Multi-mode composite laser beam wire powder co-feeding additive manufacturing device and method

Abstract

The invention relates to a multi-mode composite laser beam wire powder co-feeding additive manufacturing device and method, and belongs to the technical field of metal material additive manufacturing. The device comprises a wire feeding mechanism, a supporting frame, a continuous laser head, a swing laser head and a control system, the continuous laser head is vertically arranged on the supporting frame, a plurality of powder feeding channels are formed in the side wall of the lower portion of the continuous laser head, and the wire feeding mechanism and the swing laser head are arranged on the two sides of the supporting frame through mounting plates correspondingly. The continuous laser head, the wire feeding mechanism and the swing laser head are all connected with a control system. Two laser beams with different characteristics are used for cooperative work, synchronous wire feeding and powder feeding are combined, and the defects of the prior art in the aspects of high-efficiency machining of a high-reflection material, active control over the forming quality of a molten pool and preparation of a gradient structure material are overcome.

Description

Technical Field

[0001] This invention relates to a multimodal composite laser beam powder co-feeding additive manufacturing apparatus and method, belonging to the field of metal material additive manufacturing technology. Background Technology

[0002] In the fields of marine equipment, aerospace equipment, and military equipment, the manufacture of large, critical metal components such as ship propellers, aircraft engine nacelles, and aircraft frames is increasingly utilizing non-ferrous metals such as aluminum alloys and titanium alloys. As service environments move towards the deep sea and deep space, the performance requirements for key non-ferrous metal components in large equipment are becoming increasingly stringent. However, the low hardness and poor wear resistance of non-ferrous metals significantly limit their further application. Furthermore, with the development of additive manufacturing technology, key additive manufacturing components require not only high manufacturing efficiency but also stringent defect control. Therefore, additive manufacturing technology for non-ferrous metals not only needs high efficiency and low defect rates but also needs to simultaneously improve the wear resistance of the materials.

[0003] Currently, additive manufacturing technologies for non-ferrous metals mostly face the following prominent problems. First, existing laser / dual-laser synchronous powder feeding technologies are facing difficulties in solving the problem of high-efficiency forming. For example, the dual-laser beam cladding forming impact forging composite additive manufacturing method disclosed in Chinese patent document CN107475709A has low preparation efficiency and limited application in additive manufacturing of large key components.

[0004] Secondly, existing single laser or single arc additive manufacturing synchronous wire feeding technologies face the challenge of simultaneously improving material wear resistance while achieving efficient forming. For example, Chinese patent document CN204185561U discloses an optical coaxial composite wire feeding and powder feeding laser cladding system, and Chinese patent document CN117464214A discloses a universal device for laser welding wire and powder feeding. The above technologies revolve around a single or composite heat source (such as laser or arc) combined with wire feeding technology to improve deposition efficiency. However, the material performance is limited by the performance of the welding wire and cannot simultaneously improve the strength, toughness and wear resistance of the material when preparing gradient materials.

[0005] Third, although existing laser / arc synchronous wire and powder feeding technologies can solve the problems of efficient preparation and improved wear resistance, they are difficult to solve the problems of many defects and coarse grains in the preparation of non-ferrous metal materials. For example, Chinese patent document CN110587139A discloses an arc laser coaxial wire and powder feeding printing nozzle and additive manufacturing device.

[0006] Therefore, for molten pools of highly reflective non-ferrous metals, there is an urgent need for a more direct, efficient, and easily integrated active perturbation method to break the initial reflection barrier, reduce defects, and refine grains. Achieving high-quality coating preparation while simultaneously improving the high-efficiency additive manufacturing and the toughness and wear resistance of the material is a pressing technical problem that needs to be solved. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a multimodal composite laser beam and powder co-feeding additive manufacturing apparatus and method. It uses two laser beams with different characteristics (oscillating laser and continuous laser) to work together, combined with synchronous wire and powder feeding, to solve the deficiencies of existing technologies in high-efficiency processing of high-reflectivity materials, active control of molten pool forming quality, and preparation of gradient structure materials.

[0008] The technical solution of the present invention is as follows:

[0009] A multimodal composite laser beam powder co-feeding additive manufacturing device includes a wire feeding mechanism, a support frame, a continuous laser head, a oscillating laser head, and a control system. The continuous laser head is vertically mounted on the support frame, and several powder feeding channels are provided on the lower side wall of the continuous laser head. The wire feeding mechanism and the oscillating laser head are respectively mounted on both sides of the support frame via mounting plates. The continuous laser head, the wire feeding mechanism, and the oscillating laser head are all connected to the control system.

[0010] The oscillating laser head is an existing device, which is driven to oscillate by an internal drive mechanism. The wire feeding mechanism uses existing welding wire feeding equipment.

[0011] According to a preferred embodiment of the present invention, at least three powder feeding channels are provided, which are arranged in a ring around the periphery of the continuous laser beam path. The powder is fed through the powder outlet of the powder feeding channel and converges in a conical beam onto the surface of the molten pool below the laser spot.

[0012] According to a preferred embodiment of the present invention, a cooling channel and a gas channel are provided on the lower sidewall of the continuous laser head for cooling control and gas protection of the continuous laser head.

[0013] According to a preferred embodiment of the present invention, the optical path axis of the oscillating laser head and the optical path axis of the continuous laser head are at an angle of 30° and intersect at the processing plane.

[0014] According to a preferred embodiment of the present invention, the wire feeding direction of the wire feeding mechanism forms a 60° angle with the vertical direction to ensure smooth wire feeding.

[0015] According to a preferred embodiment of the present invention, the oscillation mode of the oscillating laser head is reciprocating, sinusoidal, ○, ∞, or 8, and the oscillation mode is an oscillating shape with a frequency range of 1-500 Hz.

[0016] According to a preferred embodiment of the present invention, a continuous laser head is used to generate a continuous beam with a power of 0-6 kW and a spot diameter of 1-6 mm, which acts on the center of the molten pool to rapidly melt the welding wire and powder.

[0017] The working method of the above-mentioned multimodal composite laser beam powder co-feeding additive manufacturing device is as follows:

[0018] (1) The wire feeding mechanism is connected to the welding wire, the powder feeding channel is connected to the powder pipe through the powder inlet, the cooling channel is connected to the coolant through the water inlet and water outlet, and the gas channel is connected to the protective gas through the air inlet.

[0019] (2) After the substrate is pretreated (cleaned or preheated), the device is started. The laser generated by the continuous laser head irradiates the substrate to form the center of the molten pool. Simultaneously, the wire and powder are fed, and the material melts rapidly. The laser generated by the oscillating laser head disturbs the molten pool from the side, enhances the flow of the melt, makes the powder evenly dispersed, and reduces defects.

[0020] (3) By controlling the power of the continuous laser head and the oscillating laser head and the ratio of wire feeding and powder feeding, a composition or performance gradient structure is formed in the deposition layer.

[0021] According to a preferred embodiment of the present invention, in step (1), the diameter of the welding wire is 0.8-1.6 mm, and the powder is a reinforcing phase powder, such as B4C, TiC, TiB2, etc., with a particle size of 10-100 μm.

[0022] According to a preferred embodiment of the present invention, in step (3), the wire feeding speed is 0-3 kg / h, the powder feeding speed is 0-50 g / min, and the ratio can be adjusted to achieve a component gradient.

[0023] This invention utilizes dual laser beams (a oscillating laser and a continuous laser), with clearly defined roles: the continuous laser efficiently melts the welding wire and powder at the center, while the oscillating laser disturbs the molten pool from the side. Its dynamically changing energy density helps break down the laser reflection barrier on the surface of highly reflective materials, achieving efficient melting and promoting material mixing and gas escape, reducing porosity and cracks, while simultaneously refining grain size. This design avoids the problem of uneven heat input in laser-arc composite processes, and the frequencies and powers of the two lasers can be independently adjusted for more precise thermal management. Through the synergistic effect of the two lasers, this invention achieves rapid melting in the continuous laser region and component homogenization in the oscillating laser region, thereby enabling more precise fabrication of gradient structures. This invention is applicable to various metal wires, and the powder can be various ceramic powders. For example, reinforcing phase powders (such as B4C) can fully react with non-ferrous metal matrices (such as aluminum and titanium) under the action of the oscillating laser to generate hard ceramic phases (such as TiB2 and TiC) in situ, achieving a wear-resistant and tough gradient transition from the matrix to the surface, directly addressing the harsh operating conditions of marine and aerospace equipment.

[0024] The beneficial effects of this invention are as follows:

[0025] This invention provides a dual-laser beam composite heat source combining a oscillating laser and a continuous laser, along with synchronous wire and powder feeding technology, for use in additive manufacturing, laser cladding, or welding. Through the synergistic effect of the two laser beams, combined with synchronous wire and powder feeding, high-efficiency, high-quality material deposition is achieved, and gradient structure materials can be fabricated. The specific design is as follows:

[0026] First, a dual-laser beam collaborative mechanism was designed: the oscillating laser and the continuous laser work together, the continuous laser ensures high deposition efficiency, and the oscillating laser improves the dynamics of the molten pool and improves the forming quality. Compared with a single laser or laser-arc composite, the heat input is more uniform and the residual stress is reduced. The dual laser heads can be integrated into a robot or CNC system to achieve multi-axis motion, which is suitable for processing curved surfaces or complex structures.

[0027] Second, active molten pool disturbance: the oscillating laser directly disturbs the molten pool by oscillating the spot (amplitude 1-5 mm), breaking the temperature gradient and compositional segregation, promoting grain refinement and gas discharge. Compared with existing ultrasonic or post-heat source technology, it has a faster response, more precise control, high density of formed parts (>99.5%), and low surface roughness (Ra < 10 μm).

[0028] Third, precise fabrication of gradient structures: By adjusting the type and proportion of conveying metal wires and ceramic powders, combined with selective melting of dual lasers, compositional gradients at the microscale can be achieved, which is suitable for complex components in aerospace, automotive and other fields.

[0029] Fourth, efficient synchronous wire and powder feeding: Wire feeding provides the main matrix material, which can be stainless steel wire, titanium alloy wire, or aluminum alloy wire. Powder feeding introduces the reinforcing phase, which can be various oxide, carbide, or boron nitride ceramic powders. The synchronous feeding of both avoids the limitations of a single material, and the material deposition rate is close to 100%, resulting in a significant improvement in efficiency. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the present invention;

[0031] Figure 2 This is a schematic diagram of the powder feeding channel structure of the present invention;

[0032] Figure 3 This is a schematic diagram of a partial working state of the present invention;

[0033] Figure 4 This is a drawing of an additively manufactured prototype of the present invention;

[0034] Figure 5 This is a graph showing the change in hardness of the gradient material of the present invention with depth;

[0035] Among them, 1. substrate, 2. additive sample, 3. wire feeding mechanism, 4. powder inlet, 5. water inlet, 6. mounting plate, 7. continuous laser head, 8. support frame, 9. water outlet, 10. air inlet, 11. oscillating laser head, 12. welding wire, 13. continuous laser beam, 14. powder, 15. oscillating laser beam. Detailed Implementation

[0036] The present invention will be further described below with reference to the embodiments and accompanying drawings, but is not limited thereto.

[0037] Example 1:

[0038] like Figure 1-3 As shown, this embodiment provides a multimodal composite laser beam powder co-feeding additive manufacturing device, including a wire feeding mechanism 3, a support frame 8, a continuous laser head 7, a swing laser head 11, and a control system. The continuous laser head 7 is vertically arranged on the support frame 8, and several powder feeding channels are arranged on the lower side wall of the continuous laser head 7. The wire feeding mechanism 3 and the swing laser head 11 are respectively arranged on both sides of the support frame 8 through mounting plates 6. The continuous laser head 7, the wire feeding mechanism 3, and the swing laser head 11 are all connected to the control system.

[0039] The oscillating laser head is an existing device, which is driven to oscillate by an internal drive mechanism. The wire feeding mechanism uses existing welding wire feeding equipment.

[0040] There are three powder feeding channels, which are arranged in a ring around the periphery of the continuous laser beam path. The powder is fed through the powder outlet of the powder feeding channel and converges in a cone-shaped beam onto the surface of the molten pool below the laser spot.

[0041] The lower side wall of the continuous laser head 7 is provided with a cooling channel and a gas channel for cooling control and gas protection of the continuous laser head.

[0042] The optical path axis of the oscillating laser head 11 forms an angle of 30° with the optical path axis of the continuous laser head, and they intersect on the processing plane.

[0043] The wire feeding mechanism 3 has a 60° angle with the vertical direction to ensure smooth wire feeding.

[0044] The oscillation mode of the oscillating laser head 11 is sinusoidal, ○, or ∞, such as... Figure 3 As shown, the oscillation mode is an oscillating shape, with a frequency range of 1-500 Hz.

[0045] The continuous laser head 7 is used to generate a continuous laser beam with a laser power of 2-5kW and a spot diameter of 3-5mm. It acts on the center of the molten pool to rapidly melt the welding wire and powder.

[0046] The working method of the above-mentioned multimodal composite laser beam powder co-feed additive manufacturing device involves preparing an additive sample 2 with continuously varying composition and properties along its length on a TC4 titanium alloy substrate. One end of the additive sample is made of high-toughness TC4, the other end is made of high-wear-resistant TiB2 reinforced composite material, and the middle is a gradient transition zone. This sample is used in a support component in aero-engines that combines connection function and wear resistance requirements. The steps are as follows:

[0047] (1) The wire feeding mechanism is connected to the welding wire 12, the powder feeding channel is connected to the powder pipe through the powder inlet 4, the cooling channel is connected to the coolant through the water inlet 5 and the water outlet 9, the gas channel is connected to the protective gas through the air inlet 10, and the welding wire diameter is 0.8-1.6 mm.

[0048] (2) After pretreatment (cleaning or preheating) of substrate 1, the device is started. The continuous laser beam 13 (power set to 3500W, spot diameter 3.0 mm) is vertically irradiated on the substrate surface, instantly forming a small and bright core molten pool. At the same time, the oscillating laser beam 15 (power 1000 W) scans and disturbs the molten pool from the side with a frequency of 200 Hz, a circular oscillating trajectory, and a diameter of 2.0 mm. The wire feeding mechanism feeds the TC4 welding wire from the wire feeding nozzle at a speed of 6 m / min. Its tip is inserted into the center of the core molten pool formed by the high-speed laser. TiB2 powder (particle size 10-100 μm, powder feeding speed 0-50 g / min) falls from the coaxial powder feeding channel. Part of it is directly melted by the high-speed laser, and part of it is rolled into the outer area of ​​the molten pool disturbed by the oscillating laser.

[0049] The device moves at a constant speed of 600 mm / min along the X direction to begin layer-by-layer deposition, such as... Figure 3 As shown. The core role of the continuous laser: It is always the main energy provider, responsible for melting the TC4 welding wire and most of the powder 14 delivered to the center of the molten pool, forming the main body of the deposition layer and ensuring its metallurgical bonding with the underlying layer. Its high power density ensures efficient melting of titanium alloy materials. The control effect of the oscillating laser: Molten pool stirring and composition homogenization: In the transition zone, when the powder feeding system linearly switches the proportion of TiB2 powder according to the program, the ring scan of the oscillating laser forms strong convection in the molten pool. This mechanical stirring effect greatly promotes the diffusion and mixing of liquid metals with different compositions, avoids solidification cracks caused by compositional differences, and achieves a smooth compositional transition at the microscale.

[0050] Wire feeding and powder feeding work in tandem: Wire feeding is the main force in forming the "skeleton" of the deposit and ensuring deposition efficiency, providing the majority of the matrix metal, while powder feeding is key to achieving compositional gradient and functionalization (such as wear resistance). In the high TiB2 region, the disturbance of the oscillating laser is crucial. After entering the molten pool, TiB2 powder tends to float. The molten pool vortex caused by the oscillating laser re-entrains these lightweight particles into the molten pool, avoiding the floating and agglomeration of the reinforcing phase and ensuring its uniform distribution in the deposited layer. Optimized reaction kinetics: The intense thermal cycling and stirring brought by the oscillating laser control the reaction process between TiB2 and liquid Ti, promoting the in-situ formation of fine, fibrous TiB whiskers rather than the formation of coarse, brittle blocky phases, such as... Figure 4 As shown. The material prepared using a dual-beam composite heat source of oscillating laser + continuous laser and synchronous wire and powder feeding technology achieves a density of over 99.5%, and the hardness of the graded material ranges from 500 HV to... 0.2 Gradually decreased to 350 HV 0.2 ,like Figure 5 As shown.

Claims

1. A multimodal composite laser beam powder co-feed additive manufacturing apparatus, characterized in that, It includes a wire feeding mechanism, a support frame, a continuous laser head, a oscillating laser head, and a control system. The continuous laser head is vertically mounted on the support frame, and several powder feeding channels are provided on the lower side wall of the continuous laser head. The wire feeding mechanism and the oscillating laser head are respectively mounted on the two sides of the support frame via mounting plates. The continuous laser head, the wire feeding mechanism, and the oscillating laser head are all connected to the control system.

2. The multimodal composite laser beam powder co-feeding additive manufacturing apparatus as described in claim 1, characterized in that, There are at least three powder feeding channels, which are arranged in a ring around the periphery of the continuous laser beam path. The powder is fed through the powder outlet of the powder feeding channel and converges in a conical beam onto the surface of the molten pool below the laser spot.

3. The multimodal composite laser beam powder co-feeding additive manufacturing apparatus as described in claim 2, characterized in that, Cooling channels and gas channels are provided on the lower side wall of the continuous laser head.

4. The multimodal composite laser beam powder co-feeding additive manufacturing apparatus as described in claim 1, characterized in that, The optical path axis of the oscillating laser head and the optical path axis of the continuous laser head are at an angle of 30° and intersect on the processing plane.

5. The multimodal composite laser beam powder co-feeding additive manufacturing apparatus as described in claim 1, characterized in that, The wire feeding direction of the wire feeding mechanism forms a 60° angle with the vertical direction.

6. The multimodal composite laser beam powder co-feed additive manufacturing apparatus as described in claim 1, characterized in that, The oscillation mode of the oscillating laser head is reciprocating, sinusoidal, ○, ∞ or 8, and the oscillation pattern is the oscillation shape, with a frequency range of 1-500 Hz.

7. The multimodal composite laser beam powder co-feeding additive manufacturing apparatus as described in claim 1, characterized in that, A continuous laser head is used to generate a continuous beam with a power of 0-6 kW and a spot diameter of 1-6 mm, which acts on the center of the molten pool.

8. The operating method of the multimodal composite laser beam powder co-feeding additive manufacturing device as described in claim 3, characterized in that, The steps are as follows: (1) The wire feeding mechanism is connected to the welding wire, the powder feeding channel is connected to the powder pipe through the powder inlet, the cooling channel is connected to the coolant through the water inlet and water outlet, and the gas channel is connected to the protective gas through the air inlet. (2) After the substrate is pretreated (cleaned or preheated), the device is started. The laser generated by the continuous laser head irradiates the substrate to form the center of the molten pool. Simultaneously, the wire and powder are fed and the material is melted. The laser generated by the oscillating laser head disturbs the molten pool from the side, enhances the flow of the melt, and makes the powder evenly dispersed. (3) By controlling the power of the continuous laser head and the oscillating laser head and the ratio of wire feeding and powder feeding, a composition or performance gradient structure is formed in the deposition layer.

9. The operating method of the multimodal composite laser beam powder co-feeding additive manufacturing device as described in claim 8, characterized in that, In step (1), the diameter of the welding wire is 0.8-1.6 mm, and the powder is a reinforcing phase powder with a particle size of 10-100 μm.

10. The operating method of the multimodal composite laser beam powder co-feeding additive manufacturing apparatus as described in claim 8, characterized in that, In step (3), the wire feeding speed is 0-3 kg / h and the powder feeding speed is 0-50 g / min.

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