Method and device for repairing water turbine based on stirring friction cooperating with laser deposition

Abstract

The invention provides a method for repairing a water turbine based on stirring friction cooperating with laser deposition. The method comprises the following steps that S1, defects are recognized and classified; s2, carrying out pretreatment; s3, laser deposition and stirring friction synergistic repair; and S4, carrying out post-treatment. The invention discloses a device for repairing a water turbine based on stirring friction and laser deposition. The device comprises a three-dimensional scanning unit for acquiring three-dimensional shape data of a damaged part of the water turbine, a nondestructive testing unit for detecting internal defect information of the damaged part, a repairing execution unit and a central control unit, the repair execution unit comprises an annular track, a laser deposition repair robot, a machining robot and various end executors; the central control unit is electrically connected with the three-dimensional scanning unit, the nondestructive testing unit and the repair execution unit. According to the method, the adaptability and reliability of the repairing process are improved, insufficient repairing or excessive repairing is avoided, and the microstructure of the laser deposition repairing layer is improved.

Description

Technical Field

[0001] This invention relates to the field of water turbine repair technology, specifically to a method and apparatus for repairing water turbines based on friction stir combined with laser deposition. Background Technology

[0002] As the core component of a hydroelectric power station, the turbine is responsible for converting water energy into electrical energy, and its performance directly determines the technical and economic indicators of the power station and even the power grid. However, the prolonged cutting of water flow inevitably produces cavitation erosion, where local fluid pressure drops below vaporization pressure, forming cavitation bubbles. These bubbles then collapse, generating microjet streams and shock waves that repeatedly impact material surfaces, causing erosion, pitting, and sponge-like damage. This disrupts the original flow pattern, leading to decreased efficiency and output; in extreme cases, turbine blades may chip, curl, perforate, or even break completely. Furthermore, river sediment carries the turbine under constant erosion, further exacerbating wear. In addition, erosion and cavitation erosion can mutually reinforce each other. Specifically, sand particles, due to their uneven surfaces, easily attract gas, increasing the number of cavitation nuclei. As sand particles move in the water flow, a pressure drop zone forms behind them, easily leading to the formation of bubbles. The collapse of bubbles causes strong local disturbances in the water flow, which greatly accelerates the mud and sand particles in the water flow, increasing the impact kinetic energy of the sand particles and thus accelerating the damage to the water turbine.

[0003] Currently, the strengthening and remanufacturing of wear- and corrosion-resistant turbine blades still relies mainly on traditional methods: arc welding, plasma spraying, supersonic flame spraying, and induction hardening are the most common. However, these processes all have significant shortcomings: 1. The bonding between various thermal spray coatings and the substrate is mainly mechanical, with a bonding strength typically below 70 MPa. Under the coupled action of sand-containing high-speed water flow erosion and cavitation, interlayer delamination and localized peeling are prone to occur, making it difficult to significantly extend the service life; 2. The high heat input introduced by cladding welding results in a heat-affected zone width of 2–4 mm, coarsening of the microstructure, concentration of residual tensile stress, and a dilution rate exceeding 30%, which weakens the original fatigue performance of the blade and easily induces crack initiation; 3. Although surface hardening can improve hardness, it has poor adaptability to complex curved surfaces, the depth and uniformity of the hardened layer are difficult to control precisely, and it cannot repair existing pits or cracks. Therefore, there is an urgent need to develop new green remanufacturing technologies with high metallurgical bonding, low heat input, and in-situ implementation to achieve efficient strengthening and damage repair of turbine blades under in-service conditions. Summary of the Invention

[0004] To address the technical problems existing in the background art, this invention proposes a method and apparatus for repairing water turbines based on friction stirring and laser deposition.

[0005] This invention proposes a method for repairing hydraulic turbines based on friction stir combined with laser deposition, comprising the following steps: S1. Defect Identification and Classification: Identify the damaged areas of turbine components and classify them as surface wear or deep cracking based on the morphology and depth of the damage. S2. Pretreatment: For the classified damaged areas, prepare a regularized geometric interface suitable for laser deposition repair; S3. Laser deposition and friction stir synergistic repair: Based on defect classification, perform differentiated synergistic repair operations; When the damage is classified as surface wear, the first repair strategy is implemented: a single-layer laser deposition is performed on the regularized geometric interface, followed by a stirring and friction treatment of the deposited layer surface using a needleless stirring head; When the damage is classified as deep cracking, a second repair strategy is implemented: multilayer laser deposition is performed within the regularized geometric interface, and interlayer stirring friction treatment is performed using a needle-type stirring head when the deposition layer thickness reaches a set thickness. S4. Post-processing: Fine-machining is performed on the areas that have undergone friction stirring to restore the original profile and surface condition of the parts.

[0006] Preferably, for surface wear, the regularized geometric interface prepared in step S2 is an open bevel with a specific inclination angle and root fillet.

[0007] Preferably, for deep cracks, the regularized geometric interface prepared in step S2 is a closed groove with a mechanical interlocking effect.

[0008] Preferably, in the first repair strategy, when performing single-layer laser deposition, an inter-pass overlap rate of 40%-60% is adopted.

[0009] Preferably, the overlap rate between tracks is 50%.

[0010] Preferably, step S1, defect identification and classification, specifically includes: S11. Perform a three-dimensional scan of the damaged area of ​​the turbine and generate a defect envelope; S12. Use non-destructive testing methods to detect and quantitatively analyze the damaged area; S13. Based on the morphology and depth of the damage, it is classified as surface wear or deep cracking.

[0011] Preferably, step S4, post-processing specifically includes: S41. Adaptive grinding is performed on the repair area based on 3D scanning data to restore the original contour; S42. Perform non-destructive testing and surface roughness testing on the finished area. After confirming that there are no defects, apply a corrosion-resistant coating of a predetermined thickness. S43. Perform dynamic balancing verification on the repaired components.

[0012] Preferably, the grinding in step S41 employs multi-level incremental precision grinding, and ultimately retains a predetermined polishing allowance.

[0013] This invention proposes a device for repairing hydraulic turbines based on friction stir combined with laser deposition. This device, used to implement the aforementioned method, includes: a three-dimensional scanning unit, a non-destructive testing unit, a repair execution unit, and a central control unit, wherein: The 3D scanning unit is used to acquire 3D topographic data of the damaged parts of the water turbine; The non-destructive testing unit is used to detect internal defects in damaged areas; The repair execution unit includes a circular track, a laser deposition repair robot, a machining robot, and various end effectors. The circular track is fixed inside the turbine by circumferentially distributed positioning mechanisms. The laser deposition repair robot is mounted on the circular track via a first track-walking trolley. The machining robot is mounted on the circular track via a second track-walking trolley. The various end effectors include at least a needleless stirring head and a needle-type stirring head for tissue modification, a milling head for material removal, and a grinding head for surface finishing. Each end effector is mounted at the end of the machining robot in an alternating manner. The central control unit is electrically connected to the 3D scanning unit, the non-destructive testing unit, and the repair execution unit. The central control unit includes a data processing module and a control module. The data processing module is configured to receive and fuse the 3D morphology data and internal defect information, and determine the damage as surface wear or deep cracking according to preset classification rules. The control module stores a first control strategy corresponding to surface wear and a second control strategy corresponding to deep cracking, and calls the corresponding first control strategy or second control strategy based on the judgment result of the data processing module.

[0014] Preferably, the control module is configured as follows: When surface wear is detected, the first control strategy is executed: first, the machining robot is controlled to carry a milling head to perform pretreatment, then the laser deposition repair device is controlled to perform single-layer laser deposition, and then the machining robot is controlled to carry a needleless stirring head to perform stirring and friction treatment on the deposited layer surface. When a deep crack is identified, the second control strategy is executed: first, the machining robot is controlled to carry a milling head to perform pretreatment, then the laser deposition repair device is controlled to perform multi-layer laser deposition, and after each layer is deposited, the machining robot is controlled to carry a needle-type stirring head to perform interlayer stirring and friction treatment on that layer. Finally, the control robot carries the grinding head to perform post-processing.

[0015] Preferably, the preset classification rule in the data processing module is: to classify based on the weighted calculated value of defect area and defect depth.

[0016] Preferably, the data processing module is further configured to: adaptively plan the motion paths of the laser deposition repair robot and the machining robot based on the data obtained by the 3D scanning unit.

[0017] Preferably, the motion path of the laser deposition repair robot is adaptively planned based on the curvature of the repair area, and the specific interpolation step size of the repair robot is... ΔL Based on the maximum principal curvature of the repair area Determine whether the following relationship is satisfied: .

[0018] Preferably, the machining robot includes an articulated robot and a power mechanism disposed at the end of the articulated robot, wherein the power mechanism is an electric spindle, which can be connected to any one of the various end effectors via a standard tool holder interface or a quick-change disc.

[0019] Preferably, the positioning mechanism includes a connecting seat fixedly connected to the annular track, a connecting hole provided on the connecting seat, and a connecting bolt adapted to the connecting hole.

[0020] This invention classifies defects and specifies differentiated collaborative repair based on defect type, achieving efficient, high-quality, on-site repair of different types of damage to turbine components. It improves the adaptability and reliability of the repair process, avoids insufficient or excessive repair, and the introduction of friction stirring treatment fundamentally improves the microstructure of the laser-deposited layer, making the mechanical properties and corrosion resistance of the repaired area superior to traditional welding repair.

[0021] Figure 1 This is a schematic diagram of the repair execution unit in the device for repairing a water turbine based on friction stir synergy laser deposition proposed in this invention; Figure 2 This is a schematic diagram of the installation of the repair execution unit in the water turbine in the device for repairing a water turbine based on friction stir synergy laser deposition proposed in this invention; Figure 3 This is a schematic diagram of the repair execution unit working in the turbine runner chamber of the device for repairing a water turbine based on friction stir synergy laser deposition proposed in this invention; Figure 4 This is a schematic diagram of the deep crack repair process in the method and apparatus for repairing water turbines based on friction stir synergy laser deposition proposed in this invention; Figure 5 This is a comparison diagram showing the effect of friction stirring on the closure of pore defects in the deposited repair layer in the method and apparatus for repairing water turbines based on friction stirring and laser deposition proposed in this invention. Figure 6This is a comparison diagram showing the effect of friction stirring on grain refinement of the deposited repair layer in the method and apparatus for repairing water turbines based on friction stirring and laser deposition proposed in this invention. Figure 7 This is a comparison diagram showing the effect of friction stirring on the homogenization of deposited precipitates in the method and apparatus for repairing water turbines based on friction stirring and laser deposition proposed in this invention. Figure 8 This is a comparison diagram showing the effect of friction stirring processing on improving the mechanical properties of the deposited repair layer in the method and apparatus for repairing water turbines based on friction stirring and laser deposition proposed in this invention. Detailed Implementation

[0022] Example 1: Method for repairing a water turbine This invention proposes a method for repairing hydraulic turbines based on friction stir combined with laser deposition, comprising the following steps: S1. Defect Identification and Classification The specific steps for identifying damaged areas of turbine components and classifying them as surface wear or deep cracking based on damage morphology and depth are as follows: S11. Perform a three-dimensional scan of the damaged area of ​​the water turbine and generate a defect envelope.

[0023] S12. Non-destructive testing methods are used to detect and quantitatively analyze the damaged area.

[0024] S13. Based on the morphology and depth of the damage, it is classified as surface wear or deep cracking.

[0025] S2, Preprocessing For the classified damage areas, regularized geometric interfaces suitable for laser deposition repair are prepared. Specifically, for surface wear defects, an open bevel model with a specific tilt angle and root fillet is prepared, and for deep crack defects, a closed groove model with mechanical interlocking effect is prepared.

[0026] S3, Synergistic Repair of Laser Deposition and Stirring Friction When the damage is classified as surface wear, the first repair strategy is implemented: a single-layer laser deposition is performed on the regularized geometric interface, followed by a stirring friction treatment of the deposited layer surface using a needleless stirring head.

[0027] When the damage is classified as deep cracking, a second repair strategy is implemented: multilayer laser deposition is performed within the regularized geometric interface, and when the deposition layer thickness reaches the set thickness, the deposition layer is subjected to interlayer stirring friction treatment using a needle-type stirring head. Specifically, the set thickness of the deposition layer is obtained by matching the length of the stirring needle of the needle-type stirring head.

[0028] S4. Post-processing: The areas treated with friction stirring are then precision-machined to restore the original profile and surface condition of the parts. The specific steps are as follows: S41. Adaptive grinding is performed on the repair area based on 3D scanning data to restore the original contour.

[0029] S42. Perform non-destructive testing and surface roughness testing on the finished area. After confirming that there are no defects, apply a corrosion-resistant coating of a predetermined thickness.

[0030] S43. Perform dynamic balancing verification on the repaired components.

[0031] Example 2: Apparatus for repairing a water turbine, which is used to implement the above-described method for repairing a water turbine.

[0032] The present invention proposes a device for repairing a water turbine based on friction stir combined with laser deposition, comprising: a three-dimensional scanning unit, a non-destructive testing unit, a repair execution unit, and a central control unit.

[0033] The 3D scanning unit is used to acquire 3D topographic data of the damaged areas of the turbine. The non-destructive testing unit is used to detect internal defects in the damaged areas.

[0034] like Figure 1 As shown, the repair execution unit includes a circular track 1, a laser deposition repair robot 2, a machining robot 3, and various end effectors. These end effectors include at least a needle-free stirring head and a needle-type stirring head for tissue modification, a milling head for material removal, and a grinding head for surface finishing. The circular track 1 is fixed inside the turbine by a circumferentially distributed positioning mechanism. The positioning mechanism includes a connecting seat fixedly connected to the circular track 1, a connecting hole on the connecting seat, and connecting bolts adapted to the connecting hole. The laser deposition repair robot 2 is mounted on the circular track 1 via a first track-traveling carriage 4. The laser deposition repair robot 2 includes an articulated robot and a laser deposition nozzle mounted at the end of the articulated robot. The machining robot 3 is mounted on the circular track 1 via a second track-traveling carriage 5. It includes an articulated robot and a power mechanism located at the end of the articulated robot. The power mechanism is an electric spindle, which can be connected to any of the various end effectors via a standard tool holder interface or a quick-change disc.

[0035] The central control unit is electrically connected to the 3D scanning unit, the non-destructive testing unit, and the repair execution unit. The central control unit includes a data processing module and a control module. The data processing module has a preset classification rule: grading based on a weighted calculation of defect area and defect depth. The data processing module is configured to receive and fuse the 3D topography data and internal defect information, and determine the damage as surface wear or deep cracking according to the preset classification rule. The control module internally stores a first control strategy corresponding to surface wear and a second control strategy corresponding to deep cracking, and is configured to: When surface wear is determined, the first control strategy is executed: first, the machining robot 3 is controlled to carry a milling head to perform pre-treatment, then the laser deposition repair device is controlled to perform single-layer laser deposition, and then the machining robot 3 is controlled to carry a needleless stirring head to perform stirring and friction treatment on the surface of the deposited layer. When a deep crack is determined, the second control strategy is executed: first, the machining robot 3 is controlled to carry a milling head to perform pretreatment, then the laser deposition repair device is controlled to perform multi-layer laser deposition, and after each layer is deposited, the machining robot 3 is controlled to carry a needle-type stirring head to perform interlayer stirring and friction treatment on the layer. Finally, the control machining robot 3 carries the grinding head to perform post-processing.

[0036] In a further embodiment, the data processing module is also configured to: adaptively plan the motion paths of the laser deposition repair robot 2 and the machining robot 3 based on the data obtained by the three-dimensional scanning unit.

[0037] The specific implementation method of this device is as follows: 1. Equipment Installation like Figure 2 As shown, the circular track 1 is fixed inside the turbine runner by its circumferentially distributed positioning mechanism (the connecting seat in the positioning mechanism is fixed to a predetermined anchor point or a specially set support structure in the turbine runner chamber by connecting bolts), surrounding the blade that needs to be repaired. The laser deposition repair robot 2 and the machining robot 3 are respectively installed on the circular track 1 by their first track-walking trolley 4 and second track-walking trolley 5.

[0038] 2. Data Collection A 3D scanning unit (e.g., a handheld 3D scanner, or a 3D scanner integrated into the end of a laser deposition repair robot 2 or a machining robot 3) scans the damaged area. A non-destructive testing unit (e.g., an ultrasonic flaw detector) probes the damaged area.

[0039] 3. Central control The central control unit receives all data. Its data processing module merges the data and performs calculations based on a preset weighted algorithm. If the defect index is below a threshold, it is determined to be surface wear; if it is above the threshold, it is determined to be deep cracking. Based on the classification results (in this example, both surface wear and deep cracking exist), its control module invokes the corresponding first and second control strategies. 4. Repair execution: like Figure 3 As shown, firstly, the data processing module plans the motion path of the machining robot 3, and the control module controls the machining robot 3 to carry the milling head to complete the pre-processing of the defective parts (open bevel or closed groove).

[0040] Subsequently, the laser deposition repair robot 2 is controlled to move along the circular track 1, with its interpolation step size ΔL based on the maximum principal curvature of the repair area. Perform adaptive adjustments and ensure the interpolation step size ΔL The following relationship must be satisfied: This ensures denser paths and more precise deposition in areas with high curvature.

[0041] Maximum principal curvature Real-time calculation using the three-point collinear probe method: If the probe spacing is d, the measured height is... , , Then the formula for calculating curvature κ is: When the laser deposition repair robot 2 deposits on defects, after each deposition is completed or between layers, the control module instructs the machining robot 3 to carry the corresponding stirring head (needleless stirring head for the surface layer, and needle-equipped stirring head for the deep interlayer layer) to perform stirring and friction treatment.

[0042] Finally, the control machining robot 3 carries the grinding head to perform post-processing grinding.

[0043] Example 3: On-site repair of turbine runner blades, such as... Figure 4 As shown: Step 1: Defect Identification and Classification (S1) 1. 3D Scanning (S11): Using a handheld or fixed 3D laser scanner, the damaged areas of turbine runner blades, guide vanes, and other components awaiting repair are scanned to acquire high-precision 3D point cloud data. Point cloud processing software is then used to generate an envelope model of the defective area, accurately quantifying the volume, area, and maximum depth of the defect.

[0044] 2. Non-destructive testing (S12): Using methods such as ultrasonic testing or penetrant testing, the damaged area is internally probed. The focus is on detecting the presence of microcracks invisible to the naked eye, fatigue damage, etc., and quantitatively analyzing the embedment depth and length of defects.

[0045] 3. Classification (S13): The data processing module in the central control unit integrates three-dimensional topographic data and non-destructive testing information, and performs weighted calculations based on defect depth and area according to preset classification rules. For example, a depth threshold D (e.g., 3mm) is set. When the maximum depth of the defect is less than D and there is no internal crack propagation, it is judged as surface wear; when the defect depth is greater than or equal to D, or there are obvious internal cracks, it is judged as deep cracking.

[0046] Step 2: Preprocessing (S2) For surface wear: The control machining robot 3 carries a milling head and, according to the generated path, processes the irregular wear area into an open bevel with a specific angle (e.g., 30°-45°) and a root radius (R1-R3mm). This bevel design is beneficial for the adhesion and formation of subsequent single-layer deposited materials.

[0047] For deep cracks: The machining robot 3, carrying a milling head, completely removes the defect along the crack path, creating a closed groove with a mechanically interlocking structure such as an inverted trapezoid or dovetail groove. This structure effectively increases the bonding area between the deposited material and the substrate, preventing the repair layer from detaching during service.

[0048] Step 3: Synergistic Repair of Laser Deposition and Friction Stirring (S3) When the damage is classified as surface wear, the first repair strategy is implemented: First, the laser deposition repair robot 2 is controlled to perform laser cladding within a prepared bevel using metal powder (such as martensitic stainless steel powder) that matches the substrate material. Parameters such as laser power, scanning speed, and powder feed rate are pre-optimized based on the material. To ensure a smooth and dense deposition layer, a 50% overlap rate is used for the scanning path planning. Then, after single-layer deposition, the machining robot 3, equipped with a needleless stirring head, performs agitation and friction treatment on the still-warm deposition layer surface by setting appropriate pressure, rotation speed, and travel speed. This process effectively eliminates porosity and microcracks on the deposition layer surface, significantly refines the surface grains, and improves its hardness and corrosion resistance.

[0049] When the damage is classified as deep cracking, a second repair strategy is implemented: multi-layer, multi-pass laser deposition is performed within the prepared groove until it is filled and slightly raised. After each layer is deposited, the machining robot 3 immediately carries a needle-equipped stirring head to perform interlayer agitation and friction treatment on the deposited layer. The insertion depth of the stirring needle must penetrate the current deposited layer and form a metallurgical bond with the treated microstructure below. This strategy, by strictly controlling the deposition thickness and agitation and friction process parameters of each layer, ensures that the microstructure of each layer is sufficiently densified and the grains refined, thereby avoiding defects such as poor interlayer bonding and coarse microstructure common in multi-layer deposition, and achieving a uniform improvement in the overall thickness performance of the repaired area.

[0050] Step 4: Post-processing (S4) 1. Grinding (S41): The machining robot 3 carries a grinding head or polishing head. Based on the comparison between the 3D scan data before repair and the real-time scan data after repair, a digital model and target contour of the repair area are generated. The machining robot 3 is controlled to perform multi-level incremental grinding (such as rough grinding to remove most of the excess material, and then fine grinding to approach the target profile), and finally retains a polishing allowance of about 0.1-0.2mm to restore the original aerodynamic contour of the part.

[0051] 2. Re-inspection (S42): Use non-destructive testing methods to re-inspect the finished area to ensure that there are no internal defects exceeding the standard. At the same time, check the surface roughness. After it meets the design requirements, apply a corrosion-resistant coating (such as epoxy resin coating or ceramic coating) of a predetermined thickness (such as 50-100μm) to the repaired area by spraying or brushing.

[0052] 3. Verification (S43): For high-speed rotating components such as wheels, verification on a dynamic balancing machine is required after repair. If necessary, remove counterweights from non-critical areas to ensure the dynamic balance accuracy of the entire component meets operating standards.

[0053] like Figure 4-8 As shown above, this invention, based on defect characteristics for classification and strategy selection, achieves efficient and high-quality on-site repair of different types of damage to turbine components. This improves the adaptability and reliability of the repair process, avoiding under- or over-repair. Furthermore, the introduction of friction stirring fundamentally improves the microstructure of the laser-deposited layer, resulting in superior mechanical properties and corrosion resistance in the repaired area compared to traditional welding. In addition, the integrated device and adaptive path planning enable efficient and high-quality on-site repair of large, complex curved surface components of turbines, significantly shortening the maintenance cycle.

[0054] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for repairing a hydraulic turbine based on a combination of friction stir and laser deposition, characterized in that, The method comprises the following steps: S1, defect identification and classification: identifying the damage area of the turbine component, and classifying it into surface wear or deep cracking according to the damage morphology and depth; S2, pretreatment: preparing a regularized geometric interface suitable for laser deposition repair for the classified damage area; S3, laser deposition and friction stir synergistic repair: based on defect classification, differential synergistic repair is performed; When the damage is classified as surface wear, a first repair strategy is performed: single-layer laser deposition is performed on the regularized geometric interface, and then a needleless stir head is used to perform friction stir processing on the surface of the deposited layer; When the damage is classified as deep cracking, a second repair strategy is performed: multi-layer laser deposition is performed in the regularized geometric interface, and when the deposited layer thickness reaches the set thickness, a needle stir head is used for interlayer friction stir processing; S4, post-processing: finishing the area subjected to friction stir processing to restore the original profile and surface state of the component.

2. The method of claim 1, wherein the method is a method of repairing a hydraulic turbine based on the combination of friction stir and laser deposition. For surface wear, the regularized geometric interface prepared in step S2 is an open groove with a specific inclination angle and a root roundness.

3. The method of claim 1, wherein the method is a method of repairing a hydraulic turbine based on the combination of friction stir processing and laser deposition. For deep cracking, the regularized geometric interface prepared in step S2 is a closed groove with a mechanical interlocking effect.

4. The method of claim 1, wherein the method is a method of repairing a hydraulic turbine based on the combination of friction stir processing and laser deposition. In the first repair strategy, when single-layer laser deposition is performed, an interpass overlap rate of 40%-60% is used; Preferably, the interpass overlap rate is 50%.

5. The method of claim 1, wherein the method is based on the combination of friction stir processing and laser deposition repair of the water turbine. Step S1, defect identification and classification specifically includes: S11, three-dimensional scanning of the turbine damage area and generating a defect envelope; S12, using non-destructive testing methods to detect and quantitatively analyze the damage area; S13, classifying it into surface wear or deep cracking according to the damage morphology and depth.

6. The method of claim 1, wherein the method is a method of repairing a hydraulic turbine based on the combination of friction stir processing and laser deposition. Step S4, post-processing specifically includes: S41, adaptive grinding of the repaired area based on three-dimensional scanning data to restore the original profile; S42, non-destructive testing and surface roughness testing of the finished area, and after confirming that there are no defects, applying a predetermined thickness of corrosion-resistant coating; S43, dynamic balance verification of the repaired component; Preferably, the grinding in step S41 uses multi-stage incremental precision grinding, and finally retains a predetermined value of polishing allowance.

7. An apparatus for repairing a hydraulic turbine based on a stir friction synergy with laser deposition, which is used to implement the method for repairing a hydraulic turbine based on a stir friction synergy with laser deposition according to any one of claims 1-6, characterized in that, It comprises: a three-dimensional scanning unit, a non-destructive testing unit, a repair execution unit, and a central control unit, wherein: the three-dimensional scanning unit is used to obtain three-dimensional morphology data of the damaged part of the turbine; the non-destructive testing unit is used to detect internal defect information of the damaged part; The repair execution unit comprises a ring track (1), a laser deposition repair robot (2), a machining robot (3), and a plurality of end effectors; the ring track (1) is fixed in the water turbine through circumferentially distributed positioning mechanisms; the laser deposition repair robot (2) is installed on the ring track (1) through a first track walking trolley (4); the machining robot (3) is installed on the ring track (1) through a second track walking trolley (5); the plurality of end effectors at least include a needleless stirring head and a needle stirring head for tissue modification, and a milling head for material removal and a polishing head for surface finishing, and each end effector is installed at the end of the machining robot (3) in a one-to-one manner; The central control unit is electrically connected with the three-dimensional scanning unit, the non-destructive testing unit and the repair execution unit; the central control unit comprises a data processing module and a control module, wherein the data processing module is configured to receive and fuse the three-dimensional topographic data and the internal defect information, and determine the damage as surface wear or deep cracking according to a preset classification rule; the control module internally stores a first control strategy corresponding to the surface wear and a second control strategy corresponding to the deep cracking, and calls the corresponding first control strategy or second control strategy based on the judgment result of the data processing module.

8. The apparatus for repairing the water turbine based on the friction stir cooperation and the laser deposition of claim 7, wherein, The control module is configured to: when determining the surface wear, execute the first control strategy: first control the machining robot (3) to carry the milling head to perform pre-processing, then control the laser deposition repair device to perform single-layer laser deposition, and then control the machining robot (3) to carry the needleless stirring head to perform stirring friction processing on the surface of the deposited layer; when determining the deep cracking, execute the second control strategy: first control the machining robot (3) to carry the milling head to perform pre-processing, then control the laser deposition repair device to perform multi-layer laser deposition, and after each layer is deposited, control the machining robot (3) to carry the needle stirring head to perform interlayer stirring friction processing on the layer; finally, control the machining robot (3) to carry the polishing head to perform post-processing.

9. The apparatus for repairing the water turbine based on the friction stir cooperation and the laser deposition of claim 7, wherein, The preset classification rule in the data processing module is that the weighted calculation value based on the defect area and the defect depth is graded; Preferably, the data processing module is further configured to adaptively plan the motion path of the laser deposition repair robot (2) and the machining robot (3) according to the data obtained by the three-dimensional scanning unit. Preferably, the laser deposition repair robot (2) motion path is adaptively planned based on the curvature of the repair area, in particular the repair robot interpolation step size The machining robot (3) comprises a joint robot and a power mechanism arranged at the end of the joint robot; the power mechanism is an electric spindle, which can be connected with any one of the plurality of end effectors through a standard tool holder interface or a quick-change disc; in accordance with the maximum principal curvature of the repair area is determined and satisfies the following relationship: .

10. The apparatus for repairing a hydraulic turbine based on the friction stir cooperation and laser deposition of any one of claims 7-9, wherein, Preferably, the positioning mechanism comprises a connecting seat fixedly connected with the ring track (1), a connecting hole arranged on the connecting seat, and a connecting bolt adapted to the connecting hole. ​

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