Method and device for machining air film hole of blade with thermal barrier coating

Abstract

The invention provides a film hole machining method and device for a blade with a thermal barrier coating, and the machining method comprises the following steps: S1, the blade with the thermal barrier coating is fixed, the thermal barrier coating at the punching part is removed by using femtosecond laser, the surface of a blade body is exposed, the incident angle alpha of the femtosecond laser is larger than or equal to 30 degrees and larger than or equal to 15 degrees; s2, direct punching is conducted on the punching part through millisecond laser, a blind hole is formed in the blade body, the incident angle of the millisecond laser is beta, and beta-alpha is larger than or equal to 5 degrees and smaller than or equal to 20 degrees; s3, the bottom hole is punched in a mechanical drilling mode, and a through hole is formed; and S4, the hole wall is trimmed through an electro-hydraulic beam, and the air film hole is obtained through machining. According to the air film hole machining device, the technology of double-laser machining, mechanical drilling and electro-hydraulic beam hole repairing is adopted, the machining efficiency and quality of the air film hole are effectively improved, it is ensured that the machined air film hole meets the requirements in the aspects of size precision, surface quality and the like, and the high-quality air film hole can be efficiently obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of blade film hole processing, and in particular to a method and device for processing a blade film hole with a thermal barrier coating. Background Art

[0002] With the continuous development of advanced aircraft engines, the temperature of the gas before the turbine has gradually increased, which has put forward higher requirements on the temperature bearing capacity of the turbine blades. In order to meet the requirements of hot end components such as turbine blades in extreme service environments such as high temperature, high pressure and high speed, the field of aircraft engines has been using thermal barrier coating technology and air film hole cooling technology to reduce the service temperature of hot end components, thereby extending their service life.

[0003] Thermal barrier coatings are generally double-layer structures, i.e., a ceramic layer on the surface and an adhesive layer on the inner layer, and their main functions are heat insulation and anti-oxidation. Traditional film hole processing methods such as electric spark drilling cannot process thermal barrier coatings with poor conductivity. The solution of first making holes and then coating is required, which inevitably produces problems such as shrinkage and hole blockage, and the design compliance is poor. In order to directly drill holes on thermal barrier coatings, the prior art proposes the use of laser processing. For example, patent document CN201410213528.7 discloses a film cooling hole preparation process based on picosecond laser assisted processing, and patent document CN201711450432.2 discloses a femtosecond laser processing method and device for film holes on blades with thermal barrier coatings. However, these processing technologies have the problems of low processing efficiency and poor quality of film holes. Summary of the invention

[0004] In view of the deficiencies of the prior art, the purpose of the present invention is to develop a film hole processing technology for blades with thermal barrier coatings to improve processing efficiency and quality.

[0005] To achieve the above object, the present invention provides a method for machining film holes of a blade with a thermal barrier coating, comprising the following steps: S1. Fix the blade with thermal barrier coating, use femtosecond laser to remove the thermal barrier coating at the punched part, and expose the surface of the blade body. The incident angle of the femtosecond laser is α, 30°≥α≥15°; S2. Use millisecond laser to perform direct punching at the punching position to form a blind hole on the blade body. The incident angle of the millisecond laser is β, 20°≥β-α≥5°; S3, drilling through the bottom hole by mechanical drilling to form a through hole; S4. Use an electro-hydraulic beam to trim the hole wall of the air film hole to obtain the air film hole.

[0006] The present invention adopts dual laser processing, mechanical drilling, and combined with electro-hydraulic beam hole repair technology. First, a femtosecond laser is used to remove the thermal barrier coating at the punching site. By utilizing its ultra-short pulse and high-precision characteristics, the coating can be accurately removed with little damage to the blade body. Combined with millisecond laser direct punching, blind holes are quickly formed, and then through holes are formed by mechanical drilling, and the hole walls are basically flat. Finally, an electro-hydraulic beam is used to fine-tune the hole walls, forming a complete set of processing procedures, which effectively improves the efficiency and quality of air film hole processing, ensures that the processed air film holes meet the requirements in terms of dimensional accuracy, surface quality, etc., and can efficiently obtain high-quality air film holes.

[0007] Furthermore, the present invention makes differentiated designs for the incident angles of femtosecond laser and millisecond laser. The obliquely incident femtosecond laser increases the contact area between the laser and the coating, improves the photon energy absorption rate, accelerates the stripping of the thermal barrier coating, and is limited to 30°≥α≥15°, thereby ensuring that the laser energy is concentrated on the surface of the coating to avoid deep penetration and damage to the blade body. The millisecond laser and the femtosecond laser have a certain angle difference to prevent accidental ablation of the exposed edge area of ​​the blade body during millisecond laser processing, reduce the burrs at the air film orifice and the thickness of the heat-affected zone, and the angle difference guides the millisecond laser melt to be discharged along the outside of the hole wall, inhibits the formation of a recast layer, and reduces the workload of subsequent hole wall finishing.

[0008] In a preferred or optional solution, in step S1, the thickness of the thermal barrier coating is less than or equal to 0.5 mm, the pulse width of the femtosecond laser is less than 1 ps, the single pulse energy is 20-1000 μJ, the scanning speed is 0.1-3 m / s, and the processing time is less than or equal to 10 s. The femtosecond laser parameters are limited according to the thickness of the thermal barrier coating, so that the process of removing the thermal barrier coating by femtosecond laser is more accurate, efficient and controllable, and the thermal barrier coating is quickly removed, while ensuring the removal effect and avoiding excessive heat effects.

[0009] In the preferred or optional solution, in step S1, the scanning speed of the femtosecond laser is adjusted according to the curvature of the blade surface, V=0.1+0.05×(1 / R), where V is the scanning speed of the femtosecond laser, in m / s, and R is the local curvature radius of the blade, in mm. The scanning speed of the femtosecond laser is dynamically adjusted according to the curvature of the blade surface, so that the laser removal of the thermal barrier coating can better fit the complex curved surface shape of the blade, ensuring that processing can be performed at a suitable speed at different curvature positions, thereby improving the quality and accuracy of the coating removal, avoiding unclean coating removal or damage to the blade body due to inappropriate speed, and further improving the adaptability and reliability of the processing.

[0010] In a preferred or optional solution, in step S2, the pulse width of the millisecond laser used is greater than or equal to 1ms, the single pulse energy is greater than or equal to 1J, and the processing time is less than or equal to 1s. The present invention uses millisecond laser direct punching, and the larger pulse width and single pulse energy can provide sufficient energy density, making the punching process more efficient, controlling the processing time within 1s, and quickly completing the forming of the air film hole. The obtained air film hole depth-to-diameter ratio and diameter meet specific requirements, ensuring the performance and cooling effect of the air film hole.

[0011] In a preferred or optional solution, in step S2, the blind hole has a depth-to-diameter ratio greater than or equal to 20, and a diameter greater than or equal to 0.3 mm. A larger depth-to-diameter ratio and diameter are conducive to the circulation of the cooling medium, improve the cooling efficiency, meet the cooling requirements of the blade in actual work, and ensure the reliability and service life of the blade in a high temperature environment.

[0012] In a preferred or optional solution, in step S4, the electro-hydraulic beam machining voltage is 12-300 V, and the machining time is less than or equal to 10 s. Appropriate machining voltage can ensure the electro-hydraulic beam finishing effect on the hole wall and improve the surface quality of the air film hole.

[0013] In a preferred or optional solution, in step S3, 20-50 nm Al2O3 abrasive is added to the electrolyte for electro-hydraulic beam machining. Adding Al2O3 abrasive to the electrolyte enhances the polishing effect, further improves the surface quality of the hole wall, reduces the roughness of the hole wall, and improves the cooling effect and overall performance of the blade.

[0014] In a preferred or optional solution, the mass of the blade body material removed in step S2 is a, and the total mass of the blade body material removed in steps S3 and S4 is b, satisfying a / b> 9. Using millisecond laser to quickly remove more than 90% of the material is conducive to shortening the time required for the electro-hydraulic beam processing step and improving the overall processing efficiency.

[0015] A second aspect of the present invention provides a device for implementing the above-mentioned method for machining air film holes of a blade with a thermal barrier coating, comprising: A five-axis system includes three linear axis drive modules and two rotary axis drive modules, wherein the three linear axis drive modules are respectively an X-axis drive module, a Y-axis drive module and a Z-axis drive module, and the two rotary axis drive modules are respectively an A-axis drive module and a C-axis drive module; A stage, used to fix the blade to be processed, the A-axis driving module and the C-axis driving module are drivingly connected to the stage; A processing assembly, wherein the processing assembly includes a femtosecond laser processing head, a millisecond laser processing head, a drill bit and a rotatable electro-hydraulic beam processing head, and the X-axis drive module, the Y-axis drive module and the Z-axis drive module are used to drive the processing assembly to move linearly; Dynamic focusing system for real-time scanning of blade surface curvature; A control system, wherein the control system is electrically connected to the five-axis system, the dynamic focusing system and the processing component, the dynamic focusing system is used to input surface curvature data into the control system, and the control system is used to control the movement of the five-axis system, adjust the angles of the stage and the processing component, and control the process parameters of the processing component.

[0016] The processing device of the present invention realizes multi-angle and multi-directional processing through a five-axis system, and can flexibly adapt to the complex shapes of blades and the processing requirements of different parts; the processing components integrate femtosecond laser, millisecond laser, electro-hydraulic beam processing head and drill bit, and can complete the entire processing process on one device, thereby improving processing efficiency and accuracy; the dynamic focusing system scans the curvature of the blade surface in real time, providing accurate data support for the control system, so that the control system can accurately control the movement of the five-axis system and the processing components, and realize precise regulation of the processing process, thereby ensuring that the quality of the processed air film holes is stable and reliable, meeting the design requirements, and improving the degree of automation and controllability of the entire processing technology.

[0017] In the preferred or optional scheme, a mounting bracket is also included, and the femtosecond laser processing head, the millisecond laser processing head, the drill bit and the electro-hydraulic beam processing head are arranged on the mounting bracket, and the X-axis drive module, the Y-axis drive module and the Z-axis drive module are all connected to the mounting bracket. The mounting bracket integrates the femtosecond laser processing head, the millisecond laser processing head, the drill bit and the electro-hydraulic beam processing head, which is convenient for the coordinated operation and switching between the processing heads. At the same time, the X, Y, and Z axis drive modules are connected to the mounting bracket, which can accurately control the position and movement trajectory of the processing components in space, further improve the processing accuracy and flexibility, ensure that each processing step can be accurately performed at the corresponding part of the blade, ensure the processing quality and efficiency, and facilitate the overall structural layout and operation and maintenance of the device.

[0018] In a preferred or optional solution, a first lifting mechanism and a second lifting mechanism are further provided on the mounting bracket, wherein the first lifting mechanism is drivingly connected to the millisecond laser processing head, and the second lifting mechanism is drivingly connected to the drill bit. The two lifting mechanisms can realize precise adjustment of the millisecond laser processing head and the drill bit in the vertical direction, so that the millisecond laser and the drill bit can better align with the punching parts at different heights of the blade, adapt to the three-dimensional curved surface shape of the blade, and ensure the accuracy and quality of the direct punching.

[0019] In summary, the present invention overcomes the industry problem of balancing quality and efficiency in the processing of film holes for blades with thermal barrier coatings through multi-process collaborative optimization, and provides a reliable solution for the manufacture of high-performance blades for aircraft engines and gas turbines. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the blade structure after femtosecond laser processing in an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the blade structure after millisecond laser processing in a specific implementation manner of the present invention.

[0022] Figure 3 It is a schematic diagram of the blade structure after electro-hydraulic jet processing in a specific implementation manner of the present invention.

[0023] Figure 4 This is an overall structural diagram of the air film hole processing device in Example 1 of the present invention.

[0024] Figure 5 This is an assembly structure diagram of the processing components in Example 1 of the present invention.

[0025] Figure 6 This is a cross-sectional view of the air film hole obtained after millisecond laser processing in Example 2 of the present invention.

[0026] Figure 7 This is a SEM image of the air film holes obtained after millisecond laser processing in Example 2 of the present invention.

[0027] Figure 8 This is a morphology of the hole wall of the air film hole after electro-hydraulic beam trimming in Example 2 of the present invention.

[0028] Description of reference numerals: 1. Frame; 21. X-axis drive module; 22. Y-axis drive module; 23. Z-axis drive module; 24. A-axis drive module; 25. C-axis drive module; 3. Stage; 41. Femtosecond laser processing head; 42. Millisecond laser processing head; 43. Drill bit; 44. Electro-hydraulic beam processing head; 5. Mounting bracket; 51. First lifting mechanism; 52. Second lifting mechanism; 6. Dynamic focusing system; 7. Control system; 81. Thermal barrier coating; 82. Blade body; 83. Air film hole. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0030] It should be noted that similar symbols and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition and explanation in the subsequent drawings.

[0031] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "inside", "outside", "front", "back", etc. are based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0032] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0033] A specific embodiment of the present invention provides a method for machining air film holes in a blade with a thermal barrier coating, comprising the following steps: S1. Fix the blade with thermal barrier coating 81, and use femtosecond laser with an incident angle of α to remove the thermal barrier coating 81 at the punched part to expose the surface of the blade body 82. The structure of the blade after this step is as follows: Figure 1 shown.

[0034] In a specific embodiment, the incident angle α of the femtosecond laser is between 15° and 30°. The obliquely incident femtosecond laser can ensure that the laser energy is concentrated on the thermal barrier coating 81, so that the thermal barrier coating 81 is quickly peeled off while avoiding damage to the blade body 82.

[0035] In a specific embodiment, the thickness of the thermal barrier coating 81 is less than or equal to 0.5 mm, the pulse width of the femtosecond laser is less than 1 ps, the single pulse energy is 20~1000 μJ, the scanning speed is 0.1~3 m / s, and the processing time is less than or equal to 10 s. The parameters of the femtosecond laser are limited according to the thickness of the thermal barrier coating 81, so that the process of removing the thermal barrier coating 81 by the femtosecond laser is more accurate, efficient and controllable. Furthermore, the scanning speed of the femtosecond laser is adjusted according to the curvature of the blade surface, so that the process of laser removal of the thermal barrier coating 81 can better fit the complex curved surface shape of the blade, ensuring that processing can be performed at a suitable speed at different curvature positions, thereby improving the quality and accuracy of removing the thermal barrier coating 81. The specific calculation formula is V=0.1+0.05×(1 / R), where V is the scanning speed of the femtosecond laser, in m / s, and R is the local curvature radius of the blade, in mm.

[0036] S2, use millisecond laser to punch holes at the punching position, the incident angle of the millisecond laser is β, and a blind hole is formed on the blade body 82. After this step, the blade structure is as follows Figure 2 shown.

[0037] In a specific embodiment, the pulse width of the millisecond laser used is greater than or equal to 1ms, the single pulse energy is greater than or equal to 1J, the processing time is less than or equal to 1s, and the obtained blind hole depth-to-diameter ratio is greater than or equal to 20, and the diameter is greater than or equal to 0.3mm. Using millisecond laser direct punching, the larger pulse width and single pulse energy can provide sufficient energy density, making the punching process more efficient, quickly completing the formation of the blind hole, and the obtained blind hole depth-to-diameter ratio and diameter meet the cooling requirements of the blade in actual work.

[0038] Furthermore, the millisecond laser incident angle β and the femtosecond laser incident angle α are designed differently to meet 20°≥β-α≥5°. Accordingly, the millisecond laser processing area should be slightly smaller than the thermal barrier coating 81 peeling area to avoid interference. The differentiated design of the millisecond laser incident angle can prevent the exposed edge area of ​​the blade body 82 from being accidentally ablated during millisecond laser processing, reduce the hole burr and the thickness of the heat-affected zone, and the angle difference guides the millisecond laser melt to be discharged along the outside of the hole wall, inhibiting the formation of the recast layer and reducing the workload of subsequent hole finishing.

[0039] S3, drilling the bottom hole by mechanical drilling to form a through hole. In this step, the through hole is formed by mechanical drilling, and the hole wall is basically flat, thereby improving the surface quality of the hole wall.

[0040] S4, use the electro-hydraulic beam to trim the hole wall. The blade structure after this step is as follows Figure 3 As shown, the air film hole 83 is obtained by machining. In a specific embodiment, the voltage of the electro-hydraulic beam machining is 12-300V, and the machining time is less than or equal to 10s.

[0041] In a specific embodiment, the mass of the blade body material removed in step S2 is a, and the total mass of the blade body material removed in steps S3 and S4 is b, satisfying a / b>9, that is, using millisecond laser to quickly remove more than 90% of the material, which is beneficial to shorten the time required for the electro-hydraulic beam processing step and improve the overall processing efficiency.

[0042] Furthermore, adding 20~50nm Al2O3 abrasive to the electrolyte used for electro-hydraulic beam machining can enhance the polishing effect, improve the surface quality of the hole wall, reduce the roughness of the hole wall, and improve the cooling effect and overall performance of the blade.

[0043] The above method uses dual laser processing combined with an electro-hydraulic beam hole making process. First, a femtosecond laser is used to remove the non-conductive thermal barrier coating 81, and then a millisecond laser is used to quickly form a blind hole. Then, a through hole is formed by mechanical drilling, and the hole wall is made basically flat. Finally, a rotatable electro-hydraulic beam is used to refine the hole wall, so as to efficiently obtain high-quality air film holes 83.

[0044] Example 1

[0045] Combination Figure 4 and Figure 5 As shown, this embodiment provides a processing device for air film holes of blades with thermal barrier coatings, which is used to implement the above-mentioned processing method. The device includes a control system 7, a frame 1, and a five-axis system, a stage 3, a processing assembly, a dynamic focusing system 6 and other components arranged on the frame 1. The five-axis system includes three linear axis drive modules and two rotary axis drive modules, the three linear axis drive modules are respectively an X-axis drive module 21, a Y-axis drive module 22 and a Z-axis drive module 23, and the two rotary axis drive modules are respectively an A-axis drive module 24 and a C-axis drive module 25. The processing assembly includes four processing heads, namely a femtosecond laser processing head 41, a millisecond laser processing head 42, a drill bit 43 and a rotatable electro-hydraulic beam processing head 44. The X-axis drive module 21, the Y-axis drive module 22 and the Z-axis drive module 23 are used to drive the processing assembly to move linearly. The stage 3 is arranged on the frame 1 for fixing the blade to be processed. The A-axis drive module 24 and the C-axis drive module 25 are connected to the stage 3 in driving manner, and can drive the stage 3 to rotate in both directions. The processing device controls the relative position and angle of each processing head and the blade to be processed through the five-axis drive module. The dynamic focusing system 6 is used to scan the curvature of the blade surface in real time, including a surface profile scanner and an adaptive zoom lens group. The control system 7 is used to control the operation of the device, which is electrically connected to the five-axis system, the dynamic focusing system 6 and the processing assembly.

[0046] During the processing, the dynamic focusing system 6 inputs the curvature data of the blade surface into the control system 7, and the control system 7 controls the movement of the five-axis system, uses the interpolation algorithm to discretize the tool path into small line segments, calculates the movement of each axis segment by segment, and adjusts the angle of the stage 3 and the processing component. After the processing head moves to the appropriate position, the control system 7 also controls the process parameters of the processing head to ensure the precise control of the entire processing process.

[0047] In this embodiment, a mounting bracket 5 is provided on the frame 1, and a femtosecond laser processing head 41, a millisecond laser processing head 42, a drill bit 43, and an electro-hydraulic beam processing head 44 are arranged on the mounting bracket 5. The X-axis driving module 21, the Y-axis driving module 22, and the Z-axis driving module 23 are all connected to the mounting bracket 5, and can drive multiple processing heads to move synchronously in the X-axis, Y-axis, and Z-axis directions. The mounting bracket 5 is also provided with a first lifting mechanism 51 and a second lifting mechanism 52, the first lifting mechanism 51 is connected to the millisecond laser processing head 42, and the second lifting mechanism 52 is connected to the drill bit 43, thereby accurately adjusting the vertical position of the millisecond laser processing head 42 and the drill bit 43, and can accurately align the punching position, thereby ensuring the quality and accuracy of the straight punching and drilling.

[0048] The above-mentioned processing device integrates femtosecond laser, millisecond laser, electro-hydraulic beam and mechanical processing into one device, and realizes laser, mechanical and electro-hydraulic beam composite processing of air film holes in blades with thermal barrier coating through one device. It has high processing efficiency and is suitable for processing common conductive blade materials such as metal materials. The material applicability is good and the obtained air film holes are of good quality.

[0049] Example 2

[0050] This embodiment uses the processing device provided in Embodiment 1 to make holes, and the specific steps are as follows: (1) A blade with a thermal barrier coating is fixed on a stage. The thickness of the thermal barrier coating is 0.4 mm and the blade body is made of metal.

[0051] (2) Aim the femtosecond laser processing head at the punching area, with an incident angle α of 20° and a single pulse energy of 100 μJ. The scanning speed is adjusted according to the curvature of the blade surface. The calculation formula is V = 0.1 + 0.05 × (1 / R). The processing time is 8 s. The thermal barrier coating at the punching area is removed, exposing the surface of the blade body.

[0052] (3) Aim the millisecond laser processing head at the punching part, use a millisecond laser with a single pulse energy of 2J to perform direct punching at the punching part, with an incident angle β of 30° and a processing time of 0.5s to form a blind hole with a diameter of 0.7mm and a depth of 5mm. The morphology of the air film hole obtained by millisecond laser processing is shown in Figure 2. Figure 6 and Figure 7 As shown, there are cracks, recast layer and heat affected zone.

[0053] (4) Align the drill bit with the blind hole and use mechanical drilling to drill through the bottom hole to form a through hole and make the hole wall basically flat.

[0054] (5) Align the electro-hydraulic beam machining head to the through hole and use the electro-hydraulic beam to trim the hole wall. The machining voltage is 50 V, the feed speed is 0.1 mm / s, and the machining time is 8 s. The morphology of the air film hole obtained by machining is as follows: Figure 8As shown, the air film hole has no cracks, no recast layer, and no heat affected zone.

[0055] In this embodiment, the composite hole-making process can directly make holes on the blade with thermal barrier coating, without the need to use the processing method of first making holes and then coating. The single hole processing time is controlled within 20 seconds, which is significantly shortened compared to the time required for single hole processing using femtosecond laser alone. The obtained air film holes have no cracks, no recast layer, and no heat-affected zone, thereby improving the quality of the air film holes.

[0056] Example 3

[0057] This embodiment uses the processing device provided in Embodiment 1 to make holes, and the specific steps are as follows: (1) A blade with a thermal barrier coating is fixed on a stage. The thickness of the thermal barrier coating is 0.3 mm, and the blade body is made of carbon fiber material.

[0058] (2) The femtosecond laser processing head is aligned with the punching position, the incident angle α is 30°, the single pulse energy is 200 μJ, the scanning speed is 0.5 m / s, the processing time is 6 s, and the thermal barrier coating at the punching position is removed to expose the surface of the blade body.

[0059] (3) Aim the millisecond laser processing head at the punching area and use a millisecond laser with a single pulse energy of 2J to perform direct punching at the punching area. The incident angle β is 45° and the processing time is 1s, forming a blind hole with a diameter of 1mm and a depth of 6mm.

[0060] (4) Align the drill bit with the blind hole and use mechanical drilling to drill through the bottom hole to form a through hole and make the hole wall basically flat.

[0061] (5) Align the electro-hydraulic beam machining head to the through hole and use the electro-hydraulic beam to trim the hole wall. The machining voltage is 100 V, the feed speed is 0.05 mm / s, and the machining time is 9 s. The air film hole machined in this embodiment has no cracks, no recast layer, and no heat-affected zone.

[0062] The embodiments of the present invention provide a complete set of methods and devices for processing air film holes on blades with thermal barrier coatings, which effectively solve the problems of low efficiency and poor quality existing in traditional processing technologies. In terms of processing methods, the respective advantages of femtosecond laser, millisecond laser, mechanical processing and electro-hydraulic beam are utilized, combined with precise parameter control and step connection, to achieve high-precision and high-quality processing of blade air film holes, improve processing efficiency, ensure the dimensional accuracy, surface quality and cooling performance of air film holes, and meet the strict requirements of high-temperature components such as aircraft engines on blade performance. In terms of devices, the coordinated work of the five-axis system, dynamic focusing system and control system realizes the automation, intelligence and high-precision of the processing process, further improves the processing efficiency and quality stability, reduces the difficulty and error of manual operation, has significant economic and social benefits, and plays an important role in promoting the development of aircraft engine blade manufacturing technology.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for machining air film holes on a blade with a thermal barrier coating, characterized in that: The following steps are involved: S1. Fix the blade with thermal barrier coating, use femtosecond laser to remove the thermal barrier coating at the punched part, and expose the surface of the blade body. The incident angle of the femtosecond laser is α, 30°≥α≥15°; S2. Use millisecond laser to perform direct punching at the punching position to form a blind hole on the blade body. The incident angle of the millisecond laser is β, 20°≥β-α≥5°; S3, drilling through the bottom hole by mechanical drilling to form a through hole; S4. Use an electro-hydraulic beam to trim the hole wall to obtain an air film hole.

2. The method for machining air film holes of a blade with thermal barrier coating according to claim 1, characterized in that: In the step S1, the thickness of the thermal barrier coating is less than or equal to 0.5 mm, the pulse width of the femtosecond laser is less than 1 ps, the single pulse energy is 20-1000 μJ, the scanning speed is 0.1-3 m / s, and the processing time is less than or equal to 10 s.

3. The method for machining air film holes of a blade with thermal barrier coating according to claim 2, characterized in that: In step S1, the scanning speed of the femtosecond laser is adjusted according to the curvature of the blade surface, V=0.1+0.05×(1 / R), where V is the scanning speed of the femtosecond laser, in m / s, and R is the local curvature radius of the blade, in mm.

4. The method for machining film holes of a blade with thermal barrier coating according to claim 1, characterized in that: In step S2, the pulse width of the millisecond laser used is greater than or equal to 1 ms, the single pulse energy is greater than or equal to 1 J, and the processing time is less than or equal to 1 s.

5. The method for machining air film holes of a blade with thermal barrier coating according to claim 4, characterized in that: In step S2, the aspect ratio of the obtained blind hole is greater than or equal to 20, and the diameter is greater than or equal to 0.3 mm.

6. The method for machining film holes of a blade with thermal barrier coating according to claim 1, characterized in that: In step S4, the electro-hydraulic beam machining voltage is 12-300V, and the machining time is less than or equal to 10s.

7. The method for machining film holes of a blade with thermal barrier coating according to claim 6, characterized in that: In the step S4, 20-50 nm Al2O3 abrasive is added to the electrolyte for electro-hydraulic beam machining.

8. The method for machining film holes of a blade with thermal barrier coating according to claim 1, characterized in that: The mass of the blade body material removed in step S2 is a, and the total mass of the blade body material removed in steps S3 and S4 is b, satisfying a / b>9.

9. A device for implementing the method for machining air film holes in a blade with a thermal barrier coating as claimed in any one of claims 1 to 8, characterized in that: include: A five-axis system, comprising three linear axis drive modules and two rotary axis drive modules, wherein the three linear axis drive modules are respectively an X-axis drive module (21), a Y-axis drive module (22) and a Z-axis drive module (23), and the two rotary axis drive modules are respectively an A-axis drive module (24) and a C-axis drive module (25); A stage (3) is used to fix the blade to be processed, and the A-axis driving module (24) and the C-axis driving module (25) are drivingly connected to the stage (3); A processing assembly, the processing assembly comprising a femtosecond laser processing head (41), a millisecond laser processing head (42), a drill bit (43) and a rotatable electro-hydraulic beam processing head (44), the X-axis driving module (21), the Y-axis driving module (22) and the Z-axis driving module (23) being used to drive the processing assembly to move linearly; A dynamic focusing system (6) for scanning the curvature of the blade surface in real time; A control system (7), wherein the control system (7) is electrically connected to the five-axis system, the dynamic focusing system (6) and the processing component, wherein the dynamic focusing system (6) is used to input surface curvature data into the control system (7), and the control system (7) is used to control the movement of the five-axis system, adjust the angle between the stage (3) and the processing component, and control the process parameters of the processing component.

10. The device according to claim 9, characterized in that The invention also comprises a mounting bracket (5), wherein the femtosecond laser processing head (41), the millisecond laser processing head (42), the drill bit (43) and the electro-hydraulic beam processing head (44) are arranged on the mounting bracket (5), and the X-axis driving module (21), the Y-axis driving module (22) and the Z-axis driving module (23) are all drivingly connected to the mounting bracket (5).

11. The device according to claim 10, characterized in that It also includes a first lifting mechanism (51) and a second lifting mechanism (52) arranged on the mounting bracket (5), wherein the first lifting mechanism (51) is drivingly connected to the millisecond laser processing head (42), and the second lifting mechanism (52) is drivingly connected to the drill head (43).

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