Strengthening machining system and method for titanium alloy blade of aero-engine

Abstract

The invention belongs to the technical field of machining, and discloses an aero-engine titanium alloy blade strengthening machining system and method. The mechanical arm is used for clamping a blade to be strengthened, and the mechanical arm is electrically connected with the controller; the laser etching unit is electrically connected with the controller and used for outputting a picosecond-level pulse laser beam according to a machining instruction issued by the controller, and the picosecond-level pulse laser beam is used for conducting etching machining on the surface of the blade to be strengthened on the mechanical arm according to a preset light spot path; and the acquisition unit is electrically connected with the controller and is used for acquiring the strengthening pattern of the laser etching unit in the light path calibration process and uploading the acquired strengthening pattern to the controller. The method can improve the machining efficiency, can be used for surface strengthening of the titanium alloy complex thin blade of the aero-engine, overcomes the defects of large deformation and laser-induced shock wave rebound when the traditional technology is applied to the thin-wall blade, and can be used for surface strengthening of high-added-value thin-wall parts in the aerospace field.

Description

Technical Field

[0001] The invention belongs to the technical field of processing, and in particular relates to a system and method for strengthening processing of titanium alloy blades of an aero-engine. Background Art

[0002] Laser shock peening (LSP) is a surface treatment technology that has been widely studied and proven to significantly improve the high-cycle fatigue performance of metal materials. This technology enhances the fatigue resistance of materials by producing surface nanocrystal refinement and introducing residual compressive stress.

[0003] Nevertheless, the technology still faces several limitations in practical applications, including: 1. Large spot diameter (usually more than 1 mm): This limits the precise application of LSP on small or fine geometric features, thus affecting the processing accuracy; 2. Harsh processing conditions: LSP usually requires applying a protective layer (such as a water-soluble coating or aluminum foil) and a water confinement layer on the material surface to protect the material surface and improve the laser energy absorption efficiency, which increases the complexity and cost of the process; 3. Extensive plastic deformation of the material surface: The LSP process may cause undesirable plastic deformation of the material surface, which is unacceptable for thin-walled aero-engine blades.

[0004] Therefore, a new surface strengthening technology is urgently needed to improve the fatigue performance of the blades while controlling the deformation of thin-walled blades. Summary of the invention

[0005] The purpose of the present invention is to provide an aircraft engine titanium alloy blade strengthening processing system and method to solve the problems of low processing accuracy, harsh processing conditions and easy plastic deformation in the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides an aircraft engine titanium alloy blade strengthening processing system, the system comprising: Controller; A mechanical arm, used for clamping the blade to be strengthened, wherein the mechanical arm is electrically connected to the controller; A laser etching unit is electrically connected to the controller and is used to output a picosecond pulse laser beam according to a processing instruction issued by the controller, wherein the picosecond pulse laser beam is used to perform etching processing on the surface of the blade to be strengthened on the robot arm according to a preset spot path; A collection unit, electrically connected to the controller, for collecting the enhanced pattern of the laser etching unit during the optical path calibration process, and uploading the collected enhanced pattern to the controller; The controller is used to: segment the reinforcement pattern to obtain the boundary features of the reinforcement area image, identify the boundary features of the reinforcement area image to obtain the reinforcement pattern, and determine whether the reinforcement pattern covers the preset reinforcement part; when the reinforcement pattern covers the preset reinforcement part, generate a processing instruction and send the processing instruction to the laser etching unit.

[0007] Preferably, the preset light spot path is a zigzag structure.

[0008] Preferably, the laser etching unit comprises: a laser, a laser optical path, a laser galvanometer and a laser field mirror; The laser is electrically connected to the controller, and the laser is used to output a picosecond pulse laser beam; The laser optical path is used to guide the picosecond pulse laser beam output by the laser to the laser galvanometer; The laser galvanometer is electrically connected to the controller, and the laser galvanometer is used to adjust the position of the picosecond pulse laser beam; The laser field mirror is used to focus the position-adjusted picosecond pulse laser beam onto the surface of the blade to be strengthened.

[0009] Preferably, the controller is also used to: when the reinforcement pattern does not cover the preset reinforcement position, identify the erroneous area of ​​the reinforcement pattern based on a pre-built neural network model to obtain a recognition result, generate a path adjustment instruction according to the recognition result, and send the path adjustment instruction to the laser etching unit to adjust the spot path of the picosecond pulse laser beam of the laser etching unit until the reinforcement pattern covers the preset reinforcement position.

[0010] Preferably, the acquisition unit is also used to collect the real-time light spot path of the laser etching unit during the etching process on the surface of the blade to be strengthened, and the controller is also used to determine whether the real-time light spot path is offset. If so, generate a strengthening termination instruction and send the strengthening termination instruction to the laser etching unit to make the laser etching unit terminate the strengthening of the blade to be strengthened.

[0011] In a second aspect, the present invention provides a method for strengthening a titanium alloy blade of an aero-engine, the method comprising: Pre-processing the blades to be strengthened, the pre-processing comprising: cleaning and clamping; Calibrate the strengthening processing system of titanium alloy blades of aircraft engines; Adjusting the laser parameters of the picosecond pulse laser beam output by the laser etching unit of the calibrated aircraft engine titanium alloy blade strengthening processing system to obtain an adjusted picosecond pulse laser beam, wherein the laser parameters at least include: power density, spot diameter, spot interval and repetition frequency; The calibrated aero-engine titanium alloy blade strengthening processing system performs laser strengthening on the surface of the blade to be strengthened with an adjusted picosecond pulse laser beam to obtain a strengthened blade; The strengthened blades are subjected to secondary treatment to obtain strengthened blade samples.

[0012] Preferably, the calibration process of the aircraft engine titanium alloy blade strengthening processing system includes: calibrating the single-point indicator light focus of the laser etching unit of the aircraft engine titanium alloy blade strengthening processing system; The single-point indicator light focusing calibration of the laser etching unit of the aircraft engine titanium alloy blade strengthening processing system includes: The laser etching unit emits a single point of indication light onto the surface of the blade to be strengthened; The acquisition unit of the aircraft engine titanium alloy blade strengthening processing system collects the single-point indicator light image on the surface of the blade to be strengthened in real time; The controller of the aircraft engine titanium alloy blade strengthening processing system determines whether the single-point indicator light is focused on the surface of the blade to be strengthened according to the single-point indicator light image on the surface of the blade to be strengthened, and if not, generates a focus adjustment instruction and sends the focus calibration instruction to the robot arm; The mechanical arm responds to the focus calibration instruction and adjusts the focus of the single-point indicator light until the single-point indicator light is focused on the surface of the blade to be strengthened.

[0013] Preferably, the calibration process of the aircraft engine titanium alloy blade strengthening processing system further includes: calibrating the spot path of the laser etching unit of the aircraft engine titanium alloy blade strengthening processing system; The spot path calibration of the laser etching unit of the aircraft engine titanium alloy blade strengthening processing system includes: After the single-point indicator light is focused on the surface of the blade to be strengthened, the laser etching unit emits the indicator light onto the surface of the blade to be strengthened, so that a strengthening pattern is formed on the surface of the blade to be strengthened; The collection unit collects the reinforcement pattern and uploads the collected reinforcement pattern to the controller; The controller segments the enhancement pattern to obtain the image boundary features of the enhancement area, identifies the image boundary features of the enhancement area to obtain the enhancement pattern, and determines whether the enhancement pattern covers the preset enhancement position; if not, the erroneous area of ​​the enhancement pattern is identified based on a pre-built neural network model to obtain an identification result, and a path adjustment instruction is generated according to the identification result, and the path adjustment instruction is sent to the laser etching unit to adjust the spot path of the picosecond pulse laser beam of the laser etching unit until the enhancement pattern covers the preset enhancement position.

[0014] Preferably, the secondary treatment includes: grinding treatment, ultrasonic cleaning treatment and drying treatment; the secondary treatment of the strengthened blade to obtain a strengthened blade sample includes: The strengthened blade is polished using 2500-3500 mesh sandpaper to obtain a first blade; The first leaf is placed in anhydrous ethanol for ultrasonic cleaning for 8 to 12 minutes to obtain a second leaf; The second leaf is placed in air for drying to obtain a reinforced leaf sample.

[0015] Preferably, the method further comprises: performing a mechanical property test on the reinforced blade sample, comprising: Obtain the cross-sectional microhardness distribution and cross-sectional residual stress distribution of the strengthened blade sample; Determine the strengthening effect index based on the cross-sectional microhardness distribution and cross-sectional residual stress distribution of the strengthened blade sample; When the strengthening effect index reaches a preset index value, a fatigue test is performed on the strengthened blade sample to obtain the fatigue of the strengthened blade sample, and the fatigue of the strengthened blade sample is used to characterize the mechanical properties of the strengthened blade sample.

[0016] Beneficial effects: 1. The present invention uses a picosecond pulse laser beam to strengthen the blade to be strengthened, which can improve processing efficiency and can be used for surface strengthening of complex thin blades of titanium alloy of aircraft engines. It overcomes the defects of large deformation and laser-induced shock wave rebound when traditional technologies are applied to thin-walled blades, and can be used for surface strengthening of high value-added thin-walled parts in the aerospace field; 2. The present invention improves the processing accuracy of the blade to be strengthened by calibrating the optical path of the picosecond pulse laser beam emitted by the photoetching unit; 3. The present invention collects the enhancement pattern through the acquisition unit, and the controller segments the enhancement pattern to obtain the boundary features of the enhancement area image, identifies the boundary features of the enhancement area image, obtains the enhancement pattern, and determines whether the enhancement pattern covers the preset enhancement part, which can effectively realize the optical path calibration and further improve the processing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings: Figure 1 It is a block diagram of an aircraft engine titanium alloy blade strengthening processing system provided by one embodiment of the present invention; Figure 2It is a flow chart of a method for strengthening processing of titanium alloy blades of an aero-engine provided by one embodiment of the present invention; Figure 3 is the cross-sectional residual stress distribution diagram of the strengthened blade sample; Figure 4 is the cross-sectional microhardness distribution diagram of the strengthened blade sample; Figure 5 This is a schematic diagram comparing the fatigue limit of the blade to be strengthened after three picosecond laser strengthenings and the fatigue limit of the blade to be strengthened before strengthening.

[0018] Description of reference numerals: 1. Controller; 2. Laser; 3. Laser optical path; 4. Laser galvanometer; 5. Laser field mirror; 6. Blades to be strengthened; 7. Robotic arm; 8. Collection unit. DETAILED DESCRIPTION

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the structure of the drawings is only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0020] Embodiment 1 Figure 1 FIG. 1 is a block diagram of an aircraft engine titanium alloy blade strengthening processing system provided by an embodiment of the present invention. Figure 1 As shown, this embodiment provides an aircraft engine titanium alloy blade strengthening processing system, the system includes: a controller 1, a mechanical arm 7, a laser etching unit and a collection unit 8, wherein the controller 1 can be a PLC controller 1 or a single-chip minimum system, the mechanical arm 7 uses a six-axis mechanical arm 7, and the collection unit 8 is a camera; Among them, the robotic arm 7 is used to clamp the blade to be strengthened 6. The robotic arm 7 is electrically connected to the controller 1. The movements of the robotic arm 7 can be controlled by the controller 1, such as clamping the blade to be strengthened 6 and releasing the blade to be strengthened 6, thereby improving the processing convenience of the blade to be strengthened 6.

[0021] Among them, the laser etching unit is electrically connected to the controller 1, and is used to output a picosecond pulse laser beam according to the processing instructions issued by the controller 1. The picosecond pulse laser beam is used to etch the surface of the blade 6 to be strengthened on the robotic arm 7 according to a preset spot path; in this embodiment, the blade 6 to be strengthened is strengthened with a picosecond pulse laser beam, which can improve the processing efficiency and can be used for the surface strengthening of complex thin blades of titanium alloy of aero-engines. It overcomes the defects of large deformation and laser-induced shock wave rebound when traditional technologies are applied to thin-walled blades, and can be used for surface strengthening of high value-added thin-walled parts in the aerospace field.

[0022] Among them, the collection unit 8 is electrically connected to the controller 1, and is used to collect the strengthening pattern of the laser etching unit during the optical path calibration process, and upload the collected strengthening pattern to the controller 1; in this embodiment, the processing accuracy of the blade 6 to be strengthened is improved by performing optical path calibration on the picosecond pulse laser beam emitted by the optical etching unit.

[0023] Among them, the controller 1 is used to: segment the enhancement pattern to obtain the image boundary features of the enhancement area, identify the image boundary features of the enhancement area, obtain the enhancement pattern, and judge whether the enhancement pattern covers the preset enhancement position; when the enhancement pattern covers the preset enhancement position, generate a processing instruction, and send the processing instruction to the laser etching unit; in this embodiment, the enhancement pattern is collected by the acquisition unit 8, the controller 1 segments the enhancement pattern to obtain the image boundary features of the enhancement area, identifies the image boundary features of the enhancement area, obtains the enhancement pattern, and judges whether the enhancement pattern covers the preset enhancement position, which can efficiently realize the optical path calibration and further improve the processing efficiency.

[0024] As a further optimization of this embodiment, the preset light spot path is a zigzag structure.

[0025] As a further optimization of this embodiment, the laser etching unit includes: a laser 2, a laser optical path 3, a laser galvanometer 4 and a laser field mirror 5; The laser 2 is electrically connected to the controller 1, and the laser 2 is used to output a picosecond pulse laser beam; The laser optical path 3 is used to guide the picosecond pulse laser beam output by the laser 2 to the laser galvanometer 4; The laser galvanometer 4 is electrically connected to the controller 1, and the laser galvanometer 4 is used to adjust the position of the laser beam of the picosecond pulse; The laser field mirror 5 is used to focus the position-adjusted picosecond pulse laser beam onto the surface of the blade 6 to be strengthened.

[0026] Among them, the laser galvanometer 4 is composed of an XY optical scanning head, an electronic driving amplifier circuit and an optical reflective lens. The electronic driving amplifier circuit is electrically connected to the controller 1. The signal provided by the controller 1 drives the optical scanning head through the driving amplifier circuit, thereby controlling the deflection of the laser beam in the XY plane.

[0027] When the picosecond pulse laser beam output by the laser 2 enters the laser galvanometer 4 through the laser optical path 3, it is reflected by the XY axis reflector of the laser galvanometer 4 and focused on the blade surface through the laser field mirror 5. At the same time, the X-axis and Y-axis lenses rotate to realize the XY direction scanning processing within the processing format. The blade 6 to be strengthened can be clamped by the robot arm 7 and spatially positioned, so that the laser focus of the picosecond pulse laser beam is always perpendicular to the surface of the blade 6 to be strengthened, thereby completing the function of strengthening the surface of the titanium alloy thin blade of the aircraft engine.

[0028] In this embodiment, the distance between the clamping end of the mechanical arm 7 and the laser field mirror 5 can be controlled by the controller 1, so that the focusing adjustment of the picosecond pulse laser beam can be achieved.

[0029] As a further optimization of this embodiment, the controller 1 is also used to: when the reinforcement pattern does not cover the preset reinforcement position, identify the erroneous area of ​​the reinforcement pattern based on a pre-built neural network model to obtain a recognition result, generate a path adjustment instruction according to the recognition result, and send the path adjustment instruction to the laser etching unit to adjust the spot path of the picosecond pulse laser beam of the laser etching unit until the reinforcement pattern covers the preset reinforcement position.

[0030] In this embodiment, when the reinforcement pattern covers the preset reinforcement part, the parameters such as the spot path and path adjustment instructions of the laser etching unit are obtained as new sample data, and the neural network model is repeatedly trained with the new sample data to increase the recognition accuracy and adjustment speed of the neural network model.

[0031] As a further optimization of this embodiment, the acquisition unit 8 is also used to collect the real-time spot path of the laser etching unit during the etching process on the surface of the blade to be strengthened 6, and the controller 1 is also used to: determine whether the real-time spot path is offset, and if so, generate a strengthening termination instruction, and send the strengthening termination instruction to the laser etching unit to make the laser etching unit terminate the strengthening of the blade to be strengthened 6.

[0032] In this embodiment, the real-time light spot path collected is the processed video data. The real-time light spot path can be obtained by identifying each frame of the processed video data. When the real-time light spot path is offset, it means that it is impossible to strengthen according to the current path and needs to be recalibrated. At this time, the laser etching unit is controlled to stop strengthening the blade 6 to be strengthened to avoid the occurrence of defective strengthened products.

[0033] Embodiment 2 Figure 2 FIG. 1 is a flow chart of a method for strengthening a titanium alloy blade of an aero-engine provided by one embodiment of the present invention. Figure 2 As shown, this embodiment provides a method for strengthening processing of titanium alloy blades of an aero-engine, the method comprising: Step S10: pre-processing the blade 6 to be strengthened, wherein the pre-processing includes cleaning and clamping.

[0034] In this embodiment, the blade 6 to be strengthened is a titanium alloy blade that needs to be strengthened. The blade 6 to be strengthened is first cleaned, for example, the titanium alloy blade to be strengthened is ultrasonically cleaned in an anhydrous ethanol solution for 20 minutes, and then dried after cleaning; after drying, the titanium alloy blade to be strengthened is clamped, that is, the titanium alloy blade to be strengthened is clamped on the robotic arm 7.

[0035] Step S20: Calibrate the aircraft engine titanium alloy blade strengthening processing system.

[0036] In this embodiment, the aircraft engine titanium alloy blade strengthening processing system includes: a controller 1, a robotic arm 7, a laser etching unit and a collection unit 8. The robotic arm 7 is used to clamp the blade 6 to be strengthened. The robotic arm 7 is electrically connected to the controller 1. The laser etching unit includes: a laser 2, a laser optical path 3, a laser galvanometer 4 and a laser field mirror 5.

[0037] In this embodiment, the calibration process of the aircraft engine titanium alloy blade strengthening processing system includes: calibrating the single-point indicator light focus of the laser etching unit of the aircraft engine titanium alloy blade strengthening processing system; The single-point indicator light focusing calibration of the laser etching unit of the aircraft engine titanium alloy blade strengthening processing system includes: Step a10: the laser etching unit emits a single point indication light onto the surface of the blade 6 to be strengthened; Step a20: the acquisition unit 8 of the aircraft engine titanium alloy blade strengthening processing system acquires a single-point indicator light image on the surface of the blade to be strengthened 6 in real time; Step a30: the controller 1 of the aircraft engine titanium alloy blade strengthening processing system determines whether the single-point indicator light is focused on the surface of the blade to be strengthened 6 according to the single-point indicator light image on the surface of the blade to be strengthened 6, and if not, generates a focus adjustment instruction, and sends the focus calibration instruction to the robot arm 7 of the aircraft engine titanium alloy blade strengthening processing system; Step a40: The robot arm 7 of the aircraft engine titanium alloy blade strengthening processing system responds to the focus calibration instruction and adjusts the focus of the single-point indicator light until the single-point indicator light is focused on the surface of the blade 6 to be strengthened.

[0038] In this embodiment, the single-point indication light is output by the laser 2 of the laser etching unit. The single-point indication light passes through the laser optical path 3, the laser galvanometer 4 and the laser field mirror 5 in sequence, and can be projected onto the surface of the blade 6 to be strengthened. The camera can collect image data of the single-point indication light projected on the surface of the blade 6 to be strengthened, that is, the single-point indication light image. The controller 1 determines whether the single-point indication light is focused on the surface of the blade 6 to be strengthened based on the single-point indication light image. If the single-point indication light is not focused on the surface of the blade 6 to be strengthened, the controller 1 controls the movement of the robotic arm 7 to adjust the distance between the blade 6 to be strengthened and the laser field mirror 5 so that the single-point indication light is focused on the surface of the blade 6 to be strengthened.

[0039] As a further optimization of this embodiment, the calibration process of the aircraft engine titanium alloy blade strengthening processing system further includes: calibrating the spot path of the laser etching unit of the aircraft engine titanium alloy blade strengthening processing system; The spot path calibration of the laser etching unit of the aircraft engine titanium alloy blade strengthening processing system includes: Step b10: after the single-point indicator light is focused on the surface of the blade 6 to be strengthened, the laser etching unit emits the indicator light onto the surface of the blade 6 to be strengthened, so that a strengthening pattern is formed on the surface of the blade 6 to be strengthened; Step b20: the acquisition unit 8 acquires the enhanced pattern and uploads the acquired enhanced pattern to the controller 1; Step b30: The controller 1 segments the enhancement pattern to obtain the image boundary features of the enhancement area, identifies the image boundary features of the enhancement area to obtain the enhancement pattern, and determines whether the enhancement pattern covers the preset enhancement position; if not, the error area of ​​the enhancement pattern is identified based on a pre-constructed neural network model to obtain an identification result, and a path adjustment instruction is generated according to the identification result, and the path adjustment instruction is sent to the laser etching unit to adjust the spot path of the picosecond pulse laser beam of the laser etching unit until the enhancement pattern covers the preset enhancement position.

[0040] In this embodiment, when the reinforcement pattern covers the preset reinforcement part, the parameters such as the spot path and path adjustment instructions of the laser etching unit are obtained as new sample data, and the neural network model is repeatedly trained with the new sample data to increase the recognition accuracy and adjustment speed of the neural network model.

[0041] The present invention improves the processing accuracy of the blade 6 to be strengthened by calibrating the optical path of the picosecond pulse laser beam emitted by the photoetching unit.

[0042] Step S30: Adjust the laser parameters of the picosecond pulse laser beam output by the laser etching unit of the calibrated aircraft engine titanium alloy blade strengthening processing system to obtain an adjusted picosecond pulse laser beam, wherein the laser parameters include at least: power density, spot diameter, spot interval and repetition frequency.

[0043] In this embodiment, the laser parameters can be adjusted on the controller 1 , and then the controller 1 is used to control the laser 2 to output a picosecond pulse laser beam corresponding to the laser parameters.

[0044] Step S40: The calibrated aero-engine titanium alloy blade strengthening processing system performs laser strengthening on the surface of the blade to be strengthened 6 with an adjusted picosecond pulse laser beam to obtain a strengthened blade.

[0045] Step S50: performing secondary processing on the strengthened blades to obtain strengthened blade samples.

[0046] In this embodiment, the secondary treatment includes: grinding treatment, ultrasonic cleaning treatment and drying treatment; the secondary treatment of the strengthened blade to obtain a strengthened blade sample includes: Step S501: grinding the strengthened blade with 2500-3500 mesh sandpaper to obtain a first blade; Step S502: placing the first leaf into anhydrous ethanol for ultrasonic cleaning, and continuing the cleaning for 8 minutes to 12 minutes to obtain a second leaf; Step S503: placing the second leaf in air for drying to obtain a strengthened leaf sample.

[0047] In step S501, the strengthened blades are preferably polished with 3000-grit sandpaper to remove the surface oxide layer; in step S502, the continuous cleaning time is preferably 10 minutes.

[0048] As a further optimization of this embodiment, the method further includes: performing a mechanical property test on the reinforced blade sample, including: Step c10: Obtain the cross-sectional microhardness distribution and cross-sectional residual stress distribution of the reinforced blade sample.

[0049] In this embodiment, a microhardness tester can be used to measure the cross-sectional microhardness distribution of the alloy sample. The microhardness tester is electrically connected to the controller 1, and the microhardness tester uploads the measured cross-sectional microhardness distribution of the alloy sample to the controller 1; In this embodiment, an X-ray diffractometer can be used to analyze the cross-sectional residual stress distribution of the reinforced blade sample. The X-ray diffractometer is electrically connected to the controller 1, and the X-ray diffractometer uploads the analyzed cross-sectional residual stress distribution of the reinforced blade sample to the controller 1; at this time, the controller 1 can obtain the cross-sectional microhardness distribution and cross-sectional residual stress distribution of the reinforced blade sample.

[0050] Step c20: Determine the strengthening effect index according to the cross-sectional microhardness distribution and cross-sectional residual stress distribution of the strengthened blade sample.

[0051] Step c30: When the strengthening effect index reaches a preset index value, a fatigue test is performed on the strengthened blade sample to obtain the fatigue of the strengthened blade sample, and the fatigue of the strengthened blade sample is used to characterize the mechanical properties of the strengthened blade sample.

[0052] In this embodiment, the aircraft engine titanium alloy blade strengthening processing system also includes a display, which is electrically connected to the controller 1. The display can be used to display the cross-sectional microhardness distribution and cross-sectional residual stress distribution of the strengthened blade sample.

[0053] In this embodiment, if it is found that the surface microhardness of the titanium alloy is improved after strengthening and compressive stress is introduced on the surface, it means that the strengthening is effective (in this case, the surface microhardness of the titanium alloy is improved after strengthening and compressive stress is introduced on the surface as the preset indicator value).

[0054] Then, fatigue limit test was carried out by high cycle fatigue machine with the working frequency set to 80 Hz.

[0055] Figure 3 is the residual stress distribution diagram of the cross section of the strengthened blade sample, Figure 4 is the cross-sectional microhardness distribution diagram of the reinforced blade sample. Figure 3 and Figure 4 As shown in the figure, the cross-sectional residual stress of the reinforced blade sample presents a gradient distribution. The picosecond laser introduces residual compressive stress on the material surface. The depth of the compressive stress affected layer is about 250μm, and the microhardness also presents a gradient distribution. This special gradient structure can effectively improve the high-cycle fatigue performance of metal materials.

[0056] Figure 5 FIG. 6 is a schematic diagram comparing the fatigue limit of the blade 6 to be strengthened after three picosecond laser strengthening and the fatigue limit of the blade 6 to be strengthened before strengthening. Figure 5 As shown in the figure, the high cycle fatigue limit of the titanium alloy after three picosecond laser strengthening is 497 MPa, which is 20.3% higher than that of the untreated strengthened blade sample (413 MPa).

[0057] Therefore, the picosecond laser introduced a large amount of residual compressive stress on the surface of the titanium alloy. In addition, a gradient distribution structure of microhardness and residual stress was generated in the cross section. High-cycle fatigue experiments showed that the fatigue limit of the titanium alloy increased by 20.3% after three picosecond laser strengthening.

[0058] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0059] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0060] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. An aircraft engine titanium alloy blade strengthening processing system, characterized in that: The system comprises: Controller (1); A mechanical arm (7) for clamping the blade to be strengthened (6), the mechanical arm (7) being electrically connected to the controller (1); A laser etching unit is electrically connected to the controller (1) and is used to output a picosecond pulse laser beam according to a processing instruction issued by the controller (1), wherein the picosecond pulse laser beam is used to perform etching processing on the surface of the blade (6) to be strengthened on the robot arm (7) according to a preset spot path; A collection unit (8) is electrically connected to the controller (1) and is used to collect the enhanced pattern of the laser etching unit during the optical path calibration process and upload the collected enhanced pattern to the controller (1); The controller (1) is used to: segment the strengthening pattern to obtain the boundary features of the strengthening area image, identify the boundary features of the strengthening area image to obtain the strengthening pattern, and judge whether the strengthening pattern covers the preset strengthening part; when the strengthening pattern covers the preset strengthening part, generate a processing instruction, and send the processing instruction to the laser etching unit.

2. The aircraft engine titanium alloy blade strengthening processing system according to claim 1 is characterized in that: The preset light spot path is a zigzag structure.

3. The aircraft engine titanium alloy blade strengthening processing system according to claim 1 is characterized in that: The laser etching unit comprises: a laser (2), a laser optical path (3), a laser galvanometer (4) and a laser field mirror (5); The laser (2) is electrically connected to the controller (1), and the laser (2) is used to output a picosecond pulse laser beam; The laser optical path (3) is used to guide the picosecond pulse laser beam output by the laser (2) to the laser galvanometer (4); The laser galvanometer (4) is electrically connected to the controller (1), and the laser galvanometer (4) is used to adjust the position of a picosecond pulse laser beam; The laser field mirror (5) is used to focus the position-adjusted picosecond pulse laser beam onto the surface of the blade (6) to be strengthened.

4. The aircraft engine titanium alloy blade strengthening processing system according to claim 1, characterized in that: The controller (1) is also used to: when the strengthening pattern does not cover the preset strengthening position, identify the erroneous area of ​​the strengthening pattern based on the pre-constructed neural network model to obtain a recognition result, generate a path adjustment instruction according to the recognition result, and send the path adjustment instruction to the laser etching unit to adjust the spot path of the picosecond pulse laser beam of the laser etching unit until the strengthening pattern covers the preset strengthening position.

5. The aircraft engine titanium alloy blade strengthening processing system according to claim 1, characterized in that: The acquisition unit (8) is also used to acquire in real time the real-time light spot path during the etching process of the laser etching unit on the surface of the blade to be strengthened (6). The controller (1) is also used to determine whether the real-time light spot path is offset, and if so, generate a strengthening termination instruction, and send the strengthening termination instruction to the laser etching unit, so that the laser etching unit terminates strengthening of the blade to be strengthened (6).

6. A method for strengthening a titanium alloy blade of an aero-engine, characterized in that: The method comprises: Pre-processing the blade (6) to be strengthened, the pre-processing comprising: cleaning and clamping; Calibrate the aero-engine titanium alloy blade strengthening processing system according to any one of claims 1 to 5; Adjusting the laser parameters of the picosecond pulse laser beam output by the laser etching unit of the calibrated aircraft engine titanium alloy blade strengthening processing system to obtain an adjusted picosecond pulse laser beam, wherein the laser parameters at least include: power density, spot diameter, spot interval and repetition frequency; The calibrated aero-engine titanium alloy blade strengthening processing system performs laser strengthening on the surface of the blade to be strengthened (6) with an adjusted picosecond pulse laser beam to obtain a strengthened blade; The strengthened blades are subjected to secondary treatment to obtain strengthened blade samples.

7. The method for strengthening the titanium alloy blade of an aircraft engine according to claim 6, characterized in that: The calibration process of the aircraft engine titanium alloy blade strengthening processing system includes: single point indicator light focusing calibration of the laser etching unit of the aircraft engine titanium alloy blade strengthening processing system; The single-point indicator light focusing calibration of the laser etching unit of the aircraft engine titanium alloy blade strengthening processing system includes: The laser etching unit emits a single point of indication light onto the surface of the blade (6) to be strengthened; The acquisition unit (8) of the aircraft engine titanium alloy blade strengthening processing system acquires a single-point indicator light image on the surface of the blade (6) to be strengthened in real time; The controller (1) of the aircraft engine titanium alloy blade strengthening processing system determines whether the single point indicator light is focused on the surface of the blade (6) to be strengthened according to the single point indicator light image on the surface of the blade (6) to be strengthened, and if not, generates a focus adjustment instruction, and sends the focus calibration instruction to the mechanical arm (7) of the aircraft engine titanium alloy blade strengthening processing system; The mechanical arm (7) of the aircraft engine titanium alloy blade strengthening processing system responds to the focus calibration instruction and adjusts the focus of the single point indication light until the single point indication light is focused on the surface of the blade (6) to be strengthened.

8. The method for strengthening the titanium alloy blade of an aircraft engine according to claim 7, characterized in that: The calibration process of the aircraft engine titanium alloy blade strengthening processing system also includes: calibrating the spot path of the laser etching unit of the aircraft engine titanium alloy blade strengthening processing system; The spot path calibration of the laser etching unit of the aircraft engine titanium alloy blade strengthening processing system includes: After the single-point indicator light is focused on the surface of the blade to be strengthened (6), the laser etching unit emits the indicator light onto the surface of the blade to be strengthened (6), so that a strengthening pattern is formed on the surface of the blade to be strengthened (6); The collection unit (8) collects the reinforcement pattern and uploads the collected reinforcement pattern to the controller (1); The controller (1) segments the enhancement pattern to obtain the image boundary features of the enhancement area, identifies the image boundary features of the enhancement area to obtain the enhancement pattern, and determines whether the enhancement pattern covers the preset enhancement position; if not, identifies the error area of ​​the enhancement pattern based on a pre-constructed neural network model to obtain an identification result, generates a path adjustment instruction based on the identification result, and sends the path adjustment instruction to the laser etching unit to adjust the spot path of the picosecond pulse laser beam of the laser etching unit until the enhancement pattern covers the preset enhancement position.

9. The method for strengthening the titanium alloy blade of an aircraft engine according to claim 6, characterized in that: The secondary treatment includes: grinding treatment, ultrasonic cleaning treatment and drying treatment; the secondary treatment is performed on the strengthened blade to obtain a strengthened blade sample, including: The strengthened blade is polished using 2500-3500 mesh sandpaper to obtain a first blade; The first leaf is placed in anhydrous ethanol for ultrasonic cleaning for 8 to 12 minutes to obtain a second leaf; The second leaf is placed in air for drying to obtain a reinforced leaf sample.

10. The method for strengthening aero-engine titanium alloy blades according to claim 6, characterized in that: The method further comprises: performing a mechanical property test on the reinforced blade sample, including: Obtain the cross-sectional microhardness distribution and cross-sectional residual stress distribution of the strengthened blade sample; Determine the strengthening effect index based on the cross-sectional microhardness distribution and cross-sectional residual stress distribution of the strengthened blade sample; When the strengthening effect index reaches a preset index value, a fatigue test is performed on the strengthened blade sample to obtain the fatigue of the strengthened blade sample, and the fatigue of the strengthened blade sample is used to characterize the mechanical properties of the strengthened blade sample.

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