Laser arc composite additive machining method

Abstract

The invention relates to a laser arc composite additive machining method, which belongs to the technical field of additive manufacturing, and comprises the following steps: conveying a wire and connecting a fuse power supply to the wire; a first composite laser beam and a second composite laser beam are emitted, the first composite laser beam is adjusted to be closer to the wire than the second composite laser beam, and the first composite laser beam, the second composite laser beam and the electric arc act on the base material to form a molten pool; high-melting-point powder is conveyed to the high-energy area of the molten pool, matrix powder is conveyed to the medium-energy area of the molten pool, the high-melting-point powder and the substrate have preferential absorptivity for the wavelength laser with the maximum power proportion in the first composite laser beam, and the matrix powder has preferential absorptivity for the wavelength laser with the maximum power proportion in the second composite laser beam. The method has the effects that multiple materials are efficiently melted, energy is reasonably matched, and components are evenly distributed in the additive manufacturing process.

Description

Technical Field

[0001] This application relates to the field of additive manufacturing technology, and particularly to a laser-arc hybrid additive manufacturing method. Background Art

[0002] As an advanced manufacturing process, additive manufacturing has been widely applied in the rapid prototyping of metal parts and the manufacturing of complex structures. According to different heat source types, common additive manufacturing technologies include those based on laser heat sources or arc heat sources, etc.; in terms of material feeding forms, wire feeding or powder feeding is often used, and in some processes, an attempt is also made to use both simultaneously to improve deposition efficiency and material adaptability.

[0003] In practical applications, to meet the functional requirements of high-performance structural components, two or more metal materials with different physical properties or compositional functions are often introduced during the additive manufacturing process, such as high-melting-point strengthening phase powder materials and medium-melting-point matrix materials, or some functional metal powders with special properties. To improve the forming efficiency, these materials are often fed into the same molten pool area simultaneously and melted synergistically. However, the traditional additive manufacturing processes applied to high-throughput materials have the following problems.

[0004] Firstly, in the manufacturing of composite components or gradient structures, a variety of powder materials such as high-melting-point alloys, matrix metals, and fluxes are often required to be used simultaneously. If all the powders are uniformly fed into the center of the molten pool (i.e., the high-energy area), it is easy to cause over-melting of medium- and low-melting-point materials or even element burnout, resulting in alloy composition segregation and tissue coarsening, seriously affecting the properties of the deposited layer. However, if materials with different melting points are fed into areas with appropriate temperatures in the molten pool, for example, medium-melting-point materials are fed into the medium-energy area and low-melting-point materials are fed into the low-energy area, there will be insufficient mixing of each component in the molten pool during the deposition process, and it is extremely easy to form microsegregation or layered structures, affecting the stability of subsequent mechanical properties. Moreover, the existing additive manufacturing methods generally use a single wavelength of laser or a composite laser for additive manufacturing. However, different materials have significantly different absorption efficiencies for lasers with different wavelengths, and the absorption rate of some powders for this single laser is extremely low, which will lead to the reflection or dissipation of laser energy, not only causing energy waste but also reducing the melting efficiency and forming quality.

[0005] In summary, the existing additive manufacturing processes have problems such as difficult control of multi-material melting, low energy utilization efficiency, and uneven mixing of components. Summary of the Invention

[0006] In order to achieve the effects of efficient melting of multi-materials, reasonable energy matching, and uniform distribution of components in additive manufacturing, this application provides a laser-arc hybrid additive manufacturing method.

[0007] A laser-arc hybrid additive manufacturing method provided by this application adopts the following technical solution: A laser-arc hybrid additive manufacturing method includes the following steps: conveying a wire and connecting a wire melting power supply to the wire; Emitting a first composite laser beam and a second composite laser beam, and adjusting the first composite laser beam to be closer to the wire than the second composite laser beam. The first composite laser beam, the second composite laser beam, and the arc act on a substrate to form a molten pool; Conveying high-melting-point powder to the high-energy region of the molten pool and conveying matrix powder to the medium-energy region of the molten pool. The high-melting-point powder and the substrate have a preferential absorption property for the laser with the largest power proportion wavelength in the first composite laser beam, and the matrix powder has a preferential absorption property for the laser with the largest power proportion wavelength in the second composite laser beam.

[0008] By adopting the above technical solution, the first composite laser beam is used in cooperation with the arc to act on the high-energy region, which can quickly melt the high-melting-point powder; the second composite laser beam acts on the medium-energy region, which can efficiently melt the medium-melting-point matrix powder; the arc acts on the wire, which can promote the rapid melting of the high-melting-point wire. According to the absorption characteristics of each material for different wavelength lasers, the beam is designed to avoid energy waste and improve the melting efficiency; Moreover, due to the strong molten pool disturbance and stirring ability of the arc, it can effectively improve the degree of fusion of materials from different sources in the molten pool and avoid the problem of uneven composition caused by powder feeding in different zones; at the same time, as the deposition head moves, the molten pool area dynamically transfers, which is conducive to further mixing; As the deposition head moves, the second composite laser beam acting on the medium-energy region at the rear end of the molten pool enters the high-energy region at the front end of the molten pool, which helps to reduce the cooling rate of the high-energy region, relieve the thermal stress concentration, and reduce defects such as cold cracks and interlayer separation; after the high-energy region of the molten pool enters the medium-energy region at the front end of the molten pool, it can also supplement the high-melting-point wire and powder, which is beneficial to improving the height and density of the deposited layer; Since a variety of powders are quickly melted and stirred and mixed in the molten pool, but there will still be mixed unmelted powder in the molten pool. Therefore, in the composite laser beam, the auxiliary wavelength laser with a relatively small power proportion (such as the red light component in blue light) can play a role in adjusting the laser to achieve auxiliary melting and reducing the inclusion of unmelted powder; And the auxiliary wavelength laser with a relatively small power proportion can avoid the sudden change of energy distribution caused by the direct switching of the laser wavelength, maintain the continuity of the overall molten pool thermal field, and thus reduce the microcracks or stress concentration caused by the severe change of the boundary temperature difference.

[0009] Optionally, a third composite laser beam is emitted, the second composite laser beam is adjusted to be closer to the wire than the third composite laser beam, and the third composite laser beam acts on the rear section of the molten pool, and functional powder materials are transported to the low-energy area of the rear section of the molten pool. The functional powder materials have preferential absorption of the laser with the largest power proportion in the third composite laser beam, and the absorption rate of the matrix powder materials for the laser with the largest power proportion in the third composite laser beam is less than 35%.

[0010] By adopting the above technical solution, the third composite laser beam is arranged in the low-energy area at the rear end of the molten pool and is specifically used for melting low-melting-point functional powder materials, so as to form a functional coating or a functional area (such as an anti-corrosion layer, a conductive layer, an optical reflection layer, etc.) on the surface of the stacking layer without interfering with the forming process of the main alloy; Since the absorption rate of the matrix powder materials for the main wavelength laser in the third composite laser beam is lower than 35%, the laser energy of the third composite laser beam mainly acts on the functional powder materials, avoiding the risk of repeated heating and over-melting of the matrix material. At the same time, the third composite laser beam can control the temperature slowdown of the newly formed stacking layer in the rear section of the molten pool, achieving the effect of annealing treatment, helping to release thermal stress and slow down the cooling rate.

[0011] Optionally, an on-line vision detection system detects the surface roughness of the current deposition layer, and uses the first laser to remelt the area where the surface roughness of the current deposition layer does not meet the standard. The matrix powder materials have preferential absorption of the first laser.

[0012] By adopting the above technical solution, since the matrix powder materials have preferential absorption of the main wavelength of the first laser, the laser energy is mainly concentrated on the matrix material to be remelted on the surface, realizing rapid and shallow micro-melting repair, concentrating the laser energy on the surface of the material in the rough area, and having the least influence on the lower-layer structure during the remelting process, avoiding excessive melting depth from causing tissue changes or thermal cracks.

[0013] Optionally, a second laser is added to cooperate with the first laser to remelt the area where the surface roughness of the pre-deposited layer does not meet the standard. The absorption rate of the matrix powder materials for the second laser is less than 35%, and the power density of the first laser is set to be greater than that of the second laser, and the light spot of the first laser is located within the coverage range of the light spot of the second laser.

[0014] By adopting the above technical solution, the wavelength of the first laser matches the absorption peak of the matrix material, has a high power density and is focused on the rough defect area, quickly melting the micro-protrusions to achieve surface micro-planarization. The second laser has a lower power density and a larger light spot range, annealing the periphery of the rough area. Since the absorption rate of the matrix material for it is less than 35%, the second laser acts on the inner layer of the material more through heat conduction to achieve the purpose of annealing, realizing tissue softening and thermal stress relief.

[0015] Optionally, the high melting point powder, the matrix powder, and the functional powder all adopt the phase difference powder feeding technology, and the high melting point powder, the matrix powder, and the functional powder are alternately conveyed at a specified frequency.

[0016] By adopting the above technical solution, each nozzle works alternately within a specified frequency range. Through phase difference control, only some nozzles are in the working state at the same moment, which can effectively avoid phenomena such as powder flow interference, occlusion, and collision when multiple nozzles feed powder simultaneously.

[0017] Optionally, the high melting point powder surrounds the wire guiding tube and is conveyed coaxially with the wire, and the wire guiding tube preheats the high melting point powder.

[0018] By adopting the above technical solution, the wire guiding tube has a Joule heat effect due to being energized during the arc additive manufacturing process, which can preheat the high melting point powder conveyed coaxially around it. When the powder enters the molten pool, it is already in a relatively high temperature state, which can significantly reduce the burden of subsequent laser or arc energy, improve the melting rate of the high melting point material, enhance the deposition efficiency, avoid inclusions or poor fusion caused by insufficient melting, and the high melting point powder surrounds the wire guiding tube and is conveyed coaxially with the wire, enabling more high melting point powder to be preheated within a unit time.

[0019] Optionally, adjust the powder feeding elevation angle of the high melting point powder so that the main axis of the injection path of the high melting point powder penetrates from the top of the high energy area and exits from the bottom of the high energy area.

[0020] By adopting the above technical solution, such a design is beneficial to prolong the residence time of the high melting point powder in the high energy area of the molten pool, enabling the high melting point powder to fully absorb energy and be fully heated, improving the melting efficiency, reducing the probability of unmelted particles, and ensuring the material fusion quality.

[0021] Optionally, the high melting point powder is conveyed coaxially around the first composite laser beam, the matrix material is conveyed coaxially around the second composite laser beam, and the functional powder is conveyed coaxially around the third composite laser beam.

[0022] By adopting the above technical solution, the powder can be sent out evenly around the laser beam. The powder can be evenly distributed around the laser, enabling the powder to uniformly absorb the laser energy. Compared with the traditional single-side powder feeding method, this uniform distribution allows more powder to directly contact the high temperature area, be fully melted, and reduces the waste of some powder that fails to enter the laser irradiation range.

[0023] Optionally, increase the power of the first composite laser beam and the second composite laser beam in the front section of the molten pool, and reduce the power of the first composite laser beam and the second composite laser beam in the rear section of the molten pool.

[0024] By adopting the above technical solution, laser energy input is increased at the front end of the molten pool to promote the rapid melting of powder and wire, improving the additive manufacturing efficiency; the laser energy is appropriately reduced at the rear end of the molten pool to avoid uneven surface caused by excessive melting.

[0025] Optionally, the powder feeding amount of the high melting point powder and the matrix powder in the front section of the molten pool is increased, and the powder feeding amount of the high melting point powder and the matrix powder in the rear section of the molten pool is reduced.

[0026] By adopting the above technical solution, the input amount of high melting point powder and matrix powder is increased in the front section area of the molten pool. Combining with the relatively high laser power in this area, more materials can be melted in time, improving the forming volume corresponding to unit laser energy, and being energy-saving and efficient. While reducing the powder input in the rear section of the molten pool just matches its lower laser energy input, avoiding the residue or accumulation of materials due to insufficient melting.

[0027] In summary, the present application includes at least one of the following beneficial technical effects: 1. The first composite laser beam is combined with the arc to act on the high-energy area, which can rapidly melt the high melting point powder; the second composite laser beam acts on the medium-energy area, which can efficiently melt the medium melting point matrix powder; the arc acts on the wire, which can promote the rapid melting of the high melting point wire. According to the absorption characteristics of different materials for laser with different wavelengths, the beam is designed to avoid energy waste and improve the melting efficiency; 2. Since the arc has strong molten pool disturbance and stirring ability, it can effectively improve the fusion degree of materials from different sources in the molten pool, avoiding the problem of uneven composition caused by sectional powder feeding; at the same time, as the deposition head moves, the molten pool area dynamically transfers, which is conducive to further mixing; 3. As the deposition head moves, the second composite laser beam acting on the medium-energy area at the rear end of the molten pool enters the high-energy area at the front end of the molten pool, which helps to reduce the cooling rate in the high-energy area, relieve the thermal stress concentration, and reduce defects such as cold cracks and interlayer separation; and after the high-energy area of the molten pool enters the medium-energy area at the front end of the molten pool, it can replenish the high melting point wire and powder, which is beneficial to improving the height and density of the deposited layer; 4. The laser energy of the third composite laser beam mainly acts on the functional powder, avoiding the risk of repeated heating and over-melting of the matrix material. At the same time, the third composite laser beam can control the temperature slowdown of the newly formed deposited layer in the rear section of the molten pool, achieving the effect of annealing treatment, which helps to release the thermal stress and slow down the cooling rate; 5. During the remelting process, the first laser wavelength matches the absorption peak of the substrate material, has a high power density, and is focused on the rough defect area, quickly melting the micro-protrusions to achieve surface micro-planarization. The second laser has a lower power density and a larger spot range, annealing the periphery of the rough area. Since the absorption rate of the substrate material for it is less than 35%, the second laser acts on the inner layer of the material more through heat conduction to achieve the annealing purpose, realizing tissue softening and thermal stress relief. Description of the Drawings

[0028] Figure 1 It is a schematic diagram of the arrangement modes of the first composite laser beam, the second composite laser beam, the third composite laser beam, the wire material, the high melting point powder, the substrate powder, and the functional powder in Embodiment 1 of the present application.

[0029] Figure 2 It is a schematic diagram for embodying the arrangement modes of the first laser and the second laser during the remelting process in Embodiment 1 of the present application.

[0030] Figure 3 It is a flowchart of Embodiment 1 of the present application.

[0031] Description of the reference numerals: 11, the first composite laser beam; 12, the second composite laser beam; 13, the third composite laser beam; 14, the first laser; 15, the second laser; 21, the wire material; 22, the high melting point powder; 23, the substrate powder; 24, the functional powder; 3, the molten pool; 31, the high energy area; 32, the medium energy area; 33, the low energy area. Detailed Embodiments

[0032] The following further elaborates on the present application Figures 1-3 in conjunction with the attached drawings.

[0033] Embodiment 1 Embodiment 1 of the present application discloses a laser-arc hybrid additive manufacturing method.

[0034] As Figure 1 , Figure 2 and Figure 3 , the laser-arc hybrid additive manufacturing method includes the following steps: S1. Connect the wire guiding tube to the MIG or MAG additive fusing power supply, set the arc voltage at 28 - 32 V and the wire feeding speed at 5 - 8 m / min, so that the arc is ignited and melts the wire material 21. The wire feeding assembly continuously feeds the ER70S-6 carbon steel welding wire with a diameter of 1.2 mm into the molten pool 3 area formed by the arc in a direction perpendicular to the substrate, and the arc current is controlled within the range of 180 - 220 A. The arc first quickly melts the wire material 21 to form a molten pool 3 with a depth of about 3 - 5 mm, providing a basis for the subsequent interaction between the laser and the powder.

[0035] S2. After the electric arc is ignited, adjust the positions of multiple lasers, and according to the characteristics of the raw material, emit the first composite laser beam 11, the second composite laser beam 12, and the third composite laser beam 13 into the molten pool 3, so that the first composite laser beam 11 is closer to the wire 21 than the second composite laser beam 12, and the second composite laser beam 12 is closer to the wire 21 than the third composite laser beam 13.

[0036] In the embodiment of the present application, both the first composite laser beam 11 and the second composite laser beam 12 are provided with two beams, and the third composite laser beam 13 is provided with one beam. The two first composite laser beams 11 are symmetrically arranged about the central axis of the wire 21, the two second composite laser beams 12 are symmetrically arranged about the central axis of the wire 21, and the first composite laser beam 11, the second composite laser beam 12, and the third composite laser beam 13 intersect at a point with the central axis of the wire 21.

[0037] One first composite laser beam 11, one second composite laser beam 12, and the third composite laser beam 13 are incident from the rear section of the molten pool 3, and the other first composite laser beam 11 and the other second composite laser beam 12 are incident from the front section of the molten pool 3.

[0038] The first composite laser beam 11, the second composite laser beam 12, and the third composite laser beam 13 can be realized by devices such as a multi-wavelength semiconductor laser beam combining module / a dual-wavelength fiber coupling system, etc. In the embodiment of the present application, the first composite laser beam 11 is a mixed beam of 1064nm infrared light and 450nm blue light with a power ratio of 7:3, the second composite laser beam 12 is a mixed beam of 1064nm infrared light and 450nm blue light with a power ratio of 2:8, and the third composite laser beam 13 is a mixed beam of 1064nm infrared light and 450nm blue light with a power ratio of 9:1; The first composite laser beam 11 is 2 - 3mm closer to the central axis 2 - 3 of the wire 21 than the second composite laser beam 12, and the second composite laser beam 12 is 4 - 5mm closer to the central axis of the wire 21 than the third composite laser beam 13.

[0039] S3. Adopt a coaxial powder feeding nozzle to coaxially transport the high melting point powder 22 and the first composite laser beam 11 to the high energy area 31 of the molten pool 3, coaxially transport the matrix powder 23 and the second composite laser beam 12 to the medium energy area 32 of the molten pool 3, and coaxially transport the functional powder 24 and the third composite laser beam 13 to the low energy area 33 at the rear section of the molten pool 3.

[0040] The high-melting-point powder material 22 and the substrate have a preferential absorption property for the laser with the largest power proportion wavelength in the first composite laser beam 11. The matrix powder material 23 has a preferential absorption property for the laser with the largest power proportion wavelength in the second composite laser beam 12. The functional powder material 24 has a preferential absorption property for the laser with the largest power proportion wavelength in the third composite laser beam 13. The absorption rate of the matrix powder material 23 for the laser with the largest power proportion wavelength in the third composite laser beam 13 is less than 35%.

[0041] In the embodiment of the present application, the high-melting-point powder material 22 is WC ceramic powder with a particle size of 45 - 105 μm, and is transported to the high-energy area 31 of the molten pool 3 in the form of a coaxial annular flow with the first composite laser beam 11, and the powder feeding rate is 80 - 120 g / min. The matrix powder material 23 is 316L stainless steel with a particle size of 53 - 150 μm, and is transported to the medium-energy area 32 of the molten pool 3 in the form of a coaxial annular flow with the second composite laser beam 12, and the powder feeding rate is 150 - 200 g / min. The functional powder material 24 is 316L nickel-based powder with a particle size of 53 - 150 μm, and is transported to the low-energy area 33 of the molten pool 3 in the form of a coaxial annular flow with the third composite laser beam 13, and the powder feeding rate is 20 - 40 g / min. Among them: The absorption rate of WC ceramic powder for 1064 nm laser reaches 58% ± 3% The absorption rate of 316L stainless steel powder for 450 nm laser reaches 47% ± 2% The absorption rate of nickel-based powder for 1064 nm laser reaches 72% ± 5%.

[0042] Through the independent control of 5 coaxial powder feeding nozzles for the matrix powder material 23, the high-melting-point powder material 22 is transported to the front high-energy area 31 of the molten pool 3 by the 1st coaxial powder feeding nozzle, the high-melting-point powder material 22 is transported to the rear high-energy area 31 of the molten pool 3 by the 2nd coaxial powder feeding nozzle, the matrix powder material 23 is transported to the front medium-energy area 32 of the molten pool 3 by the 3rd coaxial powder feeding nozzle, the matrix powder material 23 is transported to the rear medium-energy area 32 of the molten pool 3 by the 4th coaxial powder feeding nozzle, and the functional powder material 24 is transported to the rear low-energy area 33 of the molten pool 3 by the 5th coaxial powder feeding nozzle.

[0043] S4. Adjust the powder feeding elevation angle of the high-melting-point powder material 22 to 55° ± 5°, so that the main axis of the powder jet trajectory of the high-melting-point powder material 22 penetrates from the top of the high-energy area 31 (temperature about 2800 °C), passes through the bottom of the molten pool 3 (temperature about 1600 °C), and the residence time of the powder in the high-energy area 31 of the molten pool 3 is extended to 0.8 - 1.2 seconds (the conventional process is 0.3 - 0.5 seconds).

[0044] S5. The high-melting-point powder material 22, the matrix powder material 23, and the functional powder material 24 all adopt the phase difference powder feeding technology, and the high-melting-point powder material 22, the matrix powder material 23, and the functional powder material 24 are alternately transported at a frequency of 0.5 - 2 Hz.

[0045] In the embodiments of the present application, the nozzles numbered 1-5 alternately convey powder at a frequency of 1 Hz.

[0046] S6. Increase the power of the first composite laser beam 11 at the front section of the molten pool 3 to 1200 W ± 50 W (20% higher than the power of the first composite laser beam 11 at the rear section of the molten pool 3), and increase the power of the second composite laser beam 12 at the front section of the molten pool 3 to 850 W ± 30 W; Reduce the power of the first composite laser beam 11 at the rear section of the molten pool 3 to 900 W, and reduce the power of the second composite laser beam 12 at the rear section of the molten pool 3 to 600 W, so as to increase the peak temperature at the front section of the molten pool 3 by about 300 °C.

[0047] S7. Increase the powder feeding amounts of the high-melting-point powder 22 and the matrix powder 23 at the front section of the molten pool 3, and reduce the powder feeding amounts of the high-melting-point powder 22 and the matrix powder 23 at the rear section of the molten pool 3.

[0048] In the embodiments of the present application, the flow rate of the 1st coaxial powder feeding nozzle is 80 g / min, the flow rate of the 2nd coaxial powder feeding nozzle is 60 g / min, the flow rate of the 3rd coaxial powder feeding nozzle is 150 g / min, the flow rate of the 4th coaxial powder feeding nozzle is 120 g / min, and the flow rate of the 5th coaxial powder feeding nozzle is 25 g / min. The coaxial powder feeding nozzles are commercially available S8. The coaxial powder feeding nozzle and the wire feeding assembly move synchronously at a speed of 8-12 mm / s for layer deposition. An online vision system (equipped with a 200-μm laser line scanning module) is used to detect the surface roughness in real time, and the coordinates of the area where Ra > 8 μm are marked (the detection accuracy is ±0.5 μm).

[0049] S9. The unqualified area is remelted by sending the first laser 14 and the second laser 15. The first laser 14 is 450-nm blue light, with a power density of 2×10 4 W / cm² and a spot diameter of 0.3 mm. The second laser 15 is 1064-nm infrared light, with a power density of 5×10³ W / cm² and a spot diameter of 1.2 mm. And the spot of the first laser 14 is completely nested within the coverage range of the spot of the second laser 15. After remelting, the surface roughness Ra is reduced to 2.8-3.2 μm (62% ± 5% lower than that before repair), and the depth of the remelted layer is controlled within 0.2-0.3 mm (about 12% of the total thickness of the deposited layer).

[0050] In the embodiments of the present application, the first laser 14 and the second laser 15 can be emitted through any two of the coaxial powder feeding nozzles numbered 1-5, but it is necessary to wait until the current layer deposition is completed. The first laser 14 and the second laser 15 can also be emitted by two other laser heads, but these two laser heads need to wait for 2-5 s to start after detecting the unqualified area.

[0051] Moreover, the matrix powder 23 has a preferential absorption of the first laser 14, and the absorption rate of the second laser 15 is less than 35%. In the embodiment of the present application, the first laser 14 is blue light with a power density of 2×10^4 W / cm², the second laser 15 is infrared light with a power density of 5×10^3 W / cm², and the remelting depth is controlled within 10%-15% of the layer thickness. Micro-region refinement is achieved through the high surface absorption characteristics of blue light, and Ra can be reduced to less than 3μm.

[0052] The implementation principle of the embodiment of the present application is as follows: The first composite laser beam 11 acts on the high-energy region 31 in cooperation with the arc, which can quickly melt the high-melting-point powder 22; the second composite laser beam 12 acts on the medium-energy region 32, which can efficiently melt the matrix powder 23 with a medium melting point; the arc acts on the wire 21, which can promote the rapid melting of the high-melting-point wire 21. The third composite laser beam 13 is arranged in the low-energy region 33 at the rear end of the molten pool 3 and is specifically used to melt the low-melting-point functional powder 24, so as to form a functional coating or functional region (such as an anti-corrosion layer, a conductive layer, an optical reflection layer, etc.) on the surface of the deposited layer without interfering with the forming process of the main alloy; Moreover, due to the strong ability of the arc to disturb and stir the molten pool 3, it can effectively improve the degree of fusion of materials from different sources in the molten pool 3 and avoid the problem of uneven composition caused by powder feeding in zones; at the same time, as the deposition head moves, the region of the molten pool 3 dynamically transfers, which is conducive to further mixing; As the deposition head moves, the second composite laser beam 12 acting on the medium-energy region 32 at the rear end of the molten pool 3 enters the high-energy region 31 at the front end of the molten pool 3, which helps to reduce the cooling rate of the high-energy region 31, relieve the concentration of thermal stress, and reduce defects such as cold cracks and interlayer separation; after the high-energy region 31 of the molten pool 3 enters the medium-energy region 32 at the front end of the molten pool 3, it can replenish the high-melting-point wire 21 and powder, which is beneficial to increasing the height and density of the deposited layer; Since various powders are quickly melted and stirred and mixed in the molten pool 3, there will still be mixed unmelted powders in the molten pool 3. Therefore, in the composite laser beam, the auxiliary wavelength laser with a relatively small power proportion (such as the red light component in blue light) can play a role in adjusting the laser to achieve auxiliary melting and reducing the inclusion of unmelted powders; Moreover, the auxiliary wavelength laser with a relatively small power proportion can avoid the sudden change in energy distribution caused by the direct switching of the laser wavelength, maintain the continuity of the overall thermal field of the molten pool 3, and thus reduce microcracks or stress concentration caused by the drastic change in the boundary temperature difference.

[0053] Embodiment 2 The difference between this embodiment and Embodiment 1 is that in step S3, the high-melting-point powder 22 is transported coaxially with the wire 21 around the wire guide tube, and the wire guide tube preheats the high-melting-point powder 22.

[0054] For the treatment of refractory materials, the wire guide tube can be preheated to 800°C - 1000°C first and then sent into the high-energy area 31. During the arc additive manufacturing process, the wire guide tube has a Joule heating effect due to the passage of current, which can preheat the high-melting-point powder 22 co-axially conveyed around it. When the powder enters the molten pool 3, it is already in a relatively high temperature state, which can significantly reduce the burden of subsequent laser or arc energy, improve the melting rate of the high-melting-point material, enhance the deposition efficiency, avoid inclusions or poor fusion caused by insufficient melting, and the high-melting-point powder 22 is co-axially conveyed around the wire guide tube with the wire 21, so that more high-melting-point powder 22 can be preheated per unit time.

[0055] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited by this. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A laser arc composite additive processing method, characterized in that: The following steps are involved: conveying the wire (21) and connecting the fuse power supply to the wire (21); A first composite laser beam (11) and a second composite laser beam (12) are emitted, and the first composite laser beam (11) is adjusted to be closer to the wire (21) than the second composite laser beam (12), and the first composite laser beam (11), the second composite laser beam (12) and the electric arc act on the substrate to form a molten pool (3); A high melting point powder (22) is transported to a high energy zone (31) of the molten pool (3), and a matrix powder (23) is transported to a medium energy zone (32) of the molten pool (3). The high melting point powder (22) and the substrate have a preferential absorption property for the wavelength laser with the largest power share in the first composite laser beam (11), and the matrix powder (23) has a preferential absorption property for the wavelength laser with the largest power share in the second composite laser beam (12).

2. The laser arc composite additive processing method according to claim 1, characterized in that: A third composite laser beam (13) is emitted, the second composite laser beam (12) is adjusted to be closer to the wire (21) than the third composite laser beam (13), and the third composite laser beam (13) acts on the rear section of the molten pool (3), and a functional powder (24) is transported to a low-energy zone (33) in the rear section of the molten pool (3), the functional powder (24) has a preferential absorption property for the wavelength laser with the largest power proportion in the third composite laser beam (13), and the absorption rate of the matrix powder (23) for the wavelength laser with the largest power proportion in the third composite laser beam (13) is less than 35%.

3. The laser arc composite additive processing method according to claim 1, characterized in that: The online visual inspection system detects the surface roughness of the current deposited layer, and uses a first laser (14) to remelt areas of the current deposited layer whose surface roughness does not meet the standard, and the matrix powder (23) has preferential absorption of the first laser (14).

4. The laser arc composite additive processing method according to claim 3, characterized in that: A second laser (15) is added to cooperate with the first laser (14) to remelt the area of ​​the surface roughness of the previous deposition layer that does not meet the standard, the absorption rate of the matrix powder (23) to the second laser (15) is less than 35%, and the power density of the first laser (14) is set to be greater than the power density of the second laser (15), and the spot of the first laser (14) is located within the spot coverage range of the second laser (15).

5. The laser arc composite additive processing method according to claim 2, characterized in that: The high melting point powder (22), the matrix powder (23) and the functional powder (24) all adopt phase difference powder feeding technology, and the high melting point powder (22), the matrix powder (23) and the functional powder (24) are alternately fed at a specified frequency.

6. The laser arc composite additive processing method according to claim 1, characterized in that: The high melting point powder (22) surrounds the wire guide tube and is transported coaxially with the wire material (21), and the wire guide tube preheats the high melting point powder (22).

7. The laser arc composite additive processing method according to claim 2, characterized in that: The powder feeding elevation angle of the high melting point powder (22) is adjusted so that the main axis of the injection path of the high melting point powder (22) penetrates from the top of the high energy zone (31) and exits from the bottom of the high energy zone (31).

8. The laser arc composite additive processing method according to claim 7, characterized in that: The high melting point powder (22) is coaxially transported around the first composite laser beam (11), the matrix powder (23) is coaxially transported around the second composite laser beam (12), and the functional powder (24) is coaxially transported around the third composite laser beam (13).

9. The laser arc composite additive processing method according to claim 1, characterized in that: The power of the first composite laser beam (11) and the second composite laser beam (12) at the front section of the molten pool (3) is increased, and the power of the first composite laser beam (11) and the second composite laser beam (12) at the rear section of the molten pool (3) is reduced.

10. The laser arc composite additive processing method according to claim 9, characterized in that: The powder feeding amount of the high melting point powder (22) and the matrix powder (23) in the front section of the molten pool (3) is increased, and the powder feeding amount of the high melting point powder (22) and the matrix powder (23) in the rear section of the molten pool (3) is reduced.

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