Laser punching device and method

Abstract

A laser punching device includes a light source module, an optical path transmission module, a laser modulation module, a focusing module, and a control module. The light source module emits a first laser beam. The optical path transmission module, laser modulation module, and focusing module are arranged sequentially along the optical path. The laser modulation module includes a beam splitter and a shaper movable in and out of the optical path. The beam splitter splits the first laser beam into at least two second laser beams, and the shaper shapes the first laser beam. The light source module, beam splitter, and shaper are all connected to the control module, which controls the parameters of the laser emitted by the light source module and controls the entry and exit of the beam splitter and shaper into and out of the optical path. The focusing module focuses the first and second laser beams onto the surface of a substrate. Furthermore, a laser punching method is also provided. The above-described laser punching device and laser punching method solve the problems of easy cracking, warping, and even peeling of the coating material of the substrate during punching, as well as the difficulty in controlling the hole diameter and poor inner wall quality.

Description

Technical Field

[0001] The present invention relates to the field of laser processing technology, and in particular to a laser punching device and method. Background Art

[0002] The combustion chamber of an aircraft engine is a device where high-pressure gas and fuel are mixed and burned. The flame tube, as the main component of the combustion chamber, is in such a high-temperature environment for a long time and the working conditions are very harsh. In order to make it suitable for such working conditions, a large number of cooling holes are usually processed by laser on the wall of the cylinder for ventilation cooling, so as to delay the failure of the parts. In recent years, in order to further extend its service life, a ceramic coating such as zirconium oxide with a thickness of 0.3-0.8mm is applied on the surface of the cylinder wall. In this way, the higher melting point of ceramic materials compared to high-temperature alloys is utilized, so that the flame tube can continue to work in an environment as high as 1200°C. In addition, the shape of the cooling hole has also evolved from the original cylindrical hole type to a special-shaped hole type such as a "Y" shape, which can improve the distribution of the airflow field and achieve the purpose of enhancing the cooling effect.

[0003] In view of the processing characteristics of this type of cooling hole, long pulse laser can be used to punch out cylindrical holes and ultra-short pulse laser can be used to fine-tune the special-shaped structural parts to obtain efficient and high-quality processing results. However, after the material is coated with a ceramic layer, long pulse laser punching brings new challenges. The traditional laser drilling method is likely to damage the ceramic layer. Summary of the invention

[0004] In view of this, it is necessary to provide a laser punching device and method that is not likely to cause damage to the ceramic layer.

[0005] A laser punching device comprises a light source module, an optical path transmission module, a laser modulation module, a focusing module and a control module;

[0006] The light source module is used to emit a first laser;

[0007] The optical path transmission module, the laser modulation module and the focusing module are sequentially arranged along the optical path;

[0008] The laser modulation module comprises a beam splitter and a shaper, wherein the beam splitter can move in and out of the optical path, and the shaper can move in and out of the optical path, wherein the beam splitter is used to split the first laser into at least two beams of second lasers, and the shaper is used to shape the first laser so that the edge energy of the light spot at the focus of the first laser is higher than the central energy;

[0009] The light source module, the beam splitter and the shaper are all connected to the control module, the control module is used to control the parameters of the laser emitted by the light source module, the control module is used to control the beam splitter to enter and exit the light path, and the control module is used to control the shaper to enter and exit the light path;

[0010] The focusing module is used to focus the first laser and the second laser onto the surface of the substrate.

[0011] In one embodiment, the beam splitter is used to split the laser into 10-40 laser beams.

[0012] In one embodiment, a hole type monitoring module is further included, and the hole type monitoring module is used to monitor the hole type of the punching hole on the substrate.

[0013] In one embodiment, the hole pattern monitoring module includes an X-ray tube and a detector, which are respectively distributed on both sides of the substrate. During the punching process, the X-ray tube emits X-rays, which pass through the punched holes on the substrate. The detector receives the X-rays and displays the hole pattern of the punched holes on the substrate.

[0014] In one embodiment, a fluid injection module is further included, wherein the fluid injection module includes a fluid injection tube, wherein the fluid injection tube is arranged facing the punching position of the substrate, and the fluid injection module is used to inject liquid nitrogen to cool the surface of the substrate.

[0015] In one embodiment, the fluid injection module is further used to inject gas, and the gas is used to remove debris formed during the punching process of the substrate.

[0016] A laser punching method comprises the following steps:

[0017] A crack network is formed on the coating surface of the substrate using a laser;

[0018] Using laser shock to form an initial hole in the area where the crack network is formed on the substrate, the diameter of the initial hole is smaller than the diameter of the target hole;

[0019] Laser is continuously used to expand the hole in the area of ​​the substrate where the initial hole is formed, until a target hole with a desired hole diameter is obtained.

[0020] In one embodiment, the step of using laser to form a crack network on the coating surface of the substrate is: splitting a first laser into two or more second laser beams, modulating the single pulse energy of the focus of the second laser to be 0.05-1J, focusing the second laser on the surface of the substrate, so that the coating on the surface of the substrate forms a crack network under the impact of the second laser;

[0021] The step of using laser shock to form an initial hole in the area where the crack network is formed on the substrate is as follows: adjusting the single pulse energy of the first laser to 10-50J, and using the first laser shock to form the initial hole in the area where the crack network is formed on the substrate;

[0022] The step of continuing to use laser to expand the hole in the area where the initial hole is formed on the substrate is as follows: shaping the first laser so that the edge energy of the light spot at the focus of the first laser is higher than the middle energy, adjusting the single pulse energy of the first laser to 20-50J to control the peak energy of the edge of the light spot to be above the damage threshold of the substrate, using the shaped first laser to expand the initial hole, and impacting to form the target hole on the basis of the initial hole, wherein the aperture of the target hole is larger than the aperture of the initial hole.

[0023] In one embodiment, the first laser is divided into 10-40 second lasers, and the second lasers are focused by a focusing mirror to form a circular array including 10-40 focal points.

[0024] In one embodiment, the peak power of the second laser is 1-3 KW, and the number of pulses is 1-3.

[0025] In one embodiment, in the step of using the first laser to shock and form initial holes in the area where the crack network is formed on the substrate, the peak power of the first laser is 10-50 KW, and the number of pulses is 3-10.

[0026] In one embodiment, in the step of shaping the first laser so that the edge energy of the light spot at the focus of the first laser is higher than the middle energy, the light spot at the focus of the first laser is an M-shaped light spot.

[0027] In one embodiment, the initial hole is expanded using the shaped first laser, and in the step of impact-forming the target hole on the basis of the initial hole, the diameter of the focus of the shaped first laser is equal to the diameter of the target hole.

[0028] In one embodiment, the initial hole is expanded using the first laser after shaping, and the step of impact-forming the target hole on the basis of the initial hole also includes the step of monitoring the hole shape of the target hole during the process of forming the target hole on the substrate. When the aperture size of the target hole reaches a preset aperture size, punching is stopped; when the aperture size of the target hole is smaller than the preset aperture size, punching is continued until the aperture size of the target hole is equal to the preset aperture size.

[0029] In one embodiment, the initial hole is expanded using the shaped first laser, and the step of impact-forming the target hole on the basis of the initial hole also includes blowing air to the punching location of the substrate to remove debris.

[0030] In one embodiment, before the step of forming a crack network on the coating surface of the substrate using a laser, the step further includes spraying liquid nitrogen on the coating area on the surface of the substrate.

[0031] The above-mentioned laser punching device first uses a beam splitter to split the first laser emitted by the light source module into multiple beams of second lasers, which can reduce the energy of the laser and create a crack network on the coating surface of the substrate to release the thermal stress of subsequent punching and prevent the coating from cracking and peeling. Next, the beam splitter is removed to increase the energy of the laser, and laser punching can be used to form an initial hole with a smaller diameter, so as to achieve rapid heat dissipation and smooth slag removal during subsequent hole expansion. Finally, a shaper is used to shape the laser into a laser with high energy in the middle and low energy at the edge, so that the initial hole can be expanded to achieve a target hole of the required size on the substrate. Therefore, the above-mentioned laser punching device can solve the problem that the coating material of the substrate is prone to cracking, warping or even peeling during punching, and causes little damage to the coating on the substrate.

[0032] The above laser punching method uses a long pulse laser to punch holes in three steps. First, a crack network is created on the coating surface to release the thermal stress of subsequent punching and prevent the coating from cracking and peeling. Then, laser punching is used to form an initial hole with a smaller diameter, which can achieve rapid heat dissipation and smooth slag removal during subsequent hole expansion. Finally, laser is used to gradually expand the hole to achieve the required size. Therefore, the above laser punching method can reduce damage to the substrate coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic structural diagram of a laser punching device according to one embodiment;

[0034] Figure 2 A schematic diagram of a structure in which a crack network is formed on a coating of a substrate using a laser;

[0035] Figure 3 A schematic diagram of the structure of forming initial holes on a substrate using a laser;

[0036] Figure 4 Schematic diagram of the structure of forming a target hole on a substrate using a laser. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. The fixed connection mentioned in the present invention includes direct fixed connection and indirect fixation.

[0038] Please refer to Figure 1 A laser punching device according to one embodiment includes a light source module, an optical path transmission module, a laser modulation module, a focusing module and a control module.

[0039] The light source module is a laser 1. The laser 1 is used to emit a first laser.

[0040] The optical path transmission module, the laser modulation module and the focusing module are arranged in sequence along the optical path.

[0041] The laser modulation module includes a beam splitter 3 and a shaper 4. The beam splitter 3 can move in and out of the optical path, and the shaper 4 can move in and out of the optical path. The beam splitter 3 is used to split the first laser into at least two beams of second lasers, and the shaper 4 is used to shape the first laser so that the edge energy of the light spot at the focus of the first laser is higher than the central energy.

[0042] The light source module, beam splitter 3 and shaper 4 are all connected to the control module, which is used to control the light source module to emit laser, control the beam splitter 3 to enter and exit the light path, and control the shaper 4 to enter and exit the light path.

[0043] The focusing module is used to focus the first laser and the second laser onto the surface of the substrate 11. That is, the first laser is focused onto the surface of the substrate 11 through the focusing module, and the second laser is also focused onto the surface of the substrate 11 through the focusing module.

[0044] In the above-mentioned laser punching device, the light source module emits a first laser and transmits it through the optical path transmission module. The beam splitter 3 controlled by the control module enters the optical path. The beam splitter 3 splits the first laser into at least two second lasers. The second laser is focused on the surface of the substrate 11 through the focusing module to form a crack network on the coating of the substrate 11. Next, the beam splitter 3 is moved out of the optical path, the energy of the first laser is adjusted, and the first laser is focused on the area where the crack network is formed on the substrate 11 through the focusing module, and the initial hole is formed by impact in the area where the crack network is formed on the substrate 11. Then, the shaper 4 is moved into the optical path, the first laser passes through the shaper 4, and the shaper 4 adjusts the edge energy of the light spot at the focus of the first laser to be higher than the center energy. The first laser expands the hole in the area where the initial hole is formed on the substrate 11 until a target hole with a desired aperture is formed.

[0045] The above-mentioned laser punching device first uses a beam splitter 3 to split the first laser emitted by the light source module into multiple beams of second lasers, which can reduce the energy of the laser and create a crack network on the coating surface of the substrate 11 to release the thermal stress of subsequent punching and prevent the coating from cracking and peeling. Next, the beam splitter 3 is removed to increase the energy of the laser, and laser punching can be used to form an initial hole with a smaller diameter, so as to achieve rapid heat dissipation and smooth slag removal during subsequent hole expansion. Finally, the shaper 4 is used to shape the laser into a laser with low energy in the center area and high energy in the edge area, so that the initial hole can be expanded to achieve a target hole of the required size on the substrate 11. Therefore, the above-mentioned laser punching device can solve the problem that the coating material of the substrate 11 is easy to crack, warp or even peel off during punching, as well as the problem that the aperture size is difficult to control and the inner wall quality is poor, so as to facilitate the subsequent hole repairing process and finally obtain a suitable cooling hole. By adopting the above-mentioned laser punching device, it has the advantages of good coating quality after punching, high aperture consistency, high inner wall finish, and fast processing efficiency, and lays a good foundation for the subsequent hole repairing process.

[0046] It can be understood that the coating of the substrate 11 can be a ceramic coating.

[0047] In one embodiment, the laser 1 is a long pulse laser for providing high-energy laser pulses, with a first laser pulse width of 0.2-50 ms, a maximum single pulse energy of 10-50 J, and a maximum single pulse peak power of 10-50 KW.

[0048] The optical transmission module is used to transmit the first laser from the light source module to the laser modulation module. In one embodiment, the optical transmission module includes a reflector 2, an aperture and a collimating beam expander arranged in sequence along the optical path. The optical transmission module may also include other optical elements.

[0049] The laser modulation module is used to shape and modulate Gaussian light.

[0050] The beam splitter 3 can select appropriate specifications according to the needs to split the first laser into several beams, and multiple focal points can be formed after focusing. Specifically, the beam splitter 3 is used to split the first laser into 10-40 second laser beams. After the first laser beam passes through the beam splitter 3, multiple second laser beams are formed, and then focused into a circular array including multiple focal points through the focusing module. The number of focal points is 10-40, and the array area is Φ0.4-Φ0.7mm.

[0051] In one embodiment, the shaper 4 may shape the Gaussian light into an M-shaped light mode with high edge energy and low center energy.

[0052] In one embodiment, two diffractive optical elements, the beam splitter 3 and the shaper 4, are respectively mounted on the guide rail 5. The beam splitter 3 and the shaper 4 can be respectively controlled to move on the guide rail 5 by a motor, so that the beam splitter 3 and the shaper 4 can be respectively moved in and out of the optical path, thereby determining the laser mode acting on the substrate 11. It can be understood that the beam splitter 3 and the shaper 4 can also enter or move out of the optical path in other ways.

[0053] In one embodiment, the focusing module includes a focusing lens 6 with a focal length f of 100-250 mm.

[0054] In one embodiment, the laser punching device further includes a hole type monitoring module, which is used to monitor the hole type of the punched hole on the substrate 11. The hole type includes hole taper and hole size.

[0055] Furthermore, the hole profile monitoring module includes an X-ray tube 7 and a detector 8, which are respectively distributed on both sides of the substrate 11. During the punching process, the X-ray tube 7 emits X-rays, which pass through the substrate 11, and the detector 8 receives the signal and displays the hole profile of the punching on the substrate 11. The hole profile monitoring module can also monitor the punching hole profile, such as hole taper and hole size, in real time.

[0056] In one embodiment, the laser punching device further includes a fluid injection module, and the fluid injection module includes a fluid injection tube 9. The fluid injection tube 9 of the fluid injection module is arranged facing the punching position of the substrate 11, and the fluid injection module is used to spray liquid nitrogen to cool the surface of the substrate 11. The fluid injection module is used to spray liquid nitrogen to quickly cool the substrate 11, so that the low-temperature brittleness of the material can be achieved.

[0057] Furthermore, during the punching process, the fluid injection module can also be connected to a gas source, and the gas source is connected to the fluid injection tube. The fluid injection module is also used to inject gas, and the gas is used to remove debris formed during the punching process of the substrate 11. The gas can be compressed air or an inert gas such as argon.

[0058] In one embodiment, the control module is an industrial computer 10. The control module can be used to adjust the parameters of the laser emitted by the light source module. The laser parameters include the pulse width of the laser, the maximum single pulse energy, the highest single pulse peak power, etc. The control module is used to switch the position of the beam splitter 3 and the shaper 4 in the laser modulation module. The control module is also used to adjust the laser parameters in real time according to the hole type monitoring results in the hole type monitoring module.

[0059] In addition, a laser punching method is provided, comprising the following steps:

[0060] S10, forming a crack network on the coating surface of the substrate 11 by using laser.

[0061] S20, forming an initial hole in the area of ​​the substrate 11 where the crack network is formed by laser shock, wherein the diameter of the initial hole is smaller than the diameter of the target hole.

[0062] S30, continuing to use laser to expand the hole in the area where the initial hole is formed on the substrate 11 until a target hole with a desired hole diameter is obtained.

[0063] In the traditional punching method of the coated substrate 11, after a long pulse laser with high single pulse energy is used to act on the surface of the coated workpiece, the material is removed by heat melting. Therefore, there is a lot of thermal stress in the processing process, which makes the ceramic coating prone to cracking, warping and even peeling, thereby losing the desired effect of the coating. If the single pulse energy is reduced for punching, it is difficult to quickly punch through the material, or the aperture is too small. If multiple low-energy pulses are used repeatedly during the punching process, the heat of multiple pulses accumulates over a long period of time, and the material temperature will also rise sharply, causing the coating to be damaged by thermal stress similar to that during high-energy punching. In addition, the aperture size consistency of long-pulse laser punching is poor, slag and recast layer remain on the inner wall, and the finish is poor, which hinders the improvement of subsequent hole repair accuracy.

[0064] In the laser punching method of the present invention, a long pulse laser is used to punch holes in three steps. First, a crack network is created on the coating surface to release the thermal stress of subsequent punching and prevent the coating from cracking and peeling. Then, laser punching is used to form an initial hole with a smaller diameter, which can achieve rapid heat dissipation and smooth slag removal during subsequent hole expansion. Finally, laser is used to gradually expand the hole to achieve the required size. Therefore, the above laser punching method can reduce damage to the substrate coating.

[0065] In the laser punching method of the present invention, the laser energy is relatively small when the crack network is formed. The laser energy is relatively large when the initial hole is formed by impact. The laser energy is relatively small when the target hole is formed by hole expansion. That is, the energy when the initial hole is formed by impact is greater than the energy when the crack network and the target hole are formed.

[0066] In one embodiment, the step of S10 is: splitting the first laser into two or more second laser beams, and modulating the single pulse energy of the focus of the second laser to 0.05-1J, focusing the second laser on the surface of the substrate 11, so that the coating on the surface of the substrate 11 forms a crack network under the impact of the second laser.

[0067] Specifically, the first laser is divided into 10-40 beams of second laser, and the second laser is focused by the focusing mirror 6 to form a circular array including 10-40 focal points.

[0068] The peak power of the second laser is 1-3KW, and the number of pulses is 1-3.

[0069] In S20, Gaussian light with high center energy and low edge energy is used to punch the initial hole. The single pulse energy is high to achieve rapid penetration of the coated substrate 11. The diameter of the initial hole is slightly smaller than the area of ​​the microcrack network.

[0070] The step of S20 is: adjusting the single pulse energy of the first laser to 10-50 J, and using the first laser to shock and form an initial hole in the area where the crack network is formed on the substrate 11.

[0071] In one embodiment, in S20, the peak power of the first laser is 10-50 KW, and the number of pulses is 3-10.

[0072] In one embodiment, before step S20, the process further includes spraying liquid nitrogen on the surface coating area of ​​the substrate 11. Specifically, the liquid nitrogen spraying time is about 2-10 seconds. The liquid nitrogen spraying process can rapidly cool the surface of the substrate 11, and increase the brittleness of the ceramic coating material through low temperature treatment, so as to facilitate the formation of microcracks by laser shock.

[0073] In S30, a focused light spot with low energy in the central area and high energy in the edge area is obtained by the shaper 4, and the energy density in the edge area is low, which will not cause cracking, warping or peeling of the coating, but is higher than the material damage threshold to achieve low-energy continuous hole expansion processing.

[0074] In one embodiment, the step of S30 is: shaping the first laser so that the edge energy of the light spot at the focus of the first laser is higher than the middle energy, adjusting the single pulse energy of the first laser to 20-50J to control the peak energy of the edge of the light spot to be above the damage threshold of the substrate 11, using the shaped first laser to expand the initial hole, and impacting to form a target hole on the basis of the initial hole, and the aperture of the target hole is larger than the aperture of the initial hole.

[0075] In one embodiment, in S30, in the step of shaping the first laser so that the edge energy of the light spot at the focus of the first laser is higher than the middle energy, the light spot at the focus of the first laser after shaping is an M-shaped light spot.

[0076] The shaped first laser is used to impact the area of ​​the substrate 11 with the initial hole. In the step of impacting and forming the target hole on the basis of the initial hole, the diameter of the focus of the shaped first laser is equal to the diameter of the target hole.

[0077] The first laser after shaping is used to impact the area of ​​the substrate 11 with the initial hole. The step of impacting to form the target hole on the basis of the initial hole also includes monitoring the hole shape of the target hole in the process of forming the target hole on the substrate 11. When the aperture size of the target hole reaches a preset aperture size, the punching is stopped; when the aperture size of the target hole is smaller than the preset aperture size, the punching is continued until the aperture size of the target hole is equal to the preset aperture size.

[0078] The hole type monitoring module can be used for hole type monitoring. X-rays are used to monitor the punching hole type online, and the number of punching pulses is automatically controlled by judging the hole size. When the punching hole size meets the requirements, the processing is automatically stopped.

[0079] The shaped first laser is used to impact the area of ​​the substrate 11 where the initial hole is formed. The step of impacting and forming the target hole on the basis of the initial hole also includes the operation of blowing air to the punching area of ​​the substrate 11 to remove debris.

[0080] In the above laser punching method, different laser modes and parameters can be modulated by the control module to perform laser processing at different stages.

[0081] The above laser punching method can be used Figure 1 The laser punching device shown punches holes in the coated substrate 11. The specific operation is as follows:

[0082] (1) The surface coating area to be processed is treated with liquid nitrogen spray through the fluid injection tube 9 for about 5-6 seconds to quickly cool the surface and increase the low-temperature brittleness of the ceramic coating.

[0083] (2) The beam splitter 3 in the laser modulation module is brought into the optical path through the control module. After the light beam passes through the beam splitter 3, a multi-beam second laser is formed, which is then focused into a circular array including multiple focal points through the focusing lens 6. The number of focal points is 10-40 and the array area is Φ0.4-Φ0.7mm. The laser parameters are modulated so that the energy of the second laser single pulse at each focal point is 0.05-1J, the peak power is 1-3KW, and the number of pulses is 1-3. When it acts on the low-temperature ceramic surface, the coating is destroyed. Due to the low pulse energy, each focal point only destroys the material in the nearby area and forms a microcrack network between each focal point. The area of ​​the microcrack network is slightly larger than the area of ​​the focal array.

[0084] (3) The beam splitter 3 is moved out of the optical path through the control module, and the light beam is restored to a single beam state, and is Gaussian light. The laser parameters are adjusted to punch holes on the coated material, with a single pulse energy of 10-50J, a peak power of 10-50KW, and a pulse number of 3-10. At the same time, slag is removed by blowing compressed air or other gases such as argon, with an air pressure of 0.3-0.5MPa, and the punched hole size is about Φ0.2-0.5mm, which is smaller than the area of ​​the microcrack network in the previous step. At this time, punching will produce strong thermal stress, but due to the presence of the microcrack network on the coating surface, the thermal stress is released, thereby effectively preventing abnormal phenomena such as cracking, warping and peeling of the coating. Through this initial hole processing, slag removal is smoother and heat dissipation is faster during further punching, thereby improving the quality of hole wall processing.

[0085] (4) The shaper 4 is transferred to the optical path through the control module so that the light spot at the focus is shaped into an M-shaped light mode with high energy at the edge and low energy in the middle. The spot size is approximately equal to the final required punching aperture size, with a diameter of 0.5-1mm. Since the peak energy of the edge area of ​​the M-shaped light is smaller than that of the Gaussian light after the Gaussian light is shaped into M-shaped light, its processing capacity is relatively low. The entire laser pulse energy is appropriately adjusted to 20-50J to control the peak energy of the edge area of ​​the M-shaped light to be above the material damage threshold, and then the heat is dissipated by blowing air, so that the material can be removed without causing damage such as coating delamination, warping and peeling caused by heat accumulation, thereby realizing hole expansion processing.

[0086] (5) When using M-shaped light for hole expansion, the hole type monitoring module is turned on to monitor the hole type. When the hole diameter reaches the required size, the punching is stopped. Otherwise, the control module is used to make the laser 1 continue to emit pulsed laser to expand the hole diameter until the monitored hole diameter meets the requirement, at which time the processing is automatically terminated.

[0087] Example 1

[0088] like Figure 1 As shown, a laser punching device includes a laser 1, a reflector 2, a beam splitter 3, a shaper 4, a guide rail 5, a focusing mirror 6, an X-ray tube 7, an X-ray detector 8, a fluid injection tube 9, an industrial computer 10 and a coated material sample 11.

[0089] The laser 1 is a long pulse width laser, which is used to provide high energy pulse laser 12, with a pulse width of 0.2-10ms, a maximum single pulse energy of 50J, and a maximum peak power of 20KW.

[0090] The reflector 2 is used to transmit the laser.

[0091] The beam splitter 3 and the shaper 4 are diffractive optical elements, which are respectively mounted on the guide rail 5. They are moved in and out of the optical path by motor control, thereby determining the laser mode acting on the material. The beam splitter 3 can split the light beam into 10 beams, which are focused into a focal array by the focusing mirror 6, and the shaper 4 can shape the Gaussian light into an M-shaped light with high edge energy and low center energy.

[0092] The focal length of the focusing lens 6 is f=150 mm.

[0093] The X-ray tube 7 and the X-ray detector 8 are respectively distributed on both sides of the processing object. During the punching process, the X-ray tube 7 emits X-rays and passes through the coated substrate, and the X-ray detector 8 receives the signal, so that the aperture can be monitored.

[0094] The fluid injection tube 9 can perform injection operations of two fluids, liquid nitrogen and compressed air, by switching.

[0095] The industrial computer 10 is used to switch the positions of different diffractive optical elements in the laser modulation module, and to adjust the laser parameters in real time according to the hole shape monitoring result in the hole shape monitoring module.

[0096] Example 2

[0097] A laser punching method comprises the following steps.

[0098] (1) The surface coating area to be processed is treated with liquid nitrogen spray through the fluid injection tube 9 for about 5-6 seconds to quickly cool the surface and increase the low-temperature brittleness of the ceramic coating.

[0099] (2) The beam splitter 3 is placed in the optical path through the industrial computer 10, such as Figure 2 As shown, the light beam forms 19 laser beams after passing through the beam splitter, and then is focused by the focusing mirror to form a multi-focus circular array 13, the number of focuses is also 19, and the array area is about Φ0.5mm. The laser parameters are modulated so that the laser single pulse energy of each focus is 0.2J, the peak power is 1.2KW, and the number of pulses is 2. When it acts on the low-temperature ceramic coating 14, the coating is destroyed and a micro-crack network 15 is formed between each focus.

[0100] (3) After the microcrack network 15 is formed in the ceramic coating 14, Figure 3 As shown, the beam splitter 3 is moved out of the light path through the industrial computer 10, and the laser 12 is restored to a single beam state, and is Gaussian light. The laser parameters are adjusted to punch holes on the coated material. The single pulse energy is 8J, the peak power is 10KW, and the number of pulses is 5. At the same time, slag is removed by blowing compressed air with an air pressure of 0.4MPa. The punched hole size is about Φ0.35mm, and the coating does not show abnormal phenomena such as cracking and peeling.

[0101] (4) Figure 4 As shown, the shaper 4 is transferred to the optical path through the industrial computer 10, so that the laser 12 is shaped into an M-shaped light mode with high edge energy and low middle energy, and the spot diameter is about Φ0.7mm. The laser pulse energy is adjusted again to 20J and the peak power is 15KW, and punching is performed pulse by pulse to expand the aperture.

[0102] (5) When M-shaped light is used for hole expansion, the hole shape is monitored by the cooperation of the X-ray tube 7 and the X-ray detector 8. When the hole diameter reaches the required size, the punching is stopped. Otherwise, the industrial computer 10 controls the laser to continue emitting pulsed laser 12 to expand the hole diameter until the monitored hole diameter meets the requirement, at which point the processing is automatically terminated.

[0103] The above laser punching device and laser punching method solve the problem that the coating material of the substrate is prone to cracking, warping or even peeling during punching, as well as the problem that the aperture size is difficult to control and the inner wall quality is poor, so as to facilitate the subsequent hole repair process and finally obtain a suitable cooling hole. By adopting the above laser punching device and laser punching method, the advantages of good coating quality after punching, high aperture consistency, high inner wall finish, high processing efficiency, etc. are achieved, and a good foundation is laid for the subsequent hole repair process.

[0104] The above are only preferred embodiments of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A laser punching method, characterized in that: The following steps are involved: A crack network is formed on the coating surface of the substrate using a laser; Using laser shock to form an initial hole in the area where the crack network is formed on the substrate, the diameter of the initial hole is smaller than the diameter of the target hole; Continue to use laser to expand the hole in the area where the initial hole is formed on the substrate until a target hole with a desired hole diameter is obtained; The steps of using laser to form a crack network on the coating surface of the substrate are: dividing a first laser into two or more second laser beams, modulating the single pulse energy of the focus of the second laser to be 0.05-1J, focusing the second laser on the surface of the substrate, so that the coating on the surface of the substrate forms a crack network under the impact of the second laser; The step of using laser shock to form an initial hole in the area where the crack network is formed on the substrate is as follows: adjusting the single pulse energy of the first laser to 10-50J, and using the first laser shock to form the initial hole in the area where the crack network is formed on the substrate; The step of continuing to use laser to expand the hole in the area where the initial hole is formed on the substrate is as follows: shaping the first laser so that the edge energy of the light spot at the focus of the first laser is higher than the middle energy, adjusting the single pulse energy of the first laser to 20-50J to control the peak energy of the edge of the light spot to be above the damage threshold of the substrate, using the shaped first laser to expand the initial hole, and impacting to form the target hole on the basis of the initial hole, wherein the aperture of the target hole is larger than the aperture of the initial hole.

2. The laser punching method according to claim 1, characterized in that: The first laser is divided into 10-40 second lasers, and the second lasers are focused by a focusing mirror to form a circular array including 10-40 focal points.

3. The laser punching method according to claim 1, characterized in that: The peak power of the second laser is 1-3 kW, and the number of pulses is 1-3.

4. The laser punching method according to claim 1, characterized in that: In the step of using the first laser to shock and form initial holes in the area where the crack network is formed on the substrate, the peak power of the first laser is 10-50 kW, and the number of pulses is 3-10.

5. The laser punching method according to claim 1, characterized in that: In the step of shaping the first laser so that the edge energy of the light spot at the focus of the first laser is higher than the middle energy, the light spot at the focus of the first laser is an M-shaped light spot.

6. The laser punching method according to claim 1, characterized in that: The initial hole is expanded by using the shaped first laser, and in the step of impact-forming the target hole on the basis of the initial hole, the diameter of the focus of the shaped first laser is equal to the diameter of the target hole.

7. The laser punching method according to claim 1, characterized in that: The initial hole is expanded using the first laser after shaping, and the step of impacting and forming the target hole on the basis of the initial hole also includes the step of monitoring the hole shape of the target hole during the process of forming the target hole on the substrate. When the aperture size of the target hole reaches a preset aperture size, punching is stopped; when the aperture size of the target hole is smaller than the preset aperture size, punching is continued until the aperture size of the target hole is equal to the preset aperture size.

8. The laser punching method according to claim 1, characterized in that: The initial hole is expanded by using the first laser after shaping, and the step of impacting and forming the target hole on the basis of the initial hole also includes the operation of blowing air to the punching location of the substrate to remove debris.

9. The laser punching method according to claim 1, characterized in that: Before the step of forming a crack network on the coating surface of the substrate by using a laser, the method further includes spraying liquid nitrogen on the coating area on the surface of the substrate.

Images