A laser off-axis synergistic powder feeding assisted electric arc hybrid additive manufacturing method

Abstract

This invention discloses a laser-assisted off-axis powder feeding method for arc composite additive manufacturing. In the arc additive manufacturing process, high-melting-point powder is added to the molten pool, and simultaneously, a galvanometer laser is irradiated into the molten pool along a preset trajectory to increase convection, causing the powder to disperse and distribute within the molten pool. During solidification, the molten pool forms an arc additive manufacturing component with fine grains. The method includes the following steps: (1) tooling the welding torch, powder feeding tube, and galvanometer laser in a manner where the arc welding wire is in front and the laser is behind, adjusting the position of the powder feeding tube to ensure that the powder can enter the molten pool; (2) starting the additive manufacturing program and implementing laser-assisted powder feeding for arc composite additive manufacturing under a protective gas atmosphere. This invention introduces high-melting-point powder into the molten pool through laser-assisted off-axis powder feeding and disperses it, thereby promoting grain refinement, improving additive manufacturing efficiency, and effectively increasing the strength of the arc additive component, achieving efficient and high-quality arc additive manufacturing.

Description

Technical Field

[0001] This invention relates to the field of electric arc additive manufacturing technology, and specifically to a laser-paraxial co-feeding powder-assisted electric arc composite additive manufacturing method. Background Technology

[0002] Additive manufacturing achieves near-net-shape three-dimensional solid parts by using the principle of layer-by-layer material deposition. Powder melting and solidification additive manufacturing processes are currently the mainstream technology, including laser powder bed fusion and laser direct metal deposition. This additive manufacturing technology has significant advantages, but its cycle time is long and its efficiency is low. In recent years, wire additive manufacturing technology, represented by arc additive manufacturing, has emerged as a new additive manufacturing technology with a clear advantage of high efficiency. However, when the heat source changes from a high-energy-density laser to a low-energy-density electric arc, the heat input increases significantly. This high heat input from arc additive manufacturing leads to the formation of coarse columnar crystals, often exceeding millimeters in size, spanning multiple layer passes. These coarse columnar crystals cause anisotropy and reduce the mechanical properties of the additive parts, severely restricting the further development of arc additive manufacturing technology.

[0003] Most current research focuses on grain refinement through external field assistance methods, such as adding magnetic fields, ultrasonic fields, and synchronous rolling. However, the addition of external fields inevitably increases equipment complexity and affects accessibility. In recent years, introducing lasers into electric arcs to achieve laser-arc composite additive manufacturing is a promising additive manufacturing technology. Compared with traditional arc-wire additive manufacturing technology (Direct Energy Deposition-Arc, DED-Arc) that uses an electric arc as a single heat source, laser-arc composite additive manufacturing technology can significantly improve additive manufacturing efficiency and forming stability. Patent CN108393587 B improves overall forming and efficiency by introducing lasers into the TIG arc additive manufacturing process of aluminum alloys. However, the addition of lasers inevitably increases heat input, which further coarsens the grains. Patent CN202110387952.3 employs a combination of a side-axis powder-feeding laser melting deposition equipment and a MIG arc welding torch for additive manufacturing of aluminum-lithium alloys. Due to the special properties of aluminum-lithium alloys, it is difficult to draw wires from ingots, thus making it impossible to use wires as additive manufacturing raw materials to form large aluminum-lithium alloy components. Therefore, this patent uses an arc welding machine to process aluminum alloy wires, while simultaneously using a side-axis laser melting deposition additive manufacturing equipment to feed high-lithium-content aluminum-lithium alloy powders, realizing in-situ preparation of aluminum-lithium alloys through laser-arc composite additive manufacturing. However, the problems of grain coarsening and powder homogenization have not yet been effectively solved. Summary of the Invention

[0004] The technical problem this invention aims to solve is to provide a laser-paraxial co-feeding powder-assisted arc composite additive manufacturing method. This method involves simultaneously feeding high-melting-point powder via a paraxial feeder and adding a galvanometer laser paraxial feeder as an auxiliary agent to stir the molten pool, thereby achieving uniform powder distribution within the molten pool and effectively refining the grains through heterogeneous nucleation. The arc additive parts prepared using this method exhibit fine and uniform grains, and their tensile strength can be increased by more than 10%.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] This invention provides a laser-parallel co-feeding powder-assisted arc composite additive manufacturing method. In the additive manufacturing process, high melting point powder is added to the molten pool of the additive substrate, and at the same time, the galvanometer laser is irradiated into the molten pool according to a preset motion trajectory to increase the convection of the molten pool, so that the high melting point powder is dispersed and distributed in the molten pool. After the molten pool solidifies, it forms a stacked layer with fine grains.

[0007] Furthermore, the laser-paraxial co-feeding powder-assisted arc composite additive manufacturing method includes the following steps:

[0008] (1) Fixture the welding gun, powder feeding tube and galvanometer laser in the manner of arc welding wire in front and laser behind, and adjust the position of the powder feeding tube to ensure that high melting point powder can enter the molten pool.

[0009] (2) Under a protective atmosphere, the welding wire on the welding gun is heated to form a molten pool. High melting point powder is fed into the molten pool through the powder feeding pipe and dispersed in the molten pool under the irradiation of the galvanometer laser. After the molten pool solidifies, it forms a stacked layer with fine grains.

[0010] (3) Repeat step (2) to perform reciprocating additive manufacturing and obtain an electric arc additive component.

[0011] Furthermore, before tooling, the surface of the additive substrate to be soldered is sanded with sandpaper, the surface oil is cleaned and removed, and then it is dried and fixed on the workbench.

[0012] Furthermore, in step (1), the arc heat source of the welding torch is cold metal transfer welding, gas metal inert welding or non-gas metal inert welding.

[0013] Furthermore, in step (1), the distance between the arc welding wire after tooling and the laser filament is 3mm to 6mm. By controlling the filament distance within a suitable range, the stability of the droplet transfer is ensured, while simultaneously achieving the function of laser stirring the arc molten pool.

[0014] Further, in step (1), the position of the powder feeding pipe is adjusted so that the powder outlet is level with or lower than the welding torch and points towards the center of the molten pool.

[0015] Furthermore, in step (2), the powder feeding pipe delivers high melting point powder to the molten pool by air-carrying powder feeding. The gas used for air-carrying powder feeding is an inert gas with a pressure of not less than 0.05 MPa to ensure that the high melting point powder is successfully delivered to the molten pool.

[0016] Furthermore, in step (3), the reciprocating additive manufacturing process involves the direction of the next additive manufacturing pass being opposite to the direction of the previous pass.

[0017] Furthermore, the material of the additive substrate may be low-carbon steel, aluminum alloy, titanium alloy or nickel alloy, depending on the material to be added, but is not limited to the above materials.

[0018] Furthermore, the high melting point powder is a powder with a melting point higher than that of the molten pool, which exists stably in the molten pool and does not react, such as TiC powder, Y2O3 powder, Al2O3 powder, etc.

[0019] Furthermore, the particle size of the high melting point powder is 3μm to 60μm, more preferably 10μm to 30μm.

[0020] Furthermore, the galvanometer laser's trajectory is an O-shape or a figure-eight shape, and the filament spacing is always greater than 3mm during the additive manufacturing process. By irradiating the melt with the galvanometer laser along a specific trajectory, the high-melting-point powder delivered to the melt surface can be dispersed throughout the melt, preventing powder aggregation or uneven powder distribution that could lead to a decrease in heterogeneous nucleation rate or stress concentration inside the arc-manufactured component, thus affecting the mechanical properties of the additive component. Simultaneously, during the additive manufacturing process, the distance between the galvanometer laser spot and the welding wire is controlled to always be greater than 3mm, thereby ensuring the stability of the molten pool.

[0021] Furthermore, the scanning frequency of the galvanometer laser is not less than 50Hz, and the laser power is not less than 400W. By applying sufficiently high laser power, laser-assisted keyhole welding is formed, thereby effectively stirring the molten pool. However, the laser power should not be too high, as excessive laser power will melt too much of the previous layer and increase heat input. Therefore, the laser power needs to be adjusted according to the size of the arc molten pool to ensure effective stirring without increasing excessive heat input.

[0022] This invention uses high-melting-point micron-sized powder as filler powder. The stirring effect of the off-axis galvanometer laser is used to achieve uniform dispersion of the high-melting-point micron-sized powder in the molten pool. The uniformly dispersed powder can act as heterogeneous nucleation points during solidification, thereby refining the grains and inhibiting the growth of coarse columnar crystals. This minimizes the strength reduction and anisotropy caused by coarse columnar crystals, thereby improving the strength of arc additive manufacturing components.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] This invention utilizes a method that combines the application of a galvanometer laser and coordinated powder feeding during the arc additive manufacturing process. The arc is positioned in front, the powder feeding is in the middle, and the galvanometer laser is behind. The galvanometer laser increases convection in the molten pool, allowing high-melting-point powder to disperse and distribute within the pool. This achieves heterogeneous nucleation, promoting grain refinement and improving mechanical properties. The arc additive components prepared by this method have small (less than 100 μm) and relatively uniform internal grain sizes, resulting in a significant increase in strength (not less than 10%). This effectively reduces the performance degradation and anisotropy caused by coarse columnar grains generated during the arc additive manufacturing process, achieving highly efficient and high-quality arc additive manufacturing. Attached Figure Description

[0025] Figure 1 A schematic diagram of laser-arc composite additive manufacturing (a) and a schematic diagram of laser-paraxial co-feeding powder-assisted arc composite additive manufacturing (b);

[0026] Figure 2 Images (a-c) taken at different times using an Inconel 718 high-speed camera for laser-assisted powder feeding and arc-assisted composite additive manufacturing;

[0027] Figure 3 Electron backscatter diffraction pattern (a) for arc additive manufacturing of Inconel 718 and electron backscatter diffraction pattern (b) for laser-paraxial co-feeding powder-assisted arc composite additive manufacturing of Inconel 718;

[0028] Figure 4 Grain size distribution diagram of Inconel 718 for laser-offaxis co-feeding powder-assisted arc composite additive manufacturing;

[0029] Figure 5 Scanning electron microscope image of Inconel 718 for laser-assisted arc composite additive manufacturing with powder feeding and laser-assisted off-axis powder feeding;

[0030] Figure 6 High-speed photographic images (a) and metallographic images (b) of Inconel 718 for laser-paraxial co-feeding powder-assisted arc composite additive manufacturing;

[0031] Figure 7 Electron backscatter diffraction pattern (a) for arc additive manufacturing of ER2319 and electron backscatter diffraction pattern (b) for laser-paraxial co-feeding powder-assisted arc composite additive manufacturing of ER2319;

[0032] Figure 8 Electron backscattering diffraction pattern for laser-arc composite additive manufacturing of Inconel 718;

[0033] Figure 9Scanning electron microscope image of Inconel 718 fabricated using an arc composite additive manufacturing process for powder feeding assistance. Detailed Implementation

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0035] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0036] Example 1

[0037] This embodiment employs a laser-off-axis co-feeding powder-assisted arc composite additive manufacturing method for Inconel 718 alloy additive manufacturing. Q420 low-carbon steel plate is used as the substrate, and 1.2mm welding wire of [grade missing]. Inconel 718 welding wire (18), cold metal transfer welding (CMT) as the heat source, and TiC powder with a particle size of 25μm as the high-melting-point powder, such as... Figure 1 As shown in (b), the specific operation is as follows:

[0038] (1) Select 10mm thick Q420 low carbon steel as the substrate. After polishing the Q420 low carbon steel with 400 grit sandpaper, remove the surface oil stains with acetone, dry it, and fix it. Fix the CMT welding gun, powder feeding tube, and galvanometer laser in the manner of arc welding wire in front and laser behind, with a wire spacing of 3mm. The powder outlet of the powder feeding tube is flush with or lower than the welding gun and points to the center of the molten pool. Set the wire feeding speed of the CMT welding gun to 10m / min, the welding speed to 60cm / min, the arc current to 100%, and the wire extension to 14mm. The shielding gas is 100% Ar gas with a gas flow rate of 30L / min. The galvanometer laser power is 1.2kW and the galvanometer laser scanning frequency is 200Hz. The gas-carried powder feeding pressure is 0.07MPa.

[0039] (2) Under a protective atmosphere, along the direction of travel, the welding wire on the welding gun is heated by the electric arc to form a melt that enters the molten pool of the additive substrate. TiC powder is fed into the molten pool through the powder feeding pipe. Under the stirring action of the galvanometer laser with the O-shaped motion trajectory, TiC powder is dispersed in the melt and forms a deposited layer after melting and solidification.

[0040] (3) Repeat step (2) to perform reciprocating additive manufacturing and obtain an arc additive manufacturing component.

[0041] High-speed photography of the above additive manufacturing process, such as Figure 2 As shown, TiC powder successfully enters the molten pool through the powder feeding pipe, and then the TiC powder is further uniformly distributed in the molten pool by the effective stirring effect of the galvanometer laser.

[0042] Figure 3 (b) is the electron backscattering diffraction pattern of the arc additive manufacturing component prepared by the laser-paraxial co-feeding powder-assisted arc composite additive manufacturing method described above in this embodiment. As shown in the figure, the component prepared by the above method has a more uniform and finer grain size, achieving fine equiaxed crystals with a size less than 100 μm, and reducing anisotropy. The grain size distribution of the above arc additive manufacturing component is as follows: Figure 4 As shown, the grain size is mainly distributed within 100μm.

[0043] Figure 5 The image shows a scanning electron microscope (SEM) image of the arc additive manufacturing component prepared by the laser-paraxial co-feeding powder-assisted arc composite additive manufacturing method described above in this embodiment. As can be seen from the image, TiC powder is uniformly dispersed in the component.

[0044] Example 2

[0045] This embodiment employs a laser-off-axis co-feeding powder-assisted arc composite additive manufacturing method for Inconel 718 alloy additive manufacturing. Q420 low-carbon steel plate is used as the substrate, and 1.2mm welding wire of [grade missing]. Using Inconel 718 welding wire (18mm), cold metal transfer welding (CMT) as the heat source, and Y2O3 powder with a particle size of 25μm as the high-melting-point powder, the specific operation is as follows:

[0046] (1) Select 10mm thick Q420 low carbon steel as the substrate. After polishing the Q420 low carbon steel with 400 grit sandpaper, remove the surface oil stains with acetone, dry it, and fix it. Fix the CMT welding gun, powder feeding tube, and galvanometer laser in the manner of arc welding wire in front and laser behind, with a wire spacing of 3mm. The powder outlet of the powder feeding tube is flush with or lower than the welding gun and points to the center of the molten pool. Set the wire feeding speed of the CMT welding gun to 10m / min, the welding speed to 60cm / min, the arc current to 100%, and the wire extension to 14mm. The shielding gas is 100% Ar gas with a gas flow rate of 30L / min. The galvanometer laser power is 1.2kW and the galvanometer laser scanning frequency is 200Hz. The gas-carried powder feeding pressure is 0.07MPa.

[0047] (2) Under a protective atmosphere, along the direction of travel, the welding wire on the welding gun is heated by the electric arc to form a melt that enters the molten pool of the additive substrate. Y2O3 powder is fed into the molten pool through the powder feeding pipe. Under the stirring action of the galvanometer laser with the O-shaped motion trajectory, the Y2O3 powder is dispersed in the melt and forms a deposited layer after melting and solidification.

[0048] (3) Repeat step (2) to perform reciprocating additive manufacturing and obtain an arc additive manufacturing component.

[0049] Figure 6 The images (a) and (b) are high-speed photographs of the arc additive manufacturing component prepared by the laser-parallel co-feeding powder-assisted arc composite additive manufacturing method in this embodiment. As can be seen from the images, multiple passes of the component prepared by the above method show obvious equiaxed crystals (~100μm).

[0050] Example 3

[0051] This embodiment employs a laser-off-axis co-feeding powder-assisted arc composite additive manufacturing method for ER2319 alloy additive manufacturing. A 2219 aluminum alloy substrate is used as the substrate, 1.2mm ER2319 welding wire is used, cold metal transfer welding is used as the heat source, and 10μm TiC powder is used as the high-melting-point powder. The specific operation is as follows:

[0052] (1) Select 10mm thick 2219 aluminum alloy as the substrate. After polishing the 2219 aluminum alloy with 400 grit sandpaper, remove the surface oil stains with acetone, dry it and fix it. The CMT welding gun, powder feeding tube and galvanometer laser are tooled in the manner of arc welding wire in front and laser behind, with a wire spacing of 3mm. The powder outlet of the powder feeding tube is flush with or lower than the welding gun and points to the center of the molten pool. The wire feeding speed of the CMT welding gun is set to 8m / min, the welding speed is set to 70cm / min, the arc current is set to 100%, and the wire extension is 14mm. The shielding gas is 100% Ar gas with a gas flow rate of 30L / min. The galvanometer laser power is 800W and the galvanometer laser scanning frequency is 200Hz. The gas-carried powder feeding pressure is 0.07MPa.

[0053] (2) Under a protective atmosphere, along the direction of travel, the welding wire on the welding gun is heated by the electric arc to form a melt that enters the molten pool of the additive substrate. TiC powder is fed into the molten pool through the powder feeding pipe. Under the stirring action of the galvanometer laser with the O-shaped motion trajectory, TiC powder is dispersed in the melt and forms a deposited layer after melting and solidification.

[0054] (3) Repeat step (2) to perform reciprocating additive manufacturing and obtain an arc additive manufacturing component.

[0055] Figure 7(b) is the electron backscatter diffraction pattern of the arc additive manufacturing component prepared by the above-mentioned laser-paraxial co-feeding powder-assisted arc composite additive manufacturing method in this embodiment. As can be seen from the figure, the grain size of the component is small, including small equiaxed crystals with a size of less than 100 μm, and the anisotropy is reduced.

[0056] Comparative Example 1

[0057] This comparative example uses arc additive manufacturing to produce Inconel 718 alloy additive products, with Q420 low-carbon steel plate as the substrate and 1.2mm welding wire of grade [grade missing]. Using Inconel 718 welding wire (18mm), and cold metal transfer welding as the heat source, the specific operation is as follows:

[0058] (1) Select 10mm thick Q420 low carbon steel as the base plate. After polishing the Q420 low carbon steel with 400 grit sandpaper, remove the surface oil stains with acetone, dry it and fix it. Set the CMT welding gun fixture, set the wire feeding speed of the CMT welding gun to 10m / min, the welding speed to 60cm / min, the arc current to 100%, and the wire extension to 14mm. The shielding gas is 100% Ar gas and the gas flow rate is 30L / min.

[0059] (2) Under a protective atmosphere, along the direction of travel, the welding wire on the welding gun is heated by the electric arc to form a melt that enters the molten pool of the additive substrate and forms a deposited layer after solidification.

[0060] (3) Repeat step (2) to perform reciprocating additive manufacturing and obtain an arc additive manufacturing component.

[0061] Figure 3 (a) is the electron backscatter diffraction pattern of the arc additive manufacturing component prepared by the arc additive manufacturing method in this comparative example. As can be seen from the figure, the grain size of the component prepared by the above method is not uniform, and the size of most grains is much larger than that of the component prepared in Example 1.

[0062] Comparative Example 2

[0063] This comparative example uses a laser-arc composite additive manufacturing method to produce Inconel 718 alloy additive products. Q420 low-carbon steel plate is used as the substrate, and 1.2mm welding wire of [grade missing]. 18mm Inconel 718 welding wire, cold metal transfer soldering (CMT) as the heat source, such as... Figure 1 As shown in (a), the specific operation is as follows:

[0064] (1) Select 10mm thick Q420 low carbon steel as the substrate. After polishing the Q420 low carbon steel with 400 grit sandpaper, remove the surface oil stains with acetone, dry it and fix it. Fix the CMT welding gun and laser in the manner of arc welding wire in front and laser behind, with a wire spacing of 3mm. Set the wire feeding speed of the CMT welding gun to 10m / min, the welding speed to 60cm / min, the arc current to 100%, and the wire extension to 14mm. The shielding gas is 100% Ar gas with a gas flow rate of 30L / min. The laser power is 1.2kW and the laser scanning frequency is 200Hz.

[0065] (2) Under a protective atmosphere, along the direction of travel, the welding wire on the welding gun is heated by the electric arc to form a melt that enters the molten pool of the additive substrate. At the same time, the laser irradiates the molten pool, and the melt solidifies to form a deposited layer.

[0066] (3) Repeat step (2) to perform reciprocating additive manufacturing and obtain an arc additive manufacturing component.

[0067] Figure 8 The electron backscatter diffraction pattern of the arc additive manufacturing component prepared by the laser-arc composite additive manufacturing method is shown in the figure. As can be seen from the figure, the grains of the Inconel 718 component prepared by laser-arc composite additive manufacturing are still millimeter-sized coarse columnar crystals.

[0068] Comparative Example 3

[0069] This comparative example uses a powder-assisted arc composite additive manufacturing method to produce Inconel 718 alloy additive products. Q420 low-carbon steel plate is used as the substrate, and 1.2mm welding wire of [grade missing]. Using Inconel 718 welding wire (18mm), cold metal transfer welding (CMT) as the heat source, and TiC powder with a particle size of 25μm as the high-melting-point powder, the specific operation is as follows:

[0070] (1) Select 10mm thick Q420 low carbon steel as the substrate. After polishing the Q420 low carbon steel with 400 grit sandpaper, remove the surface oil stains with acetone, dry it, and fix it. Set the CMT welding gun and powder feeding tube fixture so that the powder outlet of the powder feeding tube is flush with or lower than the welding gun and points to the center of the molten pool. Set the wire feeding speed of the CMT welding gun to 10m / min, the welding speed to 60cm / min, the arc current to 100%, and the wire extension to 14mm. The shielding gas is 100% Ar gas with a gas flow rate of 30L / min. The gas-carried powder feeding pressure is 0.07MPa.

[0071] (2) Under a protective atmosphere, along the direction of travel, the welding wire on the welding gun is heated by the electric arc to form a melt that enters the molten pool of the additive substrate. TiC powder is fed into the molten pool through the powder feeding pipe and forms a deposited layer after melting and solidification.

[0072] (3) Repeat step (2) to perform reciprocating additive manufacturing and obtain an arc additive manufacturing component.

[0073] Figure 9 The image shows a scanning electron microscope (SEM) image of an arc additive manufacturing component prepared by the powder-assisted arc composite additive manufacturing method in this comparative example. As can be seen from the image, obvious TiC powder agglomeration occurs in the component prepared by the above method (black area in the image).

[0074] Comparative Example 4

[0075] This comparative example uses arc additive manufacturing to produce ER2319 alloy additive manufacturing. A 2219 aluminum alloy substrate is used as the substrate, 1.2mm ER2319 welding wire is used, and cold metal transfer welding is used as the heat source. The specific operation is as follows:

[0076] (1) Select 10mm thick 2219 aluminum alloy as the substrate. After polishing the 2219 aluminum alloy with 400 grit sandpaper, remove the surface oil stains with acetone, dry it and fix it. Set the CMT welding gun fixture and set the wire feeding speed of the CMT welding gun to 8m / min, the welding speed to 70cm / min, the arc current to 100%, and the wire extension to 14mm. The shielding gas is 100% Ar gas and the gas flow rate is 30L / min.

[0077] (2) Under a protective atmosphere, along the direction of travel, the welding wire on the welding gun is heated by the electric arc to form a melt that enters the molten pool of the additive substrate and forms a deposited layer after solidification.

[0078] (3) Repeat step (2) to perform reciprocating additive manufacturing and obtain an arc additive manufacturing component.

[0079] Figure 7 (a) is the electron backscatter diffraction pattern of the arc additive manufacturing component prepared by the arc additive manufacturing method in this comparative example. As can be seen from the figure, the uniformity of grain size in the component prepared by the above method is poor, and the size of most grains is larger than that of the component prepared in Example 3.

[0080] Performance Characterization

[0081] (1) Grain size distribution of arc additive components prepared by different additive manufacturing methods

[0082] Examples 1 and Comparative Examples 1-3 used different additive manufacturing methods to additively manufacture Q420 low-carbon steel plates. The grain size distribution of the prepared arc additive components is shown in Table 1 below:

[0083] Table 1. Grain size distribution of arc additive components prepared by different additive manufacturing methods

[0084] sample Additive manufacturing methods Grain size distribution (average) Example 1 Laser-to-offset (TiC) assisted arc composite additive manufacturing components 16-499μm (~76μm) Example 2 <![CDATA[Laser paraxial powder feeding (Y2O3) assisted arc hybrid additive manufacturing component]]> 16-450μm (~70μm) Comparative Example 1 Arc additive manufacturing components millimeter level Comparative Example 2 Laser-arc composite additive manufacturing components millimeter level Comparative Example 3 Powder-fed (TiC) assisted arc composite additive manufacturing components 40-599μm (~100μm)

[0085] As shown in Table 1, powder-assisted arc composite additive manufacturing can effectively reduce grain size. However, when using a single powder-assisted arc for additive manufacturing, the high-melting-point powder introduced is prone to local agglomeration in the component, affecting the mechanical properties of the component.

[0086] (2) Strength of arc additive components prepared by different additive manufacturing methods

[0087] The tensile strength of the additive components prepared in the above embodiments and comparative examples was tested, and the test results are shown in Table 2 below:

[0088] Table 2 Strength of Arc Additive Components Prepared by Different Additive Manufacturing Methods

[0089]

[0090]

[0091] As shown in Table 2, compared with arc additive manufacturing, the tensile strength of components prepared by the laser-assisted arc composite additive manufacturing method described in this invention is significantly improved. Specifically, the tensile strength of Inconel 718 alloy components is increased by 10%, and the tensile strength of ER2319 alloy components is increased by 15%. However, the tensile strength of components prepared by laser-assisted arc additive manufacturing is almost unchanged. The tensile strength of components prepared by the powder-assisted arc composite additive manufacturing method is improved due to the refinement of grain size. However, due to the uneven distribution of powder in the components, there is obvious agglomeration, which to some extent affects the strength of the components.

[0092] The embodiments described above are merely preferred examples to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A laser-paraxial co-feeding powder-assisted arc composite additive manufacturing method, characterized in that, In the additive manufacturing process, high-melting-point powder is added to the molten pool of the additive substrate, and a galvanometer laser is simultaneously irradiated into the molten pool according to a preset trajectory to increase convection, causing the high-melting-point powder to disperse and distribute within the molten pool. After solidification, the molten pool forms an accumulation layer with fine grains. The high-melting-point powder is a powder with a melting point higher than that of the molten pool, which exists stably in the molten pool and does not react. The high-melting-point powder is selected from one or more of TiC powder, Y2O3 powder, and Al2O3 powder. The trajectory of the galvanometer laser is an O-shape or a figure-eight shape. The particle size of the high-melting-point powder is 10 μm to 30 μm. The additive substrate is made of low-carbon steel or aluminum alloy; the scanning frequency of the galvanometer laser is 50-200 Hz, and the laser power is 400-1200 W. The laser-paraxial co-feeding powder-assisted arc composite additive manufacturing method includes the following steps: (1) Fixture the welding gun, powder feeding tube and galvanometer laser in the manner of arc welding wire in front and laser behind, adjust the position of the powder feeding tube to ensure that high melting point powder can enter the molten pool; the distance between the arc welding wire and the laser filament after fixture is 3 mm to 6 mm. (2) Under a protective atmosphere, the welding wire on the welding gun is heated to form a molten pool. High melting point powder is fed into the molten pool through the powder feeding pipe and dispersed in the molten pool under the irradiation of the galvanometer laser. After the molten pool solidifies, it forms a stacked layer with fine grains. (3) Repeat step (2) to perform reciprocating additive manufacturing and obtain an electric arc additive component.

2. The laser-paraxial co-feeding powder-assisted arc composite additive manufacturing method according to claim 1, characterized in that, In step (1), the arc heat source of the welding torch is cold metal transfer welding, gas metal arc welding or non-gas metal arc welding.

3. The laser-paraxial co-feeding powder-assisted arc composite additive manufacturing method according to claim 1, characterized in that, In step (1), adjust the position of the powder feeding pipe so that the powder outlet of the powder feeding pipe is level with or lower than the welding torch and points towards the center of the molten pool.

4. The laser-paraxial co-feeding powder-assisted arc composite additive manufacturing method according to claim 1, characterized in that, In step (2), the powder feeding pipe delivers high melting point powder to the molten pool by air-carrying powder feeding. The gas used for air-carrying powder feeding is an inert gas with a pressure of not less than 0.05 MPa.

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