Method and equipment for dynamic control of molten droplets in laser cladding forming

Abstract

This invention relates to a method and equipment for dynamic control of molten droplets in laser cladding forming. The method includes: acquiring the size, position, and morphological characteristics of the area to be repaired or formed through a detection and positioning mechanism; coordinating the wire feeding rate and laser output power based on the acquired feature data by a control system to form a molten droplet matching the size of the corresponding area at an appropriate working position; and delivering the molten droplet to the area to be repaired or formed through gravity dripping or gas-assisted dripping according to the morphological characteristics of the corresponding area, completing the filling and forming of the repair area or the complete forming of the formed area through single-pass cladding or multi-layer superimposed cladding. This invention uses laser to directly act on the wire, melting it and forming a molten droplet. Simultaneously, it dynamically adjusts the size of the molten droplet according to the specifications of the object being repaired, ensuring that after the molten droplet enters the area to be filled, a uniform and dense cladding layer is formed on the surface to be repaired, achieving precise repair of surfaces with special features.

Description

Technical Field

[0001] This invention relates to the field of laser cladding technology, specifically to a method and equipment for laser cladding forming with dynamic control of molten droplets. Background Technology

[0002] Laser cladding forming technology, as an advanced surface modification and additive manufacturing technology, has wide applications in complex workpiece processing and component repair. Currently, most existing laser cladding repair nozzles (such as CN106444049A, CN105562951A, CN107627002A, CN107217257A, CN106583726A, etc.) operate using a negative defocusing method. They form a molten pool by irradiating the substrate with a laser beam, and then transport a powder beam or filament to the molten pool, scanning along a set trajectory to form a cladding layer or shaped part. However, in practical applications, these nozzles have the following problems: 1. When repairing concave surfaces or large overhangs on parts, if existing powder beam nozzles are used, the laser beam must first irradiate the concave surface to form a molten pool, and then the powder beam is sprayed from inside the nozzle into the molten pool. In this method, due to the divergent characteristics of the powder beam, powder is easily scattered around the molten pool, resulting in poor surface roughness of the cladding layer. At the same time, the powder morphology is difficult to control precisely, making it impossible to perform high-precision repair and filling of the concave surface.

[0003] While existing wire feeding nozzles can solve the powder dispersion problem, certain issues remain: for example, the wire feeding amount is difficult to control precisely, resulting in an inaccurate shape of the repaired area; to achieve precise control of the repaired area's shape, multiple process parameters such as laser power, defocusing amount, and wire feeding speed need to be adjusted simultaneously, and the coordinated changes of multiple parameters will significantly increase the complexity of the control system and the cost of equipment.

[0004] 2. When repairing special features such as narrow grooves, blind holes, and tapered holes, existing technologies can use a structure of laser-wrapped wire. However, because laser-wrapped wire requires a large space for both the laser beam and the nozzle, when the diameter of the hole or the size of the groove to be repaired is smaller than the size of the nozzle or the laser beam, the wire cannot be accurately delivered to the surface of the inner cavity to be repaired, making it difficult to effectively carry out repair work for special features such as narrow grooves, blind holes, and tapered holes.

[0005] Furthermore, the laser cladding auxiliary device and method for wire with patent publication number CN113913817A, although this patented technology can achieve the effects of refining the cladding layer structure, reducing porosity and microcrack tendency, reducing residual stress, improving the uniformity of the transition between the base material and the cladding layer structure, and reducing surface roughness, still has obvious technical limitations in practical applications: Because the patent cannot precisely control the size of the molten droplets, the consistency of the molten droplet formation is difficult to guarantee. When dealing with repair scenarios involving special features such as narrow grooves, blind holes, and conical holes, the cladding equipment occupies a large space and cannot accurately deliver the wire to the surface of the repair cavity, making it difficult to carry out the repair work of special structures such as narrow grooves, blind holes, and conical holes in a high-efficiency manner. Summary of the Invention

[0006] This invention provides a method and equipment for dynamic control of molten droplets in laser cladding forming, in order to solve the problems mentioned in the background art.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for dynamically controlled laser cladding forming of molten droplets includes: The size, position, and morphological features of the area to be repaired or formed are obtained through a detection and positioning mechanism; the control system adjusts the wire feeding rate and laser output power in a coordinated manner based on the obtained feature data, and forms a droplet with the size matching the area at the appropriate working position in the corresponding area; According to the morphological characteristics of the corresponding area, the molten droplets are delivered to the area to be repaired or the area to be formed by gravity dripping or gas-assisted dripping. The repair area is filled and formed or the formed area is completely formed by single cladding or multi-layer superposition cladding.

[0008] Preferably, the area to be repaired includes curved surface pits, narrow grooves, blind holes, tapered holes, and damaged areas of large overhanging parts.

[0009] Preferably, when the area to be repaired is a curved surface pit, the forming step includes the following steps: Step 1: Scan the surface of the workpiece using a CCD camera to detect and locate a curved recess, accurately identify the position and size data of the recess, and transmit it to the control system in real time. Step 2: Based on the data of the pit, the control system first controls the nozzle mechanism to move to the working position corresponding to the pit through the multi-axis motion platform, and then dynamically adjusts the wire feeding rate and laser power parameters to match it. Step 3: Start the wire feeding mechanism and laser, and form a molten droplet that matches the size of the pit according to the adjusted parameters. The single cladding filling of the pit is completed by gravity dripping. Step 4: After completing the cladding of the pit, the CCD camera continues to scan the workpiece surface to detect and locate the next curved surface pit. Repeat steps 2 and 3 until all curved surface pits are clad.

[0010] Preferably, when the area to be repaired is a narrow groove, a blind hole, or a tapered hole, the forming step includes the following steps: Step 1: Scan the workpiece surface with a CCD camera to detect and locate the narrow grooves, blind holes or tapered holes to be repaired, and accurately identify the size and position data of their internal cavities. Step 2: Based on the internal cavity data of the area to be repaired, the control system controls the nozzle mechanism to move to the working position above the cavity opening of the area to be repaired through a multi-axis motion platform, while simultaneously adjusting the wire feeding rate and laser power parameters in real time. Step 3: Start the wire feeding system and laser, and form a droplet that matches the cavity size of the area to be repaired according to the adjusted parameters. Complete the single cladding of the inner cavity surface by gravity dripping. Step 4: After completing a single cladding of the area to be repaired, the morphological data of the cladding area is detected in real time by a CCD camera and transmitted to the control system. Step 5: Repeat steps 2 to 4, gradually filling the cavity of the area to be repaired by multi-layer cladding until the cladding layer is smoothly connected to the workpiece surface.

[0011] Preferably, when the area to be repaired is a damaged area of ​​a large overhanging part, the forming step includes the following steps: Step 1: Scan the damaged area of ​​the large overhanging part with a CCD camera, detect and locate a damaged area, accurately identify the location, size and molten pool morphology data of the damaged area, and transmit it to the control system in real time. Step 2: Based on the detection data of the damaged area, the control system first controls the nozzle mechanism to move to the working position of the damaged area through the multi-axis motion platform, and then dynamically adjusts the matching wire feeding rate, laser power parameters and protective gas delivery parameters. Step 3: Activate the gas cylinder device to apply protective gas to the molten pool area of ​​the damaged area; Step 4: Start the wire feeding system and laser, form a droplet adapted to the damaged area according to the adjusted parameters, and deliver the droplet to the damaged area by gas-assisted dripping to complete a single cladding process; Step 5: After completing the cladding of the damaged area, the CCD camera continues to scan the surface of the large overhanging part, detects and locates the next damaged area, and repeats steps 2 to 4 until all damaged areas of the large overhanging part are repaired.

[0012] Preferably, the droplet size increases when the wire feed rate and laser power increase, and the droplet size decreases when the wire feed rate and laser power decrease, so as to form a droplet that matches the size of the area to be repaired.

[0013] This invention also proposes a droplet dynamic control laser cladding forming equipment for implementing the above-described droplet dynamic control laser cladding forming method, comprising: The nozzle mechanism has a nozzle for discharging cladding material; A detection and positioning mechanism, wherein the detection and positioning mechanism is a CCD camera, the CCD camera is connected to the nozzle mechanism and is used to detect the nozzle orifice area; The wire feeding mechanism includes a wire feeding tube connected to one end of the nozzle orifice and a wire feeder connected to the other end of the wire feeding tube. The laser mechanism includes a collimator device fixedly connected to the nozzle mechanism, a laser connected to the light input end of the collimator device, and a laser reflection and focusing assembly disposed inside the nozzle mechanism. The laser reflection and focusing assembly is used to focus the light beam emitted by the laser to the nozzle orifice to melt the filament output from the nozzle orifice and form molten droplets. The control system is used to receive the detection data from the CCD camera in real time and control the wire feeding rate of the wire feeder and the laser output power of the laser.

[0014] Preferably, it also includes a gas cylinder device for outputting protective gas, wherein the protective gas output by the gas cylinder device is located outside the nozzle orifice and is used to assist in delivering the molten droplets to the area to be repaired.

[0015] Preferably, the laser reflection and focusing assembly includes a convex lens located inside the collimator device and a beam splitter and a reflector disposed in the inner cavity of the nozzle mechanism. The laser beam emitted by the laser passes through the convex lens, the beam splitter and the reflector in sequence and then converges below the nozzle opening.

[0016] Preferably, it also includes a multi-axis motion platform for controlling the movement of the nozzle mechanism.

[0017] By adopting the above technical solution, the beneficial effects achieved by the present invention are as follows: 1. This invention addresses the repair of concave surfaces or large overhanging parts by directly employing wire cladding. First, a CCD camera dynamically acquires the actual shape and size data of the concave surface. Then, based on the acquired data, the laser power and wire feed speed are dynamically adjusted in real time to ensure the wire precisely passes through the focal point of the laser beam, melting at the focal point to form a droplet. By precisely matching the droplet size with the concave surface size, high-precision repair of the concave surface is achieved, effectively improving the forming accuracy after repair. Compared to powder-feed cladding, this invention avoids the problem of high surface roughness caused by powder dispersion from the outset. Compared to traditional wire-feed cladding nozzles, this solution achieves repair adaptation through precise control of droplet size, involving fewer process parameters (no need to adjust defocusing), resulting in a simpler supporting system and significantly reducing equipment and operational costs.

[0018] 2. This invention addresses the repair of deep cavity features such as narrow grooves, blind holes, and tapered holes. It eliminates the need to insert the wire or laser beam into the cavity; instead, it simply forms a droplet above the surface of the feature and allows it to fall. Specifically, a CCD camera is used to precisely detect the internal dimensions of the deep cavity. Based on this data, the size of the droplet is dynamically adjusted, allowing it to fall precisely onto the surface to be repaired under the assistance of a protective gas or gravity, completing the cladding process. This invention completely avoids the technical limitations of traditional wire feeding nozzles and laser beams that cannot penetrate the cavity due to structural interference. It overcomes the limitations of repairing deep cavity features, significantly expands the application scenarios of laser cladding technology, and effectively solves the technical pain points of repairing special feature surfaces in the industry. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the equipment in Embodiment 1 of the present invention.

[0020] Figure 2 This is a bottom-view schematic diagram of the equipment in Embodiment 1 of the present invention.

[0021] Figure 3 This is a frontal cross-sectional view of the equipment in Embodiment 1 of the present invention.

[0022] Figure 4 This is a schematic diagram of the method flow of the present invention.

[0023] Figure 5 This is a schematic diagram illustrating the droplet size variation of the present invention.

[0024] Figure 6 This is a schematic diagram of the repair of small-sized curved surface pits according to Embodiment 3 of the present invention.

[0025] Figure 7 This is a schematic diagram of the repair of medium-sized curved surface pits according to Embodiment 3 of the present invention.

[0026] Figure 8 This is a schematic diagram of the repair of large-sized curved surface pits according to Embodiment 3 of the present invention.

[0027] Figure 9 This is a schematic diagram of a single repair for a narrow groove according to Embodiment 4 of the present invention.

[0028] Figure 10 This is based on Embodiment 4 of the present invention. Figure 9 A schematic diagram of a single repair after the initial repair.

[0029] Figure 11 This is a schematic diagram of a single-layer repair for a narrow groove according to Embodiment 4 of the present invention.

[0030] Figure 12This is a schematic diagram of the repair of a narrow groove using a layer-by-layer stacking method according to Embodiment 4 of the present invention.

[0031] Figure 13 This is a schematic diagram of a single repair of a blind hole in Embodiment 5 of the present invention.

[0032] Figure 14 This is based on Embodiment 5 of the present invention. Figure 13 A schematic diagram of a single repair after the initial repair.

[0033] Figure 15 This is a schematic diagram of the repair of blind holes using layer-by-layer stacking in Embodiment 5 of the present invention.

[0034] Figure 16 This is a schematic diagram of a single-layer repair for a conical hole according to Embodiment Six of the present invention.

[0035] Figure 17 This is based on Embodiment Six of the present invention. Figure 16 A schematic diagram of the single-layer repair after restoration.

[0036] Figure 18 This is a schematic diagram of the repair of a tapered hole using layer-by-layer stacking, as described in Embodiment Six of the present invention.

[0037] Figure 19 This is a schematic diagram of the repair of a small-sized damaged area on a large overhanging component according to Embodiment 7 of the present invention.

[0038] Figure 20 This is a schematic diagram illustrating the repair of a dimensionally damaged area in a large suspension component according to Embodiment 7 of the present invention.

[0039] Figure 21 This is a schematic diagram of the repair of a large-sized damaged area on a large overhanging component according to Embodiment 7 of the present invention.

[0040] Figure 22 This is a schematic diagram of the cladding forming of a large overhanging part according to Embodiment 8 of the present invention.

[0041] Figure 23 This is a schematic diagram of the process for forming curved surface concave pits according to the present invention.

[0042] Figure 24 This is a schematic diagram of the cladding process for narrow grooves, blind holes, and tapered holes according to the present invention.

[0043] Figure 25 This is a schematic diagram of the cladding forming process for the damaged area of ​​a large overhanging part according to the present invention.

[0044] In the diagram: 1. Nozzle mechanism; 11. Nozzle opening; 2. Detection and positioning mechanism; 3. Wire feeding tube; 4. Collimator device; 5. Convex lens; 6. Beam splitter; 7. Reflector; 8. Optical path port. Detailed Implementation

[0045] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0046] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification. Example 1

[0047] like Figures 1-4 As shown, the present invention provides a laser cladding forming equipment for dynamic control of molten droplets, comprising: The nozzle mechanism 1 has a nozzle orifice 11 for outputting cladding material, and the cladding material is made of wire.

[0048] The detection and positioning mechanism 2 is a CCD camera connected to the nozzle mechanism 1 and used to detect the nozzle orifice 11 area and the area to be repaired. Since the nozzle orifice 11 needs to correspond to the area to be repaired when the nozzle mechanism 1 is in use, the CCD camera can simultaneously detect the defects of the filament at the nozzle orifice 11 and the area to be repaired.

[0049] The wire feeding mechanism includes a wire feeding tube 3 connected to one end of the nozzle 11 and a wire feeder connected to the other end of the wire feeding tube 3; the wire feeder is used to transport the wire so that the wire can be guided to the nozzle 11 through the wire feeding tube 2.

[0050] The laser mechanism includes a collimator device 4 fixedly connected to the nozzle mechanism 1, a laser connected to the light input end of the collimator device 4, and a laser reflection and focusing assembly disposed inside the nozzle mechanism 1. The laser reflection and focusing assembly is used to focus the light beam emitted by the laser to the nozzle orifice 11 to melt the filament output from the nozzle orifice 11 and form molten droplets. The laser mechanism also includes multiple optical path openings 8 opened at the bottom of the nozzle mechanism 1. Protective lenses are disposed inside the optical path openings 8 to prevent dust.

[0051] As a further step, the laser reflection and focusing assembly includes a convex lens 5 located inside the collimator device 4, and a beam splitter 6 and a reflector 7 located inside the nozzle mechanism 1. The laser beam emitted by the laser passes through the convex lens 5, the beam splitter 6 and the reflector 7 in sequence and then converges below the nozzle orifice 11.

[0052] The convex lens 5 is used to convert the scattered light emitted by the laser into a parallel beam. The beam splitter 6 can uniformly split a parallel beam into multiple fine beams and guide them to the corresponding reflectors 7. When the laser beam enters the collimator device 4, it is first collimated by the convex lens 5 to convert the divergent beam into a parallel beam. Then the parallel beam is transmitted to the beam splitter 6, and then guided by the beam splitter 6 to the corresponding reflector 7, so that the reflector 7 can reflect the beam and converge it below the nozzle orifice 11 through the optical path port 8. Then, the converged beam can directly act on the wire to melt it and form a molten droplet.

[0053] The present invention also includes a multi-axis motion platform for controlling the movement of the nozzle mechanism 1 and a control system for controlling the movement of the multi-axis motion platform. The control system is used to receive CCD camera detection data in real time and control the wire feeding rate of the wire feeder and the laser output power of the laser.

[0054] The gas cylinder device outputs protective gas through a gas pipeline. The protective gas output by the gas cylinder device is located outside the nozzle 11 and wraps around the nozzle 11. At the same time, the protective gas can also be used to assist in delivering the molten droplets to the area to be repaired.

[0055] refer to Figure 5 The diagram showing the droplet size change states indicates that the droplet size increases when the wire feed rate and laser power increase, and decreases when the wire feed rate and laser power decrease. This allows for dynamic adjustment of the laser power and wire feed speed to form droplets that are compatible with the size of the area to be repaired. Example 2

[0056] Based on the equipment proposed in Example 1, the present invention also proposes a method for dynamic control of molten droplets in laser cladding forming, the forming method comprising: The size, position and morphological features of the area to be repaired or formed are obtained by the detection and positioning mechanism 2; the control system adjusts the wire feeding rate and laser output power in a coordinated manner based on the obtained feature data, and forms a droplet that matches the size of the area at the appropriate working position in the corresponding area; The areas to be repaired include curved surface pits, narrow grooves, blind holes, tapered holes, and damaged areas of large overhanging parts; According to the morphological characteristics of the corresponding area, the molten droplets are delivered to the area to be repaired or the area to be formed by gravity dripping or gas-assisted dripping. The repair area is filled and formed or the formed area is completely formed by single cladding or multi-layer superposition cladding. Example 3

[0057] Combination Figures 6-8 as well as Figure 23As shown, based on the forming method proposed in Embodiment 2, when the area to be repaired in this forming method is a curved surface pit, the forming steps include the following steps: Step 1: Scan the surface of the workpiece using a CCD camera to detect and locate a curved recess, accurately identify the position and size data of the recess, and transmit it to the control system in real time. Step 2: Based on the data obtained from the pit, the control system first controls the nozzle mechanism 1 to move to the working position corresponding to the pit through the multi-axis motion platform (preferably the center of the curved pit is the best position), and then dynamically adjusts the wire feeding rate and laser power parameters to match it. Step 3: Start the wire feeding mechanism and laser, and form a molten droplet that matches the size of the pit according to the adjusted parameters. The single cladding filling of the pit is completed by gravity dripping. Step 4: After completing the cladding of the pit, the CCD camera continues to scan the workpiece surface to detect and locate the next curved surface pit. Repeat steps 2 and 3 until all curved surface pits are clad.

[0058] In this embodiment, the repair of multiple curved surface pits only requires controlling the nozzle mechanism 1 to move to the corresponding working position of each pit via a multi-axis motion platform, eliminating the need for defocusing adjustments throughout the process. This design simplifies the control system structure and reduces the difficulty of process parameter control, thereby effectively ensuring cost control during the repair process. Example 4

[0059] Combination Figures 9-12 as well as Figure 24 As shown, based on the forming method proposed in Embodiment 2, when the area to be repaired in this forming method is a narrow groove, the forming steps include the following steps: Step 1: Scan the surface of the workpiece with a CCD camera to detect and locate the narrow groove to be repaired, accurately identify the size and position data of its cavity, and transmit it to the control system in real time. Step 2: Based on the internal cavity data of the area to be repaired, the control system controls the nozzle mechanism 1 to move to the working position above the cavity opening of the area to be repaired through a multi-axis motion platform, while simultaneously adjusting the matching wire feeding rate and laser power parameters in real time. Step 3: Start the wire feeding system and laser, and form a droplet that matches the cavity size of the area to be repaired according to the adjusted parameters. Complete the single cladding of the inner cavity surface by gravity dripping. Step 4: After completing a single cladding of the area to be repaired, the morphological data of the cladding area is detected in real time by a CCD camera and transmitted to the control system; then steps 2 and 3 are repeated so that multiple single claddings form a single layer of cladding. Step 5: Repeat the above steps to gradually fill the inner cavity of the narrow groove by multi-layer cladding until the cladding layer is smoothly connected to the workpiece surface.

[0060] In this embodiment, the cross-section of the narrow groove includes, but is not limited to, a strip hole. When repairing the inner cavity of the narrow groove in the forming step of this embodiment, when moving from one end of the groove to the other end, the multi-axis motion platform only needs to control the nozzle mechanism 1 to move to the corresponding working position at the same height, and no defocusing adjustment operation is required throughout the process. Example 5

[0061] Combination Figures 13 to 15 as well as Figure 24 As shown, based on the forming method proposed in Embodiment 2, when the area to be repaired in this forming method is a blind hole, the forming steps include the following steps: Step 1: Scan the surface of the workpiece with a CCD camera to detect and locate the narrow blind hole to be repaired, accurately identify the size and position data of its cavity, and transmit it to the control system in real time. Step 2: Based on the internal cavity data of the area to be repaired, the control system controls the nozzle mechanism 1 to move to the working position above the cavity opening of the area to be repaired (preferably the center of the blind hole is the best position) through the multi-axis motion platform. Step 3: Based on the internal cavity data of the area to be repaired, adjust the wire feed rate and laser power parameters in real time to match them. Step 4: Start the wire feeding system and laser, and form a droplet that matches the cavity size of the area to be repaired according to the adjusted parameters. Complete the single cladding of the inner cavity surface by gravity dripping. Step 5: After completing a single cladding of the area to be repaired, the morphological data of the cladding area is detected in real time by a CCD camera and transmitted to the control system. Step 6: Repeat steps 3 to 5, gradually filling the cavity of the area to be repaired by multi-layer cladding until the cladding layer is smoothly connected to the workpiece surface.

[0062] It is important to emphasize that, in this embodiment, when repairing blind holes multiple times, it is only necessary to initially control the nozzle mechanism 1 to move to the corresponding working position above the cavity opening via the multi-axis motion platform. Subsequent multi-layer cladding processes do not require further position adjustments; only the wire feeding rate and laser power parameters need to be adjusted accordingly. This operation eliminates the need for defocusing adjustments, thus reducing the difficulty of process parameter control. Furthermore, this embodiment employs a method of forming molten droplets from the wire, eliminating the need for the wire feeding nozzle or laser beam to enter the cavity to be repaired, effectively solving the problem that traditional nozzles cannot repair narrow blind holes. Example 6

[0063] Combination Figures 16 to 18 as well as Figure 24As shown, based on the forming method proposed in Embodiment 2, when the area to be repaired in this forming method is a tapered hole, the forming steps include the following steps: Step 1: Scan the surface of the workpiece with a CCD camera to detect and locate the narrow tapered hole to be repaired, accurately identify the size and position data of its inner cavity, and transmit it to the control system in real time. Step 2: Based on the internal cavity data of the area to be repaired, the control system controls the nozzle mechanism 1 to move to the working position above the cavity opening of the area to be repaired (preferably the center of the conical hole is the best position) through the multi-axis motion platform. Step 3: Based on the internal cavity data of the area to be repaired, adjust the wire feed rate and laser power parameters in real time to match them. Step 4: Start the wire feeding system and laser, and form a droplet that matches the cavity size of the area to be repaired according to the adjusted parameters. Complete the single cladding of the inner cavity surface by gravity dripping. Step 5: After completing a single cladding of the area to be repaired, the morphological data of the cladding area is detected in real time by a CCD camera and transmitted to the control system. Step 6: Repeat steps 3 and 4, gradually filling the cavity of the area to be repaired by multi-layer cladding until the cladding layer is smoothly connected to the workpiece surface.

[0064] It is important to emphasize that, in this embodiment, when repairing the conical orifice cavity multiple times, only the nozzle mechanism 1 needs to be initially moved to the working position above the cavity opening via the multi-axis motion platform. Subsequent multi-layer cladding processes do not require further position adjustments; only the wire feeding rate and laser power parameters need to be adjusted accordingly, eliminating the need for defocusing adjustments. This design simplifies the control system structure and reduces the difficulty of process parameter control, thereby effectively ensuring controllable repair costs. Furthermore, by using a method of forming molten droplets from the wire, there is no need for the wire feeding nozzle or laser beam to enter the cavity to be repaired, effectively solving the problem that traditional nozzles cannot repair narrow conical orifices. Example 7

[0065] Combination Figures 19 to 21 as well as Figure 25 As shown, based on the forming method proposed in Embodiment 2, when the area to be repaired in this forming method is a damaged area of ​​a large overhanging part (such as a pit in a blade part), the forming steps include the following steps: Step 1: Scan the damaged area of ​​the large overhanging part with a CCD camera, detect and locate a damaged area, accurately identify the location, size and molten pool morphology data of the damaged area, and transmit it to the control system in real time. Step 2: Based on the detection data of the damaged area, the control system first controls the nozzle mechanism 1 to move to the working position of the damaged area through the multi-axis motion platform, and then dynamically adjusts the matching wire feeding rate, laser power parameters and protective gas delivery parameters. Step 3: Activate the gas cylinder device to apply protective gas to the molten pool area of ​​the damaged area to prevent the molten pool from dripping. Step 4: Start the wire feeding system and laser, form a droplet adapted to the damaged area according to the adjusted parameters, and deliver the droplet to the damaged area by gas-assisted dripping to complete a single cladding process; Step 5: After completing the cladding of the damaged area, the CCD camera continues to scan the surface of the large overhanging part, detects and locates the next damaged area, and repeats steps 2 to 4 until all damaged areas of the large overhanging part are repaired.

[0066] In summary, this invention achieves surface repair applications with special characteristics through dynamic control of molten droplets, and its advantages are as follows: I. This invention addresses the repair of concave surfaces or large overhanging parts by directly employing wire cladding. First, a CCD camera dynamically acquires the actual shape and size data of the concave surface. Then, based on the acquired data, the laser power and wire feed speed are dynamically adjusted in real time to ensure the wire precisely passes through the focal point of the laser beam, melting at the focal point to form a droplet. By precisely matching the droplet size with the concave surface size, high-precision repair of the concave surface is achieved, effectively improving the forming accuracy after repair. Compared to powder-feed cladding, this invention avoids the problem of high surface roughness caused by powder dispersion from the outset. Compared to traditional wire-feed cladding nozzles, this solution achieves repair adaptation through precise control of droplet size, involving fewer process parameters (no need to adjust defocusing), resulting in a simpler supporting system and significantly reducing equipment and operational costs.

[0067] II. When repairing deep cavities with special features such as narrow grooves, blind holes, and tapered holes, this invention eliminates the need to insert the wire or laser beam into the cavity of the feature. Instead, it simply involves forming a droplet on the area above the surface of the feature and allowing it to fall. Specifically, the internal dimensions of the deep cavity are first precisely detected using a CCD camera. Then, based on the detection data, the size of the droplet is dynamically adjusted, allowing the formed droplet to fall precisely onto the surface to be repaired within the deep cavity under the assistance of a protective gas or gravity, completing the cladding process. This invention completely avoids the technical shortcomings of traditional wire feeding nozzles and laser beams that cannot penetrate the cavity due to structural interference. It overcomes the limitations of repairing deep cavities, significantly expands the application scenarios of laser cladding technology, and effectively solves the technical pain points of special feature surface repair in the industry.

[0068] Compared with existing technologies, this invention is specifically designed to address the repair needs of special deep cavity features such as narrow grooves, blind holes, and conical holes. It can precisely control the size of the molten droplet and eliminates the need to insert wires or laser beams into the cavity of the repair feature. The molten droplet is formed only in the area above the surface of the special feature, and the repair can be achieved by the natural dripping of the droplet. This effectively solves the application pain points of existing technologies. Example 8

[0069] Combination Figure 22 As shown, based on the forming method proposed in Embodiment 2, when forming a large overhanging part, the forming steps include the following: Step 1: Scan and detect the morphology of the molten pool area using a CCD camera, and transmit the data to the control system in real time; Step 2: Based on the detection data of the molten pool area, the control system first controls the nozzle mechanism 1 to move to the working position of the molten pool area through the multi-axis motion platform, and then dynamically adjusts the wire feeding rate, laser power parameters and protective gas delivery parameters. Step 3: Activate the gas cylinder device to apply protective gas to the molten pool area to prevent the molten pool from dripping. Step 4: Start the wire feeding system and laser, form molten droplets according to the adjusted parameters, and deliver the droplets to the molten pool area via gas-assisted droplet delivery to complete the cladding. This step only completes a single cladding process. When multiple layers of cladding are required, the morphology of the cladding area in the molten pool is scanned and detected by a CCD camera, and the data is transmitted to the control system in real time. Steps 2 to 4 are repeated until the part is completely formed.

[0070] It should be noted that in the illustrations of this invention, orange arrows represent laser beam paths, red arrows represent filament paths, and green arrows represent protective gas paths; Figure 5 The yellow spots represent droplets of different sizes; the red spheres represent droplets; and the remaining red areas represent the state after cladding repair or forming.

[0071] In this invention, the term "a plurality of" refers to two or more unless otherwise expressly defined. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. The terms "installed," "connected," "linked," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "linked" can be a direct connection or an indirect connection via an intermediate medium. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0072] It should be noted that when a component is referred to as being "assembled on," "mounted on," "fixed to," or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0073] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0074] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for laser cladding forming with dynamic control of molten droplets, characterized in that, include: The size, location and morphological features of the area to be repaired or the area to be formed are obtained by the detection and positioning mechanism (2); The control system coordinates the wire feeding rate and laser output power based on the acquired feature data to form molten droplets that match the size of the corresponding area at the appropriate working position. According to the morphological characteristics of the corresponding area, the molten droplets are delivered to the area to be repaired or the area to be formed by gravity dripping or gas-assisted dripping. The repair area is filled and formed or the forming area is completely formed by single cladding or multi-layer superposition cladding.

2. The method for dynamically controlling laser cladding forming of molten droplets according to claim 1, characterized in that, The areas to be repaired include curved surface pits, narrow grooves, blind holes, tapered holes, and damaged areas of large overhanging parts.

3. The method for dynamically controlling laser cladding forming of molten droplets according to claim 2, characterized in that, When the area to be repaired is a curved surface pit, the forming steps include the following: Step 1: Scan the surface of the workpiece using a CCD camera to detect and locate a curved recess, accurately identify the position and size data of the recess, and transmit it to the control system in real time. Step 2: Based on the data of the pit, the control system first controls the nozzle mechanism (1) to move to the working position corresponding to the pit through the multi-axis motion platform, and then dynamically adjusts the wire feeding rate and laser power parameters to match it. Step 3: Start the wire feeding mechanism and laser, and form a molten droplet that matches the size of the pit according to the adjusted parameters. The single cladding filling of the pit is completed by gravity dripping. Step 4: After completing the cladding of the pit, the CCD camera continues to scan the workpiece surface to detect and locate the next curved surface pit. Repeat steps 2 and 3 until all curved surface pits are clad.

4. The method for dynamically controlling laser cladding forming of molten droplets according to claim 2, characterized in that, When the area to be repaired is a narrow groove, blind hole, or tapered hole, the forming steps include the following: Step 1: Scan the workpiece surface with a CCD camera to detect and locate the narrow grooves, blind holes or tapered holes to be repaired, and accurately identify the size and position data of their internal cavities. Step 2: Based on the internal cavity data of the area to be repaired, the control system controls the nozzle mechanism (1) to move to the working position above the cavity opening of the area to be repaired through the multi-axis motion platform, and adjusts the wire feeding rate and laser power parameters in real time to match it. Step 3: Start the wire feeding system and laser, and form a droplet that matches the cavity size of the area to be repaired according to the adjusted parameters. Complete the single cladding of the inner cavity surface by gravity dripping. Step 4: After completing a single cladding of the area to be repaired, the morphological data of the cladding area is detected in real time by a CCD camera and transmitted to the control system. Step 5: Repeat steps 2 to 4, gradually filling the cavity of the area to be repaired by multi-layer cladding until the cladding layer is smoothly connected to the workpiece surface.

5. The method for dynamically controlling laser cladding forming of molten droplets according to claim 2, characterized in that, When the area to be repaired is a damaged area of ​​a large overhanging part, the forming process includes the following steps: Step 1: Scan the damaged area of ​​the large overhanging part with a CCD camera, detect and locate a damaged area, accurately identify the location, size and molten pool morphology data of the damaged area, and transmit it to the control system in real time. Step 2: Based on the detection data of the damaged area, the control system first controls the nozzle mechanism (1) to move to the working position of the damaged area through the multi-axis motion platform, and then dynamically adjusts the wire feeding rate, laser power parameters and protective gas delivery parameters to match it. Step 3: Activate the gas cylinder device to apply protective gas to the molten pool area of ​​the damaged area; Step 4: Start the wire feeding system and laser, form a droplet adapted to the damaged area according to the adjusted parameters, and deliver the droplet to the damaged area by gas-assisted dripping to complete a single cladding process; Step 5: After completing the cladding of the damaged area, the CCD camera continues to scan the surface of the large overhanging part, detects and locates the next damaged area, and repeats steps 2 to 4 until all damaged areas of the large overhanging part are repaired.

6. The method for dynamically controlling laser cladding forming of molten droplets according to claim 1, characterized in that, The droplet size increases when the wire feed rate and laser power increase, and decreases when the wire feed rate and laser power decrease, so as to form a droplet that matches the size of the area to be repaired.

7. A laser cladding forming equipment for dynamic control of molten droplets, characterized in that, The steps for implementing the droplet dynamic control laser cladding forming method according to any one of claims 1 to 6 include: The nozzle mechanism (1) has a nozzle (11) for discharging cladding material. The detection and positioning mechanism (2) is a CCD camera, which is connected to the nozzle mechanism (1) and is used to detect the nozzle opening (11) area. The wire feeding mechanism includes a wire feeding tube (3) connected to one end of the nozzle (11) and a wire feeder connected to the other end of the wire feeding tube (3); The laser mechanism includes a collimator device (4) fixedly connected to the nozzle mechanism (1), a laser connected to the light input end of the collimator device (4), and a laser reflection and focusing assembly disposed inside the nozzle mechanism (1). The laser reflection and focusing assembly is used to focus the light beam emitted by the laser to the nozzle opening (11) to melt the filament output from the nozzle opening (11) and form molten droplets. The control system is used to receive the detection data from the CCD camera in real time and control the wire feeding rate of the wire feeder and the laser output power of the laser.

8. The laser cladding forming equipment with dynamic droplet control according to claim 7, characterized in that, It also includes a gas cylinder device for outputting protective gas, wherein the protective gas output by the gas cylinder device is located outside the nozzle (11) and is used to assist the molten droplets in being delivered to the area to be repaired.

9. The method and equipment for dynamic control of molten droplets in laser cladding forming according to claim 7, characterized in that, The laser reflection and focusing assembly includes a convex lens (5) located inside the collimator device (4) and a beam splitter (6) and a reflector (7) located inside the nozzle mechanism (1). The laser beam emitted by the laser passes through the convex lens (5), the beam splitter (6) and the reflector (7) in sequence and then converges below the nozzle opening (11).

10. The method and equipment for dynamic control of molten droplets in laser cladding forming according to claim 7, characterized in that, It also includes a multi-axis motion platform for controlling the movement of the nozzle mechanism (1).

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