SiC particle reinforced aluminum-based composite material laser in-situ welding and modeling method and system

Abstract

The invention belongs to the technical field of laser in-situ welding, and discloses a SiC particle reinforced aluminum-based composite material laser in-situ welding and modeling method, and the method comprises the steps: building a laser heat source model considering the surface optical property difference of a particle melt; establishing a multiphase flow model based on magnetohydrodynamics; and a DEM-based particle migration-heat transfer model is developed. A particle contact force and deformation relation is described based on a Hertz contact theory, a contact heat conductivity coefficient of SiC particles is obtained by combining an experimental method, and dynamic tracking of contact and heat transfer is realized by adopting a discrete element DEM method; and molten pool-keyhole-particle multi-energy field multi-phase coupling integrated modeling is carried out. According to the method, the welding heat behavior description is more accurate, the difference of optical behaviors such as laser absorption, scattering and reflection on the surfaces of the fluid and the SiC particles is considered for the first time through the established numerical simulation model, and the characterization of the energy transmission behavior and the temperature evolution behavior in the welding process is more accurate.

Description

Technical Field

[0001] The present invention belongs to but is not limited to the technical field of laser in-situ welding, and in particular relates to a SiC particle reinforced aluminum-based composite laser in-situ welding and a modeling method thereof. Background Art

[0002] SiC particle reinforced aluminum matrix composites (hereinafter referred to as SiCp / Al) take into account the light weight and thermal conductivity of aluminum and the high hardness / strength and high temperature stability of SiC, making it exhibit excellent performance in mechanics, thermodynamics, corrosion and other aspects. It is an important component of the load-bearing structural parts of aerospace high-speed carrying equipment. Welding is an important process in the manufacture of SiCp / Al. Its weld structure is complex and the length is several meters. The welding process is prone to form a brittle phase, which causes the functional gradient structure to be destroyed, and strict requirements are placed on welding technology in terms of quality and efficiency. As the technology continues to mature and the cost gradually decreases, fiber laser technology has begun to be applied to SiCp / Al welding manufacturing. However, under the action of high-energy laser beams, SiC and Al melt / gasify to form a molten pool and keyhole, resulting in ① burning and loss of SiC particles in the joint; ② segregation of SiC phases in the joint; ③ chemical reaction between SiC and Al to form brittle carbides. This eventually leads to a significant decrease in the mechanical properties of SiCp / Al joints. For a long time, researchers have reduced the decomposition of SiC particles and the formation of brittle phases by optimizing process parameters such as splicing gap, laser power, speed, scanning trajectory / frequency, and adding alloying elements (such as Zr, Ti, etc.), thereby improving the problem of uneven SiC distribution in the joint. However, studies have shown that simply regulating welding process parameters has a very limited effect on particle content / distribution and brittle phase suppression; alloying regulation methods are prone to introduce new brittle phases. Therefore, how to achieve precise control of joint particle content / distribution and brittle phase suppression is a bottleneck problem that needs to be solved in SiCp / Al laser welding. At the same time, accurate observation of keyhole oscillation, molten pool flow, particle migration and other behaviors in the SiCp / Al laser welding process is crucial to regulating the welding process and obtaining high-quality joints. However, due to the influence of observation methods, it is very difficult to accurately obtain the above characteristics. With the development of computational fluid dynamics and discrete element methods, it has become possible to characterize and analyze the evolution of SiCp / Al laser welding molten pool, keyhole, and particles through numerical simulation. However, the thermal-mechanical interaction between the fluid phase Al and the discrete phase SiC particles in the SiCp / Al laser welding process is very intense, which makes the multi-phase coupling solution more difficult. There is currently a lack of relevant numerical simulation models, resulting in a lack of theoretical guidance for the control of the SiCp / Al laser welding process.

[0003] In view of this, the present invention first proposes a new method for in-situ laser welding of SiCp / Al composites based on coordinated regulation of electromagnetic field-wire powder co-delivery, which reduces the melting of the base material while supplementing the missing SiC particles in the joint through wire powder co-delivery; the stress state of SiC is regulated by electromagnetic force, thereby realizing flexible and controllable particle migration behavior. This method aims to solve the three major challenges / problems mentioned above: ① burning and missing SiC particles in the joint, ② segregation of SiC phase in the joint, and ③ chemical reaction between SiC and Al to generate brittle phase. On this basis, the present invention further constructs a numerical simulation method for in-situ laser welding of SiCp / Al composites based on coordinated regulation of electromagnetic field-wire powder co-delivery, so as to realize the accurate characterization of the thermal-mechanical behavior of the molten pool, keyhole, and SiC particles. The new method proposed in the present invention and the new model constructed will be suitable for laser welding or laser additive manufacturing of other composite materials. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a SiC particle reinforced aluminum-based composite laser in-situ welding and a modeling method thereof.

[0005] The present invention is achieved by a method for laser in-situ welding of SiC particle reinforced aluminum-based composites, the method comprising:

[0006] S1: Taking the typical SiCp / Al butt welding as an example, before welding, a certain gap between the SiCp / Al test plates to be welded needs to be reserved, the beam scanning direction is along the +x direction, and the powder feeding head and the wire feeding head are placed in the -x direction and +x direction of the beam respectively, that is, the powder enters the molten pool through the tail of the molten pool, and the welding wire enters the molten pool through the keyhole of the molten pool; the positive and negative electrodes of the DC power supply are connected in the y direction of the SiCp / Al plate, so that the electric field direction is distributed along the y axis, and the N-level and S-level electromagnets are arranged near the x direction of the SiCp / Al plate, so that the magnetic field direction is distributed along the x axis;

[0007] S2: During the welding process, on the one hand, similar to laser brazing, the heating object of the light beam is the welding wire. When the welding wire is completely melted and the parent material is only slightly melted, the connection of the SiCp / Al test plate is realized. The SiC powder is injected from the tail of the molten pool to avoid the direct radiation of the laser. This wire-powder co-delivery method not only supplements the content of SiCp in the joint, but also greatly inhibits the melting of SiC and the occurrence of adverse chemical reactions; on the other hand, if it is found that the molten pool SiCp is easy to be segregated at the bottom of the molten pool under specific process parameters, the applied magnetic field and electric field are respectively along the +z direction and the +x direction. At this time, the molten pool is subjected to the downward Lorentz force, which increases the buoyancy of the particles and causes them to migrate upward. If it is found that the SiC particles are easy to be segregated on the surface of the molten pool, the applied magnetic field and electric field are respectively along the +z direction and the -x direction. At this time, the molten pool is subjected to the upward Lorentz force, which reduces the buoyancy of the particles and causes them to migrate downward;

[0008] S3: After welding, on the one hand, the wire and powder are co-delivered to promote the complete melting of the metal wire to fill the SiCp / Al splicing gap, and the base material is only slightly melted, which greatly reduces the burning or melting of SiCp in the base material and inhibits the formation of brittle phase in the joint. At the same time, the injection of SiCp from the tail of the molten pool can accurately control the content of SiCp in the joint, making it almost equal to that of the base material; on the other hand, according to the area where SiCp in the joint is prone to segregation, the target solidification position of the particles is determined, and then the electromagnetic field and the size / direction of the Lorentz force generated by it are designed in a targeted manner, and the migration behavior of the particles in the molten pool is directionally controlled, so that the distribution of SiCp in the joint is almost equal to that of the base material.

[0009] Another object of the present invention is to provide a modeling method for SiC particle reinforced aluminum-based composite laser in-situ welding based on the SiC particle reinforced aluminum-based composite laser in-situ welding method, the method specifically comprising:

[0010] S21: Establish a laser heat source model that takes into account the differences in optical properties of the particle melt surface;

[0011] S22: Establish a multiphase flow model based on magnetohydrodynamics; use conductivity meters, vibrating sample magnetometers (VSM) and other equipment, combined with material thermophysical parameters, to obtain key parameters such as conductivity and magnetic permeability that change with temperature, introduce the electric / magnetic field Lorentz force as a source term into the momentum conservation equation, and introduce the electric field Joule heat as a source term into the energy conservation equation, couple and calculate the temperature field, flow field, electric field, magnetic field and other multi-physical fields inside the molten pool, and further combine the Euler-Euler two-fluid method, comprehensively consider the physical processes such as melting / solidification, evaporation / condensation, electric / magnetic conduction, and mechanical factors such as Lorentz force, gravity, surface tension, recoil pressure, and drag caused by SiC particles, and establish a molten pool-keyhole multiphase flow model under the action of electromagnetic field; among them, it is necessary to first construct the electric field and magnetic field, and the calculation of conductivity is shown in the following formula:

[0012]

[0013] Where σ is the total conductivity, σ s is the solid state conductivity of aluminum alloy, σ L is the liquid conductivity of aluminum alloy, T L is the liquidus temperature of aluminum alloy, T s is the solidus temperature of aluminum alloy. The calculation method of electric field and magnetic field in fluid phase is shown in the following formula:

[0014]

[0015] Where J is the total current density, σ is the material conductivity, is the electric potential, J 1is the steady-state transmission current, u is the liquid metal flow velocity, and B is the magnetic field intensity. The Lorentz force and its introduction into the continuity conservation equation are expressed by the following formula:

[0016]

[0017] In the formula, F l is the Lorentz force, P is the fluid pressure, μ is the fluid viscosity, is the gravity vector, is the vector of other forces, including drag force, thermal buoyancy, recoil pressure, surface tension, Lorentz force, drag force of SiC particles on the fluid phase, etc. In addition, the solid-liquid phase change problem of the fluid phase can be described by the melting and solidification model:

[0018]

[0019] In the formula, ρ s and ρ l Represent the density of the solid phase and the liquid phase, C s With C l Represents the specific heat per unit volume of the solid phase and the liquid phase, T and T l Represents the temperature of the solidus and liquidus, h sl represents the latent heat of fusion. The tangential stress τ of the steam acting on the gas-liquid interface such as the keyhole wall vap and normal stress P sta It can be expressed by:

[0020]

[0021] In the formula, and Represent the two velocity components of steam in the tangential and normal directions, ρ g represents the steam density, Re is the Reynolds number;

[0022] S23: Develop a particle migration-heat transfer model based on DEM. Based on the Hertz contact theory, the relationship between particle contact force and deformation is described. The contact thermal conductivity of SiC particles is obtained by combining experimental methods. The discrete element DEM method is used to achieve dynamic tracking of contact and heat transfer. The force state, position coordinates, rotation and transient temperature of each particle can be calculated by the following formula:

[0023]

[0024] In the formula, R, θ p and T p is the radial position vector, angular displacement and temperature of the SiC particle, m p ,I p and c pThey represent the mass, moment of inertia and specific heat of the particle respectively; and They represent the normal force, tangential force, molecular cohesion and heat transfer between two particles respectively; and Q F→P Represents the drag force and heat transfer of the fluid on SiC particles;

[0025] S24: Integrated modeling of multi-phase coupling of melt pool-keyhole-particle multi-energy fields.

[0026] Further, the S21 specifically includes:

[0027] (1) Calculate key parameters such as the geometric configuration of the Gaussian beam; use a high-power laser beam quality analyzer to test key parameters such as the Gaussian beam waist radius, Rayleigh length, far-field divergence angle, and energy density, and calculate the Gaussian light field spatial distribution function. The shape of the beam is approximately a hyperbolic distribution, and the cross-sectional radius r of the beam along the Z direction is z It can be expressed as:

[0028]

[0029] In the formula, z f 、r f are the Z coordinate and radius of the focal plane, respectively. r is the Rayleigh length of the beam, which represents the radius respectively With r f The heat flux q at any coordinate (x, y, z) in the beam propagation path h (x,y,z) can be expressed by the following formula:

[0030]

[0031] Where Q is the incident laser power;

[0032] (2) Beam discretization processing: Box-Muller transformation is used to construct the photon emission points of the beam waist section that conforms to the random Gaussian distribution. Based on the characteristics of the single-leaf hyperboloid of the Gaussian beam, an equiprobable random selection function is constructed to calculate the initial energy, spatial position and incident direction vector of each sub-beam. The straight generatrix equation of the single-leaf hyperboloid can be expressed by the following formula:

[0033]

[0034] In the formula, x 0 is the horizontal coordinate of the generated point, y 0 is the ordinate of the generated point, z 0The default value is 0. a and b are the intersection points of this single-leaf hyperboloid at z=0 with the x and y axes. The energy of each sub-beam is assigned according to a certain Gaussian distribution. The energy formula is as follows:

[0035]

[0036] In the formula, q tg is the energy allocated to each discrete sub-beam, Q g is the total energy of the sub-beam, k is the energy distribution coefficient, x 0 ,y 0 The coordinates generated for the focal plane, R g is the radius of the sub-beam;

[0037] (3) Consider the progressive search ray tracing method of fluid-solid heterogeneous interface. Comprehensively consider the differences in the reflection, scattering and absorption mechanisms of SiC particles and fluids on the light beam, and combine the progressive search ray tracing method to solve the laser energy transport behavior in the highly time-varying welding wire, particles, molten pool, and keyhole wall; Among them, it is necessary to judge the phase, gas-liquid interface or SiC particle that intersects with each discrete beam of light. We divide the entire computational domain grid, find the cell containing the origin of the light beam, and define the detection radius of the particle body as R det ; The center coordinates (x, y, z) of the particles in each grid and the characteristic index i of the detected particles (x,y,z),par This is shown by the following formula:

[0038]

[0039] In the formula, i (x,y,z),ray is the original characteristic parameter of the sub-ray in this coordinate cell. If the light beam intersects the surface of the particle, the following equation should be satisfied:

[0040]

[0041] In the formula, M is the transformation matrix of the sub-ray origin relative to the world coordinate system, d ray,i is the distance between the sub-ray origin and the particle intersection point, r c is the position of the particle intersection point in the world space. On the contrary, if the above formula is not satisfied, the light is absorbed by the gas-liquid interface surface; the energy absorption phenomenon of the sub-light at the gas-liquid interface and the particle surface is described by the Fresnel reflection theory, as shown in the following equation:

[0042]

[0043] Where, is R Fluid / Particle The absorption ratio of the keyhole wall and the particle to the light beam, is the angle between the incident beam and the wall normal, and ε is the absorption coefficient related to the beam type / material properties. r It can be expressed by the following formula:

[0044] x r =x i -2(x i ·n)(8)

[0045] When the energy of the reflected light is lower than 1% of the energy of the original light, it is determined that the energy transfer behavior is completed.

[0046] Further, the S24 specifically includes:

[0047] (1) Wire-powder-plate initialization under electromagnetic field; Based on the Biot-Savart law, the external magnetic field generated by the DC fixed magnet is calculated according to the current intensity and the coil; Based on Maxwell's induction electromagnetic theory and generalized Ohm's law, the magnetic induction intensity and current density inside the test plate are solved; The particle content / distribution state of the SiCp / Al test plate is obtained by microstructure characterization, and the effective action area of ​​the powder flow on the test plate is calculated to complete the boundary condition settings such as electromagnetic field, welding wire-powder-test plate initialization; Among them, the thermal boundary adjustment can be expressed by the following formula:

[0048]

[0049] In the formula, q L is the energy input of the laser, q plume is the heat flux from the steam plume, Q P→F It represents the change in the volumetric heat energy of the molten pool caused by the injection of particles. cov ,q rad ,q evap They represent the heat loss caused by convection, radiation and evaporation in the fluid. The momentum boundary conditions in the normal and tangential directions of the interface can be expressed by the following formulas:

[0050]

[0051] In the formula, and represents the normal velocity and tangential velocity of the fluid; γ and R s Represent the surface tension coefficient and surface curvature radius respectively; P P→F and τ P→F They represent the normal and tangential stresses of SiC particles on the liquid phase. The effective action area of ​​the powder flow on the SiCp / Al test plate can be expressed by the following formula:

[0052]

[0053] Where V p represents the velocity of the particle, Vg represents the carrier gas flow velocity, θ is the powder flow divergence angle, ν is the dynamic viscosity of the gas flow, and L is the distance between the powder flow and the test plate surface;

[0054] (2) Fluid-solid bidirectional coupling integrated solution strategy: Based on the fluid-solid velocity continuity and pressure / shear balance relationship, the SiC particle / melt interface conditions are accurately solved, and the relaxation method, Newton-Raphson method, algebraic multigrid method and other methods are comprehensively analyzed to respond to the fluid-solid bidirectional coupling parameters, so as to achieve multi-physical field (electric / magnetic field) and multi-phase (molten pool-keyhole-molten droplet-particle) integrated iterative solution. Based on the MPI multi-node communication mechanism, the parallel program development is completed; among them, the DEM module updates the coordinates, velocity, temperature and other data of the particle body after one iteration, and uses the data extracted from the fluid grid unit in the previous step of the CFD module to calculate the fluid drag force of the SiC particle. and heat Q F→P , as shown in the following formula:

[0055]

[0056] In the formula, is the convective heat transfer coefficient between SiC and the fluid, μ F A represents the flow velocity of the fluid grid unit with particles, the velocity of the particles, and the viscosity of the fluid phase. P is the surface area of ​​SiC particles, R eP Represents the Reynolds number of a single particle; then the DEM data is input into the CFD module to update the velocity field and temperature field of the fluid. The effect of the particle on the fluid can be measured by the resistance of SiC to the fluid in the unit grid. Energy exchange Q between it and the fluid P→F Describe:

[0057]

[0058] Where V mesh is the volume of the grid in the computational domain, and j represents the total number of particles in the grid. Repeat the above steps to complete the iterative solution of DEM-CFD fluid-solid bidirectional coupling.

[0059] Another object of the present invention is to provide a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the modeling method for laser in-situ welding of SiC particle reinforced aluminum-based composites.

[0060] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, enables the processor to execute the steps of the modeling method for the SiC particle reinforced aluminum-based composite laser in-situ welding.

[0061] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0062] First, fiber laser provides an effective means for SiCp / Al welding, but it faces three major challenges: ① loss of SiC particles in the joint due to burning, ② segregation of SiC phase in the joint, and ③ chemical reaction between SiC and Al to form brittle phase; on the other hand, there is currently a lack of multiphase coupling numerical simulation models for SiCp / Al laser welding, resulting in a lack of theoretical guidance for process control and difficulty in obtaining high-quality joints. In response to the above problems, the present invention first proposes a new method for in-situ laser welding of SiCp / Al composites based on coordinated regulation of electromagnetic field-silk powder co-delivery to solve the three major challenges, and on this basis, further constructs a numerical simulation method for in-situ laser welding of SiCp / Al composites based on coordinated regulation of electromagnetic field-silk powder co-delivery. The new method proposed in the present invention and the established numerical simulation model have the following advantages:

[0063] (1) Advantages of the new method of SiCp / Al composite laser in-situ welding based on coordinated control of electromagnetic field and wire powder co-delivery:

[0064] 1. The scientific problem of suppressing the brittle phase and supplementing the SiC phase cannot be taken into account at the same time: Compared with the traditional welding method that only uses wire feeding or powder feeding, the wire and powder co-feeding can simultaneously reduce the melting amount of the base material and supplement the missing SiC phase of the joint, effectively solving the problem that the low melting demand of the base material SiC and the sufficient melting demand of the base material Al matrix cannot be taken into account at the same time in traditional laser welding.

[0065] 2. The distribution of SiCp is truly flexible and controllable: Traditionally, only loading electric field or magnetic field has limited control over the stress state of the molten pool, while the directional Lorentz force generated by the electromagnetic composite field can significantly change the stress state of the molten pool. At the same time, the target solidification position of the particles can be determined according to the area where SiCp in the joint is prone to segregation, and the electromagnetic field and the size / direction of the directional Lorentz force generated by it can be designed in a targeted manner, thus achieving flexible and controllable SiCp in the joint in a true sense, thereby solving its segregation problem.

[0066] 3. Higher welding efficiency while ensuring joint quality: The new SiCp / Al composite laser in-situ welding method based on electromagnetic field-silk powder co-delivery coordinated regulation proposed in the present invention can simultaneously solve the three major challenges of ① burning and loss of SiC particles in the joint, ② segregation of SiC phase in the joint, and ③ chemical reaction between SiC and Al to generate brittle phase during the welding process. No additional pre-welding treatment or post-welding treatment is required, which significantly improves the welding efficiency while ensuring the welding quality.

[0067] (2) Advantages of the numerical simulation model of SiCp / Al composite laser in-situ welding based on coordinated control of electromagnetic field and wire powder co-delivery:

[0068] 1. More accurate description of welding thermal behavior: The numerical simulation model established by the present invention will for the first time take into account the differences in optical behaviors such as laser absorption, scattering, and reflection between the fluid and the surface of SiC particles, making the characterization of energy transfer behavior and temperature evolution behavior during welding more accurate.

[0069] 2. More accurate capture of welding mechanical behavior: The numerical simulation model established by the present invention takes into account for the first time the changes in electrical conductivity and magnetic permeability over time in different regions of the welding process, and then calculates the evolution of the electromagnetic composite field and the Lorentz force generated by it, so that the stress state of SiC particles, molten pool, and keyhole can be captured more accurately.

[0070] 3. Reduce costs and improve efficiency: Compared with the traditional method of using a large number of experiments to guide process development / regulation, the numerical simulation model established by the present invention significantly reduces time and economic costs. Compared with other numerical simulation models, the numerical simulation model established by the present invention realizes the integrated solution of the magnetohydrodynamic model and the fluid-solid bidirectional coupling model, which significantly improves the calculation efficiency.

[0071] Second, the technical solution of the present invention fills the technical gap in the industry at home and abroad: a new laser in-situ welding method based on electromagnetic field-silk powder co-delivery coordinated regulation is proposed, which effectively solves the problem of brittle phase suppression and SiC particle supplementation in traditional laser welding, and realizes the flexible and controllable distribution of SiCp particles in the joint; at the same time, the directional Lorentz force generated by the electromagnetic composite field significantly improves the stress state of the molten pool and the problem of particle segregation. Combined with the precise modeling of welding thermal behavior and mechanical behavior, the present invention establishes a more physically realistic numerical simulation model, which greatly reduces the experimental cost and improves the welding efficiency and joint quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 This is a flow chart of the SiC particle reinforced aluminum-based composite laser in-situ welding method provided by an embodiment of the present invention;

[0073] Figure 2A modeling method for laser in-situ welding of SiC particle reinforced aluminum-based composites provided in an embodiment of the present invention;

[0074] Figure 3 The present invention provides an electric field / magnetic field loading method before welding, a silk powder co-delivery method, and a preset SiCp / Al test plate splicing gap;

[0075] Figure 4 The present invention provides a method for controlling the content / distribution of SiC particles and adverse chemical reactions by silk powder co-delivery and electromagnetic field during welding: (a) the control principle of the content of SiC particles by silk powder co-delivery and the inhibition principle of SiC particle burning / melting and adverse chemical reactions; (b) the control principle of the migration behavior of particles during welding by electromagnetic composite field;

[0076] Figure 5 The control effect of SiCp / Al laser in-situ welding based on electromagnetic field-wire powder co-delivery coordinated control provided by an embodiment of the present invention: (a) schematic diagram of SiCp / Al test plate joint formation after control; (b) actual macroscopic formation of the joint cross section before and after control and the content / distribution of SiC particles;

[0077] Figure 6 The laser heat source model considering the difference in optical properties of the granular melt surface provided by the embodiment of the present invention includes: (a) heat source morphology and energy distribution in different cross sections; (b) progressive search ray tracing model considering the fluid-solid heterogeneous interface;

[0078] Figure 7 It is a multiphase flow model based on magnetohydrodynamics provided by an embodiment of the present invention: (a) at 0 ms, the morphology of the molten pool without loading the electromagnetic field; (b) at 0 ms, the morphology of the molten pool with loading the electromagnetic field; (c) at 0 ms, the magnitude and direction of the molten pool current with loading the electromagnetic field; (d) at 0 ms, the magnitude and direction of the Lorentz force of the molten pool with loading the electromagnetic field; (e) at 20 ms, the morphology of the molten pool without loading the electromagnetic field; (f) at 20 ms, the morphology of the molten pool with loading the electromagnetic field; (g) at 20 ms, the magnitude and direction of the molten pool current with loading the electromagnetic field; (h) at 20 ms, the magnitude and direction of the Lorentz force of the molten pool with loading the electromagnetic field;

[0079] Figure 8 The dynamic migration and temperature evolution behavior of SiC particles during welding simulated by the DEM-based particle migration-heat transfer model provided in the embodiment of the present invention;

[0080] Fig. 9 It is an initialization model of the electromagnetic field-welding wire-powder-SiCp / Al test plate provided by an embodiment of the present invention;

[0081] Fig.10The present invention provides the following embodiments of the present invention: (a) the temperature distribution of SiC particles and welding wire on the surface of the molten pool; (b) the flow field on the surface of the molten pool and the speed of SiC particles; (c) the beam distribution in the longitudinal section of the molten pool, the flow field / temperature field of the molten pool, and the temperature / speed of SiC particles; (d) the beam distribution in the cross section of the molten pool, the flow field / temperature field of the molten pool, and the temperature / speed of SiC particles;

[0082] Fig.11 : Comparative analysis of the volume fraction of SiCp particles along the width of the fusion zone;

[0083] Fig.12 :Comparative analysis of the volume fraction of SiCp particles along the depth direction of the fusion zone. DETAILED DESCRIPTION

[0084] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0085] This welding system realizes efficient laser in-situ welding of SiC particle reinforced aluminum-based composite materials through the coordinated work of laser generator, powder feeder, wire feeder, electromagnetic field generator and control unit. The laser generator provides high-power laser to melt the welding wire and form a molten pool; the powder feeder and wire feeder accurately feed SiC powder and welding wire into the molten pool respectively; the electromagnetic field generator dynamically regulates the electric and magnetic fields in the molten pool to control the migration and distribution of particles; the control unit monitors the welding status in real time and adjusts key parameters based on feedback to ensure welding quality and efficiency.

[0086] The high-power laser generated by the laser generator acts on the welding area, melting the welding wire and forming a molten pool in the gap of the joint. During the formation of the molten pool, the laser heating simultaneously triggers the keyhole effect, promoting local melting and stirring of the material. The welding wire enters the molten pool through the keyhole, fills the gap of the joint and supplements the metal component of the parent material, ensuring the strength and performance of the welded joint.

[0087] The powder feeding device injects SiC powder into the tail of the molten pool through the powder feeding head to avoid direct exposure to laser radiation, thereby reducing the burnout rate and adverse chemical reactions of the powder. The powder feeding gas path and airflow control device ensure the precise control of the powder delivery rate and injection angle, so that the SiC particles enter the molten pool evenly. The injection of particles supplements the SiC content of the weld joint to ensure its consistency with the base material.

[0088] The electromagnetic field generator controls the distribution behavior of SiC particles in the molten pool by applying electric and magnetic fields. When the particles are concentrated at the bottom of the molten pool, the electric field is along the positive direction of the x-axis and the magnetic field is along the positive direction of the z-axis, so that the Lorentz force increases the buoyancy of the particles upward; when the particles are concentrated on the surface of the molten pool, the electric field is along the negative direction of the x-axis and the magnetic field is still along the positive direction of the z-axis, reducing the buoyancy and causing the particles to migrate downward. This dynamic control mechanism ensures that the distribution of SiC particles in the joint is consistent with that of the parent material.

[0089] The sensor module monitors the temperature field, flow field and particle distribution of the molten pool in real time, and transmits the data to the feedback control module of the control unit. According to the monitoring data, the feedback control module dynamically adjusts the laser power, powder feeding rate, wire feeding rate and electromagnetic field intensity to optimize the key parameters in the welding process and ensure the stability and accuracy of the welding process.

[0090] The algorithm optimization module of the control unit predicts the temperature field, flow field and particle distribution in the molten pool based on the multi-physics field coupling model, and adjusts the parameters in combination with real-time monitoring data. Through the optimized welding scheme, the SiC particles in the joint are evenly distributed and the performance is close to that of the parent material, and the welding defects are significantly reduced, ensuring that the welding quality meets the requirements of engineering applications.

[0091] like Figure 1 As shown, an embodiment of the present invention provides a SiC particle reinforced aluminum-based composite laser in-situ welding method, the method comprising:

[0092] S1: Taking the typical SiCp / Al butt welding as an example, before welding, a certain gap between the SiCp / Al test plates to be welded needs to be reserved, the beam scanning direction is along the +x direction, the powder feed head and the wire feed head are placed in the -x direction and +x direction of the beam respectively, that is, the powder enters the molten pool through the tail of the molten pool, and the welding wire enters the molten pool through the keyhole of the molten pool; the positive and negative electrodes of the DC power supply are connected in the y direction of the SiCp / Al plate respectively, so that the electric field direction is distributed along the y axis, and the N-level and S-level electromagnets are arranged near the x direction of the SiCp / Al plate respectively, so that the magnetic field direction is distributed along the x axis; Figure 3 shown.

[0093] S2: During the welding process, on the one hand, similar to laser brazing, the heating object of the light beam is the welding wire. When the welding wire is completely melted and the base material is only slightly melted, the connection of the SiCp / Al test plate is realized. The SiC powder is injected from the tail of the molten pool to avoid the direct radiation of the laser. This wire-powder co-delivery method not only supplements the SiCp content of the joint, but also greatly inhibits the melting of SiC and the occurrence of adverse chemical reactions; on the other hand, if it is found that the molten pool SiCp is easy to be segregated at the bottom of the molten pool under specific process parameters, the applied magnetic field and electric field are respectively along the +z direction and the +x direction. At this time, the molten pool is subjected to the downward Lorentz force, which increases the buoyancy of the particles and causes them to migrate upward. If it is found that the SiC particles are easy to be segregated on the surface of the molten pool, the applied magnetic field and electric field are respectively along the +z direction and the -x direction. At this time, the molten pool is subjected to the upward Lorentz force, which reduces the buoyancy of the particles and causes them to migrate downward; Figure 4 shown.

[0094] S3: After welding, on the one hand, the wire powder is co-delivered to promote the complete melting of the metal wire to fill the SiCp / Al joint gap, and the parent material is only slightly melted, which greatly reduces the burning or melting of SiCp in the parent material and inhibits the formation of brittle phases in the joint. At the same time, the injection of SiCp from the tail of the molten pool can accurately control the content of SiCp in the joint, making it almost equal to that of the parent material; on the other hand, according to the area where SiCp in the joint is prone to segregation, the target solidification position of the particles is determined, and then the electromagnetic field and the size / direction of the Lorentz force generated by it are designed in a targeted manner to control the migration behavior of the particles in the molten pool, so that the distribution of SiCp in the joint is almost equal to that of the parent material. Figure 5 shown.

[0095] like Figure 2 As shown, an embodiment of the present invention provides a modeling method for SiC particle reinforced aluminum-based composite laser in-situ welding based on the SiC particle reinforced aluminum-based composite laser in-situ welding method, and the method specifically includes:

[0096] S21: Establish a laser heat source model that takes into account the differences in optical properties of the particle melt surface;

[0097] S22: Establish a multiphase flow model based on magnetohydrodynamics; use conductivity meters, vibrating sample magnetometers (VSM) and other equipment, combined with material thermophysical parameters, to obtain key parameters such as conductivity and magnetic permeability that change with temperature, introduce the electric / magnetic field Lorentz force as a source term into the momentum conservation equation, and introduce the electric field Joule heat as a source term into the energy conservation equation, couple and calculate the temperature field, flow field, electric field, magnetic field and other multi-physical fields inside the molten pool, and further combine the Euler-Euler two-fluid method, comprehensively consider the physical processes such as melting / solidification, evaporation / condensation, electric / magnetic conduction, and mechanical factors such as Lorentz force, gravity, surface tension, recoil pressure, and drag caused by SiC particles, and establish a molten pool-keyhole multiphase flow model under the action of electromagnetic field; among them, it is necessary to first construct the electric field and magnetic field, and the calculation of conductivity is shown in the following formula:

[0098]

[0099] Where σ is the total conductivity, σ s is the solid state conductivity of aluminum alloy, σ L is the liquid conductivity of aluminum alloy, T L is the liquidus temperature of aluminum alloy, T s is the solidus temperature of aluminum alloy. The calculation method of electric field and magnetic field in fluid phase is shown in the following formula:

[0100]

[0101] Where J is the total current density, σ is the material conductivity, is the electric potential, J 1 is the steady-state transmission current, u is the liquid metal flow velocity, and B is the magnetic field intensity. The Lorentz force and its introduction into the continuity conservation equation are expressed by the following formula:

[0102]

[0103] In the formula, F l is the Lorentz force, P is the fluid pressure, μ is the fluid viscosity, is the gravity vector, is the vector of other forces, including drag force, thermal buoyancy, recoil pressure, surface tension, Lorentz force, drag force of SiC particles on the fluid phase, etc. In addition, the solid-liquid phase change problem of the fluid phase can be described by the melting and solidification model:

[0104]

[0105] In the formula, ρ s and ρ l Represent the density of the solid phase and the liquid phase, C s With C l Represents the specific heat per unit volume of the solid phase and the liquid phase, T and Tl Represents the temperature of the solidus and liquidus, h sl represents the latent heat of fusion. The tangential stress τ of the steam acting on the gas-liquid interface such as the keyhole wall vap and normal stress P sta It can be expressed by:

[0106]

[0107] In the formula, and Represent the two velocity components of steam in the tangential and normal directions, ρ g Represents steam density, Re is Reynolds number; the electric field distribution, magnetic field distribution, and Lorentz force distribution of the multiphase flow model based on magnetohydrodynamics constructed by the above S22 at different time steps are different from the molten pool morphology when no electromagnetic field is loaded. Figure 7 shown.

[0108] S23: Develop a particle migration-heat transfer model based on DEM. Based on the Hertz contact theory, the relationship between particle contact force and deformation is described. The contact thermal conductivity of SiC particles is obtained by combining experimental methods. The discrete element DEM method is used to achieve dynamic tracking of contact and heat transfer. The force state, position coordinates, rotation and transient temperature of each particle can be calculated by the following formula:

[0109]

[0110] In the formula, R, θ p and T p is the radial position vector, angular displacement and temperature of the SiC particle, m p ,I p and c p They represent the mass, moment of inertia and specific heat of the particle respectively; and They represent the normal force, tangential force, molecular cohesion and heat transfer between two particles respectively; and Q F→P represents the drag force and heat transfer of the fluid on the SiC particles; the migration and temperature evolution behavior of the SiC particles constructed by the above S23 during the welding process are as follows Figure 8 shown.

[0111] S24: Integrated modeling of multi-phase coupling of melt pool-keyhole-particle multi-energy fields.

[0112] Further, the S21 specifically includes:

[0113] (1) Calculate key parameters such as the geometric configuration of the Gaussian beam; use a high-power laser beam quality analyzer to test key parameters such as the Gaussian beam waist radius, Rayleigh length, far-field divergence angle, and energy density, and calculate the Gaussian light field spatial distribution function. The shape of the beam is approximately a hyperbolic distribution, and the cross-sectional radius r of the beam along the Z direction is z It can be expressed as:

[0114]

[0115] In the formula, z f 、r f are the Z coordinate and radius of the focal plane, respectively. r is the Rayleigh length of the beam, which represents the radius respectively With r f The heat flux q at any coordinate (x, y, z) in the beam propagation path h (x,y,z) can be expressed by the following formula:

[0116]

[0117] Where Q is the incident laser power; the energy distribution of the Gaussian beam reconstructed by the above sub-step (1) and its different cross-sections is as follows: Figure 6 (a) shown.

[0118] (2) Beam discretization processing: Box-Muller transformation is used to construct the photon emission points of the beam waist section that conforms to the random Gaussian distribution. Based on the characteristics of the single-leaf hyperboloid of the Gaussian beam, an equiprobable random selection function is constructed to calculate the initial energy, spatial position and incident direction vector of each sub-beam. The straight generatrix equation of the single-leaf hyperboloid can be expressed by the following formula:

[0119]

[0120] In the formula, x 0 is the horizontal coordinate of the generated point, y 0 is the ordinate of the generated point, z 0 The default value is 0. a and b are the intersection points of this single-leaf hyperboloid at z=0 with the x and y axes. The energy of each sub-beam is assigned according to a certain Gaussian distribution. The energy formula is as follows:

[0121]

[0122] In the formula, q tg is the energy allocated to each discrete sub-beam, Q g is the total energy of the sub-beam, k is the energy distribution coefficient, x 0 ,y 0 The coordinates generated for the focal plane, R gis the radius of the sub-beam;

[0123] (3) Consider the progressive search ray tracing method of fluid-solid heterogeneous interface. Comprehensively consider the differences in the reflection, scattering and absorption mechanisms of SiC particles and fluids on the light beam, and combine the progressive search ray tracing method to solve the laser energy transport behavior in the highly time-varying welding wire, particles, molten pool, and keyhole wall; Among them, it is necessary to judge the phase, gas-liquid interface or SiC particle that intersects with each discrete beam of light. We divide the entire computational domain grid, find the cell containing the origin of the light beam, and define the detection radius of the particle body as R det ; The center coordinates (x, y, z) of the particles in each grid and the characteristic index i of the detected particles (x,y,z),par This is shown by the following formula:

[0124]

[0125] In the formula, i (x,y,z),ray is the original characteristic parameter of the sub-ray in this coordinate cell. If the light beam intersects the surface of the particle, the following equation should be satisfied:

[0126]

[0127] In the formula, M is the transformation matrix of the sub-ray origin relative to the world coordinate system, d ray,i is the distance between the sub-ray origin and the particle intersection point, r c is the position of the particle intersection point in the world space. On the contrary, if the above formula is not satisfied, the light is absorbed by the gas-liquid interface surface; the energy absorption phenomenon of the sub-light at the gas-liquid interface and the particle surface is described by the Fresnel reflection theory, as shown in the following equation:

[0128]

[0129] Where, is R Fluid / Particle The absorption ratio of the keyhole wall and the particle to the light beam, is the angle between the incident beam and the wall normal, and ε is the absorption coefficient related to the beam type / material properties. r It can be expressed by the following formula:

[0130] x r =x i -2(x i ·n) (8)

[0131] When the energy of the reflected light is less than 1% of the energy of the original light, the energy transfer behavior is determined to be completed. The ray tracing model constructed using the above sub-step 1.3 is as follows Figure 6 (b) as shown.

[0132] Further, the S24 specifically includes:

[0133] (1) Wire-powder-plate initialization under electromagnetic field; Based on the Biot-Savart law, the external magnetic field generated by the DC fixed magnet is calculated according to the current intensity and the coil; Based on Maxwell's induction electromagnetic theory and generalized Ohm's law, the magnetic induction intensity and current density inside the test plate are solved; The particle content / distribution state of the SiCp / Al test plate is obtained by microstructure characterization, and the effective action area of ​​the powder flow on the test plate is calculated to complete the boundary condition settings such as electromagnetic field, welding wire-powder-test plate initialization; Among them, the thermal boundary adjustment can be expressed by the following formula:

[0134]

[0135] In the formula, q L is the energy input of the laser, q plume is the heat flux from the steam plume, Q P→F It represents the change in the volumetric heat energy of the molten pool caused by the injection of particles. cov ,q rad ,q evap They represent the heat loss caused by convection, radiation and evaporation in the fluid. The momentum boundary conditions in the normal and tangential directions of the interface can be expressed by the following formulas:

[0136]

[0137] In the formula, and represents the normal velocity and tangential velocity of the fluid; γ and R s Represent the surface tension coefficient and surface curvature radius respectively; P P→F and τ P→F They represent the normal and tangential stresses of SiC particles on the liquid phase. The effective action area of ​​the powder flow on the SiCp / Al test plate can be expressed by the following formula:

[0138]

[0139] Where V p represents the velocity of the particle, V g represents the carrier gas flow velocity, θ is the powder flow divergence angle, ν is the dynamic viscosity of the gas flow, and L is the distance between the powder flow and the test plate surface; the initialization model of the electromagnetic field-welding wire-powder-SiCp / Al test plate constructed by sub-step S24 is as follows Fig. 9 shown.

[0140] (2) Fluid-solid bidirectional coupling integrated solution strategy: Based on the fluid-solid velocity continuity and pressure / shear balance relationship, the SiC particle / melt interface conditions are accurately solved, and the relaxation method, Newton-Raphson method, algebraic multigrid method and other methods are comprehensively analyzed to respond to the fluid-solid bidirectional coupling parameters, so as to achieve multi-physical field (electric / magnetic field) and multi-phase (molten pool-keyhole-molten droplet-particle) integrated iterative solution. Based on the MPI multi-node communication mechanism, the parallel program development is completed; among them, the DEM module updates the coordinates, velocity, temperature and other data of the particle body after one iteration, and uses the data extracted from the fluid grid unit in the previous step of the CFD module to calculate the fluid drag force of the SiC particle. and heat Q F→P , as shown in the following formula:

[0141]

[0142] In the formula, is the convective heat transfer coefficient between SiC and the fluid, μ F A represents the flow velocity of the fluid grid unit with particles, the velocity of the particles, and the viscosity of the fluid phase. P is the surface area of ​​SiC particles, R eP Represents the Reynolds number of a single particle; then the DEM data is input into the CFD module to update the velocity field and temperature field of the fluid. The effect of the particle on the fluid can be measured by the resistance of SiC to the fluid in the unit grid. Energy exchange Q between it and the fluid P→F Describe:

[0143]

[0144] Where V mesh is the volume of the grid in the computational domain, and j represents the total number of particles in the grid; repeat the above steps to complete the iterative solution of DEM-CFD fluid-solid bidirectional coupling. The dynamic and heat transfer behaviors of particles and fluid in the SiCp / Al laser welding process based on the coordinated control of electromagnetic field-wire powder co-delivery are as follows: Fig.10 shown.

[0145] Fig.11 and Fig.12The results of the influence of the new method of SiCp / Al composite laser in-situ welding based on electromagnetic field-silk powder co-delivery coordinated regulation on the particle volume fraction in the width direction and depth direction are shown respectively. The red line represents the experimental results without adding the electromagnetic field, the red column represents the numerical simulation results of SiCp / Al composite laser in-situ welding without adding the electromagnetic field, the blue line represents the experimental results with the addition of the electromagnetic field, and the blue column represents the simulation results based on the electromagnetic field-silk powder co-delivery coordinated regulation with the addition of the electromagnetic field. The particle volume fraction of the two processes with and without the electromagnetic field shows a downward trend along the depth direction of the fusion zone, and a trend of first decreasing and then increasing along the width direction of the fusion zone. However, after adding the electromagnetic field, the gradient distribution degree of the electromagnetic field causing the particles to gather at the upper part of the fusion zone and the left and right boundaries is significantly weakened, and the distribution uniformity is significantly improved, which is sufficient to prove the superiority of the present invention.

[0146] Example 1: Butt welding of small-sized SiC particles reinforced aluminum-based composites

[0147] 1) Test materials and settings

[0148] Base material: SiCp / Al composite plate with a thickness of 3 mm, a particle reinforcement ratio of 10%, and an average diameter of SiC particles of 2 μm.

[0149] Welding wire: Al-Si alloy welding wire, diameter 1.2mm.

[0150] Powder feeding material: SiC powder, particle diameter 2μm, consistent with the parent material particle diameter.

[0151] Equipment settings: laser power was set to 4 kW, wire feed rate was 1.5 m / min, powder feed rate was 10 g / min, and welding speed was 10 mm / s.

[0152] Electromagnetic field parameters: electric field strength is 50 V / cm, magnetic field strength is 200 mT, and directions are along the y-axis (electric field) and x-axis (magnetic field).

[0153] 2) Welding process

[0154] A gap of 0.5 mm is reserved for the joints, and the wire and powder are fed together. The welding wire enters the molten pool through the keyhole, and SiC powder is injected from the tail of the molten pool.

[0155] The laser heats the welding wire to form a keyhole and a molten pool, and the base material is only slightly melted; the molten pool temperature is monitored in real time and the laser power is adjusted to keep it stable.

[0156] The electric field and magnetic field work together to control the floating and sinking behavior of particles and ensure the uniform distribution of particles in the molten pool.

[0157] After welding is completed, the molten pool solidifies by natural cooling.

[0158] 3) Welding effect

[0159] The SiC particles in the welded joint are evenly distributed, and the particle content is consistent with that of the base material, without obvious segregation.

[0160] The tensile strength of the joint reaches 95% of the parent material, which is significantly better than traditional welding methods.

[0161] Example 2: Large-size SiC particle reinforced aluminum-based composite splicing welding

[0162] 1) Test materials and settings

[0163] Base material: SiCp / Al composite plate with a thickness of 10 mm, a particle reinforcement ratio of 20%, and an average diameter of SiC particles of 10 μm.

[0164] Welding wire: Al-Mg alloy welding wire with a diameter of 1.6 mm.

[0165] Powder feeding material: SiC powder, particle diameter 10μm, consistent with the parent material particles.

[0166] Equipment settings: laser power was set to 6 kW, wire feed rate was 2.0 m / min, powder feed rate was 20 g / min, and welding speed was 8 mm / s.

[0167] Electromagnetic field parameters: electric field strength is 80 V / cm, magnetic field strength is 300 mT, and directions are along the y-axis (electric field) and z-axis (magnetic field).

[0168] 2) Welding process

[0169] The gap between the joints is set to 1mm, and double-layer welding is adopted. When welding the first layer, fill the bottom of the joint and adjust the direction of the electromagnetic field to make the particles migrate upward; when welding the second layer, fill the surface of the joint and control the uniform distribution of particles.

[0170] The laser directly heats the welding wire, and the molten pool forms a keyhole effect. The powder and wire feeding rates are adjusted through real-time monitoring to optimize the injection amount and distribution of particles.

[0171] The direction and intensity of the electric and magnetic fields are dynamically adjusted to prevent particles from gathering at the bottom or surface of the molten pool.

[0172] 3) Welding effect

[0173] The particle content in the joint area is consistent with that of the parent material and is evenly distributed, without obvious segregation or porosity defects.

[0174] The tensile strength and ductility of the welded joint reached 92% and 88% of the parent material respectively, making it suitable for industrial production.

[0175] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A laser in-situ welding method for SiC particle reinforced aluminum-based composite materials, characterized in that: The method comprises the following steps: (1) Before welding, a gap is reserved for the SiCp / Al test plate. The beam scanning direction is along the +x direction. The powder feeder and wire feeder are placed in the -x and +x directions of the beam, respectively, so that the powder enters the molten pool from the tail end of the molten pool, and the welding wire enters the molten pool through the keyhole of the molten pool; (2) Applying electric and magnetic fields in the welding area, so that the direction of the electric field is distributed along the y-axis and the direction of the magnetic field is distributed along the x-axis, and the direction and size of the electromagnetic field are dynamically adjusted according to the distribution state of SiC particles in the molten pool to control the particle migration behavior and achieve uniform distribution; (3) The silk-powder co-delivery technology is used to supplement the SiC particle content of the joint, optimize the laser power and process parameters, and complete the welding when the base material is only slightly melted, avoiding the burning or adverse reaction of the SiC particles, and ensuring that the performance of the welded joint matches that of the base material.

2. The laser in-situ welding method according to claim 1, characterized in that: By dynamically adjusting the directions of the electric field and the magnetic field, when the SiC particles are concentrated at the bottom of the molten pool, the direction of the magnetic field is along the positive direction of the z-axis and the direction of the electric field is along the positive direction of the x-axis, thereby increasing the upward Lorentz force on the particles; when the particles are concentrated on the surface of the molten pool, the direction of the magnetic field is along the positive direction of the z-axis and the direction of the electric field is along the negative direction of the x-axis, thereby reducing the buoyancy of the particles and achieving uniform distribution of the particles.

3. The laser in-situ welding method according to claim 1, characterized in that: The wire-powder co-feeding technology is used to fill the gap in the joint by melting the welding wire. At the same time, the powder is avoided from being directly exposed to laser radiation during the process of injecting the powder into the tail of the molten pool, thereby reducing the burning and chemical reaction of the powder.

4. The laser in-situ welding method according to claim 1, characterized in that: During the welding process, the migration behavior of the particles is controlled by applying an electromagnetic field, and the strength and direction of the electromagnetic field are designed according to the target distribution position of the joint particles so that the joint particle distribution is almost consistent with the parent material particle distribution.

5. The laser in-situ welding method according to claim 1, characterized in that: By dynamically monitoring the molten pool temperature field and flow field, the laser power, powder feeding rate and wire feeding rate are optimized in real time to ensure stable molten pool temperature and reduce welding defects.

6. The laser in-situ welding method according to claim 1, characterized in that: After welding is completed, the residual effect of the electromagnetic field is used to maintain the distribution stability of the particles in the molten pool, and the molten pool solidifies through natural cooling.

7. The laser in-situ welding method according to claim 1, characterized in that: This method is applicable to aluminum-based composite materials with different SiC particle reinforcement ratios. The particle matching and strength balance between the welded joint and the base material can be achieved by adjusting the electromagnetic field intensity and laser parameters.

8. A SiC particle reinforced aluminum matrix composite laser in-situ welding system, characterized in that: The system includes: (1) A laser generating device, used to provide high-power laser to melt the welding wire and form a molten pool; (2) a powder feeding device and a wire feeding device, wherein the powder feeding device injects SiC powder into the tail of the molten pool, and the wire feeding device feeds the welding wire into the molten pool through the keyhole; (3) an electromagnetic field generating device, which is used to apply electric and magnetic fields in the welding area and dynamically adjust the direction and intensity of the electromagnetic field according to real-time monitoring data to control the distribution behavior of particles in the molten pool; (4) A control unit connected to the laser generator, powder feeder, wire feeder and electromagnetic field generator to coordinate the work of each part and achieve real-time optimization of the welding process.

9. The welding system according to claim 8, characterized in that The powder feeding device includes a powder feeding head, a powder feeding air path and an airflow control device, which can accurately control the conveying rate and injection angle of SiC powder, ensure that the powder enters the molten pool from the tail of the molten pool and avoids direct exposure to laser radiation.

10. The welding system according to claim 8, characterized in that The electromagnetic field generating device includes an electrode device for generating an electric field and an electromagnet for generating a magnetic field. The electrode device is arranged along the y-axis of the welding area, and the electromagnet is arranged along the x-axis of the welding area. The electric field strength and the magnetic field direction are dynamically adjusted by the control unit to optimize the distribution of particles in the molten pool.

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