Laser shock peening control method and device for blade

Abstract

The application discloses a laser shock peening control method for a blade, wherein the laser shock peening control method comprises the steps of acquiring three-dimensional coordinate data of a blade wheel and establishing a model I1, planning a process parameter, blade shock peening, deformation detection, and blade straightening peening; and the laser shock peening device comprises a whole machine control system, a laser control system, a point cloud data extraction system, a powder spraying control system, and a mechanical arm control system. The application has the effects of guaranteeing that a free curved surface blade obtains a strengthening effect while controlling deformation of the blade, and improving the precision of the blade.

Description

Technical Field

[0001] This invention relates to the field of laser processing technology, and in particular, to a laser shock peening and shaping method for blades. Background Technology

[0002] Laser shock peening (LSP) is a material surface strengthening technique. It utilizes short-pulse, high-peak-power-density laser radiation on the material surface. The absorbing layer on the material surface (such as black tape or aluminum foil) absorbs the laser energy and undergoes explosive vaporization, generating high-temperature, high-pressure plasma. This plasma, constrained by a layer (such as deionized water, K9 optical glass, or silicone), produces a high-intensity pressure shock wave. This shock wave acts on the material surface and propagates into the material's interior. When the peak pressure of the shock wave exceeds the dynamic yield limit of the treated material, the material undergoes strain and hardening, generating significant compressive stress. Through LSP, residual compressive stress is obtained, thereby improving the material's fatigue resistance, corrosion resistance, and wear resistance. Therefore, it is widely used in high-end equipment fields such as aerospace, energy, and transportation.

[0003] Aero-engine blades, driven by the high-speed rotation of the rotor and the scouring of strong airflow, endure various loads such as tension, bending, and vibration, operating under harsh conditions. The edges of the titanium alloy blades in the first few stages of the engine are highly sensitive to foreign object damage; once a notch is formed, it will lead to a sharp decrease in the fatigue strength of the blade, which may reduce the service life of the blade or even cause engine failure. Therefore, laser shock peening technology can be used to improve the overall performance of engine blades. However, during the strengthening process, due to stress balancing, macroscopic deformation occurs in the blade. When the deformation exceeds a certain range, it will have a serious impact on the operation of the engine. Summary of the Invention

[0004] This invention provides a laser shock strengthening and shape control method and device for blades, aiming to ensure that freeform blades achieve strengthening effects while controlling the deformation of the blades and improving blade precision.

[0005] According to one aspect of the present invention, a laser shock peening and shaping method for blades is provided, comprising the following steps:

[0006] S1, acquire the three-dimensional coordinate data of the impeller and establish model I1;

[0007] S2, planning process parameters, including dividing the impact zone, dividing the blade into a strengthening zone and a straightening zone according to the distance between the blade and the blade root, with the strengthening zone being closer to the blade root and the straightening zone being farther away from the blade root; and dividing the strengthening zone into region a and region b according to the curvature of the blade, with region a being closer to the blade root and region b being farther away from the blade root.

[0008] S3, Blade impact strengthening, laser shock strengthening of regions a and b of the blade is carried out using planned process parameters;

[0009] S4, Deformation detection: Obtain the profile model information I2 of the strengthened bladed disk, compare it with the original data I1 and I2, calculate the deformation Q1 of the blade after strengthening, and determine whether the value of the deformation Q1 is within the required tolerance range. If the deformation Q1 is within the tolerance range, the strengthening ends; if the deformation Q1 exceeds the tolerance range Q0, the blade straightening strengthening step is performed.

[0010] S5, blade straightening and strengthening, using a single laser beam to perform straightening and strengthening impact on region c of the blade; after a single straightening and strengthening impact is completed, repeat steps S1 and S5 until the deformation Q1 is within the tolerance range.

[0011] Optionally, in step S3, the predetermined process parameters include the laser incident angle α. Based on the original bladed disk profile model I1, the optical path is simulated using simulation software to solve for the incident angle that does not interfere with other blades during impact strengthening of the blade to obtain the laser incident angle α.

[0012] Optionally, the α angle can be 20° to 70°.

[0013] Optionally, in step S3, the blade impact strengthening is performed by simultaneously applying dual lasers to both sides of the blade.

[0014] Optionally, in step S3, the predetermined process parameters include the impact path, which adopts a continuous, non-overlapping impact path, with the impact path direction from the blade root to the blade tip.

[0015] Optionally, in step S3, before performing blade impact strengthening, the blade is first subjected to a strengthening pretreatment, which includes the following steps: cleaning the impact area to ensure that the impact area is clean and free of foreign matter; and attaching an absorption layer to the impact area.

[0016] Optionally, in step S3, the predetermined process parameters include laser energy Q, and the blade thickness on the impact path is calculated based on model M1 and the impact path. The magnitude of laser energy Q is directly proportional to the blade thickness.

[0017] Optionally, in step S1, a blue light 3D scanner is used to emit a blue light beam to the impeller disk, and the reflection signal of the impeller disk is received through multiple lenses. The three-dimensional coordinates of the surface points are calculated, the reflectivity and texture information are recorded, and the impeller disk point cloud information is obtained. The surface contour information of the impeller disk is extracted from the impeller disk point cloud information as the original data I1 for the reference of the deformation of the impeller disk.

[0018] Optionally, in step S5, a single laser beam is used to perform blade straightening in region c, and a laser beam in the corresponding direction is used for straightening according to the deformation direction of the blade.

[0019] According to another aspect of the present invention, a laser shock strengthening device for blades is also provided, characterized in that the laser shock strengthening shape control method for blades described above includes: a whole machine control system, a laser control system, a point cloud data extraction system, a powder spraying control system, and a robotic arm control system, wherein the whole machine control system is connected to the laser control system, the point cloud extraction system, the powder spraying control system, and the robotic arm control system, and the whole machine system controls the coordinated operation of each subsystem.

[0020] In summary, this application includes at least one of the following beneficial technical effects:

[0021] By extracting point cloud information from the blade, laser shock peening parameters are optimized. By acquiring the specific direction and value of the blade's deformation after peening, a blade straightening process is implemented, enabling control over the amount of deformation generated during peening. Compared to existing technologies, this method achieves precise control of the peening effect through calculation of various input parameters. Furthermore, this method integrates laser peening with detection, automatically feeding the detection results back into the laser processing, saving time on blade clamping and manual inspection, and significantly improving the efficiency of laser shock peening of free-form surfaces.

[0022] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0023] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0024] Figure 1 This is a flowchart of a laser shock peening shaping method according to a preferred embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the impact region according to a preferred embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the enhancement path in a preferred embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the non-overlapping impact path of a preferred embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of the blade impact strengthening path according to a preferred embodiment of the present invention;

[0029] Figure 6 This is a schematic diagram of the blade straightening and strengthening path according to a preferred embodiment of the present invention;

[0030] Figure 7 This is a schematic diagram of a laser shock strengthening and shaping device according to a preferred embodiment of the present invention.

[0031] Legend:

[0032] 1. Computer-controlled system; 2. Laser control system; 3. 3D scanning system; 4. Powder spraying control system; 5. Robotic arm control system; 6. Powder spraying machine; 7. Blade; 8. Fixture; 9. Worktable; 10. 3D scanner; 11. Robotic arm; 12. Lighting; 13. Water coating device; 14. Water coating device; 15. Laser; 16. Laser. Detailed Implementation

[0033] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0034] The following is in conjunction with the appendix Figure 1-7 This application will be described in further detail.

[0035] This application discloses a laser shock peening and shaping method for blades.

[0036] Reference Figure 1 A laser shock peening and shaping method for blades, characterized by comprising the following steps:

[0037] S1, acquire the three-dimensional coordinate data of the impeller and establish model I1;

[0038] S2, Divide the impact zone. Based on the distance between the blade and the blade root, divide the blade into a reinforcement zone and a correction zone. The area closer to the blade root is the reinforcement zone, and the area farther from the blade root is the correction zone. Based on the curvature of the blade, divide the reinforcement zone into area a and area b. Area a is closer to the blade root, and area b is farther from the blade root.

[0039] S3, Blade impact strengthening, laser impact strengthening of regions a and b of the blade is performed using predetermined process parameters;

[0040] S4, Deformation detection: Obtain the profile model information I2 of the strengthened bladed disk, compare it with the original data I1 and I2, calculate the deformation Q1 of the blade after strengthening, and determine whether the value of the deformation Q1 is within the required tolerance range. If the deformation Q1 is within the tolerance range, the strengthening ends; if the deformation Q1 exceeds the tolerance range Q0, the blade straightening strengthening step is performed.

[0041] S5, blade straightening and strengthening, using a single laser beam to perform straightening and strengthening impact on region c of the blade; after a single straightening and strengthening impact is completed, repeat steps S1 and S5 until the deformation Q1 is within the tolerance range.

[0042] Reference Figure 2 and Figure 3 In this embodiment, the actual coordinate data of the impeller is first obtained by scanning, and a model is established. The parameters for laser shock peening are planned according to the actual shape of the impeller rather than the theoretical shape, which can improve the processing accuracy. Because the blade is a cantilever beam, the overall deformation generated in the a and b strengthening regions (near the blade root) will be superimposed, and the maximum deformation will eventually appear in the c region (near the blade tip). Therefore, the c region is straightened and strengthened according to the actual deformation. While strengthening, the cumulative deformation in the a and b regions during the shock peening process can be compensated, thereby further reducing the deformation of the blade after the strengthening process.

[0043] Step S1 involves acquiring the three-dimensional coordinate data of the impeller and establishing model I1. A blue light 3D scanner emits a blue light beam to the impeller disk, and multiple lenses receive the reflected signals. The three-dimensional coordinates of surface points are calculated, reflectivity and texture information are recorded, and point cloud information of the impeller disk is obtained. The surface contour information of the impeller disk is extracted from the point cloud information and used as the original data I1 for reference when the impeller disk deforms. In one specific implementation, a GOM ATOS Q blue light 3D scanner with an LED blue light source is used. The number of points scanned in a single scan is 8 million, the scanning area is 120×80×80mm, the point spacing is 0.033mm, the detection error is 0.003mm, and the communication with the computer host is via fiber optic transmission.

[0044] Optionally, in order to enable the impeller in step S1 to better reflect the signal and obtain more accurate coordinate data, the blade needs to be powder-coated for matte treatment before scanning. Titanium dioxide powder and 99% anhydrous ethanol are mixed at a weight ratio of 1:20 and then sprayed to ensure that the white titanium powder is evenly covered and forms a thin film mist.

[0045] In step S2, the process parameters that need to be planned include impact method, impact area, impact path, laser energy Q, and laser incident angle α.

[0046] Impact Method and Impact Area: In areas a and b, blade impact strengthening employs simultaneous dual-laser impact strengthening on both sides of the blade; in area c, a single-sided laser is used for shaping. Areas a and b are the vulnerable areas of the blade under operating conditions. The strengthening area is divided into areas a and b because there is interference between the blades, and oblique incidence at the same angle is difficult to completely cover the strengthening area. Using dual laser beams for simultaneous strengthening can strengthen both sides, and at the same time, it can partially cancel out the forces in the normal direction of the blade as a cantilever beam, reducing blade deformation. Using a double-sided strengthening method without overlapping trajectory can prevent blade surface ablation, improve the blade strengthening effect, and reduce overall blade deformation. Area c is the shaping area. Because the blade is a cantilever beam, the overall deformation generated in the strengthening areas a and b (near the blade root) will be superimposed, ultimately showing the largest deformation in area c (near the blade tip). According to the deformation direction in area c, the laser beam is used to shape the blade in the direction of deformation. The trajectory in area c is as follows. Figure 2 As shown, this can prevent blade surface ablation, improve blade strengthening effect, and reduce overall blade deformation.

[0047] Impact Path: A continuous, non-overlapping impact path is adopted, with the impact path direction from the blade root to the blade tip. In one specific embodiment, the impact path of each blade includes four impact procedures: Procedure 1, Procedure 2, Procedure 3, and Procedure 4. Each impact procedure consists of impact spots distributed in a matrix. The impact spots of Procedures 1, 2, 3, and 4 are evenly distributed on the blade, collectively covering the blade surface. To ensure that there are no gaps in the impact path and that all locations on the blade receive impact strengthening, the edges of the impact spots of Procedures 1, 2, 3, and 4 overlap. Procedures 1, 2, 3, and 4 refer to four strengthening processes in chronological order, each strengthening different parts of the same region (region a or region b).

[0048] The order of light spots in each process of the non-overlapping impact path is as follows: Figure 4 As shown in the serial number, for example Figure 4 The two light spots numbered 1 represent the first impact of two laser beams simultaneously on the front and back of the blade.

[0049] Impact paths in regions a and b are as follows: Figure 5 As shown, when both sides are impacted simultaneously, the sequence of light spots is as indicated by the numbers in the figure:

[0050] Program 1: 1-2-3-4-5-6-7-8;

[0051] Program 2: 9-10-11-12-13-14;

[0052] Program 3: 15-16-17-18-19-20-21-22;

[0053] Program 4: 23-24-25-26-27-28.

[0054] Reference Figure 6 If the impact path in region c is the same as that in region b, the impact mode is a single-sided impact.

[0055] Laser incident angle α: Based on the original bladed disk profile model I1, optical path simulation is performed using simulation software to solve for the incident angle that does not interfere with other blades during impact strengthening of the blade, thus obtaining the laser incident angle α. The value of α is between 20° and 70°. In one specific implementation, the value of α is 70°.

[0056] Laser energy Q: Based on model M1 and the impact path, the blade thickness along the impact path is calculated. The magnitude of laser energy Q is directly proportional to the blade thickness.

[0057] In step S3, before blade impact strengthening, the blade undergoes pre-strengthening treatment, which includes the following steps: cleaning the impact area to ensure it is clean and free of foreign matter; attaching an absorption layer to the impact area. Impact method: Dual-laser synchronous impact strengthening is used. Laser incident angle α = 70°. Impact area S: Areas a and b are selected as the dual-laser strengthening area, and area c is the single-laser shaping area. Impact path R: A continuous, non-overlapping impact path is used, with the direction from the blade root to the blade tip. Laser energy Q: Automatically controlled by the laser control system based on the blade thickness. Overlap rate: 30%. Spot diameter: 1 mm.

[0058] In step S5, the worktable is moved to the calibration area via the robotic arm control system. Calibration method: single-sided impact calibration. Incident angle α: perpendicular incidence. Impact path: continuous overlap, towards the blade tip. Overlap rate: 30%. Spot diameter: 1mm. Energy: The calibration energy is automatically planned based on I2 information; the laser energy Q is directly proportional to the blade thickness.

[0059] Reference Figure 7 This embodiment also discloses a laser shock strengthening device for blades, used in the above-mentioned laser shock strengthening shape control method for blades, including: a whole machine control system, a laser control system, a point cloud data extraction system, a powder spraying control system, and a robotic arm control system. The whole machine control system is connected to the laser control system, the point cloud extraction system, the powder spraying control system, and the robotic arm control system, and the whole machine system controls the coordinated operation of each subsystem.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A laser shock peening and shaping method for blades, characterized in that, Includes the following steps: S1, acquire the three-dimensional coordinate data of the impeller and establish model I1; S2, planning process parameters, including dividing the impact zone, dividing the blade into a strengthening zone and a straightening zone according to the distance between the blade and the blade root, with the strengthening zone being closer to the blade root and the straightening zone being farther away from the blade root; dividing the strengthening zone into zone a and zone b according to the curvature of the blade, with zone a being closer to the blade root and zone b being farther away from the blade root, and the straightening zone being zone c. S3, blade impact strengthening, using planned process parameters to simultaneously apply dual lasers to both sides of the blade in regions a and b for impact strengthening. S4, Deformation detection: Obtain the profile model information I2 of the strengthened bladed disk, compare the model I1 with I2, calculate the deformation Q1 of the blade after strengthening, and determine whether the value of the deformation Q1 is within the required tolerance range. If the deformation Q1 is within the tolerance range, the strengthening ends; if the deformation Q1 exceeds the tolerance range Q0, the blade straightening strengthening step is performed. S5, blade straightening and strengthening, using a single laser beam to perform unilateral straightening and strengthening impact on region c of the blade; after a single straightening and strengthening impact is completed, repeat steps S1 and S5 until the deformation Q1 is within the tolerance range.

2. The laser shock peening and shaping method for blades according to claim 1, characterized in that, In step S2, the process parameters include the laser incident angle α. Based on the original bladed disk profile model, the optical path is simulated using simulation software to solve for the incident angle that does not interfere with other blades when the blade is impact-strengthened, thus obtaining the laser incident angle α.

3. The laser shock peening and shaping method for blades according to claim 2, characterized in that, The angle α ranges from 20° to 70°.

4. The laser shock peening and shaping method for blades according to claim 1, characterized in that, In step S2, the predetermined process parameters include the impact path, which adopts a continuous non-overlapping impact path, and the impact path direction is from the blade root to the blade tip.

5. The laser shock peening and shaping method for blades according to claim 1, characterized in that, In step S3, before the blade impact strengthening is carried out, the blade is first subjected to a strengthening pretreatment, which includes the following steps: cleaning the impact area to ensure that the impact area is clean and free of foreign objects; attaching an absorption layer to the impact area.

6. The laser shock peening and shaping method for blades according to claim 5, characterized in that, In step S2, the predetermined process parameters include laser energy Q. Based on model I1 and the impact path, the blade thickness along the impact path is calculated. The magnitude of laser energy Q is directly proportional to the blade thickness.

7. The laser shock peening and shaping method for blades according to claim 1, characterized in that, In step S1, a blue light 3D scanner is used to emit a blue light beam to the impeller disk, and the reflection signal of the impeller disk is received through multiple lenses. The 3D coordinates of the surface points are calculated, the reflectivity and texture information are recorded, and the impeller disk point cloud information is obtained. The surface contour information of the impeller disk is extracted from the impeller disk point cloud information as the original data for the deformation of the impeller disk.

8. The laser shock peening and shaping method for blades according to claim 1, characterized in that, In step S5, a laser beam in the corresponding direction is used for correction according to the deformation direction of the blade.

9. A laser shock peening device for blades, characterized in that, The laser shock peening and shaping method for blades according to any one of claims 1-8 includes: The system comprises a whole machine control system, a laser control system, a point cloud data extraction system, a powder spraying control system, and a robotic arm control system. The whole machine control system is connected to the laser control system, the point cloud data extraction system, the powder spraying control system, and the robotic arm control system, and the whole machine system controls the coordinated operation of each subsystem.

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