Laser arc composite additive manufacturing method and device

Abstract

The invention discloses a laser arc composite additive manufacturing device and method based on light beam scanning and wire powder synchronization. The device comprises a laser emitting unit, a light beam scanning unit, an electric arc generating unit, a wire feeding mechanism and a powder feeding mechanism which are integrally arranged, and laser power, scanning frequency and diameter, electric arc current and wire feeding and powder feeding parameters are cooperatively regulated and controlled through a control unit; the method comprises the steps that wire feeding for generating electric arc, metal powder conveying and scanning laser beam oscillation irradiation are synchronously conducted in a deposition area, the powder feeding amount is 1.5-2.5 g / min, the laser scanning frequency is 200-400 Hz, and the scanning diameter is 1.0-1.5 mm; according to the method, through cooperation of laser, electric arc and powder, the process stability and forming precision are remarkably improved, in-situ microalloying is achieved with the help of the active powder, an Mg2Si strengthening phase is generated, and a deposition component has the excellent comprehensive performance of high strength, high hardness and low porosity.

Description

Technical Field

[0001] This application relates to the field of additive manufacturing technology, and more specifically, to a laser-arc composite additive manufacturing method and apparatus. Background Technology

[0002] Wafer-Arc Additive Manufacturing (WAAM) technology has attracted widespread attention due to its high deposition efficiency, low manufacturing cost, and ability to effectively overcome the difficulties of laser processing of highly reflective materials such as aluminum alloys. To further improve the forming quality of this technology, scanning laser-arc composite additive manufacturing technology has been developed. This technology introduces an oscillating scanning laser beam into the arc region, utilizing the synergistic effect of laser and arc to significantly enhance arc stability, increase energy density, and achieve positive progress in improving porosity defects and refining grain structure in the deposited layer. It has become an important development direction in this field.

[0003] However, existing technologies still face core challenges that urgently need to be addressed. Traditional arc additive manufacturing suffers from an inherent contradiction between low forming accuracy and difficulty in achieving process stability: to maintain molten pool stability, lower deposition rates and smaller arc currents are often required. This not only limits manufacturing efficiency but also increases internal stress and deformation risk in components, necessitating extensive subsequent machining for complex structural parts to meet accuracy requirements. Although the introduction of oscillating laser composite technology has improved process stability to some extent, its material system is severely limited by a single type of commercially available welding wire. This single material filling mode greatly restricts the flexible design and real-time control of the alloy composition of deposited components. Consequently, its microstructure control capabilities and final comprehensive mechanical properties are generally difficult to match with powder bed additive manufacturing processes such as laser selective melting, which allow for free proportioning of powder components. This severely restricts the application and promotion of this technology in the manufacturing of high-performance, complex-component components.

[0004] Magnesium (Mg) powder has been proven to be an ideal material that can synergistically improve the laser-arc composite additive manufacturing process of aluminum alloys from multiple dimensions. Under the high temperature environment of the arc, magnesium atoms are easily ionized. This process can significantly increase the density of charged particles in the arc plasma, thereby effectively improving the conductivity and energy density of the arc, making the arc combustion more concentrated and stable. At the same time, magnesium has a high affinity for elements such as nitrogen and oxygen, and can preferentially react with these harmful gases that invade the molten pool, playing a role in deoxidation and denitrification, further purifying the molten pool, and improving the metallurgical quality of the deposited layer.

[0005] This invention proposes a technical solution that deeply integrates high-frequency beam scanning with simultaneous wire and powder feeding technology. By stabilizing the arc and stirring the molten pool using an oscillating laser, and simultaneously delivering magnesium powder, in-situ microalloying of the deposited material is achieved. This not only optimizes the process at the energy level but also achieves composition optimization and grain refinement at the material level, providing a complete solution for low-cost and high-efficiency additive manufacturing of high-performance, high-precision aluminum alloy components. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a composite additive manufacturing method and apparatus that deeply integrates high-frequency beam scanning with simultaneous wire powder feeding technology. This method not only stabilizes the arc and stirs the molten pool through the physical action of the oscillating laser, fundamentally improving process stability, but also achieves in-situ micro-alloying and composition optimization of the deposited material by simultaneously feeding active alloy powder.

[0007] In a first aspect, the present invention provides a laser-arc composite additive manufacturing apparatus, characterized in that it comprises: a laser emitting unit, a beam scanning unit, an arc generating unit, a wire feeding mechanism, a powder feeding mechanism, and a control unit; the control unit is communicatively connected to the laser emitting unit, the beam scanning unit, the arc generating unit, the wire feeding mechanism, and the powder feeding mechanism, and is used to adjust at least one parameter among laser power, scanning frequency, scanning diameter, arc current, wire feeding speed, powder feeding amount, powder feeding gas flow rate, and wire-powder spacing.

[0008] Preferably, the beam scanning unit is configured to cause the laser beam to oscillate in one of the following paths: circular, elliptical, figure-eight, or figure-infinity, with a scanning frequency of 200-400Hz and a scanning diameter of 1-2mm.

[0009] Preferably, the spacing between the silk and powder is 4-6 mm, the powder feeding air flow rate is 2-4 L / min, and the powder feeding amount is 1.5-2.5 g / min.

[0010] Preferably, the arc generating unit is configured to output a current of 120~130A, and the wire feeding mechanism is configured to feed wire at a speed of 3~5m / min.

[0011] Preferably, the laser power output by the laser emitting unit is 1~3kW and the laser incident angle is 20~30°.

[0012] Secondly, the present invention provides an additive manufacturing method for a laser-arc composite additive manufacturing apparatus, characterized by comprising the following steps: S1: Provide a substrate and a filler material, wherein the filler material includes welding wire and metal powder; S2: Adjust the laser beam to oscillate with a preset scanning path and frequency, and synchronously control the wire feeding mechanism and powder feeding mechanism so that the welding wire and powder enter the arc area together. S3: The laser parameters, arc parameters, wire feeding parameters, and powder feeding parameters are adjusted in real time by the control unit to obtain the formed component.

[0013] Preferably, the amount of metal powder fed by the S2 powder feeder to the deposition area is 1.5~2.5 g / min.

[0014] Preferably, the S2 metal powder is magnesium powder; the magnesium powder accounts for 20-100% of the total weight of the powder.

[0015] Preferably, the aluminum alloy welding wire fed by the S2 wire feeding mechanism and the powder flow output by the powder feeder converge in the deposition area, and the distance between the welding wire axis and the powder flow axis is 4~6mm.

[0016] Preferably, the scanning frequency of the S2 laser beam is 200~400Hz, and the scanning diameter is 1.0~1.5mm.

[0017] In summary, the present invention has at least one of the following beneficial technical effects: 1. This invention significantly improves the stability and forming accuracy of the additive manufacturing process. Through the synergistic effect of high-frequency oscillating laser and electric arc, the electric arc is effectively compressed and stabilized, reducing droplet transfer time and suppressing arc root drift and molten pool spatter. Optimized wire-to-powder spacing and powder feeding parameters avoid interference from the powder feeding gas flow to the protective atmosphere, jointly ensuring continuous process stability and significantly improving dimensional accuracy and material utilization.

[0018] 2. This invention achieves flexible and proactive control over the microstructure and composition of deposited components, overcoming the material limitations of a single welding wire. Through a synchronous powder feeding mechanism, active magnesium powder can be precisely introduced into the molten pool at a rate of 1.5~2.5 g / min, achieving in-situ microalloying. This successfully induces the formation of a Mg2Si strengthening phase in the deposited structure, effectively reducing deformation distortion and stress concentration, thereby achieving both structural strengthening and toughening while optimizing the composition.

[0019] 3. This invention comprehensively improves the mechanical properties of deposited components. Enhanced process stability and the formation of the Mg2Si reinforcing phase significantly improve the mechanical properties of the deposited components, maintaining good ductility while increasing strength. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 The following diagram illustrates the experimental platform provided in the embodiments of this application; Figure a is a side view; Figure b is a front view; Figure 2 The following diagram illustrates a wire powder feeding device for wire powder synchronous arc additive manufacturing provided in an embodiment of this application; Figure a shows the relative position of the welding torch and the powder feeding tube; Figure b shows the protective sleeves for wide-mouth and narrow-mouth welding torches; Figure c shows the relative position of the narrow-mouth protective sleeve and the powder feeding tube after grinding. Figure 3 The following figures illustrate the macroscopic weld bead formation at different scanning frequencies according to embodiments of this application: Figure a is a macroscopic weld bead formation at 0Hz; Figure b is a macroscopic weld bead formation at 100Hz; Figure c is a macroscopic weld bead formation at 300Hz; Figure d is a macroscopic weld bead formation at 500Hz; Figure a1 is a cross-sectional view of the weld bead at 0Hz; Figure b1 is a cross-sectional view of the weld bead at 100Hz; Figure d1 is a cross-sectional view of the weld bead at 300Hz; Figure e1 is a cross-sectional view of the weld bead at 500Hz. Figure 4 This application provides a diagram showing the weld width and weld depth at the same scanning frequency according to an embodiment of the present application. Figure 5 The following figures illustrate the macroscopic forming patterns of weld beads with different scanning diameters according to embodiments of this application: Figure a shows the macroscopic forming pattern of the weld bead with D=0mm; Figure b shows the macroscopic forming pattern of the weld bead with D=0.4mm; Figure c shows the macroscopic forming pattern of the weld bead with D=0.8mm; Figure d shows the macroscopic forming pattern of the weld bead with D=1.2mm; Figure e shows the macroscopic forming pattern of the weld bead with D=1.6mm; Figure a1 shows a cross-sectional view of the weld bead with D=0mm; Figure b1 shows a cross-sectional view of the weld bead with D=0.4mm; Figure c1 shows a cross-sectional view of the weld bead with D=0.8mm; Figure d1 shows a cross-sectional view of the weld bead with D=1.2mm; Figure e1 shows a cross-sectional view of the weld bead with D=1.6mm. Figure 6 This application provides illustrations of melt width and melt depth at different scanning diameters. Figure 7 The following figures illustrate the morphological statistics of a single-layer cross-section provided in the embodiments of this application: Figure a is a single-layer cross-section morphology of a sample without powder; Figure b is a single-layer cross-section morphology of a sample with 20% Mg powder; Figure c is a single-layer cross-section morphology of a sample with 100% Mg powder. Figure 8 This application provides a statistical chart of the single-layer cross-section melt depth and melt width according to an embodiment of the present application. Figure 9 The following figures illustrate the surface morphology of the multilayer sample with simultaneous addition of Mg powder according to the embodiments of this application: Figure a is the multilayer morphology of the sample without powder; Figure b is the multilayer morphology of the sample with 20% Mg powder; Figure c is the multilayer morphology of the sample with 100% Mg powder. Figure 10 The following diagrams illustrate the results of simultaneous non-destructive testing of silk powder and other materials provided in this application: Figure a shows the results of non-destructive testing of a sample without powder; Figure b shows the results of non-destructive testing of a sample with 20% Mg powder; and Figure c shows the results of non-destructive testing of a sample with 100% Mg powder. Figure 11 The following figures illustrate the surface roughness statistics of the multi-layer cross-section of the silk powder provided in this application embodiment; Figure a is a schematic diagram of the sampling test; Figure b is a display diagram of the test results; Figure c is a statistical chart of the test results. Figure 12 The following are statistical charts showing the appearance morphology and forming accuracy of the multi-layer cross-section provided in the embodiments of this application; Figure a is the appearance morphology of the 0% Mg powder sample; Figure b is the appearance morphology of the sample with 20% Mg powder; Figure c is the appearance morphology of the sample with 100% Mg powder; Figure d is a statistical chart of η (forming width coefficient) and e (machining allowance); Figure e is a statistical chart of W E (Effective width) and W T (Total width) statistics chart; Figure f is the melt depth statistics chart; Figure 13 This illustration shows a high-speed photographic image of simultaneous scanning laser composite additive manufacturing of filament and powder provided in an embodiment of this application. Figure 14 The diagram illustrates the mechanism of the effect of powder addition on arc stability and forming morphology provided in the embodiments of this application; Figure a is a sample with 20% Mg powder added; Figure b is a sample with 100% Mg powder added. Figure 15 The metallographic structure features provided in the embodiments of this application are shown in the diagram. Figure 16 The following figures illustrate the SEM and EDS test results of 0% Mg provided in the embodiments of this application. Figure 17 The following figures illustrate the SEM and EDS test results of 20% Mg provided in the embodiments of this application. Figure 18 The following figures illustrate the SEM and EDS test results of 100% Mg provided in the embodiments of this application. Figure 19 The following figures illustrate the simultaneous XRD results of the silk powder provided in the embodiments of this application: Figure a is the XRD result of the sample with 0% Mg powder added; Figure b is the XRD result of the sample with 20% Mg powder added; and Figure c is the XRD result of the sample with 100% Mg powder added. Figure 20The 100% Mg TEM analysis diagram provided in the embodiments of this application is shown; Figure 21 This illustrates a TEM dislocation analysis diagram provided in an embodiment of this application; Figure 22 The following figures illustrate the EBSD results of the wire powder synchronous process provided in the embodiments of this application: Figure a is the EBSD diagram of the sample with 0% Mg powder; Figure b is the EBSD diagram of the sample with 20% Mg powder; Figure c is the EBSD diagram of the sample with 100% Mg powder; Figure d is the grain size statistics of the sample with 0% Mg powder; Figure e is the grain size statistics of the sample with 20% Mg powder; and Figure f is the grain size statistics of the sample with 100% Mg powder. Figure 23 The following figures illustrate the synchronous hardness statistics of the silk powder provided in the embodiments of this application; Figure a is a scatter plot of microhardness; Figure b is a statistical chart of average microhardness and variance. Figure 24 The following figures illustrate the synchronous tensile statistics of the silk powder provided in the embodiments of this application; Figure a is a stress-strain curve; Figure b is a statistical chart of tensile strength and elongation. Figure 25 This paper shows a SEM image of the synchronous tensile fracture surface of the silk powder provided in an embodiment of this application; Figure 26 A diagram illustrating the synergistic mechanism provided in an embodiment of this application is shown; Detailed Implementation The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention. Furthermore, all other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of the present invention.

[0022] Specific experimental steps or conditions are not specified in the embodiments; they can be performed according to the conventional experimental steps or conditions described in the prior art. Reagents and other instruments used, unless otherwise specified, are all commercially available conventional reagent products. Furthermore, the accompanying drawings are merely illustrative diagrams of the embodiments of the present invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore, repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0023] Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of this specification.

[0024] In the description of this invention, it should be understood that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0025] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0026] To enable those skilled in the art to better understand this application, the following embodiments will be used to provide a detailed description of a laser arc composite additive manufacturing method and apparatus provided in this application.

[0027] Example Example 1: A laser-arc composite additive manufacturing method based on beam scanning and wire-powder synchronization This embodiment provides a laser-arc composite additive manufacturing method based on beam scanning and wire-powder synchronization. The experimental platform is as follows: Figure 1 As shown, the specific steps are as follows: S1: Prepare a 6082 aluminum alloy plate with dimensions of 450mm×150mm×10mm as the substrate (composition as shown in Table 1). The filler material is ER4047 aluminum alloy welding wire with a diameter of 1.6mm and a Si content of about 12% (composition as shown in Table 2). Pure magnesium (Mg) powder is used as the additive. S2: Configure the laser arc composite additive manufacturing device as described in this invention, and set the following key process parameters: use a fine-grind welding torch protective sleeve, adjust the welding torch angle to 80°, the powder feeding tube angle to 50°, and the wire-to-powder spacing to 4mm (the distance between the welding wire tip and the powder flow focal point). Figure 2 As shown in a~c; the powder gas flow rate was 3L / min, the powder feed rate was 1.5~2.5g / min, the rotary table speed was 4r / min, the arc current was 125A, and the deposition rate was 10mm / s; the laser power was 2500W, and the laser angle was 24°; the surface and cross-sectional morphology of the single-layer single-pass sample were analyzed at different laser scanning frequencies (F), and the melt depth and melt width (e.g., Figure 3 , 4 As shown), F was set to 300Hz, and the laser oscillation mode was selected as the circular scanning mode with better forming. The surface and cross-sectional morphology of single-layer single-pass samples under different laser scanning diameters (D) were analyzed, and their melt depth and melt width were statistically analyzed (e.g., Figure 5 ,6 As shown in the figure, D is selected as 1.2mm.

[0028] Table 1 Chemical composition (wt.%) of 6082 aluminum alloy

[0029] Table 2 Chemical composition (wt.%) of 6082 and 4047 aluminum alloys

[0030] Example 2: Effects of different powder ratios on the laser-arc composite additive manufacturing process and the properties of the deposited part This embodiment sets up the following three sets of comparative experiments, and their core process parameters are shown in Table 3. The results are as follows: Figure 7 , 8 As shown in the cross-sectional morphology, after adding 20% ​​Mg, the melting depth of the single-layer deposition layer increased from 1.3 mm to 2 mm, an increase of 54%; the melting width of the deposition layer increased from 6.4 mm to 6.9 mm, an increase of 8%. The addition of 100% Mg powder resulted in a certain increase in both melting depth and melting width, while the depth-to-width ratio remained relatively unchanged. This indicates that the addition of the powder improved the utilization rate of the molten pool heat and increased the heat input.

[0031] Table 3. Parameters for Simultaneous Processing of Silk and Powder

[0032] like Figure 9 , 10 As shown, after adding 20% ​​Mg, the top surface has good flatness, with no collapse at the left and right ends, and the side surface contour is good, with the deposition path of each layer clearly visible. However, pores exist in local areas, with a porosity of 0.12%, which is an increase compared to the powder-free condition. After adding 100% Mg, the top surface is smooth and glossy, with flat left and right ends and no collapse. The side surface has high flatness due to its thin walls, without obvious grooves, good formation, and no obvious defects. There are fewer pores, with a porosity of only 0.01%. Compared to the powder-free multi-layer deposition morphology, the formation is improved after adding Mg, mainly manifested as a smooth surface, glossy color, high distinguishability between each layer, and fewer grooves. Figure 11This section presents the surface roughness statistics for the side surfaces of multi-layer cross-sections. Taking a 100% Mg molded sample as an example, a region of approximately 7 mm was selected on the side surface for roughness statistics. It can be observed that the surface flatness varies within the range of 290-345 μm. The roughness statistics are shown in Figure 11c. The roughness Ra of 0Mg without powder is 120.65 μm, and the roughness changes after adding powder. The roughness Ra of 20% Mg is 114.04 μm, showing little change compared to the powder-free sample. The roughness Ra of 100% Mg is 65.15 μm, a decrease of 46% compared to the powder-free sample, indicating that the addition of powder affects the molding roughness.

[0033] From the perspective of cross-sectional morphology ( Figure 12 The top of the cross-section of the powder-free 0Mg layer shows a circular bulge, indicating that the melt flow at the top layer tends to flow downwards. With powder, the top of the 20% Mg layer is flatter, closer to an ellipse without bulges, indicating good melt fluidity and no downward movement. It solidifies simultaneously during deposition, preventing the melt from collapsing. 100% Mg is closer to meeting the requirements for a thin-walled structure, with better cross-sectional shape and no obvious defects. Compared to powder-free 0Mg, the forming accuracy changed somewhat after adding powder. The effective width WE of 20% Mg reached 10.74 mm, a 7.2% increase compared to 10.01 mm for powder-free 0Mg. The total width WT slightly increased, and the forming width coefficient η increased from 89% to 94%, indicating that the addition of powder improves forming efficiency and material utilization. The effective width WE of 100% Mg is 9.64 mm, and the total width WT is 10.12 mm, both lower than powder-free 0Mg. However, the forming width coefficient η increased from 89% to 95%, significantly improving forming accuracy and facilitating thin-walled layer deposition. The change in remelting depth is as follows Figure 12 As shown in f, the temperature initially increased and then decreased after adding powder compared to the powder-free 0Mg layer, and the changes in Δh1 and Δh2 were not significant, indicating that the heat input during the deposition process was relatively stable and the melting depth between the upper and lower layers did not change much. In general, adding powder is beneficial to improving the forming accuracy and further improving the material utilization rate.

[0034] Example 3: Study on the influence mechanism of different magnesium powder ratios on arc characteristics, droplet transfer and porosity The addition of synchronous powder particles in this invention significantly enhances the conductive channel formed between the laser and the electric arc. Figure 13 (j) This facilitates arc combustion, further promotes the droplet transfer process, improves transfer efficiency, and enhances the force on the molten pool, which is beneficial for the escape of pores within the molten pool and reduces porosity. For example... Figure 13 Images a and f clearly show the molten pool and the molten droplets suspended at the tip of the welding wire. However, even at the base current stage after adding powder, the arc continues to burn, which not only increases the arc's combustion efficiency but also reduces the time required for droplet transfer, thereby improving the molten pool formation efficiency. Figure 13 Even after adding powder, the droplet transfer mode remains dominated by fine droplets. Quantifying the droplet transfer time further illustrates that the addition of powder helps accelerate the droplet transfer process, improves droplet transfer efficiency, and further enhances forming quality, which is also the reason for the improved forming precision.

[0035] Figure 14 The diagram illustrates the influence of different magnesium powder contents (20% Mg, 100% Mg) on ​​arc stability. As shown, the relatively low Mg particle content at 20% Mg content has a smaller impact on the arc. The arc is compressed under the traction of the laser keyhole, resulting in a wider molten pool and better forming accuracy. However, the addition of powder causes some powder particles to be burned off and retained in the molten pool, existing as pores after cooling, leading to increased porosity and making them prone to fracture during plastic deformation. When 100% Mg powder is added, the Mg particle content increases significantly. On the one hand, this facilitates further arc compression, resulting in a thinner deposition layer and higher forming accuracy. On the other hand, the increased particle content strengthens the arc force within the molten pool, helping to agitate the molten pool and promote the escape of bubbles, thereby reducing porosity.

[0036] Example 4: Effect of different magnesium powder ratios on the evolution of sedimentary layer microstructure This embodiment demonstrates the significant impact of powder addition on the thermodynamic state and solidification behavior of the molten pool by characterizing the metallographic structure under different magnesium powder addition conditions. Figure 15 As shown, the systematic increase in the melt depth of the deposited layer after the addition of magnesium powder (from 1.3 mm to 2.0 mm) demonstrates that the powder significantly improves the heat utilization rate of the molten pool. Simultaneously, the microstructure changed from a mixed growth morphology under powder-free conditions to a dendritic-dominated growth mode after powder addition, particularly with the formation of abundant dendritic structures under 100% Mg conditions. This reflects the decisive role of increased heat input and changes in cooling rate brought about by powder addition on the microstructure, providing important evidence for understanding the relationship between composition, process, and microstructure.

[0037] Figure 16 , 17 18 represents the SEM and EDS test results for 0% Mg, 20% Mg, and 100% Mg, respectively. Figure 16It can be seen that under 0Mg, the aluminum-silicon ratio is close to 85:15 wt.%, and the silicon content is greater than 12% of the raw material composition. This is related to different regions; typically, the AZ and RZ1 regions contain a large amount of eutectic silicon, and these regions have higher silicon content. Under 20%Mg, the aluminum-silicon-magnesium ratio is 87:12:0.66 wt.%, with Mg mainly distributed in the aluminum-silicon eutectic region. EDS results at the eutectic point show that due to the precipitation of Mg2Si, the contents of both Si and Mg increase, and the aluminum-silicon-magnesium ratio is 77:17:6.62 wt.%. Under 100%Mg structure, the aluminum-silicon-magnesium ratio is 85:14.5:0.45 wt.%, and the aluminum-silicon-magnesium ratio at the aluminum-silicon eutectic point is 71:22:6.65 wt.%.

[0038] Figure 19 a~c represent XRD phase analysis, which revealed the presence of a new Mg2Si phase in addition to eutectic Si. Studies show that Mg2Si exhibits weaker corrosion resistance compared to the eutectic Si and Al matrix, frequently corroding and forming black pits within the eutectic silicon structure. This indicates that the Mg2Si phase is primarily distributed within the eutectic silicon. The addition of Mg powder helps induce the formation of the new Mg2Si phase, reducing deformation distortion and stress concentration around the eutectic silicon, thus improving mechanical properties and compensating for the adverse effects caused by increased porosity.

[0039] Example 5 Characterization of magnesium-silicon reinforced phase nanostructures and study on their interaction mechanism with dislocations This embodiment utilizes transmission electron microscopy (TEM) and characterization techniques such as EDS and FFT to confirm at the atomic / nanoscale that a Mg2Si reinforcing phase was successfully precipitated in the deposited structure after the addition of magnesium powder. Systematic TEM analysis of a 20% Mg deposit sample clarified the nanoscale structural characteristics of the deposited structure after the addition of magnesium powder. EDS lattice analysis first confirmed that the grain boundary region was mainly composed of α-Al and Mg2Si phases; further FFT analysis... Figure 20 k) and high-resolution diffraction spots (k) Figure 20 (j) The existence of the nanoscale Mg2Si precipitate was confirmed, and its face-centered cubic crystal structure was determined. Observation revealed that the Mg2Si phase exhibited a needle-like morphology and was incoherent with the aluminum matrix. Figure 20 l), whose adjacent crystal plane spacing along the [0-11] zone axis is 1.60 Å. More importantly, IFFT analysis ( Figure 20 (l) Clearly revealed the presence of numerous dislocation lines within the Mg2Si phase and at the second phase / matrix interface, indicating that the Mg2Si precipitate can effectively interact with dislocations, causing significant lattice distortion, thus providing a key microscopic mechanism basis for enhancing the mechanical properties of the deposited part.

[0040] like Figure 21Morphological analysis reveals that the second phase has undergone deformation, with a certain degree of dislocations occurring around the second-phase particles. Dislocations are lattice defects in materials that can move within the material, leading to plastic deformation. When external forces are applied to the material, the presence of the second-phase Mg2Si hinders dislocation movement. It also reduces deformation distortion and stress concentration around the eutectic silicon, contributing to improved mechanical properties and increasing the material's resistance to deformation and strength.

[0041] EBSD analysis of deposited tissues with different powder ratios showed that ( Figure 22 The addition of magnesium powder significantly altered the grain morphology and size. Under powder-free conditions (0 Mg), the microstructure consisted of dendrites in the arc zone and a mixture of dendrites and equiaxed crystals in the remelted zone. After adding magnesium powder, the microstructure became significantly coarser and dominated by dendrites: with 20% Mg, the equiaxed crystals in the remelted zone decreased, while columnar crystals increased; with 100% Mg, it completely transformed into coarse dendrites. Grain size statistics showed that from powder-free conditions (44.9 μm) to the addition of 20% Mg (64.8 μm) and 100% Mg (68.8 μm), the average grain size increased by 45% and 54%, respectively, demonstrating that the addition of magnesium powder significantly increased heat input, thereby promoting grain coarsening and dendritic formation.

[0042] Example 6: Evaluation of the Influence of Different Magnesium Powder Ratios on the Hardness and Uniformity of Deposited Components This embodiment systematically studies the effect of different magnesium powder addition amounts on the microhardness of deposited components, revealing the intrinsic relationship between composition, structure, and properties. Figure 23 The results show that adding 20% ​​Mg powder increased the average hardness from 69 HV to 80 HV, an increase of 14%, confirming that the addition of magnesium effectively improves the material's resistance to plastic deformation. Notably, the 100% Mg powder sample, while maintaining a high hardness (71 HV), significantly reduced its hardness variance to 11, exhibiting excellent performance uniformity. This indicates that the optimized powder ratio (100% Mg) not only achieves effective strengthening but also yields deposited components with highly consistent microstructure and properties, which is of great significance for ensuring the reliability of components in actual service.

[0043] Figure 24This is a statistical analysis of tensile curves for different powder ratios. Compared to 0Mg, the addition of powder reduces plasticity, and the curve breaks earlier, indicating a shorter time for plastic deformation and consequently, a lower elongation. The increase in the maximum ordinate of the curve indicates improved tensile strength. Under 0Mg powder-free conditions, the tensile strength is 227 MPa, and the elongation is 14.6%. After adding powder, the tensile strength of both 20%Mg and 100%Mg increases, both exceeding 227 MPa. However, the tensile strength of 20%Mg does not increase due to increased porosity, while 100%Mg reaches 255 MPa, a 12% increase compared to 0Mg. Furthermore, the elongation decreases compared to 0Mg, with 20%Mg dropping to 9.2%, due to increased porosity. 100%Mg shows the most significant performance improvement after powder addition, with an elongation of 14%.

[0044] Scanning electron microscopy analysis of the fracture morphology of the tensile specimens ( Figure 25 The results show that different magnesium powder ratios significantly affect the fracture mechanism and ductility. The 20% Mg sample exhibited numerous pores (porosity approximately 65%) and quasi-cleavage fracture characteristics dominated by small facets and dimples, leading to a significant decrease in ductility. In contrast, the 100% Mg sample showed a reduced porosity of approximately 40%, and the fracture surface consisted of uniformly sized and deep dimples, exhibiting typical ductile fracture, corresponding to its excellent elongation (14%) and tensile strength. These results confirm that optimizing the magnesium powder content can effectively reduce porosity defects and promote ductile fracture, which is key to achieving a balance between high strength and high ductility.

[0045] Example 7: Synergistic effect mechanism of magnesium powder addition on laser-arc composite additive manufacturing process and microstructure properties This embodiment is illustrated by... Figure 26 The mechanism diagram shown systematically elucidates the synergistic effect mechanism of magnesium powder in the laser-arc composite additive manufacturing process. During the peak arc phase, magnesium powder ionization increases the concentration of charged particles in the plasma, enhances the arc current density, and compresses the arc morphology. Figure 26 a, e). Simultaneously, the high-frequency oscillating laser intensely stirs the molten pool, creating localized turbulence, promoting thermal homogenization, and disrupting columnar crystal growth. The addition of magnesium powder further enhances the energy concentration of the mixed heat source, causing the molten pool morphology to develop towards a deeper and narrower direction, significantly increasing the depth of the remelted layer and reducing the width of the thin wall (a, e). Figure 26 i, j). During the arc baseline stage, laser thermal radiation accelerates the droplet transition and forms an enhanced conductive channel with the arc plasma, significantly improving arc stability (i, j). Figure 26 (b~d). The addition of an appropriate amount of magnesium powder not only increases the plasma density but also enhances the laser-induced plasma through the combustion effect, thereby improving the droplet transfer efficiency and making the morphology more stable. Figure 26(f~h). This synergistic effect of laser-arc-powder, although leading to dendrite coarsening to some extent due to increased heat input, has comprehensively improved the process stability and effectively enhanced the forming accuracy and density of the deposited parts, providing a theoretical basis for optimizing the deposition structure and properties.

[0046] In summary, this invention provides a laser-arc composite additive manufacturing device and method that deeply integrates high-frequency beam scanning with simultaneous wire and powder feeding technology. Through optimized integrated deposition head structure, precisely controlled wire and powder spatial layout, and a synergistically matched process parameter system, it successfully achieves coordinated control of the energy field and material field. This technical solution effectively solves the inherent technical problems of poor stability, low forming accuracy, and weak material composition control in traditional arc additive manufacturing processes. It not only significantly improves arc stability, droplet transfer efficiency, and forming accuracy through the synergistic effect of oscillating laser and active powder, but also achieves optimized deposition structure and directional generation of the Mg2Si strengthening phase through in-situ microalloying. Ultimately, the deposited component achieves high strength and high hardness while maintaining good plasticity matching and a low defect rate, providing a complete technical solution for low-cost, high-efficiency additive manufacturing of high-performance aluminum alloy components.

[0047] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0048] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0049] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0050] The above provides a detailed description of the laser arc composite additive manufacturing method and apparatus provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A laser-arc composite additive manufacturing apparatus, characterized in that, include: Laser emitting unit, beam scanning unit, arc generating unit, wire feeding mechanism, powder feeding mechanism and control unit; The control unit is communicatively connected to the laser emitting unit, beam scanning unit, arc generating unit, wire feeding mechanism, and powder feeding mechanism, and is used to adjust at least one parameter among laser power, scanning frequency, scanning diameter, arc current, wire feeding speed, powder feeding amount, powder feeding air flow rate, and wire-powder spacing.

2. The laser-arc composite additive manufacturing apparatus according to claim 1, characterized in that, The beam scanning unit is configured to make the laser beam oscillate in one of the following paths: circular, elliptical, figure-eight, or figure-infinity, with a scanning frequency of 200~400Hz and a scanning diameter of 1~2mm.

3. The laser-arc composite additive manufacturing apparatus according to claim 1, characterized in that, The spacing between the silk and powder is 4~6mm, the air flow rate for feeding powder is 2~4L / min, and the powder feeding amount is 1.5~2.5g / min.

4. The laser-arc composite additive manufacturing apparatus according to claim 1, characterized in that, The arc generating unit is configured to output a current of 120~130A, and the wire feeding mechanism is configured to feed wire at a speed of 3~5m / min.

5. The laser-arc composite additive manufacturing apparatus according to claim 1, characterized in that, The laser emitting unit outputs a laser power of 1~3kW and a laser incident angle of 20~30°.

6. An additive manufacturing method using the laser-arc composite additive manufacturing apparatus as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1: Provide a substrate and a filler material, wherein the filler material includes welding wire and metal powder; S2: Adjust the laser beam to oscillate with a preset scanning path and frequency, and synchronously control the wire feeding mechanism and powder feeding mechanism so that the welding wire and powder enter the arc area together. S3: The laser parameters, arc parameters, wire feeding parameters, and powder feeding parameters are adjusted in real time by the control unit to obtain the formed component.

7. The laser-arc composite additive manufacturing method according to claim 6, characterized in that, The S2 powder feeder delivers metal powder to the deposition area at a rate of 1.5~2.5 g / min.

8. The laser-arc composite additive manufacturing method according to claim 6, characterized in that, The S2 metal powder is magnesium powder; the magnesium powder accounts for 20-100% of the total weight of the powder.

9. The laser-arc composite additive manufacturing method according to claim 1, characterized in that, The aluminum alloy welding wire fed by the S2 wire feeding mechanism and the powder flow output by the powder feeder converge in the deposition area, and the distance between the welding wire axis and the powder flow axis is 4~6mm.

10. The laser-arc composite additive manufacturing method according to claim 1, characterized in that, The scanning frequency of the S2 laser beam is 200~400Hz, and the scanning diameter is 1.0~1.5mm.

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