A laser processing method for improving aperture accuracy

Abstract

The present invention relates to a laser processing method for improving aperture accuracy, comprising the following steps: obtaining parameter information at different positions of all target holes on a part to be processed, selecting a test template with a known second thickness value according to the parameter information and calculating the hole depth value of the target hole based on the parameter information and the second thickness value, using ultrafast laser processing on the test template to obtain the first penetration time; constructing a first database in which there is a mathematical correspondence between the first penetration time and the hole depth, and a second database in which there is a mathematical correspondence between the hole depth and the process parameters of secondary processing according to the hole depth; reusing ultrafast laser to process the part to be processed with an unknown first thickness value, and selecting the process parameters in the second database for secondary processing to obtain a target hole meeting the requirements of the aperture design value. The present invention not only effectively controls the occurrence of aperture deviation caused by the deviation between the actual thickness of the part and the design, but also improves the consistency and processing accuracy of the aperture.

Description

Technical Field

[0001] The present invention relates to the technical field of laser processing, and particularly relates to a laser processing method for improving the aperture accuracy. Background Art

[0002] In the prior art, a laser with a millisecond (10 -3 s) pulse width is mainly used to process small holes. The aperture range of these small holes is generally 0.25 mm - 0.8 mm. Due to the large pulse energy (several joules or even dozens or hundreds of joules), the corresponding energy density is high, the material removal rate per unit laser pulse is high, and the penetration time of small holes with large depth is short. However, due to the large pulse width, it also leads to a relatively large thermal influence, and the accuracy of small holes and the quality of hole walls are not high. In recent years, nanosecond (10 -9 s), picosecond (10 -12 s), and femtosecond (10 -15 s) lasers have been more widely used in processing micro-holes with higher requirements for hole wall quality and dimensional accuracy because the interaction time of a single pulse with the material is much shorter and the laser power density is extremely high. Especially for picosecond and femtosecond lasers, the thermal influence during the processing is extremely small. However, the pulse energy of shorter pulse lasers is very low. For example, the nanosecond laser commonly used in material processing is only a few millijoules, and the pulse energy of picosecond and femtosecond lasers usually does not exceed 1 millijoule, so the processing depth is very limited. The impact processing and rotary cutting processing commonly used for millisecond pulse lasers in the past are not applicable for processing small holes with a large depth-to-diameter ratio. Not only is the efficiency low, but also due to the long time without penetration, the thermal accumulation inside the small hole makes the quality of the hole wall significantly worse. Therefore, when processing small holes with a large depth-to-diameter ratio, a more effective method for nanosecond, picosecond, and femtosecond lasers is the filling processing method, which can significantly improve the processing efficiency and quality. See Figure 2 .

[0003] One of the prior art methods is to process small holes by using a filling method with a scanning galvanometer scan. After the laser is focused, it is parallel to the hole axis. See Figure 3 . Since the scanning speed is faster, it has the advantage of relatively smaller thermal influence. However, the taper of the small holes processed by this method is relatively large. After optimization, there is usually still a taper of 2 - 3°. If the actual depth of the small hole to be processed is inconsistent with the theoretical calculation, that is, there is a deviation between the actual thickness of the part and the theoretical design, the process parameters selected based on the theoretical depth will result in an aperture deviation. By using an optical device with laser off-axis, tilted and self-rotating to achieve the filling processing method of tilted incidence and rotation after laser focusing, theoretically, small holes without taper can be processed, avoiding the influence of hole taper on the aperture accuracy. However, this method also has problems such as inconsistent small hole apertures caused by inappropriate process parameters such as the selected processing time, set radius, and tilt angle due to the deviation of the actual depth of the small hole. Summary of the Invention

[0004] (1) Technical Problems to be Solved

[0005] The present invention provides a laser processing method for improving aperture accuracy. Design parameter information at different positions of all target holes on a part to be processed is obtained. An experimental template with a second thickness value is selected according to the parameter information, and the hole depth value of the target hole is calculated based on the parameter information and the second thickness value. The experimental template is processed by an ultrafast laser to obtain the first penetration time. A first database with a mathematical correspondence between the first penetration time and the hole depth is constructed, and a second database with a mathematical correspondence between the hole depth and the process parameters of secondary processing is constructed according to the hole depth. Then, the part to be processed with a deviation between the actual thickness value and the first thickness value is processed by an ultrafast laser, and the process parameters in the second database are selected for secondary processing to obtain a target hole meeting the requirements of the aperture value, effectively controlling the occurrence of aperture deviation caused by thickness deviation and improving the consistency and processing accuracy of the aperture.

[0006] (2) Technical solution

[0007] In a first aspect, an embodiment of the present invention provides a laser processing method for improving aperture accuracy, which is applicable to machining small holes on a workpiece to be machined with a deviation between the actual thickness and the designed theoretical thickness. The method includes the following steps: Step S1: Obtain the design parameter information at different positions of all target holes on the workpiece to be machined. The parameter information includes the inclination angle value, the aperture design value, and the first thickness value at the position where the target hole is located. Step S2: Select a plurality of test templates made of the same material as the workpiece to be machined with known second thickness values according to the maximum and minimum values among the first thickness values in Step S1. The maximum value of the second thickness values is greater than the maximum value of the first thickness values, and the minimum value of the second thickness values is less than the minimum value of the first thickness values. The second thickness values change in a stepwise manner, and the difference between two adjacent second thickness values is not greater than 0.1 mm. Step S3: Calculate the hole depth value of the target hole according to the inclination angle value of the target hole and the second thickness value of the test template. Step S4: Use an ultrafast laser to machine the target hole on each of the test templates until it is detected that the ultrafast laser first penetrates the test template, and then immediately stop machining and record the first penetration time. Step S5: Construct a first database for establishing the mathematical correspondence between the first penetration time, the hole depth value of the target hole, the inclination angle value, and the aperture design value. Step S6: Use the ultrafast laser to perform secondary machining on the target holes on each of the test templates that have been first penetrated by the ultrafast laser in Step S4. Obtain appropriate process parameters through process tests to obtain the target holes that meet the aperture design value requirements in Step S1, and save the process parameters. Step S7: Construct a second database for establishing the mathematical correspondence between the hole depth value, the inclination angle value, the aperture design value of the target hole, and the process parameters in Step S6. Step S8: Write the first database and the second database into the controller of the ultrafast laser processing equipment for machining the workpiece to be machined. Step S9: Use the ultrafast laser in Step S4 to machine the target holes on the workpiece to be machined with an unknown first thickness value. Step S10: Obtain the first penetration time after it is detected that the ultrafast laser first penetrates the workpiece to be machined. Step S11: The controller obtains the hole depth value of the target hole according to the mathematical correspondence in the first database, and then obtains the process parameters required for secondary machining based on the obtained hole depth value according to the mathematical correspondence in the second database. Step S12: Use the ultrafast laser to perform secondary machining on the target holes on the workpiece to be machined that have been first penetrated by the ultrafast laser based on the process parameters in Step S11, and finally obtain the target holes that meet the aperture design value requirements in Step S1.

[0008] Further, in the step S2, the maximum value of the second thickness value of each of the test samples is 1.2 times the maximum value of the first thickness value, and the minimum value of the second thickness value is 0.8 times the minimum value of the first thickness value.

[0009] Further, in the step S4, the ultrafast laser processes each of the test samples based on a galvanometer scanning device, and a CCD image sensor is used to identify and record the first penetration time when the ultrafast laser first penetrates each of the test samples.

[0010] Further, the galvanometer scanning device includes an optical lens, a galvanometer scanner, and a focusing lens arranged in sequence along the transmission optical path of the ultrafast laser. The optical lens is used to reflect the ultrafast laser to the galvanometer scanner, the galvanometer scanner is used to reflect the ultrafast laser onto the focusing lens, the focusing lens is used to focus the ultrafast laser and act on the test sample and is used to transmit the visible light formed during the ultrafast laser processing of the test sample to the galvanometer scanner, the galvanometer scanner is used to reflect the visible light to the optical lens, and the CCD image sensor is arranged on one side of the optical lens to collect the image generated by the visible light transmitted by the optical lens.

[0011] Further, the process parameters of the ultrafast laser before the secondary processing in the step S9 are the same as those of the ultrafast laser used to process the target hole in the step S4.

[0012] Further, the movement path of the ultrafast laser in the step S4 and the step S9 is a plurality of concentric circles on the area of the target hole to be processed.

[0013] Further, the acquisition of the parameter information of the target hole in the step S1 is to determine the parameter information of the target hole and determine the first thickness value at this position according to the design drawing or three-dimensional design digital model of the part to be processed.

[0014] (3) Beneficial effects

[0015] In summary, the present invention pre-obtains various parameter information of all target holes on a workpiece to be machined at different positions. The parameter information includes an inclination angle value, an aperture design value, and a first thickness value at the position where the target hole is located. Then, a test sample with a known second thickness value is selected according to the first thickness value. Next, the hole depth value of the target hole is calculated based on the second thickness value and the inclination angle value. An ultrafast laser is used to machine each test sample to obtain the first penetration time when the test sample is first penetrated, and a first database with a mathematical correspondence between the first penetration time and the hole depth value is constructed, and a second database with a mathematical correspondence between the hole depth value and the process parameters of secondary machining is constructed according to the hole depth value. When machining a workpiece to be machined with an unknown first thickness, by obtaining the first penetration time of the target hole, and then using the mathematical correspondences in the first database and the second database to select the corresponding process parameters of secondary machining to continue machining the first-penetrated target hole to obtain a target hole that meets the requirements of the aperture design value, it not only effectively controls the occurrence of aperture deviation caused by the deviation between the actual thickness and the designed theoretical thickness due to the machining error of the workpiece to be machined, but also improves the consistency and machining accuracy of the aperture of the target hole.

[0016] The present invention uses an ultrafast laser with a pulse width in picoseconds and femtoseconds to improve the accuracy of hole making, that is, under the same process conditions (such as machining methods, process parameters, etc.) and the same workpiece state (such as the same material, etc.), the ultrafast laser has a more definite time period for penetrating materials of the same thickness, and the corresponding recognition accuracy and precision are higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 is the process flow chart of the laser processing method of the present invention.

[0019] Figure 2 is the schematic diagram of the movement path of the ultrafast laser of the present invention.

[0020] Figure 3 is the schematic diagram of the principle of vertical incident machining of the ultrafast laser of the present invention.

[0021] Figure 4 is the schematic diagram of the structure of the double-layer flat test piece of the present invention.

[0022] Figure 5 is the working principle diagram of the scanning galvanometer device of the present invention.

[0023] In the figure:

[0024] 1 - Scanning galvanometer; 2 - Optical lens; 3 - CCD image sensor; 4 - Focusing lens; 5 - Flat test piece; 6 - Protective material. Specific embodiments

[0025] The following further describes in detail the embodiments of the present invention in conjunction with the accompanying drawings and embodiments. The following detailed description of the embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present invention, but cannot be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments, and covers any modifications, substitutions, and improvements of parts, components, and connection methods without departing from the spirit of the present invention.

[0026] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following will detail the present application with reference to the accompanying drawings and embodiments.

[0027] Figure 1 is a process flow chart of a laser processing method of an invention in an embodiment of the present invention, as Figures 1 to 5As shown in the figure, the laser processing method for improving the aperture accuracy is applicable to machining small holes on a workpiece to be machined with a deviation between the actual thickness and the theoretically designed thickness. The small holes are the film holes of an aero-engine blade, and the method includes the following steps: Step S1: Obtain the parameter information at different positions of all target holes on the workpiece to be machined. The parameter information includes the inclination angle value (the inclination angle value is the included angle formed by the axis of the target hole and the tangential direction of the surface of the workpiece to be machined), the aperture design value (the aperture design value is the size of the aperture of the target hole that has been determined on the workpiece to be machined as actually required), and the first thickness value at the position where the target hole is located (the first thickness value is the theoretically determined thickness value based on the designed hole depth of the target hole). The acquisition of the parameter information of the target hole is to determine the position of the target hole according to the design drawing or three-dimensional design model of the workpiece to be machined, and determine the first thickness value at this position according to the parameter information of the target hole, that is, the inclination angle value and the hole depth value. It can also be based on the corresponding design description or design data information of the workpiece to be machined. These data information includes the first thickness value at the position where the target hole is located, the inclination angle value, and the aperture design value; Step S2: Determine the range of the second thickness value of the test template according to the maximum and minimum values of the first thickness values in Step S1. That is, the specific second thickness values of each test template are known, and the maximum value of the second thickness values of each test template 5 is greater than the maximum value of the first thickness values, and the minimum thickness value of the second thickness values of each test template 5 is less than the minimum value of the first thickness values. The other second thickness values of each test template 5 are distributed in a stepped manner between the maximum and minimum values, and the difference between two adjacent second thickness values is not greater than 0.1 mm.Step S3: Calculate the hole depth value of the target hole according to the inclination angle value of the target hole and the second thickness value of the test sample. This hole depth value is calculated based on the known inclination angle value and the second thickness value according to the trigonometric mathematical formula. Since there are multiple inclination angle values and second thickness values, there are also multiple corresponding calculated hole depth values; Step S4: Use an ultrafast laser to process all target holes on each test sample 5 (the processing method of this ultrafast laser is the filling processing method in the prior art), and immediately stop processing and record the first penetration time when it is detected that the ultrafast laser first penetrates the test sample 5 for the first time. This ultrafast laser uses a laser with a pulse width of femtoseconds or picoseconds; Step S5: Construct a first database for establishing the mathematical correspondence between the first penetration time and the hole depth value, inclination angle value, and aperture design value of the target hole; Step S6: Use the ultrafast laser to perform secondary processing on the target holes on each test sample 5 that have been first penetrated by the ultrafast laser in Step S4. Through a process test (this process test is a processing process in which the ultrafast laser repeatedly adjusts and tests according to the process parameters of the first processed test sample 5 to finally obtain the aperture design value that meets the requirements), obtain appropriate process parameters to meet the target holes with the aperture design value requirements in Step S1, and save these process parameters; Step S7: Construct a second database for establishing the mathematical correspondence between the hole depth value, inclination angle value, aperture design value of the target hole and the process parameters in Step S6; Step S8: Write the first database and the second database into the controller of the ultrafast laser processing equipment for processing the parts to be processed; Step S9: Use the ultrafast laser in Step S4 to process the target holes of the parts to be processed with an unknown first thickness value. Among them, according to the parameter information of the target hole, the aperture design value and the inclination angle value of the target hole can be determined first. That is, before formally processing the parts to be processed with an unknown first thickness value (specifically, the actual thickness of the parts to be processed that deviates from the theoretical design thickness due to processing), the aperture design value and the inclination angle value of the target hole on the parts to be processed are determined in advance, and then the same process parameters as those used in the ultrafast laser processing of the target hole in Step S4 are selected, that is, laser parameters, nozzle size, lens focal length, etc. and the actual power of the laser at the outlet of the coaxial auxiliary blowing nozzle, movement path, scanning speed, focal position, type of auxiliary blowing, pressure, distance between the nozzle outlet end and the workpiece, relative position between the laser and the nozzle outlet, etc. are all the same; Step S10: Obtain the first penetration time after detecting that the ultrafast laser first penetrates the parts to be processed; Step S11: The controller obtains the hole depth value of the target hole according to the mathematical correspondence in the first database, and then obtains the process parameters required for secondary processing based on the obtained hole depth value according to the mathematical correspondence in the second database; Step S12: Use the ultrafast laser to perform secondary processing on the target holes on the parts to be processed that have been first penetrated by the ultrafast laser based on the process parameters in Step S11, and finally obtain the target holes that meet the aperture design value requirements in Step S1.It should be noted that if the part to be processed has a cavity structure, such as a blade, when constructing the test template 5, a double-layer structure with two upper and lower arrangements will be adopted, and a protective material (such as Figure 4 as shown) will be filled between the double-layer structures. The thickness values of the upper and lower flat plates of the double-layer structure are both the second thickness value of the test template 5.

[0028] By pre-obtaining various parameter information of all target holes on the part to be processed at different positions, the parameter information includes the inclination angle value, the aperture design value, and the first thickness value at the position where the target hole is located, and selecting a test template with a known second thickness value according to the first thickness value, then calculating the hole depth value of the target hole based on the second thickness value and the inclination angle value, using an ultrafast laser to process each test template to obtain the first penetration time for first penetrating the test template, and constructing a first database with a mathematical correspondence between the first penetration time and the hole depth value, and a second database with a mathematical correspondence between the hole depth value and the process parameters of secondary processing according to the hole depth value. When processing a part to be processed with an unknown first thickness, by obtaining the first penetration time of the target hole, and then using the mathematical correspondences in the first database and the second database to select the corresponding process parameters of secondary processing to continue processing the first-penetrated target hole to obtain a target hole that meets the requirements of the aperture design value, not only effectively controls the occurrence of aperture deviation, but also improves the consistency and processing accuracy of the aperture.

[0029] As another preferred embodiment, as Figure 1 shown, in step S2, the maximum value of the second thickness values of each test template 5 is 1.2 times the maximum value of the first thickness values, and the minimum thickness value of the second thickness values of each test template 5 is 0.8 times the minimum value of the first thickness values. According to the inclination angle value and the first thickness value, estimate the maximum hole depth of processing the target hole on the test template 5. Considering the margin design requirements of the test template 5, by designing a difference between the second thickness value of each test template 5 and its corresponding first thickness value, it is ensured that the hole depth value requirements of the target hole on the part to be processed can be simulated on the test template 5, avoiding the risk of incorrect processing of the target hole due to distortion of the data in the subsequent constructed database of the hole depth value and the first penetration time, and being used to ensure the accuracy of the corresponding relationship between the numerical parameters (inclination angle value, aperture design value, hole depth value, and second thickness value) in the first database.

[0030] As other alternative embodiments.

[0031] Preferably, as Figures 1 to 5As shown, preferably, in step S4, the ultrafast laser also processes the target holes of each test sample 5 along its movement path, i.e., the movement trajectory required for processing. If the inclination angle value of the target hole is 0°, the transmission direction of the ultrafast laser processes the test sample 5 in a direction perpendicular to the surface tangent of the test sample 5. If the inclination angle value of the target hole is greater than 0° and less than 90°, the transmission direction of the ultrafast laser forms a certain angle with the plane where the surface tangent of the test sample 5 is located to process the target hole of the test sample 5. Regardless of the size of the inclination angle value of the target hole, the processing method of the ultrafast laser for the test sample 5 is to use the filling processing method in the prior art to process the target holes of each batch of test samples 5, and the inclination angle value is kept consistent with the aperture design value when processing each batch of test samples 5, so as to obtain different first penetration times under the same inclination angle value and aperture design value on the test samples 5 with different second thickness values, thereby constructing the accuracy of the data correspondence in the first database of different hole depth values and corresponding first penetration times. For example, for the first time, target holes with an inclination angle of 30° and an aperture of 400 μm are processed on all test samples 5 in the first batch; for the second time, target holes with an inclination angle of 45° and an aperture of 400 μm are processed on all test samples 5 in the second batch; for the third time, target holes with an inclination angle of 40° and an aperture of 400 μm are processed on all test samples 5 in the third batch. At the same time, sufficient processing time is set each time to ensure that all test samples 5 can be penetrated when processing target holes with different inclination angle values and aperture design values.

[0032] Preferably, as Figure 5 shown, in step S4, the ultrafast laser processes each test sample 5 based on a scanning galvanometer device, and a CCD image sensor 3 is used to identify and record the first penetration time when the ultrafast laser first penetrates each test sample 5. Specifically, the CCD image sensor 3 is used to identify that each test sample 5 is first penetrated by the ultrafast laser, and then controls the ultrafast laser to stop processing, and automatically records the time from the start to the stop of the ultrafast laser as the first penetration time. The CCD image sensor 3 collects the visible color image digital signal in the hole area of the target hole processed by the laser, and judges whether the target hole is first penetrated through the change of image features, including image color change, change range, change degree and other feature changes.

[0033] Preferably, as Figure 2 shown, the movement path of the ultrafast laser is a plurality of concentric circles on the aperture area of the target hole to be processed on each test sample 5, and the diameter of the largest circle is usually greater than or equal to the aperture design value of the target hole when using a scanning galvanometer device for processing.

[0034] To further illustrate the mathematical correspondence between the hole depth value and the first penetration time in the first database of the present invention, as Figures 1 to 5 shown, adjust the laser output power of the laser generator (not shown in the figure) on the laser processing equipment to 41.5 W (the laser output power at the outlet of the laser output channel nozzle) and the coaxial auxiliary blowing pressure to 0.4 MPa, defocus -1 mm, and the distance between the outlet position of the laser output channel nozzle and the test sample 5 is 4 mm. Then set the movement path of the ultrafast laser, as Figure 2 shown. With point O as the center and R as the maximum radius, i.e., 200 μm, the concentric circles are spaced 50 μm apart, that is, 4 concentric circles. Use a scanning galvanometer device as Figure 5 to transmit the ultrafast laser L and drive the entire ultrafast laser L to rotate synchronously with the scanning galvanometer device to perform 0° hole machining on the test sample 5 (as Figure 3 shown). Set the scanning speed to 427 mm / s. Stop machining until the ultrafast laser L first penetrates the test sample 5 and is recognized by the CCD image sensor. The mathematical correspondence between the test sample 5 with different second thicknesses penetrated vertically and the number of circular scans (which can be converted into the first penetration time) can be obtained, as shown in Table 1,

[0035] Table 1 Correspondence table of hole depth and number of circular scans for the first penetration

[0036] Hole depth (mm) Number of cycles for first penetration 1 330 1.2 450 1.4 630 1.5 700 1.8 850 2 1000 2.2 1100 2.5 1350 2.8 1850 3 2500 3.2 2950 3.5 3600

[0037] Adjust the transmission direction of the ultrafast laser to form a certain angle with the plane where the tangent of the surface of the test sample 5 is located (i.e., the inclination angle value of the target hole) to perform filling machining of the target hole on the test sample 5. Set the rotation speed to 427 mm / s. Stop machining until the ultrafast laser L first penetrates the test sample 5 and is recognized by the CCD image sensor. The mathematical correspondence between the test sample 5 with different second thicknesses penetrated at different inclination angles and the first penetration time can be obtained, as shown in Table 2,

[0038] Table 2 Correspondence table of hole depth, inclination angle and first penetration time

[0039]

[0040]

[0041] The ranges of the first penetration times for different hole depth values are significantly different. It can be seen that the method of the present invention for judging the hole depth by measuring the first penetration time of the hole and then improving the consistency of the aperture of the target hole on the part to be machined is feasible.

[0042] It should be clear that the various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, reference can be made to each other, and each embodiment focuses on the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. Also, for the sake of brevity, the detailed description of known methods and techniques is omitted here.

[0043] The above are only the embodiments of the present application and do not limit the present application. For those skilled in the art, various changes and modifications can be made to the present application without departing from the scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A laser processing method for improving aperture accuracy, which is applicable to processing small holes on a to-be-processed part with a deviation between the actual thickness and the designed theoretical thickness. Characterized in that, It includes the following steps: Step S1: Obtain the parameter information at different positions of all target holes on the to-be-processed part, where the parameter information includes the inclination angle value, the aperture design value, and the first thickness value at the position where the target hole is located. Step S2: Select and use test samples (5) made of the same material as the to-be-processed part with multiple known second thickness values according to the maximum and minimum values among the first thickness values in Step S1. The maximum value of the second thickness values is greater than the maximum value of the first thickness values, the minimum value of the second thickness values is less than the minimum value of the first thickness values, and the second thickness values change in a stepped manner with the difference between adjacent two second thickness values not exceeding 0.1 mm. Step S3: Calculate the hole depth value of the target hole according to the inclination angle value of the target hole and the second thickness value of the test sample. Step S4: Use ultrafast laser to process the target holes on each of the test samples (5) until it is detected that the ultrafast laser first penetrates the test sample (5), and immediately stop the processing and record the first penetration time. Step S5: Construct a first database for establishing the mathematical correspondence between the first penetration time, the hole depth value of the target hole, the inclination angle value, and the aperture design value of the target hole. Step S6: Use ultrafast laser to reprocess the target holes on each of the test samples (5) that have been first penetrated by the ultrafast laser in Step S4. Obtain appropriate process parameters through process tests to obtain the target holes that meet the aperture design value requirements in Step S1, and save the process parameters. Step S7: Construct a second database for establishing the mathematical correspondence between the hole depth value, inclination angle value, aperture design value of the target hole, and the process parameters in Step S6. Step S8: Write the first database and the second database into the controller of the ultrafast laser processing equipment for processing the to-be-processed part. Step S9: Use the ultrafast laser in Step S4 to process the target holes on the to-be-processed part with an unknown first thickness value. Step S10: Obtain the first penetration time after it is detected that the ultrafast laser first penetrates the to-be-processed part. Step S11: The controller obtains the hole depth value of the target hole according to the mathematical correspondence in the first database, and then obtains the process parameters required for reprocessing based on the obtained hole depth value according to the mathematical correspondence in the second database. Step S12: Use the ultrafast laser to reprocess the target holes on the to-be-processed part that have been first penetrated by the ultrafast laser based on the process parameters in Step S11, and finally obtain the target holes that meet the aperture design value requirements in Step S1.

2. The laser processing method for improving aperture accuracy according to claim 1, Characterized in that, In the step S2, the maximum value of the second thickness value of each of the test samples (5) is 1.2 times the maximum value of the first thickness value, and the minimum value of the second thickness value is 0.8 times the minimum value of the first thickness value.

3. The laser processing method for improving the aperture accuracy according to claim 1, wherein, in the step S4, the ultrafast laser processes each of the test samples (5) based on the scanning galvanometer device, and the CCD image sensor (3) is used to identify the first penetration of the ultrafast laser through each of the test samples (5) and record the first penetration time.

4. The laser processing method for improving the aperture accuracy according to claim 3, wherein, the scanning galvanometer device includes an optical lens (2), a scanning galvanometer (1), and a focusing lens (4) arranged in sequence along the transmission optical path of the ultrafast laser. The optical lens (2) is used to reflect the ultrafast laser to the scanning galvanometer (1), the scanning galvanometer (1) is used to reflect the ultrafast laser onto the focusing lens (4), the focusing lens (4) is used to focus the ultrafast laser and act on the test sample (5) and is used to transmit the visible light formed during the ultrafast laser processing of the test sample (5) to the scanning galvanometer (1), the scanning galvanometer (1) is used to reflect the visible light to the optical lens (2), and the CCD image sensor (3) is arranged on one side of the optical lens (2) to collect the image generated by the visible light transmitted by the optical lens (2).

5. The laser processing method for improving the aperture accuracy according to claim 1, wherein, the process parameters of the ultrafast laser before the secondary processing in the step S9 are the same as the process parameters used by the ultrafast laser to process the target hole in the step S4.

6. The laser processing method for improving the aperture accuracy according to claim 4, wherein, the movement path of the ultrafast laser in the step S4 and the step S9 is a plurality of concentric circles on the area of the target hole to be processed.

7. For the laser processing method for improving the aperture accuracy according to claim 1, the acquisition of the parameter information of the target hole in the step S1 is to determine the position of the target hole according to the design drawing or the three-dimensional design digital model of the part to be processed, and determine the first thickness value at this position according to the parameter information of the target hole.

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