Device and method for realizing directional energy deposition of complex-structure multidirectional laser fuse wire through magnetic field regulation and control

Abstract

The invention discloses a device and method for achieving complex structure multi-direction laser fuse directional energy deposition through magnetic field regulation and control, and belongs to the field of wire electric arc additive manufacturing. The method is realized through pretreatment and model construction, system initialization and calibration, collaborative deposition manufacturing and a magnetic confinement principle, dynamic switching and integral forming, and the powerful capability of the method in the aspect of realizing multidirectional free forming of the complex structure is shown. The dynamic magnetic field provides constraint, an auxiliary steady flow mode of the dynamic magnetic field also has an active metallurgical function, the structure can be refined, composition segregation can be reduced, residual stress can be reduced, and therefore the strength, toughness and fatigue performance of a deposition component can be synchronously improved. A positioner and a supporting structure are completely abandoned, equipment configuration is simplified, consumption of expensive metal welding wires is reduced, secondary machining cost and potential damage risks caused by removal of supports are eliminated, and the cost of the whole life cycle is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of arc additive manufacturing of wire materials, specifically to an apparatus and method for achieving multi-directional laser filament directional energy deposition of complex structures through magnetic field control. Background Technology

[0002] Additive manufacturing technology, particularly directional energy deposition (OED), shows great potential in manufacturing large, complex metal components. This technology uses a high-energy beam (such as a laser) as a heat source to melt synchronously transported metal powder or filaments within a deposition region, stacking them layer by layer to form a three-dimensional solid.

[0003] Currently, mainstream laser filament directed energy deposition (FED) technology typically employs a printhead fixed to the Z-axis to deposit material on a substrate. This "bottom-up" deposition method has fundamental limitations for components with significant deflection, concavity, or lateral features. To fabricate such structures, existing technologies mainly rely on the following approaches:

[0004] Multi-axis CNC machine tools and positioners work in tandem: a five-axis machine tool or robot drives the printhead to move at multiple angles, while the positioner rotates and tilts the workpiece, keeping the deposition surface in a nearly horizontal position. However, this method has significant drawbacks: first, for ultra-large structural parts, the load capacity and size of the positioner become bottlenecks, resulting in high equipment costs; second, when manufacturing certain closed or semi-closed internal cavity structures, interference can occur between the movement space of the positioner and the printhead, making molding impossible.

[0005] Pre-design and print support structures: Simultaneously print additional support material below the overhanging area, such as... Figure 3 As shown. While this method is feasible, it leads to material waste and increases the complexity of subsequent support removal processes, resulting in inefficiency and potential damage to the component itself.

[0006] Limited printhead deflection angle: Some advanced devices allow the printhead to deflect within a certain angle range (e.g., ±30° relative to the Z-axis). However, this method is still ineffective for extreme cases requiring perfectly horizontal (90°) or large-angle tilted deposition. The fundamental reason is that when the deposition angle is too large, the molten pool will flow, collapse, or even separate from the substrate under gravity, making it impossible to form a stable and well-formed deposition layer.

[0007] In summary, existing laser filament directional energy deposition (ELED) technology is constrained by the influence of gravity on the molten pool, making it difficult to achieve truly multi-directional and multi-angle free forming without relying on large positioners and supporting structures. This severely limits the application of this technology in the manufacturing of complex integrated components in aerospace, energy equipment, and other fields. Therefore, there is an urgent need for a new method that can actively control the molten pool morphology, counteract or weaken the adverse effects of gravity, and thus achieve stable multi-directional deposition.

[0008] This invention aims to overcome the core physical limitations and engineering bottlenecks faced by existing laser filament directional energy deposition technology in achieving free-form shapes in multiple directions and angles. Specifically, the following problems urgently need to be solved:

[0009] Intrinsic stability issues of the molten pool: In non-horizontal deposition conditions, the component of gravity can cause the molten metal in the pool to flow, accumulate, or even drip. This geometric instability not only damages the dimensional accuracy and surface morphology of the deposited layer, but also leads to internal defects such as pores and lack of fusion, severely degrading the mechanical properties of the component.

[0010] Limited geometric freedom in forming: Existing technologies heavily rely on the "position deposition" strategy, which involves adjusting the deposition surface to a near-horizontal orientation using a positioner. This method cannot achieve true "directional deposition," severely limiting the ability to manufacture lightweight, functionally integrated structures with complex topologies, internal flow channels, and enclosed cavities.

[0011] High auxiliary process costs: Whether using large multi-axis positioners or printing sacrificial support structures, both significantly increase equipment investment, material consumption, and post-processing time, resulting in low efficiency and poor economy of the entire manufacturing process, which hinders the large-scale application of this technology in large critical load-bearing components. Summary of the Invention

[0012] To address the aforementioned systemic challenges, this invention innovatively proposes the overall concept of "dynamic magnetic field active constraint and printhead attitude adaptive collaborative control," providing a device and method for achieving multi-directional laser filament directional energy deposition in complex structures through magnetic field modulation.

[0013] A method for achieving multi-directional laser filament directional energy deposition of complex structures through magnetic field control includes the following steps:

[0014] Step 1: Import the 3D model of the target component into the central control unit, perform adaptive slicing processing, and generate a composite printing path file based on the digital twin model;

[0015] Step 2: Start the device, initialize each subsystem, and perform position calibration and magnetic field spatial calibration of the substrate through the vision system and Hall sensor array;

[0016] Step 3: Establish a preset main constraint magnetic field and auxiliary steady current magnetic field through a magnetic field generator to form a composite magnetic field system;

[0017] Step 4: The central control unit instructs the actuator to move to the path point and controls the integrated deposition printhead to deflect to the target direction to begin the deposition operation;

[0018] Step 5: During the deposition process, the status of the molten pool and the magnetic field distribution signal are detected in real time and fed back to the central control unit. The central control unit compares the feedback signal with the digital twin model and adaptively fine-tunes the magnetic field parameters and laser power.

[0019] Step 6: Repeat steps 3 to 5 to deposit layers one by one, and finally obtain the desired multi-directional additive manufacturing target component on the substrate.

[0020] Furthermore, the digital twin model in step 1 includes the three-dimensional CAD geometric information of the target component, the pre-planned layered slicing and multi-directional printing path, the thermophysical and electromagnetic property database of the material, and the physical model of the molten pool-magnetic field coupling effect.

[0021] Furthermore, the generated composite printing path file includes the actuator spatial coordinates, integrated deposition printhead orientation, laser power, filament feed speed, and preset magnetic field parameters.

[0022] Furthermore, in step 2, the Hall sensor array is arranged near the deposition point to measure the actual magnetic field distribution generated by the magnetic field generator and feed the data back to the central control unit for comparison and compensation with the model prediction value to ensure the accuracy of magnetic field control.

[0023] Furthermore, the main constraint magnetic field strength (B_main) ranges from 0.3T to 3.0T, the main constraint magnetic field gradient (∇B) ranges from 10T / m to 80T / m, and the auxiliary steady current magnetic field frequency (f) ranges from 5Hz to 150Hz.

[0024] Furthermore, the adaptive fine-tuning in step 5 specifically includes the following steps:

[0025] Step 5.1: Based on the spatial position and orientation vector of the current integrated deposition printhead, calculate the magnitude and direction of the component of gravity in the local coordinate system of the molten pool;

[0026] Step 5.2: Call the molten pool-magnetic field coupling model to calculate the strength B and gradient ∇B of the main constraint magnetic field required to counteract the gravitational component and achieve the ideal molten pool shape;

[0027] Step 5.3: Determine the frequency and waveform parameters of the auxiliary steady-state magnetic field based on the metallurgical properties and thermal state of the material;

[0028] Step 5.4: The calculated parameter set is synchronously sent to the magnetic field control power cabinet and the integrated deposition printhead deflection controller via a high-speed bus to achieve real-time, dynamic, and adaptive matching of the magnetic field constraint force and the deposition direction.

[0029] Furthermore, the beam axis and wire flow axis of the integrated deposition printhead can be independently deflected by more than ±90° relative to the end flange of the actuator.

[0030] Furthermore, both the substrate and the metal material used are high-strength steel with ferromagnetic properties.

[0031] A device for achieving multi-directional laser filament directional energy deposition of complex structures through magnetic field control, used to implement the method described in any one of claims 1-8, comprising an actuator, an integrated deposition printhead, a magnetic field generator, a magnetic field control power supply cabinet, a central control unit, and a Hall sensor array.

[0032] Actuator: The core motion carrier is an industrial robot or a five-axis CNC machine tool with at least five-axis linkage, and its end flange provides great motion flexibility and workspace;

[0033] The integrated deposition printhead includes an infrared thermometer and a high-speed CCD camera; the infrared thermometer is used to monitor the molten pool temperature in real time; the high-speed CCD camera is used to monitor the morphology and size of the molten pool.

[0034] The magnetic field generating device includes a main constraint magnetic field generator and an auxiliary steady current magnetic field generator;

[0035] The main confinement magnetic field generator includes one or more pairs of high-performance water-cooled electromagnetic coils, symmetrically arranged on both sides of the deposition area. Helmholtz coils are used to generate a highly uniform strong magnetic field or Maxwell coils are used to generate a high-intensity gradient magnetic field, which is used to generate a high-intensity, high-gradient main confinement magnetic field in the molten pool area to provide the main directional confinement force for the molten pool.

[0036] The auxiliary current-stabilizing magnetic field generator includes multiple small high-frequency electromagnet arrays surrounding the print head or deposition point. The array can generate an alternating magnetic field or pulsed magnetic field with adjustable frequency and direction to form an auxiliary current-stabilizing magnetic field, which is used to suppress convection inside the molten pool, break dendrites, and refine grains. At the same time, it further stabilizes the molten pool profile and improves the deposition quality through electromagnetic stirring.

[0037] The magnetic field control power cabinet is used to provide accurate, stable, and fast-response current output to all magnetic field generators, ensuring precise control of magnetic field parameters.

[0038] The central control unit uses a high-performance industrial computer or PLC, and has a digital twin model built inside it.

[0039] The Hall sensor array is positioned near the deposition point to measure the actual magnetic field distribution generated by the magnetic field generator and feed the data back to the central control unit.

[0040] The beneficial effects of this invention are as follows:

[0041] (1) Revolutionary process capability: For the first time, the problem of runaway melt pool in multi-directional forming of DED technology has been completely solved in principle, turning "directional deposition" from a concept into reality, providing almost infinite geometric freedom for the design end, and enabling the direct manufacture of extremely complex structures that traditional methods must process separately and then reassemble.

[0042] (2) Significant performance improvement: The dynamic magnetic field not only provides constraint, but its auxiliary flow stabilization mode also has active metallurgical function, which can refine the structure, reduce component segregation and reduce residual stress, thereby simultaneously improving the strength, toughness and fatigue performance of the deposited components.

[0043] (3) Economic optimization of the whole process: The positioner and support structure are completely eliminated, the equipment configuration is simplified, the consumption of expensive metal welding wire is saved, and the secondary processing cost and potential damage risk caused by support removal are eliminated, resulting in a significant reduction in the total life cycle cost. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the structure and regional planning required for multi-directional additive manufacturing in this invention;

[0045] Figure 2 This is a schematic diagram illustrating the lateral material-free deposition achieved by magnetic field control according to the present invention.

[0046] Figure 3 (a) Components and their common construction directions B; (b) Supports required for the components (orange parts); (c) Multi-directional additive manufacturing and various construction directions of the components. Schematic diagram.

[0047] Figure descriptions: 1 - Overall structure requiring multi-directional additive manufacturing; 2 - Substrate; 3 - Longitudinal deposition region 1; 4 - Longitudinal deposition region 2; 5 - Lateral deposition region 1; 6 - Lateral deposition region 2; 7 - Lateral deposition region 3; 8 - Lateral deposition region 4; 9 - Layered slicing deposition path of region 8; 10 - Welding robot; 11 - Laser welding head; 12 - Laser; 13 - Molten pool; 14 - Lateral deposition layer; 15 - Magnetic field; 16 - Magnetic field control power supply; 17 - Central control unit; 18 - Magnetic field generator; 19 - Magnetic field parameter control device; 20 - Wire feeder; 21 - Welding wire. Detailed Implementation

[0048] The following is combined Figure 1 , Figure 2 The present invention will be further described below.

[0049] The technical solution of the present invention is described in detail below:

[0050] Part One: The Apparatus

[0051] A device for achieving multi-directional laser filament directional energy deposition of complex structures through dynamic magnetic field control is a highly integrated electromechanical-optical-magnetic system, the core components of which include:

[0052] High-degree-of-freedom motion and sedimentation units:

[0053] Actuator: The core motion carrier is an industrial robot or a five-axis CNC machine tool with at least five-axis linkage, and its end flange provides great motion flexibility and workspace.

[0054] Integrated Deposition Printhead: This printhead, fixed to the end of the actuator, is a multi-functional integrated module. Internally, it integrates the optical path system of a high-power laser output, coaxial or off-axis powder delivery nozzles, wire gathering and protective gas path, and a real-time monitoring module. Crucially, the printhead's beam axis and wire flow axis can independently deflect at ±90° or more relative to the actuator's end flange. This means the printhead itself has the ability to "raise" and "lower" its orientation, which, combined with the robot's wide range of movements, enables near-zero blind-angle deposition.

[0055] Multi-mode dynamic magnetic field generation unit:

[0056] This unit is the core innovation of this invention. Its design goes beyond a simple single field source, forming a composite magnetic field system:

[0057] The main confinement magnetic field generator consists of one or more pairs of high-performance water-cooled electromagnetic coils, using a Helmholtz coil (for generating a highly uniform strong magnetic field) or Maxwell coil (for generating a high-intensity gradient magnetic field) configuration, symmetrically arranged on both sides of the deposition area. Its main function is to generate a high-intensity, high-gradient steady-state magnetic field in the molten pool region, providing the main directional confinement force (magnetic volume force) for the molten pool.

[0058] Auxiliary current-stabilizing magnetic field generator: This consists of multiple small high-frequency electromagnet arrays arranged around the printhead or deposition point. This array can generate alternating magnetic fields or pulsed magnetic fields with adjustable frequency and direction. Its function is to suppress convection within the molten pool, break dendrites, refine grains, and further stabilize the molten pool profile through electromagnetic stirring, thereby improving deposition quality.

[0059] Magnetic field control power supply cabinet: provides precise, stable and fast-responding current output for all magnetic field generators, with current stability better than 0.1% and response time less than 1 millisecond, ensuring accurate control of magnetic field parameters.

[0060] Multi-information-flow fusion sensing and central control unit:

[0061] This unit is the brain of the system, responsible for coordinating and optimizing the entire process.

[0062] Central controller: Employs a high-performance industrial computer or PLC, which internally houses a digital twin model. This model integrates: the part's 3D CAD geometric information, pre-planned layered slicing and multi-directional printing paths, a database of the material's thermophysical and electromagnetic properties, and a physical model of the molten pool-magnetic field coupling.

[0063] The sensor subsystem includes an infrared thermometer integrated inside the printhead for real-time monitoring of the molten pool temperature; a high-speed CCD camera for monitoring the morphology and size of the molten pool; and a Hall effect sensor array positioned near the deposition area for real-time feedback of the spatial distribution of the actual magnetic field strength.

[0064] Synchronous control logic: The central controller receives multiple feedback signals from the robot controller (providing real-time feedback of the printhead's spatial pose [X, Y, Z, A, B, C]) and the sensor subsystem. Based on the digital twin model, the controller performs real-time calculations:

[0065] a. Based on the current spatial position and direction vector of the printhead, calculate the magnitude and direction of the component of gravity in the local coordinate system of the molten pool.

[0066] b. Call the molten pool-magnetic field coupling model to calculate the strength B and gradient ∇B of the main constraint magnetic field required to counteract the gravitational component and achieve the ideal molten pool shape.

[0067] c. Determine the frequency and waveform parameters of the auxiliary steady-state magnetic field based on the metallurgical properties of the material (such as fluidity and surface tension) and thermal state.

[0068] d. Subsequently, the controller synchronously sends the calculated parameter set to the magnetic field control power cabinet and the printhead deflection controller via a high-speed bus, realizing real-time, dynamic, and adaptive matching of the magnetic field constraint force and the deposition direction.

[0069] Part Two: Methods

[0070] Based on the above-described apparatus, a method for achieving multi-directional laser filament directional energy deposition includes the following steps:

[0071] Preprocessing and path planning: Adaptively slice the target 3D model and generate a composite printing path file containing spatial coordinates P(x,y,z), print head posture O(i,j,k), laser power L, filament feed speed F, and preset magnetic field parameters M(B, ∇B, f).

[0072] System initialization and calibration: The device is started to initialize each subsystem and the working point of the printhead and the spatial distribution of the magnetic field are precisely calibrated through the vision system and Hall sensor array.

[0073] Synergistic deposition process:

[0074] a. The central controller instructs the robot to move to the path point and controls the print head to deflect in the target direction.

[0075] b. A moment before the laser is turned on and the wire feeding is started, a preset main constraint magnetic field and auxiliary stabilizing magnetic field are established in advance to form an "invisible mold".

[0076] c. During the deposition process, infrared thermography, high-speed vision, and magnetic field sensors collect process signals in real time and feed them back to the central controller.

[0077] d. Based on the feedback signal, the controller compares with the digital twin model and adaptively fine-tunes the magnetic field parameters and laser power (closed-loop control) to cope with fluctuations in actual working conditions and ensure forming stability.

[0078] Dynamic switching and continuous manufacturing: When the deposition direction needs to be changed, the system smoothly transitions the magnetic field parameters, so that it can be seamlessly connected with the mechanical environment of the new direction, thereby realizing continuous and stable deposition in any direction, from vertical upward to horizontal lateral, or even upward tilt, until the entire component is processed.

[0079] To enable those skilled in the art to better understand and implement the present invention, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings, taking the manufacture of a complex high-strength steel structural component as an example. In this embodiment, the substrate (2) and the metal material used are both high-strength steel with ferromagnetism (such as HLSA-100 grade or similar grade).

[0080] Step 1: Preprocessing and Model Building

[0081] First, the 3D CAD model of the target component—the overall structure (1) requiring multi-directional additive manufacturing—is imported into the central control unit (17). The system performs adaptive slicing, with the layer thickness set between 0.8 mm and 3.0 mm (the layer thickness in wire feeding processes is usually greater than that in powder feeding processes), which can be adjusted according to structural characteristics. Thinner layer thicknesses are used for large tilt angles or overhanging areas (such as the transverse deposition area 8). Subsequently, multi-directional printing path planning is performed. The digital twin model built within the central control unit (17) integrates the material data of the high-strength steel, including its melting point between 1400°C and 1500°C, its relative permeability in the solid state between 50 and 500, and its Curie temperature of approximately 700°C to 800°C. Based on these data, the model pre-calculates the range of magnetic field (15) parameters required to stabilize the molten pool. Finally, a composite printing path file is generated, which not only contains the spatial coordinates P(x,y,z) and posture O(i,j,k) of the welding robot (10) and the laser welding head (11), but also synchronously associates the following process parameter ranges:

[0082] Laser power (L): 3000W to 4000W.

[0083] Wire feed speed (V_wire): 2m / min to 10m / min (controlled by wire feeder (20)).

[0084] Scanning speed: 5 mm / s to 10 mm / s.

[0085] Main confinement magnetic field strength (B_main): 0.3T to 3.0T.

[0086] Principal constraint magnetic field gradient (∇B): 10 T / m to 80 T / m.

[0087] Auxiliary steady current magnetic field frequency (f): 5Hz to 150Hz.

[0088] Step 2: System Initialization and Calibration

[0089] The entire system is started, including the welding robot (10), laser, wire feeder (20), magnetic field generator (18), and magnetic field parameter control device (19). The position of the substrate (2) is calibrated by the vision system integrated in the laser welding head (11). The wire feeder (20) feeds the welding wire (21) to the exit end of the laser welding head (11) through a special conduit and adjusts the angle and position of the wire feed nozzle to ensure that the welding wire (21) can be accurately fed into the molten pool. Since the substrate (2) itself is a magnetic body, it will interfere with the preset magnetic field. Therefore, magnetic field spatial calibration is required: the distribution of the actual magnetic field (15) generated by the magnetic field generator (18) (Maxwell coil) is measured by a Hall sensor array arranged near the deposition point, and the data is fed back to the central control unit (17) for comparison and compensation with the model prediction value to ensure the accuracy of magnetic field control. The magnetic field control power supply (16) provides a drive current with a stability of better than 0.1% to 0.5% during this process.

[0090] Step 3: Collaborative deposition fabrication and realization of magnetic confinement principles

[0091] The manufacturing process is fully automated and coordinated by the central control unit (17). The core is to use the magnetic volume force generated by the magnetic field to overcome gravity.

[0092] Principle of magnetic force generation: For ferromagnetic or paramagnetic molten metal (molten pool 13) in a strong gradient magnetic field (15), the magnetic volume force F_mag it experiences can be expressed as F_mag ∝ (B · ∇B) / μ0. By controlling the magnetic field generating device (18), we can precisely control the magnitude and direction of B (magnetic field strength) and ∇B (magnetic field gradient).

[0093] Overcoming gravity: Gravity F_grav = ρgV. By designing and controlling the magnetic field, the direction of the magnetic volume force F_mag is made opposite to the direction of gravity or its component. When F_mag and F_grav are in numerical equilibrium or slightly larger, the flow and collapse of the molten pool can be effectively suppressed.

[0094] The specific deposition process is as follows:

[0095] After the conventional longitudinal deposition zone 3 is completed, the process transitions to the transverse deposition zone 8. The welding robot (10) moves its position, while the laser welding head (11) actively deflects to the horizontal direction. During this process, the central control unit (17) calculates in real time and instructs the magnetic field generator (18) to dynamically increase the intensity of the main constraint magnetic field (15) from 0.5s to 2s to 1.5T to 2T, with the gradient increasing to 40T / m to 80T / m. This strong magnetic field generates a powerful, upward-pointing magnetic volume force in the area below the horizontally deposited molten pool (13), acting like an "invisible lifting platform" that successfully counteracts all gravity and prevents the collapse of the transverse deposition layer (14). The wire feeder (20) synchronously adjusts the wire feeding speed to 3 m / min to 5 m / min to adapt to different deposition postures.

[0096] Auxiliary metallurgical control: Throughout the process, the auxiliary steady current magnetic field generator (integrated in the magnetic field generating device 18) works simultaneously to generate an alternating magnetic field (15) with a frequency in the range of 500 Hz to 1000 Hz, which electromagnetically stirs the molten pool (13) to refine the grains and reduce porosity.

[0097] Closed-loop control: An infrared thermometer and a high-speed camera integrated on the laser welding head (11) monitor the state of the molten pool (13) in real time (temperature between 1500°C and 1750°C, morphological size fluctuation within ±1.0mm), and feed the data back to the central control unit (17). The controller then fine-tunes the laser power, wire feed speed, and magnetic field parameters accordingly to achieve adaptive closed-loop control.

[0098] Step 4: Dynamic Switching and Overall Formation

[0099] The system continuously and dynamically adjusts the parameters of the magnetic field (15) as it changes the deposition direction (e.g., switching between lateral deposition regions 5, 6, and 7) according to a preset path, so that the magnetic confinement force matches the gravitational challenge under the current deposition direction in real time. The magnetic field parameter control device (19) and the magnetic field control power supply (16) ensure the speed and stability of the magnetic field changes. Finally, the entire structure (1) is manufactured in one piece without the need for a positioner and a physical support structure, by continuously feeding welding wire (21) through a wire feeder (20), demonstrating the powerful ability of this invention to achieve multi-directional free forming of complex structures.

[0100] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for multi-directional laser wire directed energy deposition with complex structures by magnetic field manipulation, characterized in that: The method comprises the following steps: Step 1: importing the three-dimensional model of the target component into the central control unit, performing adaptive slicing processing, and generating a composite printing path file according to the digital twin model; Step 2: starting the device, initializing each subsystem, and calibrating the position of the substrate and the magnetic field space through the visual system and the Hall sensor array; Step 3: establishing a preset main constraint magnetic field and an auxiliary steady flow magnetic field through the magnetic field generating device to form a composite magnetic field system; Step 4: the central control unit instructs the execution mechanism to move to the path point and controls the integrated deposition printing head to deflect to the target direction, and starts the deposition operation; Step 5: during the deposition process, the molten pool state and the magnetic field distribution signal are detected in real time and fed back to the central control unit, and the central control unit compares the feedback signal with the digital twin model and performs adaptive fine tuning on the magnetic field parameters and the laser power; Step 6: repeating steps 3 to 5 to perform layer-by-layer accumulation, and finally obtaining the target component of multi-directional additive manufacturing on the substrate.

2. The method of claim 1, wherein the method is characterized by: The digital twin model in step 1 includes three-dimensional CAD geometric information of the target component, pre-planned layered slicing and multi-directional printing path, material thermal physical and electromagnetic property database, and physical model of molten pool-magnetic field coupling.

3. The method of claim 2, wherein the method is characterized by: The generated composite printing path file includes execution mechanism spatial coordinates, integrated deposition printing head attitude, laser power, wire feeding speed, and preset magnetic field parameters.

4. The method of claim 3, wherein the method is characterized by: The Hall sensor array in step 2 is arranged near the deposition point to measure the actual magnetic field distribution generated by the magnetic field generating device, and the data is fed back to the central control unit for comparison and compensation with the model prediction value to ensure the accuracy of the magnetic field control.

5. The method of claim 4, wherein the method is characterized by: The main constraint magnetic field strength (B_main) ranges from 0.3T to 3.0T, the main constraint magnetic field gradient (∇B) ranges from 10T / m to 80T / m, and the auxiliary steady flow magnetic field frequency (f) ranges from 5Hz to 150Hz.

6. The method of claim 5, wherein the method is characterized by: The adaptive fine tuning in step 5 includes the following steps: Step 5.1: according to the spatial position and direction vector of the current integrated deposition printing head, the size and direction of the gravity component in the local coordinate system of the molten pool are calculated; Step 5.2: calling the molten pool-magnetic field coupling model, the strength B and gradient ∇B of the main constraint magnetic field required to offset the gravity component and achieve the ideal molten pool shape are calculated; Step 5.3: according to the metallurgical characteristics and thermal state of the material, the frequency and waveform parameters of the auxiliary steady flow magnetic field are determined; Step 5.4: the parameter set calculated is sent to the magnetic field regulation power cabinet and the integrated deposition printing head deflection controller through the high-speed bus in synchronization, realizing real-time, dynamic, and adaptive matching of the magnetic field constraint force and the deposition direction.

7. The method of claim 6, wherein the method is characterized by: The beam axis and the wire flow axis of the integrated deposition printing head can be independently deflected by ±90° or more relative to the end flange of the execution mechanism.

8. The method of claim 1, wherein the method is characterized by: The substrate and the metal material used are high-strength steel with ferromagnetic properties.

9. An apparatus for complex structure multi-directional laser wire directed energy deposition by magnetic field manipulation for implementing the method of any one of claims 1-8, characterized in that: It comprises an execution mechanism, an integrated deposition printing head, a magnetic field generating device, a magnetic field regulation power cabinet, a central control unit, and a Hall sensor array; Actuator: an industrial robot with at least five-axis linkage or a five-axis CNC machine tool as the core motion carrier, whose end flange provides great motion flexibility and working space; The integrated deposition print head comprises an infrared temperature detector and a high-speed CCD camera; the infrared temperature detector is used for monitoring the temperature of the molten pool in real time; and the high-speed CCD camera is used for monitoring the morphology and size of the molten pool; The magnetic field generating device comprises a main confinement magnetic field generator and an auxiliary steady flow magnetic field generator; The main confinement magnetic field generator comprises one or more pairs of high-performance water-cooled electromagnetic coils symmetrically arranged on both sides of the deposition area, and adopts a Helmholtz coil for generating a highly uniform strong magnetic field or a Maxwell coil for generating a high-intensity gradient magnetic field, so as to generate a high-intensity, high-gradient main confinement magnetic field in the molten pool area, and provide the molten pool with a main directional confinement force; The auxiliary steady flow magnetic field generator comprises a plurality of small high-frequency electromagnets arranged around the print head or the deposition point, and the array can generate an alternating magnetic field or a pulse magnetic field with adjustable frequency and direction, so as to form an auxiliary steady flow magnetic field, suppress the convection in the molten pool, break the dendritic crystals, refine the grains, and further stabilize the molten pool profile through electromagnetic stirring to improve the deposition quality; The magnetic field regulating power cabinet is used for providing accurate, stable and fast response current output for all magnetic field generators, so as to ensure accurate control of the magnetic field parameters; The central control unit adopts a high-performance industrial computer or a PLC, and a digital twin model is built in the central control unit; A Hall sensor array is arranged near the deposition point, measures the actual magnetic field distribution generated by the magnetic field generating device, and feeds back the data to the central control unit.

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