A laser-arc hybrid additive manufacturing method

Abstract

The application relates to a laser-arc hybrid additive manufacturing method, and belongs to the technical field of additive manufacturing. The method comprises the following steps: conveying a wire material and connecting a fuse power supply to the wire material; emitting a first hybrid laser beam and a second hybrid laser beam, and adjusting the first hybrid laser beam to be closer to the wire material than the second hybrid laser beam; the first hybrid laser beam, the second hybrid laser beam and an electric arc act on a base material to form a molten pool; conveying high-melting-point powder to a high-energy area of the molten pool, and conveying base material powder to a middle-energy area of the molten pool; the high-melting-point powder and the base material have preferential absorption to laser with the largest power proportion in the first hybrid laser beam; and the base material powder has preferential absorption to laser with the largest power proportion in the second hybrid laser beam. The application has the effects of realizing efficient melting of multiple materials, reasonable matching of energy and uniform distribution of components in additive manufacturing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of additive manufacturing, in particular to a laser-arc hybrid additive manufacturing method. BACKGROUND

[0002] As an advanced manufacturing process, additive manufacturing has been widely used in rapid prototyping of metal parts and manufacturing of complex structures. According to the type of heat source, common additive manufacturing technologies include laser heat source or arc heat source, etc. In terms of material delivery form, wire feeding or powder feeding is commonly used, and in some processes, both are used simultaneously to improve deposition efficiency and material adaptability.

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

[0004] Firstly, in the manufacturing of composite materials or gradient structures, multiple powder materials such as high-melting-point alloy, matrix metal, and flux are often used simultaneously. If all the powders are 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, even element burning, resulting in alloy composition segregation, microstructure coarsening, and serious impact on the performance of the deposited layer;

[0005] However, if materials with different melting points are fed into the molten pool at a suitable temperature, such as medium-melting-point materials into the medium-energy area and low-melting-point materials into the low-energy area, there will be a problem of insufficient mixing of each component in the molten pool during deposition, which easily forms micro-segregation or layered structure, affecting the stability of subsequent mechanical properties;

[0006] Moreover, the existing additive manufacturing method generally uses a single wavelength laser or a single composite laser for additive manufacturing. However, the absorption efficiency of different materials to different wavelengths of laser is significantly different, and the absorption rate of some powders to this single laser is very low, which will cause the laser energy to be reflected or dissipated, not only causing energy waste, but also reducing the melting efficiency and forming quality.

[0007] In summary, the existing additive manufacturing process has the problems of difficulty in controlling the melting of multiple materials, low energy utilization efficiency, and uneven mixing of components. SUMMARY

[0008] In order to achieve the effects of efficient melting of multiple materials, reasonable matching of energy, and uniform distribution of components in additive manufacturing, the present application provides a laser-arc hybrid additive manufacturing method.

[0009] The laser-arc hybrid additive manufacturing method provided by the application adopts the technical scheme as follows:

[0010] A laser-arc hybrid additive manufacturing method, comprising the following steps: conveying a wire and connecting a fuse power to the wire;

[0011] 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 acting on the base material to form a molten pool;

[0012] conveying high-melting-point powder to a high-energy area of the molten pool and conveying base material powder to a medium-energy area of the molten pool, the high-melting-point powder and the base material having preferential absorption to the wavelength laser with the largest power ratio in the first composite laser beam, and the base material powder having preferential absorption to the wavelength laser with the largest power ratio in the second composite laser beam.

[0013] By adopting the above technical scheme, the first composite laser beam cooperates with the arc to act on the high-energy area, which can quickly melt the high-melting-point powder; the second composite laser beam acts on the medium-energy area, which can efficiently melt the base material powder with a medium melting point; and 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 to different wavelengths of laser, the beam is designed, energy waste is avoided, and the melting efficiency is improved;

[0014] Moreover, since the arc has strong molten pool disturbance and stirring capacity, the fusion degree of different source materials in the molten pool can be effectively improved, and the composition unevenness problem caused by the partitioned powder feeding can be avoided; at the same time, with the movement of the deposition head, the molten pool area dynamically shifts, which is beneficial to further mixing;

[0015] With the movement of the deposition head, 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 of the high-energy area, relieve 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, the high-melting-point wire and powder can be supplemented, which is beneficial to improve the deposition layer height and density;

[0016] Since a plurality of powders are quickly melted and stirred and mixed in the molten pool, but there are still mixed un-melted powders in the molten pool, in the composite laser beam, the auxiliary wavelength laser with a small power ratio (such as the red component in blue light) can play a role in adjusting the laser to achieve auxiliary melting and reduce un-melted powder inclusions;

[0017] Moreover, the auxiliary wavelength laser with a small power ratio can avoid the energy distribution mutation caused by direct switching of the laser wavelength, maintain the continuity of the overall molten pool thermal field, and thus reduce micro-cracks or stress concentration caused by a sharp change in boundary temperature difference.

[0018] 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 to transport functional powder to the low-energy area of the rear section of the molten pool, the functional powder has preferential absorption to the wavelength laser with the largest power ratio in the third composite laser beam, and the absorption rate of the matrix powder to the wavelength laser with the largest power ratio in the third composite laser beam is less than 35%.

[0019] 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, is dedicated to melting the low-melting functional powder, and forms a functional coating or functional area (such as a corrosion-resistant layer, a conductive layer, an optical reflection layer, etc.) on the surface of the accumulated layer without interfering with the main alloy forming process.

[0020] Since the absorption rate of the matrix powder to the main wavelength laser in the third composite laser beam is less than 35%, the laser energy of the third composite laser beam mainly acts on the functional powder, avoiding repeated heating and over-melting of the matrix material, and at the same time, the third composite laser beam can control the temperature of the newly formed accumulated layer in the rear section of the molten pool to slow down, achieving the effect of annealing treatment, which helps to release thermal stress and slow down the cooling rate.

[0021] Optionally, the online visual inspection system detects the surface roughness of the current deposition layer, and the first laser is used to remelt the area with unqualified surface roughness of the current deposition layer, and the matrix powder has preferential absorption to the first laser.

[0022] By adopting the above technical solution, since the matrix powder has preferential absorption to the main wavelength of the first laser, the laser energy mainly concentrates on the surface of the matrix material to be remelted, realizing rapid and shallow micro-melting repair, so that the laser energy is concentrated on the surface of the rough area, the remelting process has minimal impact on the lower layer, and the excessive melting depth is avoided to cause changes in the organization or thermal cracking.

[0023] Optionally, a second laser is added to cooperate with the first laser to remelt the area with unqualified surface roughness of the current deposition layer, the absorption rate of the matrix powder to the second laser is less than 35%, the power density of the first laser is greater than that of the second laser, and the spot of the first laser is located within the coverage range of the spot of the second laser.

[0024] By adopting the technical scheme, the first laser wavelength matches the absorption peak of the base material, has high power density and is focused on the rough defect area, quickly melts the micro-protrusions, realizes surface micro-plainness, the second laser has low power density and large spot range, and realizes annealing on the periphery of the rough area. Since the absorption rate of the base material is less than 35%, the second laser more acts on the inner layer of the material through heat conduction, realizes the annealing purpose, realizes tissue softening and heat stress relief.

[0025] Optionally, the high-melting-point powder, the base material powder and the functional powder all adopt phase difference powder feeding technology, and the high-melting-point powder, the base material powder and the functional powder are alternately transported according to a specified frequency.

[0026] By adopting the technical scheme, the nozzles alternately work in a specified frequency range, and only part of the nozzles are in a working state at the same time through phase difference control, so that powder flow interference, shielding and collision phenomena caused when multiple nozzles feed powder at the same time can be effectively avoided.

[0027] Optionally, the high-melting-point powder surrounds the wire guide tube and is coaxially transported with the wire material, and the wire guide tube preheats the high-melting-point powder.

[0028] By adopting the technical scheme, the wire guide tube has a Joule heat effect due to power supply in the electric arc additive process, so that the high-melting-point powder coaxially transported around the wire guide tube can be preheated. The high-melting-point powder is in a high temperature state before entering the molten pool, so that the burden of subsequent laser or electric arc energy can be significantly reduced, the melting rate of the high-melting-point material is improved, the deposition efficiency is enhanced, the inclusion or poor fusion caused by insufficient melting is avoided, and the high-melting-point powder is coaxially transported around the wire guide tube with the wire material, so that more high-melting-point powder is preheated in unit time.

[0029] Optionally, the feeding angle of the high-melting-point powder is adjusted, so that the main axis of the jet 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.

[0030] By adopting the technical scheme, such a design is beneficial to prolonging the residence time of the high-melting-point powder in the high-energy area of the molten pool, so that the high-melting-point powder can sufficiently absorb energy and be sufficiently heated, the melting efficiency is improved, the probability of un-melted particles is reduced, and the material fusion quality is ensured.

[0031] Optionally, the high-melting-point powder is coaxially transported around the first composite laser beam, the base material is coaxially transported around the second composite laser beam, and the functional powder is coaxially transported around the third composite laser beam.

[0032] By adopting the technical scheme, the powder can be uniformly sent around the laser beam. The powder can be uniformly distributed around the laser, so that the powder uniformly absorbs laser energy. Compared with the traditional single-side powder feeding mode, the uniform distribution can make more powder directly contact the high-temperature area and be fully melted, and reduces the waste of part of the powder due to failure to enter the laser irradiation range.

[0033] Optionally, the power of the first composite laser beam and the second composite laser beam in the front section of the molten pool is increased, and the power of the first composite laser beam and the second composite laser beam in the rear section of the molten pool is reduced.

[0034] By adopting the technical scheme, the laser energy input is increased at the front end of the molten pool to promote the rapid melting of the powder and the wire material and improve the additive efficiency; and the laser energy is appropriately reduced at the rear end of the molten pool to avoid surface unevenness caused by excessive melting.

[0035] Optionally, the powder feeding amount of the high-melting-point powder material and the base powder material in the front section of the molten pool is increased, and the powder feeding amount of the high-melting-point powder material and the base powder material in the rear section of the molten pool is reduced.

[0036] By adopting the technical scheme, the input amount of the high-melting-point powder material and the base powder material is increased in the front section of the molten pool, and combined with the higher laser power in this region, more materials can be timely melted, the forming volume corresponding to unit laser energy is improved, and energy is saved and efficiency is improved. The powder input is reduced in the rear section of the molten pool, which is matched with the lower laser energy input, so as to avoid material residues or accumulation due to insufficient melting.

[0037] In summary, the present application includes at least one of the following beneficial technical effects:

[0038] 1. The first composite laser beam cooperates with the electric arc to act on the high-energy area, which can quickly melt the high-melting-point powder material; the second composite laser beam acts on the medium-energy area, which can efficiently melt the base powder material with a medium melting point; and the electric arc acts on the wire material, which can promote the rapid melting of the high-melting-point wire material. According to the absorption characteristics of different materials to different wavelengths of laser, the beam is designed to avoid energy waste and improve the melting efficiency;

[0039] 2. Since the electric arc has strong molten pool disturbance and stirring capacity, it can effectively improve the fusion degree of materials of different sources in the molten pool, and avoid the composition uneven problem caused by the partitioned powder feeding; at the same time, with the movement of the deposition head, the molten pool area is dynamically transferred, which is beneficial to further mixing;

[0040] 3. As the deposition head moves, the second composite laser beam acting on the medium energy zone at the back end of the molten pool enters the high energy zone at the front end of the molten pool, which helps to reduce the cooling rate of the high energy zone, alleviate thermal stress concentration, reduce defects such as cold cracks and interlayer separation; and after the high energy zone of the molten pool enters the medium energy zone at the front end of the molten pool, the high melting point wire and the powder can be supplemented, which is beneficial to improve the height and density of the deposited layer;

[0041] 4. The laser energy of the third composite laser beam mainly acts on the functional powder, avoiding repeated heating and over-melting of the base material, while the third composite laser beam can control the temperature of the newly formed accumulation layer in the rear section of the molten pool, achieving the effect of annealing treatment, which helps to release thermal stress and slow down the cooling rate;

[0042] 5. In the remelting process, the first laser wavelength matches the absorption peak of the base material, has high power density and is focused on the rough defect area, quickly melts the micro-protrusions, realizes the micro-roughness of the surface, the second laser has lower power density and larger spot range, and realizes annealing around the rough area. Since the absorption rate of the base material is less than 35%, the second laser acts on the inner layer of the material more through heat conduction, achieving the purpose of annealing, realizing the softening of the organization and the relief of thermal stress. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 is a schematic diagram of the arrangement of the first composite laser beam, the second composite laser beam, the third composite laser beam, the wire, the high melting point powder, the base powder and the functional powder of the embodiment 1 of the present application.

[0044] Figure 2 is a schematic diagram of the arrangement of the first laser and the second laser in the remelting process of the embodiment 1 of the present application.

[0045] Figure 3 is a flow chart of the embodiment 1 of the present application.

[0046] Reference signs: 11, first composite laser beam; 12, second composite laser beam; 13, third composite laser beam; 14, first laser; 15, second laser; 21, wire; 22, high melting point powder; 23, base powder; 24, functional powder; 3, molten pool; 31, high energy zone; 32, medium energy zone; 33, low energy zone. DETAILED DESCRIPTION

[0047] The following will be described in detail in combination with the drawings Figures 1-3 The present application will be further described in detail.

[0048] Embodiment 1

[0049] The embodiment 1 of the present application discloses a laser electric arc composite additive manufacturing method.

[0050] AsFigure 1 、 Figure 2 and Figure 3 The laser-arc hybrid additive manufacturing method comprises the following steps:

[0051] S1, connecting the guide tube to the MIG or MAG additive wire melting power supply, setting the arc voltage to 28-32V, and the wire feeding speed to 5-8m / min, so that the arc is ignited and the wire 21 is melted. The wire feeding assembly continuously feeds the ER70S-6 carbon steel welding wire with a diameter of 1.2mm into the molten pool 3 area formed by the arc in a direction perpendicular to the substrate, and the arc current is controlled in the range of 180-220A. The arc first rapidly melts the wire 21 to form a molten pool 3 with a depth of about 3-5mm, providing a basis for the subsequent action of the laser and the powder.

[0052] S2, after the arc is ignited, the positions of the multiple lasers are adjusted, and according to the characteristics of the raw material, the first hybrid laser beam 11, the second hybrid laser beam 12 and the third hybrid laser beam 13 are emitted to the molten pool 3, so that the first hybrid laser beam 11 is closer to the wire 21 than the second hybrid laser beam 12, and the second hybrid laser beam 12 is closer to the wire 21 than the third hybrid laser beam 13.

[0053] In the embodiment of the application, the first hybrid laser beam 11 and the second hybrid laser beam 12 are each provided with two, and the third hybrid laser beam 13 is provided with one, the two first hybrid laser beams 11 are symmetrically arranged about the central axis of the wire 21, and the two second hybrid laser beams 12 are symmetrically arranged about the central axis of the wire 21, and the first hybrid laser beam 11, the second hybrid laser beam 12 and the third hybrid laser beam 13 intersect the central axis of the wire 21 at a point.

[0054] One first hybrid laser beam 11, one second hybrid laser beam 12 and the third hybrid laser beam 13 are emitted from the rear section of the molten pool 3, and the other first hybrid laser beam 11 and the other second hybrid laser beam 12 are emitted from the front section of the molten pool 3.

[0055] The first hybrid laser beam 11, the second hybrid laser beam 12 and the third hybrid laser beam 13 can be realized by a multi-wavelength semiconductor laser beam combining module / dual-wavelength fiber coupling system or the like. In the embodiment of the application, the first hybrid laser beam 11 is a mixed light beam of 1064nm infrared light and 450nm blue light with a power ratio of 7:3, the second hybrid laser beam 12 is a mixed light beam of 1064nm infrared light and 450nm blue light with a power ratio of 2:8, and the third hybrid laser beam 13 is a mixed light beam of 1064nm infrared light and 450nm blue light with a power ratio of 9:1.

[0056] The first hybrid laser beam 11 is 2-3mm closer to the central axis of the wire 21 than the second hybrid laser beam 12, and the second hybrid laser beam 12 is 4-5mm closer to the central axis of the wire 21 than the third hybrid laser beam 13.

[0057] S3, the high melting point powder 22 is coaxially transported with the first composite laser beam 11 to the high energy area 31 of the molten pool 3, the base powder 23 is coaxially transported with the second composite laser beam 12 to the medium energy area 32 of the molten pool 3, and the functional powder 24 is coaxially transported with the third composite laser beam 13 to the low energy area 33 of the rear section of the molten pool 3.

[0058] The high melting point powder 22 and the base plate have preferential absorption to the wavelength laser with the largest power ratio in the first composite laser beam 11, the base powder 23 has preferential absorption to the wavelength laser with the largest power ratio in the second composite laser beam 12, and the functional powder 24 has preferential absorption to the wavelength laser with the largest power ratio in the third composite laser beam 13. The absorption rate of the base powder 23 to the wavelength laser with the largest power ratio in the third composite laser beam 13 is less than 35%.

[0059] In the embodiment of the application, the high melting point powder 22 is WC ceramic powder with a particle size of 45-105μm, which is delivered to the high energy area 31 of the molten pool 3 in the form of coaxial annular flow with the first composite laser beam 11, and the powder delivery rate is 80-120g / min. The base powder 23 is 316L stainless steel with a particle size of 53-150μm, which is delivered to the medium energy area 32 of the molten pool 3 in the form of coaxial annular flow with the second composite laser beam 12, and the powder delivery rate is 150-200g / min. The functional powder 24 is 316L nickel-based powder with a particle size of 53-150μm, which is delivered to the low energy area 33 of the molten pool 3 in the form of coaxial annular flow with the third composite laser beam 13, and the powder delivery rate is 20-40g / min. Among them:

[0060] The absorption rate of the WC ceramic powder to the 1064nm laser is 58%±3%

[0061] The absorption rate of the 316L stainless steel powder to the 450nm laser is 47%±2%

[0062] The absorption rate of the nickel-based powder to the 1064nm laser is 72%±5%.

[0063] The base powder 23 is controlled independently by 5 coaxial powder feeding nozzles, so that the No. 1 coaxial powder feeding nozzle delivers the high melting point powder 22 to the high energy area 31 of the front section of the molten pool 3, the No. 2 coaxial powder feeding nozzle delivers the high melting point powder 22 to the high energy area 31 of the rear section of the molten pool 3, the No. 3 coaxial powder feeding nozzle delivers the base powder 23 to the medium energy area 32 of the front section of the molten pool 3, the No. 4 coaxial powder feeding nozzle delivers the base powder 23 to the medium energy area 32 of the rear section of the molten pool 3, and the No. 5 coaxial powder feeding nozzle delivers the functional powder 24 to the low energy area 33 of the rear section of the molten pool 3.

[0064] S4, adjust the powder feeding angle of the high melting point powder 22 to 55°±5°, so that the powder injection track principal axis of the high melting point powder 22 penetrates from the top of the high-energy area 31 (temperature about 2800℃) to the bottom of the molten pool 3 (temperature about 1600℃), and the powder stays in the high-energy area 31 of the molten pool 3 for a longer time of 0.8-1.2 seconds (the conventional process is 0.3-0.5 seconds).

[0065] S5, the phase difference powder feeding technology is used for the high melting point powder 22, the base powder 23 and the functional powder 24, and the high melting point powder 22, the base powder 23 and the functional powder 24 are alternately transported at a frequency of 0.5-2 Hz.

[0066] In the embodiment of the application, the no. 1-5 nozzles alternately transport the powder at a frequency of 1 Hz.

[0067] S6, the power of the first composite laser beam 11 at the front end of the molten pool 3 is increased to 1200W±50W (20% higher than the power of the first composite laser beam 11 at the rear end of the molten pool 3), and the power of the second composite laser beam 12 at the front end of the molten pool 3 is increased to 850W±30W.

[0068] The power of the first composite laser beam 11 at the rear end of the molten pool 3 is reduced to 900W, and the power of the second composite laser beam 12 at the rear end of the molten pool 3 is reduced to 600W, so as to realize that the peak temperature at the front end of the molten pool 3 is increased by about 300℃.

[0069] S7, the powder feeding amount of the high melting point powder 22 and the base powder 23 at the front end of the molten pool 3 is increased, and the powder feeding amount of the high melting point powder 22 and the base powder 23 at the rear end of the molten pool 3 is reduced.

[0070] In the embodiment of the application, the flow rate of the no. 1 coaxial powder feeding nozzle is 80g / min, the flow rate of the no. 2 coaxial powder feeding nozzle is 60g / min, the flow rate of the no. 3 coaxial powder feeding nozzle is 150g / min, the flow rate of the no. 4 coaxial powder feeding nozzle is 120g / min, and the flow rate of the no. 5 coaxial powder feeding nozzle is 25g / min. The coaxial powder feeding nozzle is a coaxial powder feeding nozzle on the market.

[0071] S8, the coaxial powder feeding nozzle and the wire feeding assembly are synchronously moved at a speed of 8-12mm / s to perform layer deposition, and an online visual system (combined with a 200μm laser line scanning module) is used to detect the surface roughness in real time, and the coordinates of the area with Ra>8μm are marked (detection accuracy ±0.5μm).

[0072] S9, the unqualified area is remelted by the first laser 14 and the second laser 15. The first laser 14 is a 450nm blue light, the power density is 2×10 4W / cm2, spot diameter 0.3mm. The second laser 15 is 1064nm infrared light, power density 5x103W / cm2, spot diameter 1.2mm. And the first laser 14 spot is completely nested in the second laser 15 spot coverage. After remelting, the surface roughness Ra is reduced to 2.8-3.2μm (62%±5% lower than before repair), and the remelted layer depth is controlled at 0.2-0.3mm (about 12% of the total thickness of the deposited layer).

[0073] In the embodiments of the present application, the first laser 14 and the second laser 15 can be emitted by any two of the coaxial powder feeding nozzles 1-5, but must wait for the current layer to be completed. The first laser 14 and the second laser 15 can also be emitted by two additional laser heads, but the two laser heads need to wait for 2-5s before starting after detecting the unqualified area.

[0074] And the base powder 23 has preferential absorption to the first laser 14, and the absorption rate of the second laser 15 is less than 35%. In the embodiments of the present application, the first laser 14 is blue light, the power density is 2x104W / cm2, the second laser 15 is infrared light, the power density is 5x103W / cm2, and the remelted depth is controlled at 10%-15% of the layer thickness. Through the high surface absorption characteristics of blue light, micro-area fine repair is realized, and Ra can be reduced to below 3μm.

[0075] The principle of the embodiments of the present application is that: the first composite laser beam 11 acts on the high-energy area 31 in cooperation with the electric arc, which can quickly melt the high-melting-point powder 22; the second composite laser beam 12 acts on the medium-energy area 32, which can efficiently melt the medium-melting-point base powder 23; the electric 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 area 33 at the rear end of the molten pool 3, which is used for melting the low-melting-point functional powder 24, so as to form a functional coating or functional area (such as corrosion-resistant layer, conductive layer, optical reflection layer, etc.) on the surface of the deposited layer, without interfering with the main body alloy forming process;

[0076] And, due to the strong disturbance and stirring ability of the electric arc to the molten pool 3, the fusion degree of different source materials in the molten pool 3 can be effectively improved, avoiding the problem of uneven composition caused by partitioned powder feeding; at the same time, with the movement of the deposition head, the molten pool 3 area is dynamically transferred, which is beneficial to further mixing;

[0077] With the movement of the deposition head, the second composite laser beam 12 acting on the medium-energy area 32 at the rear end of the molten pool 3 enters the high-energy area 31 at the front end of the molten pool 3, which helps to reduce the cooling rate of the high-energy area 31, relieve thermal stress concentration, and reduce defects such as cold cracks and interlayer separation; and after the high-energy area 31 of the molten pool 3 enters the medium-energy area 32 at the front end of the molten pool 3, the high-melting-point wire 21 and the powder can be supplemented, which is beneficial to improve the deposited layer height and density;

[0078] Since the multiple powders are rapidly melted and then mixed by stirring in the molten pool 3, but there are still mixed unmelted powders in the molten pool 3, in the composite laser beam, the auxiliary wavelength laser with a small power proportion (such as the red component in the blue light) can play a role of adjusting the laser to achieve auxiliary melting and reduce the inclusion of unmelted powders.

[0079] And the auxiliary wavelength laser with a small power proportion can avoid the energy distribution mutation caused by direct switching of the laser wavelength, maintain the continuity of the overall molten pool 3 thermal field, and thus reduce the micro-cracks or stress concentration caused by the sharp change of the boundary temperature difference.

[0080] Embodiment 2

[0081] The difference between this embodiment and embodiment 1 is that in step S3, the high-melting-point powder 22 is transported around the wire feeding pipe and coaxially with the wire material 21, and the wire feeding pipe preheats the high-melting-point powder 22.

[0082] For the processing of refractory materials, the wire feeding pipe can be preheated to 800°C-1000°C and then sent to the high-energy area 31. The wire feeding pipe has a joule heating effect due to power supply in the electric arc additive process, so that the high-melting-point powder 22 transported coaxially around it can be preheated. When the powder enters the molten pool 3, it is already in a high-temperature state, which can significantly reduce the burden of subsequent laser or arc energy, improve the melting rate of high-melting-point materials, enhance the deposition efficiency, avoid inclusions or poor fusion caused by insufficient melting, and the high-melting-point powder 22 is transported coaxially around the wire feeding pipe and the wire material 21, which can preheat more high-melting-point powder 22 in unit time.

[0083] The above are preferred embodiments of the present application, and do not limit the protection scope of the present application, so: any equivalent changes made on the basis of the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A laser-arc hybrid additive manufacturing method, characterized by: The method comprises the following steps: delivering the wire material (21) and connecting a fuse power to the wire material (21); emitting a first composite laser beam (11) and a second composite laser beam (12), and adjusting the first composite laser beam (11) to be closer to the wire material (21) than the second composite laser beam (12), the first composite laser beam (11), the second composite laser beam (12) and the electric arc acting on the base material to form a molten pool (3); delivering high-melting-point powder (22) to a high-energy area (31) of the molten pool (3) and delivering base material powder (23) to a medium-energy area (32) of the molten pool (3), the high-melting-point powder (22) and the base material powder (23) having preferential absorption to the wavelength laser with the largest power ratio in the first composite laser beam (11) and the base material powder (23) having preferential absorption to the wavelength laser with the largest power ratio in the second composite laser beam (12).

2. The laser-arc hybrid additive processing method of claim 1, wherein: emitting a third composite laser beam (13), adjusting the second composite laser beam (12) to be closer to the wire material (21) than the third composite laser beam (13), and the third composite laser beam (13) acting on the rear section of the molten pool (3), and delivering functional powder (24) to a low-energy area (33) of the rear section of the molten pool (3), the functional powder (24) having preferential absorption to the wavelength laser with the largest power ratio in the third composite laser beam (13), and the base material powder (23) having an absorption rate of less than 35% to the wavelength laser with the largest power ratio in the third composite laser beam (13).

3. The laser-arc hybrid additive processing method of claim 1, wherein: An online visual inspection system detects surface roughness of the current deposition layer, and a first laser (14) is used to remelt the area of the current deposition layer surface roughness that does not meet the standard, and the base material powder (23) has preferential absorption to the first laser (14).

4. The laser-arc hybrid additive processing method of claim 3, wherein: A second laser (15) is added to cooperate with the first laser (14) to remelt the area of the current deposition layer surface roughness that does not meet the standard, the base material powder (23) has an absorption rate of less than 35% to the second laser (15), and the power density of the first laser (14) is greater than that of the second laser (15), and the light spot of the first laser (14) is located within the light spot coverage range of the second laser (15).

5. The laser-arc hybrid additive processing method of claim 2, wherein: The high-melting-point powder (22), the base material powder (23) and the functional powder (24) all use phase difference powder feeding technology, and the high-melting-point powder (22), the base material powder (23) and the functional powder (24) are alternately delivered according to a specified frequency.

6. The laser-arc hybrid additive processing method of claim 1, wherein: The high-melting-point powder (22) is delivered coaxially around the wire guide tube and the wire material (21), and the wire guide tube preheats the high-melting-point powder (22).

7. The laser-arc hybrid additive processing method of claim 2, wherein: The powder feeding angle of the high-melting-point powder (22) is adjusted so that the main axis of the jet path of the high-melting-point powder (22) penetrates from the top of the high-energy area (31) and exits from the bottom of the high-energy area (31).

8. The laser-arc hybrid additive process method of claim 7, wherein: The high melting point powder (22) is coaxially delivered around the first composite laser beam (11), the matrix powder (23) is coaxially delivered around the second composite laser beam (12), and the functional powder (24) is coaxially delivered around the third composite laser beam (13).

9. The laser-arc hybrid additive processing method of claim 1, wherein: The power of the first composite laser beam (11) and the second composite laser beam (12) in 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) in the rear section of the molten pool (3) is reduced.

10. The laser-arc hybrid additive processing method of claim 9, wherein: 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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