Laser finishing method for electron beam selective area additive curved surface structure

Abstract

The invention relates to a laser finishing method for an electron beam selective additive curved surface structure, and aims to solve the problem that a laser finishing technology especially for an electron beam selective melting additive complex surface does not exist in the prior art for a surface manufactured by a traditional method or a laser selective additive / laser energy deposition additive manufacturing method, so that the laser finishing method for the electron beam selective additive curved surface structure is developed. The preprocessed electron beam selective area additive free-form surface is subjected to dynamic composite finishing through continuous wave laser and pulse wave laser, and the finishing state is monitored in real time through an online monitoring system, so that an ideal surface is obtained.

Description

Technical Field

[0001] The invention relates to a laser finishing method for an electron beam selected area additive curved surface structure, belonging to the field of additive manufacturing post-processing. Background Art

[0002] At present, additive manufacturing (AM) has made it possible to achieve material-structure-performance integrated manufacturing in the fields of aerospace, automobile, energy and biomaterials. However, the application of additive manufacturing in the manufacturing of some special high-performance materials is still relatively small. The biggest problem is that specific manufacturing environment conditions are required, such as high vacuum or inert atmosphere required for the manufacture of titanium alloys and other active materials, and high temperature environment required for the manufacture of refractory metals and high-temperature alloys. The second is the characteristics of the heat source. For example, a high energy density heat source should be used to process reflective materials, metal matrix composites and gradient materials. Electron beam has certain advantages in processing special high-performance materials. Compared with laser selective melting additive, electron beam selective melting additive has the following advantages: (i) vacuum environment reduces atmospheric pollution, which is particularly suitable for the manufacture of active metals such as titanium; (ii) higher energy density, which can process refractory metals and high-temperature alloys; (iii) higher scanning speed allows innovative preheating and melting strategies, which is crucial for the manufacture of brittle metal materials (such as TiAl intermetallic alloys); (iv) reduce the formation of thermal deformation and reduce the post-processing process without filling support. However, depending on the material properties and processing parameters, porosity and unfused areas will appear in the surface and near-surface areas during the electron beam selective melting additive manufacturing process. The resulting additive defects lead to reduced material strength, insufficient mechanical properties, and surface roughness are still the main factors that currently hinder the application of this new process in industry.

[0003] Laser polishing technology uses laser beam to irradiate the surface of the workpiece to be polished. A thin surface layer of the workpiece is re-melted, and the surface of the workpiece becomes smooth due to the combined effect of interfacial tension flow and Marangoni flow. Compared with other polishing methods, laser polishing technology realizes the automatic processing of 3D surfaces, the polishing results are less affected by human factors, the processing speed is fast, the reproducibility is high, and the selected areas are selectively polished. Due to the non-contact process, the mechanical stress on the parts is low, there is no grinding and polishing waste, and no abrasives and polishing agents are mixed into the surface. Patent CN202011430777.3 discloses an ultrafast-continuous laser asynchronous polishing powder feeding additive manufacturing metal surface process, which uses ultrafast laser to perform laser micro-milling on the surface of powder feeding additive manufacturing metal materials, removes the macro-convex deposition layer on the surface of powder feeding additive manufacturing metal materials, and obtains a sample with a flat processing surface; the sample is placed in an oxygen-proof container and a protective gas is introduced, and the processing surface of the sample is laser polished using a continuous laser, so that the processing surface material is heated and reaches a molten state, and the surface tension of the liquid material forms a material micro-flow, removes the micro-morphology left by the laser micro-milling process, and forms a smooth surface after cooling and solidification, realizing the surface polishing of the powder feeding additive manufacturing metal material from large waviness to submicron level. Patent CN202210851244.5 discloses a method for improving the surface quality of laser additive manufacturing high entropy alloy formed parts, and laser polishing is performed once for each layer of high entropy alloy cladding layer deposited, and repeated back and forth until the manufacturing of the formed part is completed. This method can greatly improve and improve the surface quality and mechanical properties of high entropy alloy additive parts. Patent CN202110481286.X discloses a nano-pico-femtosecond combined laser parallel finishing and polishing processing method, the steps of which are: using reverse engineering modeling software to establish a digital model of the metal additive manufacturing parts, and determining the processing allowance of the metal additive manufacturing parts through model processing software; using CAM path planning software to pass the processing allowance path of the metal additive manufacturing parts through a computer control system; using the computer control system to start the nanosecond laser, picosecond laser and femtosecond laser to emit light at the same time, combining the three light beams into one to form a nano-pico-femtosecond combined laser beam, and transmitting the nano-pico-femtosecond combined laser beam to a three-dimensional scanning galvanometer; using the computer control system to irradiate the nano-pico-femtosecond combined laser beam onto the surface of the metal additive manufacturing parts along the planned processing path of the CAM path planning software.

[0004] The above-mentioned additive surface finishing methods are all aimed at surfaces manufactured by traditional manufacturing or laser selective additive manufacturing / laser energy deposition additive manufacturing. Currently, there is no laser finishing technology specifically for complex surfaces of electron beam selective melting additive manufacturing. Summary of the invention

[0005] The technical problem solved by the present invention is: in view of the blank of laser finishing technology for complex surfaces of electron beam selective melting additive materials in the current prior art, a laser finishing method for curved surface structures of electron beam selective melting additive materials is proposed.

[0006] The present invention solves the above technical problems by the following technical solutions:

[0007] A laser finishing method for electron beam selective additive curved surface structure, comprising:

[0008] Preset the electron beam selection area additive material, prepare the rough blank of the curved surface structure, and pre-treat the rough blank of the curved surface structure;

[0009] Perform rough finishing treatment on the rough surface of the curved surface structure after pretreatment;

[0010] Perform fine finishing on the rough surface of the curved structure after rough finishing;

[0011] During the rough finishing and fine finishing processes, the surface focal length of the rough blank of the curved structure is dynamically tracked, and the structural parameters of the rough blank of the curved structure are monitored in real time;

[0012] If the monitoring results show that all structural parameters of the curved surface structure after fine finishing meet the requirements for the preparation of curved surface structure products, the finishing process is completed to obtain the curved surface structure product; otherwise, the curved surface structure rough blank pretreatment and subsequent curved surface structure product finishing preparation are carried out again.

[0013] The method of roughing and pre-processing the curved surface structure is as follows:

[0014] The curved surface structure rough blank is subjected to mechanical sandblasting to remove oxidation marks and large-particle adhesives on the rough blank surface, thereby obtaining the curved surface structure rough blank after surface pretreatment.

[0015] Mechanical sandblasting methods are:

[0016] Pre-select 10-100 mesh corundum sand, set the sandblasting pressure according to the electron beam selection additive material, adjust the distance between the nozzle and the surface of the curved structure rough blank and the nozzle incident angle according to the structure and preset size required for the preparation of the curved structure product. The distance between the nozzle and the surface of the curved structure rough blank is set in the range of 10mm-500mm, and the nozzle incident angle is set in the range of 20°-80°.

[0017] The rough finishing method is:

[0018] According to the structure and preset size required for the preparation of the curved structure product, the continuous wave laser and finishing path are set, and the surface of the curved structure rough blank after pretreatment is subjected to continuous wave laser rough finishing according to the finishing path, wherein:

[0019] The smoothing path is set as a reciprocating arcuate path, and the overlapping range of adjacent arcuate paths is set to: ∈[0.3×continuous wave laser spot diameter, 0.7×continuous wave laser spot diameter]. The path angle between each continuous wave laser is rotated 66.67° clockwise or counterclockwise, and the number of passes is ≤5.

[0020] The finishing treatment method is:

[0021] The pulse laser and finishing path are set according to the structure and preset size of the required casting, and the rough surface of the curved structure rough blank after rough finishing is subjected to pulse laser finishing according to the finishing path, wherein:

[0022] The smoothing path is set as a reciprocating arcuate path, and the overlapping range of adjacent arcuate paths is set to: ∈[0.2×pulse laser spot diameter, 0.85×pulse laser spot diameter], and the path angle between each pulse laser is rotated 66.67° clockwise or counterclockwise, and the number of passes is ≤5.

[0023] The fine finishing treatment is performed after the rough finishing treatment is completed and the rough surface structure blank after the rough finishing treatment is cooled to a specified temperature; the first pulse path of the fine finishing treatment and the last continuous wave laser path of the rough finishing treatment form an angle of 90°.

[0024] During the rough finishing and fine finishing processes, laser collaborative control is achieved through a collaborative motion mechanism, which includes a 3D galvanometer and a motion platform. The laser collaborative control method is as follows:

[0025] Receive control instructions generated according to the preparation requirements of curved structure products, drive the motion platform according to the control instructions and drive the 3D galvanometer to track the curved focal length of the curved structure products;

[0026] The motion platform performs real-time error compensation on the 3D galvanometer to ensure that the curved surface focal length tracking error is within an allowable range.

[0027] During the rough finishing and fine finishing processes, the structural parameters of the rough surface blank are monitored in real time through the online monitoring system to determine whether the rough finishing and fine finishing processes are in place.

[0028] The structural parameters of the curved structure rough blank include temperature, surface roughness, and plasma spectrum. If any type of parameter exceeds the structural parameter range required for the preparation of the curved structure product, the preparation is stopped, and the curved structure rough blank pretreatment and subsequent curved structure product finishing preparation are carried out again.

[0029] The stroke, maximum speed, motion accuracy of the motion platform and the typical deflection angle, positioning accuracy, drift, dynamic focal offset and following error of the 3D galvanometer are all determined according to the preparation requirements of curved structure products. The stroke of the motion platform is set to 800mm×800mm, the maximum speed is set to 2000mm / s, and the accuracy is set to ±5μm; the 3D galvanometer is set to ±0.2rad, the positioning accuracy is set to 2urad, the drift is set to 0.3mrad, the dynamic focal offset is set to 0.01mm, and the following error is set to 120us.

[0030] The temperature detection is achieved by infrared detection, the measurement range is set to 15°C-1000°C, and the measurement error is set to ±2°C;

[0031] The surface roughness is achieved by non-contact detection, and the maximum operating speed is set to 320m / min;

[0032] The detection parameters of the plasma spectrum are: the wavelength range coverage is set to 200-1100 nm, the monitoring resolution is set to 0.05-20 nm, the integration time is set to 9 μs-40 s, and the sampling speed is set to 0.70 ms / scan.

[0033] The advantages of the present invention compared with the prior art are:

[0034] The present invention provides a laser finishing method for electron beam selective additive curved surface structure. The method uses pre-processing, rough finishing and fine finishing techniques, is equipped with dynamic tracking of the focal length of the curved surface and real-time monitoring of the structural parameters of the rough blank of the curved surface structure, and realizes laser finishing of the same material based on the remelting principle. Except for the adhesion and inclusions that must be removed on the surface, basically no amount is removed, and the minimum margin filling of the blank can be achieved. At the same time, contact polishing is reduced, the mechanical stress of the workpiece is small, the finishing deformation is small, and the introduction of chemical polishing agents is avoided. The method can fully adapt to the finishing of various complex free-form surfaces and avoid the dead zone of mechanical polishing. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of the design of the electron beam selective additive curved surface structure laser finishing system provided by the present invention;

[0036] Figure 2 A flow chart of the electron beam selective area additive curved surface structure laser finishing method provided by the present invention;

[0037] Figure 3 This is a schematic diagram of the curved surface structure product of the electron beam selective additive workpiece provided by the present invention. DETAILED DESCRIPTION

[0038] A laser finishing method for electron beam selective additive curved surface structure is developed. For surfaces manufactured by traditional manufacturing or laser selective additive manufacturing / laser energy deposition additive manufacturing, the prior art does not have a laser finishing technology specifically for complex surfaces of electron beam selective melting additives. The pre-treated electron beam selective additive free-form surface is dynamically composite-finished by continuous wave laser + pulse wave laser, and the finishing status is monitored in real time by an online monitoring system to obtain an ideal surface.

[0039] The laser finishing method of electron beam selective additive surface structure has the following specific steps:

[0040] Preset the electron beam selection area additive material, prepare the rough blank of the curved surface structure, and pre-treat the rough blank of the curved surface structure;

[0041] Perform rough finishing treatment on the rough surface of the curved surface structure after pretreatment;

[0042] Perform fine finishing on the rough surface of the curved structure after rough finishing;

[0043] During the rough finishing and fine finishing processes, the surface focal length of the rough blank of the curved structure is dynamically tracked, and the structural parameters of the rough blank of the curved structure are monitored in real time;

[0044] If the monitoring results show that all structural parameters of the curved surface structure after fine finishing meet the requirements for the preparation of curved surface structure products, the finishing process is completed to obtain the curved surface structure product; otherwise, the curved surface structure rough blank pretreatment and subsequent curved surface structure product finishing preparation are carried out again.

[0045] The method of roughing and pre-processing the curved surface structure is as follows:

[0046] The curved surface structure rough blank is subjected to mechanical sandblasting to remove oxidation marks and large-particle adhesives on the rough blank surface, thereby obtaining the curved surface structure rough blank after surface pretreatment.

[0047] Mechanical sandblasting methods are:

[0048] Pre-select 10-100 mesh corundum sand, set the sandblasting pressure according to the electron beam selection additive material, adjust the distance between the nozzle and the surface of the curved structure rough blank and the nozzle incident angle according to the structure and preset size required for the preparation of the curved structure product. The distance between the nozzle and the surface of the curved structure rough blank is set in the range of 10mm-500mm, and the nozzle incident angle is set in the range of 20°-80°.

[0049] The rough finishing method is:

[0050] According to the structure and preset size required for the preparation of the curved structure product, the continuous wave laser and finishing path are set, and the surface of the curved structure rough blank after pretreatment is subjected to continuous wave laser rough finishing according to the finishing path, wherein:

[0051] The smoothing path is set as a reciprocating arcuate path, and the overlapping range of adjacent arcuate paths is set to: ∈[0.3×continuous wave laser spot diameter, 0.7×continuous wave laser spot diameter]. The path angle between each continuous wave laser is rotated 66.67° clockwise or counterclockwise, and the number of passes is ≤5.

[0052] The finishing treatment method is:

[0053] The pulse laser and finishing path are set according to the structure and preset size of the required casting, and the rough surface of the curved structure rough blank after rough finishing is subjected to pulse laser finishing according to the finishing path, wherein:

[0054] The smoothing path is set as a reciprocating arcuate path, and the overlapping range of adjacent arcuate paths is set to: ∈[0.2×pulse laser spot diameter, 0.85×pulse laser spot diameter], and the path angle between each pulse laser is rotated 66.67° clockwise or counterclockwise, and the number of passes is ≤5.

[0055] The fine finishing treatment is carried out after the rough finishing treatment is completed and the rough surface structure blank after the rough finishing treatment is cooled to the specified temperature; the first pulse path of the fine finishing treatment and the last continuous wave laser path of the rough finishing treatment are at a 90° angle.

[0056] During the rough finishing and fine finishing processes, laser collaborative control is achieved through a collaborative motion mechanism, which includes a 3D galvanometer and a motion platform. The laser collaborative control method is as follows:

[0057] Receive control instructions generated according to the preparation requirements of curved structure products, drive the motion platform according to the control instructions and drive the 3D galvanometer to track the curved focal length of the curved structure products;

[0058] The motion platform performs real-time error compensation on the 3D galvanometer to ensure that the curved surface focal length tracking error is within an allowable range.

[0059] During the rough finishing and fine finishing processes, the structural parameters of the rough surface blank are monitored in real time through the online monitoring system to determine whether the rough finishing and fine finishing processes are in place.

[0060] The structural parameters of the curved structure rough blank include temperature, surface roughness, and plasma spectrum. If any type of parameter exceeds the structural parameter range required for the preparation of the curved structure product, the preparation is stopped, and the curved structure rough blank pretreatment and subsequent curved structure product finishing preparation are carried out again.

[0061] The stroke, maximum speed, motion accuracy of the motion platform and the typical deflection angle, positioning accuracy, drift, dynamic focal offset and following error of the 3D galvanometer are all determined according to the preparation requirements of the curved structure products. The stroke of the motion platform is set to 800mm×800mm, the maximum speed is set to 2000mm / s, and the accuracy is set to ±5μm; the 3D galvanometer is set to ±0.2rad, the positioning accuracy is set to 2urad, the drift is set to 0.3mrad, the dynamic focal offset is set to 0.01mm, and the following error is set to 120us.

[0062] Temperature detection is achieved through infrared detection, the measurement range is set to 15℃-1000℃, and the measurement error is set to ±2℃;

[0063] The surface roughness is achieved by non-contact detection, and the maximum operating speed is set to 320m / min;

[0064] The detection parameters of the plasma spectrum are: the wavelength range coverage is set to 200-1100 nm, the monitoring resolution is set to 0.05-20 nm, the integration time is set to 9 μs-40 s, and the sampling speed is set to 0.70 ms / scan.

[0065] The following is further described in conjunction with the accompanying drawings and preferred embodiments of the specification:

[0066] In the current embodiment, the process is as follows Figure 2 The specific design method is as follows:

[0067] Curved surface rough blank, such as Figure 3 Shown is the surface extended by the cubic curve.

[0068] The pretreatment is mechanical sandblasting to remove surface oxide inclusions and large particles bonding to obtain a preliminary surface.

[0069] Surface structures, including but not limited to those with elementary analytical surfaces or free-form surfaces, cabin sections, structural parts and other component structures manufactured by electron beam selective additive manufacturing.

[0070] Continuous wave laser + pulse wave laser are dynamically compounded, including multi-pass continuous wave laser rough polishing + multi-pass pulse laser fine polishing. The two light beams are polished in a set composite manner. The motion system and 3D galvanometer assist in coordinated movement, and the 3D galvanometer realizes dynamic tracking of the curved surface focal length.

[0071] The online monitoring system includes but is not limited to a plasma spectrum online detection system, a curved surface molten pool temperature online detection system, and a surface roughness online detection system.

[0072] Ideal surface, surface roughness ≤3.2Ra, uniform removal ≤(initial surface removal×1.2), no oxide inclusions, no bonding, and no molten pool undercut.

[0073] Mechanical sand blasting uses corundum sand distributed in 10-100 mesh, with a sand blasting pressure of 0.1MPa-3.0MPa. According to the structure and size of the casting, the nozzle distance is maintained at 10mm-500mm according to the different curved surface structures, and the nozzle incident angle should be controlled at 20°-80°.

[0074] Preliminary surface, surface roughness ≤12.0Ra, according to the process requirements, uniform removal ≤0.5mm, remove oxide inclusions and large particles, allow surface hole depth ≤0.5mm, surface diameter ≤0.6mm, surface hole spacing ≥ adjacent hole diameter.

[0075] Multi-pass continuous wave laser rough finishing is performed by continuous wave laser. The finishing path is in the form of "bow" reciprocating finishing. Adjacent paths overlap ∈[0.3×continuous wave laser spot diameter, 0.7×continuous wave laser spot diameter]. The path between passes rotates 66.67° clockwise or counterclockwise. The number of passes is ≤5.

[0076] Multi-pass pulsed laser fine polishing is performed by pulsed laser. The polishing path is in the form of "bow" reciprocating polishing. Adjacent paths overlap ∈[0.2×continuous wave laser spot diameter, 0.85×continuous wave laser spot diameter]. The path between passes rotates 66.67° clockwise or counterclockwise. The number of passes is ≤8.

[0077] Composite finishing method: multi-pass pulse laser fine finishing is carried out after multi-pass continuous wave laser rough finishing is completed and cooled to the specified temperature. The first pass path of pulse laser fine finishing is at a 90° angle with the last pass of continuous wave laser rough finishing.

[0078] In collaborative motion, the control signal generated by the servo control system is sent to the motion system and the 3D galvanometer at the same time, and the 3D galvanometer compensates for the following error in real time.

[0079] The motion system is an XY motion system with a stroke of 800mm×800mm, a maximum speed of 2000mm / s, and an accuracy better than ±5μm.

[0080] 3D galvanometer, typical deflection angle ≤±0.3rad, repeatability accuracy ≤2urad, 8-hour long-term drift ≤0.4mrad. The dynamic tracking of the curved surface focal length is performed by the 3D galvanometer, dynamic focal offset ≤0.01mm, and tracking error ≤150us.

[0081] The plasma spectrum online detection system has a wavelength range of 200-1100nm, a monitoring resolution of 0.05-20nm, an integration time of 9μs-40s, and a sampling speed of 0.70ms / scan.

[0082] The curved surface molten pool temperature online detection system uses infrared detection with a measurement range of 15℃-1000℃ and a measurement error of ≤±2℃.

[0083] Surface roughness online detection system, non-contact online measurement of surface roughness, maximum line running speed ≥ 280m / min.

[0084] Surface roughness online detection system, non-contact online measurement of surface roughness, maximum line running speed ≥ 280m / min.

[0085] Pulse laser, laser power 20W-120W, pulse width 10ns-600ns, spot diameter 25μm-80μm, repetition frequency 50-1500kHZ, scanning speed 100mm / s-1000mm / s.

[0086] The specified temperature is measured by the curved surface molten pool temperature online monitoring system. It is room temperature when the envelope size is ≤200mm, 45°C when 200mm<envelope size≤400mm, and 60°C when 200mm<envelope size≤600mm.

[0087] Among them, Figure 1 The following is the hardware structure of laser finishing including the rough blank to be processed, including

[0088] 1. Pretreatment module; 2. Laser finishing module; 3. Online monitoring system; 4. Electron beam selection additive workpiece; 1-1. Nozzle; 1-2. Sandblasting turntable; 2-1. X-axis motion platform; 2-2. Y-axis motion platform; 2-3. Finishing platform; 2-4. Continuous wave laser galvanometer; 2-5. Pulse laser galvanometer; 3-1. Plasma spectrum online detection system; 3-2. Curved surface molten pool temperature online detection system; 3-3. Surface roughness online detection system.

[0089] Among them, the pretreatment module is used for the pretreatment of the rough blank of the curved structure; the laser finishing module is used to realize the rough finishing and fine finishing; the online monitoring system dynamically tracks and monitors the focal length of the curved surface in real time during the rough finishing and fine finishing processes; 3-1. Plasma spectrum online detection system; 3-2. Curved surface molten pool temperature online detection system; 3-3. Surface roughness online detection system is used for the detection of various curved structure rough blank structural parameters.

[0090] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0091] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A laser finishing method for electron beam selective additive curved surface structure, characterized in that include: Preset the electron beam selection area additive material, prepare the rough blank of the curved surface structure, and pre-treat the rough blank of the curved surface structure; Perform rough finishing treatment on the rough surface of the curved surface structure after pretreatment; Perform fine finishing on the rough surface of the curved structure after rough finishing; During the rough finishing and fine finishing processes, the surface focal length of the rough blank of the curved structure is dynamically tracked, and the structural parameters of the rough blank of the curved structure are monitored in real time; If the monitoring results show that all structural parameters of the curved surface structure after fine finishing meet the requirements for the preparation of curved surface structure products, the finishing process is completed to obtain the curved surface structure product; otherwise, the curved surface structure rough blank pretreatment and subsequent curved surface structure product finishing preparation are carried out again.

2. The laser finishing method for electron beam selective additive curved surface structure according to claim 1, characterized in that: The method of roughing and pre-processing the curved surface structure is as follows: The curved surface structure rough blank is subjected to mechanical sandblasting to remove oxidation marks and large-particle adhesives on the rough blank surface, thereby obtaining the curved surface structure rough blank after surface pretreatment.

3. The laser finishing method for electron beam selective additive curved surface structure according to claim 1, characterized in that: Mechanical sandblasting methods are: Pre-select 10-100 mesh corundum sand, set the sandblasting pressure according to the electron beam selection additive material, adjust the distance between the nozzle and the surface of the curved structure rough blank and the nozzle incident angle according to the structure and preset size required for the preparation of the curved structure product. The distance between the nozzle and the surface of the curved structure rough blank is set in the range of 10mm-500mm, and the nozzle incident angle is set in the range of 20°-80°.

4. The laser finishing method for electron beam selective additive curved surface structure according to claim 1, characterized in that: The rough finishing method is: According to the structure and preset size required for the preparation of the curved structure product, the continuous wave laser and finishing path are set, and the surface of the curved structure rough blank after pretreatment is subjected to continuous wave laser rough finishing according to the finishing path, wherein: The smoothing path is set as a reciprocating arcuate path, and the overlapping range of adjacent arcuate paths is set to: ∈[0.3×continuous wave laser spot diameter, 0.7×continuous wave laser spot diameter]. The path angle between each continuous wave laser is rotated 66.67° clockwise or counterclockwise, and the number of passes is ≤5.

5. The laser finishing method for electron beam selective additive curved surface structure according to claim 4, characterized in that: The finishing treatment method is: The pulse laser and finishing path are set according to the structure and preset size of the required casting, and the rough surface of the curved structure rough blank after rough finishing is subjected to pulse laser finishing according to the finishing path, wherein: The smoothing path is set as a reciprocating arcuate path, and the overlapping range of adjacent arcuate paths is set to: ∈[0.2×pulse laser spot diameter, 0.85×pulse laser spot diameter], and the path angle between each pulse laser is rotated 66.67° clockwise or counterclockwise, and the number of passes is ≤5.

6. The laser finishing method for electron beam selective additive curved surface structure according to claim 5, characterized in that: The fine finishing treatment is performed after the rough finishing treatment is completed and the rough surface structure blank after the rough finishing treatment is cooled to a specified temperature; the first pulse path of the fine finishing treatment and the last continuous wave laser path of the rough finishing treatment form an angle of 90°.

7. The laser finishing method for electron beam selective additive curved surface structure according to claim 1, characterized in that: During the rough finishing and fine finishing processes, laser collaborative control is achieved through a collaborative motion mechanism, which includes a 3D galvanometer and a motion platform. The laser collaborative control method is as follows: Receive control instructions generated according to the preparation requirements of curved structure products, drive the motion platform according to the control instructions and drive the 3D galvanometer to track the curved focal length of the curved structure products; The motion platform performs real-time error compensation on the 3D galvanometer to ensure that the curved surface focal length tracking error is within an allowable range.

8. The laser finishing method for electron beam selective additive curved surface structure according to claim 1, characterized in that: During the rough finishing and fine finishing processes, the structural parameters of the rough surface blank are monitored in real time through the online monitoring system to determine whether the rough finishing and fine finishing processes are in place. The structural parameters of the curved structure rough blank include temperature, surface roughness, and plasma spectrum. If any type of parameter exceeds the structural parameter range required for the preparation of the curved structure product, the preparation is stopped, and the curved structure rough blank pretreatment and subsequent curved structure product finishing preparation are carried out again.

9. The laser finishing method for electron beam selective additive curved surface structure according to claim 7, characterized in that: The stroke, maximum speed, motion accuracy of the motion platform and the typical deflection angle, positioning accuracy, drift, dynamic focal offset and following error of the 3D galvanometer are all determined according to the preparation requirements of curved structure products. The stroke of the motion platform is set to 800mm×800mm, the maximum speed is set to 2000mm / s, and the accuracy is set to ±5μm; the 3D galvanometer is set to ±0.2rad, the positioning accuracy is set to 2urad, the drift is set to 0.3mrad, the dynamic focal offset is set to 0.01mm, and the following error is set to 120us.

10. The laser finishing method for electron beam selective additive curved surface structure according to claim 8, characterized in that: The temperature detection is achieved by infrared detection, the measurement range is set to 15°C-1000°C, and the measurement error is set to ±2°C; The surface roughness is achieved by non-contact detection, and the maximum operating speed is set to 320m / min; The detection parameters of the plasma spectrum are: the wavelength range coverage is set to 200-1100 nm, the monitoring resolution is set to 0.05-20 nm, the integration time is set to 9 μs-40 s, and the sampling speed is set to 0.70 ms / scan.

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