distribution measurement system, which includes a magnetic field detection device 23 and a position recording and control system 24.

[0045] The magnetic field detection device 23 is installed on the slide rail device 13 and maintains a certain safety distance from the annular magnetic control symmetrical generation device 14. The magnetic field detection device 23 is composed of a three-dimensional Hall sensor array and can simultaneously measure the magnetic field components in three directions at any point in space. The detection range covers the additive manufacturing molten pool area and the surrounding space.

[0046] The position recording and control system 24 is provided with a data acquisition unit for synchronously acquiring magnetic field intensity signals and position signals. The sampling frequency is adjustable. The system also has a data processing module that can calculate the magnetic field vector and the magnetic field orthogonality at different positions in real time. By measuring the magnetic field intensity at the preset spatial grid points, the magnetic field spatial distribution data is obtained. Using the magnetic field vector analysis method, the included angle distribution of the two magnetic field directions is calculated. Based on the magnetic field orthogonality evaluation index, the best magnetic field coupling position is determined, and the calibration results are converted into position parameters of the magnetic field generation device. Finally, the best position parameter information is transmitted to the motion system to ensure the accuracy of the magnetic field spatial coupling position.

[0047] The high-speed camera 17 is connected and fixed to the mounting seat of the welding head 6 by bolts 18. It is designed with a folding support arm 19. The support arms 19 are connected to each other through hinge nodes. Bolts are arranged at the key connection points to ensure stability. The design avoids interference with other parts of the welding head 6.

[0048] When the welding head 6 performs additive manufacturing along the preset trajectory, the high-speed camera 17 and the welding head 6 form a synchronous motion as a whole, and always maintain a certain relative positional relationship. By precisely adjusting the joint angles of the support arm 19, the shooting field of view of the high-speed camera 17 can be accurately aligned with the molten pool area, realizing real-time monitoring of the molten pool morphology, size and dynamic characteristics in the additive manufacturing process. The high-speed camera 17 analyzes the obtained images and transmits the information to the controller 20. The controller 20 generates corresponding control instructions to adjust the output power and its ratio of the two electromagnetic emissions in the double electromagnetic generator 21. The double magnetic field ratio and power information are transmitted to the double electromagnetic generator 21.

[0049] After receiving the instruction from the controller 20, the double electromagnetic generator 21 adjusts the electromagnetic field of the magnetic pressure induction system 8 and the symmetric slip magnetic field generation system respectively, independently adjusts the intensity of each electromagnetic field, realizes the proportional control of the electromagnetic field intensity, and dynamically changes the electromagnetic field ratio. The controller is used to receive the information analyzed by the high-speed camera after obtaining the image, and generate corresponding control instructions to adjust the output power and ratio of the two electromagnetic emissions in the double electromagnetic generator.

[0050] The workpiece 3 of additive manufacturing is fixed on the bottom wing type bottom plate 4, the wing type bottom plate 4 adopts a symmetric double wing design, each side has an independent adjustable protective plate 25, the double side protective plate 25 ensures the safety and process stability of the additive manufacturing process, and the four corners of each protective plate 25 are provided with a fixed point 27, so that the structure is more stable and reliable, and the wing type bottom plate 4 forms a semi-closed additive manufacturing working space.

[0051] A laser coaxial wire additive manufacturing method based on double magnetic field cooperation, comprising the following steps:

[0052] S1, pretreatment and installation of the workpiece 3: clean the workpiece surface to ensure that there is no contaminant, fix the workpiece 3 on the wing type bottom plate 4, adjust the position of the protective plate 25 to form a semi-closed additive manufacturing space, load the welding wire 5 into the wire feeding mechanism, check the operation state of the wire feeding system, and ensure that the welding wire conveying channel is unobstructed;

[0053] S2, spatial layout and parameter setting of the magnetic field generation device: first, install the Helmholtz coil 16, so that its axis is parallel to the additive manufacturing direction, and the center of the coil is coplanar with the optical axis of the laser welding head 6, set a reasonable coil spacing according to the coil radius to ensure that a uniform magnetic field is formed in the additive manufacturing area, then install the magnetic pressure induction system 8 above the welding head 6, and adjust the position to make the generated magnetic field direction perpendicular to the workpiece surface;

[0054] A magnetic shielding layer 30 is installed outside the magnetic field generation device for limiting the diffusion range of the magnetic field; the excitation parameters of the Helmholtz coil 16 and the magnetic pressure induction system 8 are adjusted according to the process requirements, the horizontal and vertical magnetic fields of the required strength are formed, and the orthogonal relationship between the two magnetic fields is maintained;

[0055] S3, measurement and calibration of the magnetic field space distribution: use the magnetic field detection device 23 to conduct a comprehensive three-dimensional magnetic field distribution scanning on the additive manufacturing area, collect and analyze the magnetic field intensity data through the position recording and control system 24, accurately adjust the position and angle of the Helmholtz coil 16 according to the measurement results, ensure that the horizontal magnetic field uniformity, the vertical magnetic field gradient distribution and the spatial orthogonality of the two magnetic fields meet the process requirements; at the same time, install the spiral refrigeration loop 22 to effectively control the temperature of the magnetic field generation device;

[0056] S4, additive manufacturing process start and control: start each system component in a predetermined order, including wire feeding mechanism 26, protective gas supply, laser system and position recording and control system 24, to ensure the continuity and stability of the additive manufacturing process;

[0057] S5, real-time monitoring and parameter optimization: the molten pool state is monitored in real time by high-speed camera 17, and controller 20 analyzes the collected image data to obtain molten pool shape feature information; based on the analysis result, the system dynamically adjusts the strength of the vertical and horizontal magnetic fields through double electromagnetic generator 21, and uses a gradual adjustment method to ensure the stability of the additive manufacturing process and accurately control the droplet transfer and molten pool flow;

[0058] S6, additive manufacturing completion and post-processing: after the additive manufacturing is completed, each system is closed in turn according to the established program, the workpiece 3 is quality inspected, and the process parameter data including magnetic field strength, laser power and wire feeding speed are recorded.

[0059] Therefore, the application provides a laser coaxial wire additive manufacturing device and method based on double magnetic field cooperation, so that the wire feeding direction always remains coaxial with the laser beam, overcoming the problem of unstable droplet transport caused by changes in the wire feeding angle in traditional lateral wire feeding, and improving the reliability of the welding process. The magnetic pressure induction system and the symmetric sliding magnetic field generation system in the application constitute a double magnetic field auxiliary system that cooperates with each other, and by adjusting the reasonable double magnetic field ratio, not only the molten pool depth is increased, but also the technical bottleneck of the traditional single magnetic field that is difficult to achieve deep penetration welding is solved. At the same time, it can produce stronger electromagnetic stirring effect, promote the heat and mass transfer inside the molten pool, improve the uniformity and stability of the penetration, and the molten pool flow is more uniform.

[0060] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the application and not to limit it, although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that: it can still modify or equivalently replace the technical solutions of the application, and these modifications or equivalent replacements also cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the application.

Claims

1. A laser coaxial fuse additive manufacturing device based on dual magnetic field collaboration, characterized in that: The device includes a motion system, a coaxial fused wire additive manufacturing system, a dual magnetic field auxiliary system, and a control and monitoring system. A wire feeding mechanism is configured on the outside of the device. The motion system consists of a guide rail system and a bottom support structure. The coaxial fused wire additive manufacturing system includes a welding head and a welding head support mechanism. The dual magnetic field auxiliary system consists of a magnetic pressure induction system and a symmetrical sliding magnetic field generation system. The control and monitoring system consists of a high-speed camera and a controller. The welding head is fastened to the inner side of the welding head support mechanism, and a wire feeding nozzle is installed below the welding head mounting seat. The magnetic pressure induction system is arranged around the welding head and fixed on the upper outer wall of the wire feed nozzle, and the magnetic field action area intersects with the axis of the welding head; the magnetic pressure induction system is composed of a magnetic induction coil, a cooling guide seat, an annular magnetic pole assembly and a magnetic shielding layer; the magnetic induction coil is formed by winding an insulated coated copper wire with a rectangular cross section, and adopts a radial multi-layer concentric annular structure, which is coaxially arranged with the welding head, and each layer of coils is concentrically arranged and has the same number of turns, and a magnetic shielding layer is arranged on the outer layer; the magnetic induction coil is installed on the annular magnetic pole assembly, and the lead-out end of the magnetic induction coil is connected to the dual electromagnetic generator. The dual electromagnetic generator adjusts and controls the input power of the magnetic induction coil through a power control unit; the cooling guide seat is an annular structure with a water inlet on the top and a cooling water channel inside; the annular magnetic pole assembly is made of a high-permeability soft magnetic material, located at the bottom of the magnetic pressure induction system, coaxial with the magnetic induction coil, and its inner diameter matches the welding head; the annular magnetic pole assembly has an annular cooling water channel inside and a water outlet at the bottom. The cooling water channel is connected to the water channel of the cooling guide seat, and the water inlet and outlet are connected through a water cooler to form a closed-loop cooling system; the annular magnetic pole assembly is fixed to the cooling guide seat by a detachable structure; The symmetrical sliding magnetic field generating system is composed of a bilaterally symmetrical slide rail device and an annular magnetic control symmetrical generating device; the annular magnetic control symmetrical generating device includes a coil mounting seat, which is arranged on both sides of the additive manufacturing work surface, and the central axis of the coil is parallel to the additive manufacturing direction; the coil mounting seat is made of non-magnetic material, and a Helmholtz coil is coaxially arranged in the coil mounting seat, and an insulating gap is formed between the inner wall of the coil mounting seat and the outer wall of the Helmholtz coil; the Helmholtz coil is made of a hollow wire, and a spiral refrigeration loop is formed inside it for passing a cooling medium. The Helmholtz coil has a spiral structure and is wound along its axial direction, and the axial direction is set at a preset angle to the additive manufacturing direction; the spiral refrigeration loop is coaxially arranged with the Helmholtz coil and extends in the spiral direction; The magnetic flux lines of the magnetic pressure induction system are distributed in the vertical direction, and the magnetic flux lines of the symmetrical sliding magnetic field generating system are distributed in the horizontal direction. The two magnetic fields form an orthogonal magnetic field configuration in the molten pool area.

2. The laser coaxial fuse additive manufacturing device based on dual magnetic field collaboration according to claim 1 is characterized in that: The guide rail system includes a horizontal X-guide rail and a Y-guide rail perpendicular to the horizontal X-guide rail, and is connected to a gear transmission mechanism to form an XY platform structure that moves in a horizontal plane; the guide rail system controls the vertical movement of the welding head through the Z-guide rail; the guide rail system as a whole is a three-dimensional motion control system.

3. The laser coaxial fuse additive manufacturing device based on dual magnetic field collaboration according to claim 2 is characterized in that: The support mechanism of the welding head is a trapezoidal metal three-dimensional structure; the support mechanism of the welding head is connected to the gear transmission mechanism of the guide rail system through a mechanical connection component to form a motion system that accurately adjusts the position of the welding head in three-dimensional space.

4. The laser coaxial fuse additive manufacturing device based on dual magnetic field collaboration according to claim 1 is characterized in that: The welding head is connected to an external laser generator, and the laser generator emits a high-power continuous wave laser beam into the welding head; a through coaxial shielding gas channel is provided inside the welding head, and the coaxial shielding gas channel extends axially along the welding head, and transports the shielding gas downward to the working area; an optical system is also provided in the welding head, and the optical system is used to convert the incident continuous wave laser beam into a Bessel beam with a ring-shaped intensity distribution, and the optical system also includes a focusing mirror for focusing the Bessel beam on the workpiece surface; a wire feeding channel is provided on the central axis of the welding head, and the wire feeding mechanism vertically transports the welding wire through the wire feeding channel; the conveying path of the welding wire coincides with the central axis of the welding head, so that the welding wire accurately passes through the central area of ​​the Bessel beam.

5. The laser coaxial fuse additive manufacturing device based on dual magnetic field collaboration according to claim 1 is characterized in that: The orthogonal magnetic field configuration adopts the principle of regional control, and by adjusting the magnetic pole position and adjusting the excitation parameters, a controllable and stable composite magnetic field distribution is formed in the molten pool area; the spatial coupling position of the orthogonal magnetic field is controlled by a magnetic field distribution measurement system; the magnetic field distribution measurement system includes a magnetic field detection device and a position recording and control system; the magnetic field detection device is composed of a three-dimensional Hall sensor array, and is installed on the slide rail device, and maintains a certain safety distance from the annular magnetic control symmetry generating device; the position recording and control system is provided with a data acquisition unit and also includes a data processing module.

6. The laser coaxial fuse additive manufacturing device based on dual magnetic field collaboration according to claim 1, characterized in that: The high-speed camera is fixed to the mounting base of the welding head by bolt connection, adopts a folding support arm design, and the support arms are connected to each other by hinge nodes. Bolt fastening points are set at key connections and a non-interference design is adopted; the controller is used to receive information after the high-speed camera analyzes the image obtained, and generate corresponding control instructions to control the output power and ratio of the two electromagnetic emissions in the dual electromagnetic generator.

7. The laser coaxial fuse additive manufacturing device based on dual magnetic field collaboration according to claim 1 is characterized in that: The workpiece to be additively manufactured is fixed on the platform-wing base plate at the bottom. The platform-wing base plate adopts a symmetrical double-wing design, with an independently adjustable protective plate on each side. Each protective plate has a fixed point at the four corners. The platform-wing base plate forms a semi-enclosed additive manufacturing workspace.

8. A laser coaxial fuse additive manufacturing method based on dual magnetic field collaboration using the device according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Pre-treat and install the workpiece: Clean the workpiece surface to ensure it is free of contaminants, fix the workpiece on the platform-wing bottom plate, adjust the position of the protective plate to form a semi-enclosed additive manufacturing space, load the welding wire into the wire feeding mechanism, check the operation status of the wire feeding mechanism, and ensure that the welding wire feeding channel is unobstructed; S2. Spatial layout and parameter setting of the magnetic field generating device: First, install the Helmholtz coil so that its axis is parallel to the additive manufacturing direction and the center of the coil is coplanar with the optical axis of the laser welding head. Set a reasonable coil spacing based on the coil radius to ensure a uniform magnetic field in the additive manufacturing area. Then, install the magnetic pressure induction system around the welding head and adjust its position so that the direction of the generated magnetic field is perpendicular to the workpiece surface. Install a magnetic shielding layer outside the magnetic pressure induction system. Adjust the excitation parameters of the Helmholtz coil and the magnetic pressure induction system according to the process requirements to form the horizontal and vertical magnetic fields of the required strength and maintain the orthogonal relationship between the two magnetic fields. S3. Measurement and calibration of the spatial magnetic field distribution: A magnetic field detection device is used to conduct a comprehensive three-dimensional magnetic field distribution scan of the additive manufacturing area. The position recording and control system collects and analyzes the magnetic field strength data. Based on the measurement results, the position and angle of the Helmholtz coil are precisely adjusted. A spiral refrigeration loop is also installed. S4. Additive manufacturing process start-up and control: Start each system component in a predetermined order, including the wire feed mechanism, shielding gas supply, laser system, and position recording and control system; S5. Real-time monitoring and parameter optimization: The molten pool status is monitored in real time by a high-speed camera. The controller analyzes the collected image data to obtain information on the molten pool morphology. Based on the analysis results, the system dynamically adjusts the vertical and horizontal magnetic field strengths through dual electromagnetic generators. A progressive adjustment method is used to ensure the stability of the additive manufacturing process and accurately control the droplet transfer and molten pool flow. S6. Additive manufacturing completion and post-processing: After additive manufacturing is completed, each system is shut down in sequence according to the established procedures, the workpiece is quality checked, and the process parameter data including magnetic field strength, laser power, and wire feed speed are fully recorded.

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