CN114055322B - KDP surface microdefect profiling deliquescence repair device and method - Google Patents

Abstract

The invention provides a KDP surface micro-defect profiling deliquescence repairing device and a repairing method, including a machine vision system, a profiling polishing head, a connection structure, a negative pressure device, a micro water mist channel, a micro cold plasma channel, and a negative pressure hole and KDP crystals to be repaired with surface micro-defects. The invention adopts a profiling polishing head, combined with precise identification and positioning of micro-defects on the surface of KDP, and super-hydrophilic modification of micro-cold plasma, so as to realize micro-defect profiling and deliquescence polishing repair. The beneficial effects of the invention are as follows: the water medium can be spread evenly between the profiling polishing head and the area to be repaired, the deliquescence rate and area are controllable, the introduction of new defects in the repair process is avoided, and ideal Spherical or Gaussian surface.

Description

A kind of KDP surface micro-defect profiling deliquescence repair device and repair method

【Technical field】

The invention relates to the technical field of ultra-precision machining of easily deliquescent KDP surfaces, in particular to a KDP surface micro-defect profiling deliquescence repairing device and a repairing method.

【Background technique】

KDP is currently the only nonlinear optical material that can be used for laser frequency doubling, electro-optic modulation and opto-electronic switching devices in high-energy laser circuits. Because KDP is soft and brittle, easy to deliquescence, and extremely sensitive to processing temperature, it is very easy to produce surface micro-defects during processing and service, and significantly reduce its optical performance and service life, eventually leading to KDP scrap. The current methods and existing problems of KDP micro-defect removal: 1) The surface defects of KDP are repaired by CO ₂ laser melting, femtosecond pulsed laser ablation, and micromachining. The results show that micromachining has good controllability, The advantages of better performance stability, but lead to regular knife marks and large roughness of KDP; 2) The solvent-mediated method based on AFM probe repairs the surface damage of KDP, and the light intensity inside the repaired crystal is close to Ideal surface, but can only repair micro-defects below the micron level, the efficiency is low, and cannot be applied in engineering; 3) The micro-defects on the surface of KDP are etched by a dip pen, this method can avoid introducing defects such as knife marks and sub-surface damage, but the deliquescence surface There are small-scale ripples, which will reduce the laser damage threshold, and the deliquescence area is uncontrollable, making it impossible to obtain an ideal spherical or Gaussian surface.

At present, although micromechanical repair has basically met the actual needs, defects such as tool marks, thermal stress, and subsurface damage will still occur during the repair, and the surface quality of the repaired area is far from that before the damage. Due to the essential characteristics of machining, the above problems cannot be completely solved even if the process is optimized and the equipment accuracy is improved. Therefore, new high-quality, high-efficiency and low-damage repair processes must be explored. The easy deliquescence of KDP crystals provides a new idea for the realization of high-quality repair of micro-defects, but the problems of small-scale ripples on the deliquescence surface, low efficiency, and uncontrollable deliquescence area make this process unable to obtain an ideal repair surface.

[Content of the invention]

The purpose of the present invention is to disclose a KDP surface micro-defect profiling deliquescence repair device and repair method, which can solve the technical problems of small-scale ripples on the deliquescence surface, low efficiency, and uncontrollable deliquescence area.

For achieving the above object, the technical scheme of the present invention is:

A KDP surface micro-defect profiling deliquescence repairing device, comprising a profiling polishing head 8 and a machine vision system 7; the middle of the profiling polishing head 8 is formed with a micro water mist channel 5 and a micro cold plasma channel 6, and the profiling polishing A number of negative pressure holes 4 are formed on the outer periphery of the head 8; the negative pressure holes 4 are connected with a negative pressure device 3;

The machine vision system 7 is used to identify and locate micro-defects on the surface of the KDP crystal 1;

The micro-cold plasma channel 6 is used for introducing micro-cold plasma to super-hydrophilically modify the micro-defects of the KDP crystal 1;

The micro-water mist channel 5 is used for introducing micro-water mist to deliquescence the micro-defects on the surface of the KDP crystal 1 after super-hydrophilic modification; the negative pressure hole 4 is used to form negative pressure to limit the micro-cold plasma and micro-water Fog spread area.

As a further improvement, the machine vision system 7 is also used to determine the shape and size of the selected copy polishing head 8 and the negative pressure value of each negative pressure hole 4 according to the shape of the micro-defects on the surface of the KDP crystal 1 .

As a further improvement, the profiling polishing head 8 is installed on the machine tool through the connecting structure 2 .

A further improvement, the micro-defects on the surface of the KDP crystal 1 include micro-pits, bumps, cracks, scratches, cracks and burns.

Further improvement, the machine vision system 7 collects the micro-defect pattern on the surface of the KDP crystal 1 as training data, and uses a deep learning method to construct a micro-defect recognition model; then the collected KDP surface image with micro-defects to be repaired is compared with Comparing the training data, constructing the micro-defect category, scale, and the mapping relationship between the profiling polishing head and the repair contour, assisting in the decision-making of the shape and aspect ratio of the profiling polishing head, and realizing the identification and positioning of micro-defects and profiling polishing The selection of the head; during the repair, after the precise tool setting is achieved, the micro water mist and the micro cold plasma enter the profiling polishing head corresponding to the repair contour through the micro water mist channel and the micro cold plasma channel, and then The micro-defects delivered to the KDP crystal 1 are repaired at the interface to be repaired.

For further improvement, the method for obtaining the mapping relationship is as follows: first, the machine vision system 7 obtains the shape and outline of the micro-defect on the surface of the KDP to be repaired, and determines the type of the micro-defect; Design a series of profiling polishing heads with the aspect ratio as the division requirement for different defect types; after determining the micro-defect type, the machine vision system is fitted to obtain the minimum circumscribed circle of the micro-defect shape and outline, and finally, the micro-defect type and the to-be-repaired are integrated. The size of the circumcircle of the area is selected from the spherical and Gaussian curved surface copy polishing head of the same specification, so as to minimize the repair area of the KDP crystal.

Further improvement, when the aspect ratio of the micro-defects on the KDP surface to be repaired is between 5 and 10, the spherical profiling polishing head is selected; when the aspect ratio of the micro-defects on the KDP surface to be repaired is greater than 10, the Gaussian profiling is selected. Polishing head; the parameters of the Gaussian profiling polishing head include maximum diameter, median diameter and arc diameter, and the size of the micro-defects on the surface of the KDP to be repaired ranges from 10 μm to 2 mm.

Further improvement, the micro-cold plasma channel 6 is connected with a micro-cold plasma supply device; the micro-water mist channel 5 is connected with a micro-water mist supply device; After real-time super-hydrophilic modification with the profiling polishing head, the micro-defect interface after super-hydrophilic modification adsorbs micro water mist to realize profiling deliquescence; The gap between the workpieces can adjust the moisture content to control the deliquescence rate, and through the negative pressure device, the trace moisture is limited in the profiling deliquescence area to achieve controllable profiling deliquescence.

A method for repairing micro-defect profiling and deliquescence on the surface of KDP, comprising the following steps:

Step 1. The KDP crystal 1 containing surface micro-defects to be repaired is fixed on the machine tool after cleaning, wiping and other pretreatments;

Step 2. Install the profiling polishing head 8 on the machine tool through the connection structure 2, start the machine vision system 7, accurately identify and locate the micro-defects on the surface of the KDP, and provide auxiliary decision-making for the selection of the profiling polishing head according to the defect type , to achieve precise tool setting by the machine tool;

Step 3, start the negative pressure device 3, limit the spreading area of the fine cold plasma and the tiny water mist, limit the tiny water mist to the area to be repaired, and absorb the diffused fine cold plasma and the tiny water mist through negative pressure;

Step 4: injecting the micro-cold plasma into the micro-cold plasma channel 6; injecting the micro-water mist generated by the micro-water mist supply device into the micro-water mist channel 5;

Step 5. Start the machine tool, and perform profiling, deliquescence, polishing and repair on the surface of the KDP to be repaired until the repair process is completed.

Step 6: Turn off all the devices, take out the KDP crystal after the micro-defect repair is completed, and place it in a dry and dust-free area after the gas jet drying and post-processing.

Further improvement, the fine cold plasma is generated by the working gas with the help of a low pressure plasma power source; the working gas includes N ₂ , He and Ar; the low pressure plasma power source is controlled to generate fine cold plasma with a diameter of 1-500 μm, and the profiling polishing head is Real-time modification between micro-defects on KDP surface and superhydrophilic surface.

In the present invention, after the super-hydrophilic modification of the micro-defects on the KDP surface is carried out by the use of micro-cold plasma, the super-hydrophilic interface absorbs the micro-water mist to achieve profile deliquescence; by controlling the supply flow of the micro-water mist and the profile polishing head The gap between the workpiece and the workpiece can be adjusted to adjust the water content, accurately control the deliquescence rate, and turn on the negative pressure device to limit the trace moisture in the profiling deliquescence area to achieve controllable profiling deliquescence.

The beneficial effects of the present invention are as follows: the positioning of micro-defects on the KDP surface scale from micrometers to millimeters and the tool setting of the profiling polishing head are realized through a machine vision system, and the collected images are processed by the method of deep learning to realize accurate identification of micro-defects, The selection of profiling polishing head is assisted in decision-making according to the category and scale of micro-defects. At the same time, using the principle of super-hydrophilic modification of micro-cold plasma, after precise tool setting, the profiling polishing head is aimed at the surface micro-defects of KDP, and the micro-defect area is profiled and super-hydrophilic modified by micro-cold plasma. The injected micro water mist spreads evenly between the profiling polishing head and the area to be repaired, and the deliquescence rate and area are controllable. The diffused micro-cold plasma and micro-water mist are used for negative pressure suction and removal, and an ideal spherical or Gaussian surface can be obtained after micro-defect repair.

【Description of drawings】

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, under the premise of no creative work, other drawings can also be obtained from these drawings, wherein:

Fig. 1 is the structural representation of a kind of KDP surface micro-defect profiling deliquescence repairing device of the present invention;

Fig. 2 is the structural representation of the connection structure of the present invention;

Fig. 3 is the shape schematic diagram of the serialized copying polishing head of the present invention;

FIG. 4 is a process flow of the present invention for repairing micro-defects on the surface of KDP by cold plasma-assisted profiling and deliquescence polishing.

【Detailed ways】

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Referring to FIG. 1, the present invention provides a KDP surface micro-defect profiling deliquescence repairing device, including a KDP crystal to be repaired containing surface micro-defects 1, a connecting structure 2, a negative pressure device 3, a negative pressure hole 4, a micro-deliquescence Water mist channel 5 , fine cold plasma channel 6 , machine vision system 7 , profiling polishing head 8 .

The KDP crystal with surface micro-defects is fixed on the machine tool, the profile polishing head is installed on the connecting structure, the connecting structure is installed on the machine tool, the negative pressure device is connected in the negative pressure hole, the machine The vision system is used to locate micro-defects on the KDP surface and assist in the selection and tool setting of the profiling polishing head. The micro-water mist channel and the micro-cold plasma channel are used for injecting micro-water mist and micro-cold plasma.

The plasma includes but is not limited to three working gases of N ₂ , He, and Ar.

2, in the specific embodiment of the connection structure 2, the upper end of the connection structure 2 is provided with external threads for connecting the machine tool, and the lower end of the connection structure 2 is provided with internal threads for connecting with the The external thread of the profiling polishing head 8 is matched.

Combined with Fig. 3, the micro-defect repair experiment aims to characterize the repair quality, efficiency and surface damage after profiling deliquescence polishing by designing and manufacturing a profiling polishing head, obtain the mapping relationship between process parameters and repair contour, and master the repair contour. Creation mechanism. The profiling polishing head is divided according to the aspect ratio, and a series of polishing heads are designed as shown in Figure 3. In the process of micro-defect repair, the profiling polishing head only needs to rotate at high speed and micro-feed in the axial direction, without complex motion trajectory, which can greatly improve the repair efficiency.

With reference to Fig. 4, in the repair method provided by the present invention, the micro-defect is firstly identified and identified, and then the micro-defect is super-hydrophilic modified by the micro-cold plasma, so that the micro-water mist can imitate the micro-defect in this area. The shape is uniform and deliquescence, and then the micro-defects are polished and removed by the profiling polishing head after the knife setting. Finally, the repaired KDP crystal is dried by a gas jet and placed in a dry and dust-free area.

The present invention also provides a repair method according to the described a kind of KDP surface micro-defect profiling deliquescence repair device, comprising the following steps:

Step 1. After pre-processing the KDP (1) containing surface micro-defects to be repaired, it is fixed on the machine tool;

Step 2: Install the profiling polishing head (8) on the inner thread under the connecting structure (2), start the machine vision system (7), accurately identify and locate the micro-defects on the surface of the KDP, and classify the micro-defects according to the defect type. The selection of the shaped polishing head provides auxiliary decision-making, and the machine tool realizes precise tool setting;

Step 3, starting the negative pressure device (3) to limit the spreading area of the micro-cold plasma and micro-water mist, confine the micro-water mist to the area to be repaired, and absorb the diffused micro-cold plasma and micro-water mist through negative pressure;

Step 4: injecting working gases such as N ₂ , He, and Ar into the fine cold plasma channel (6) with the aid of a low-pressure plasma power source, and producing fine cold plasma with low macroscopic temperature and high super-hydrophilic modification efficiency; The micro water mist generated by the mist supply device is injected into the micro water mist channel (5);

Specifically, by using a suitable plasma driving power supply and discharge structure, and optimizing parameters such as gas flow, pressure, driving voltage, etc., a fine cold plasma with a diameter of 1-500 μm is generated, and the real-time connection between the profiling polishing head and the micro-defects on the KDP surface is realized. Modified to a superhydrophilic surface.

Step 5. Start the machine tool, and perform profiling, deliquescence, polishing and repair on the surface of the KDP to be repaired until the repair process is completed.

It should be further explained that the liquid used in the micro water mist is deionized water. By controlling the supply flow of the micro water mist and the gap between the profiling polishing head and the workpiece, the adjustment of the water content, the precise control of the deliquescence rate, and the opening of the The negative pressure device is used to limit the trace moisture in the profiling deliquescence area to achieve controllable profiling deliquescence.

Step 6: Turn off all devices, take out the KDP crystal after the micro-defect repair is completed, and place it in a dry and dust-free area after post-processing such as gas jet drying.

The invention also provides a repair method for a KDP surface micro-defect profiling deliquescence repair device, which utilizes fine cold plasma to modify the KDP surface to be repaired into a super-hydrophilic surface in real time, so that the micro-water mist spreads evenly in the area , in order to limit the super-hydrophilic modification area and the micro-water mist spreading area to the area to be repaired, the diffused micro-cold plasma and micro-water mist are sucked out by negative pressure, and the micro-particles on the KDP surface to be repaired are removed by the machine vision system. Accurately identify and locate defects, and provide auxiliary decision-making for the selection of profiling polishing heads according to defect types. Thus, the problems of traditional deliquescence methods such as small-scale ripples on the deliquescence surface, low efficiency, and uncontrollable deliquescence area are solved.

The beneficial effects of the present invention are as follows: the positioning of micro-defects on the KDP surface scale from micrometers to millimeters and the tool setting of the profiling polishing head are realized through a machine vision system, and the collected images are processed by the method of deep learning to realize accurate identification of micro-defects, The selection of profiling polishing head is assisted in decision-making according to the category and scale of micro-defects. At the same time, using the principle of super-hydrophilic modification of micro-cold plasma, after precise tool setting, the profiling polishing head is aimed at the surface micro-defects of KDP, and the micro-defect area is profiled and super-hydrophilic modified by micro-cold plasma. The injected micro water mist spreads evenly between the profiling polishing head and the area to be repaired, and the deliquescence rate and area are controllable. The diffused micro-cold plasma and micro-water mist are used for negative pressure suction and removal, and an ideal spherical or Gaussian surface can be obtained after micro-defect repair.

Although the embodiment of the present invention has been disclosed as above, it is not limited to the application listed in the description and the embodiment, and it can be applied to various fields suitable for the present invention. For those skilled in the art, it can be easily Additional modifications are implemented, therefore, the invention is not limited to the specific details and illustrations shown and described herein without departing from the general concept defined by the appended claims and the scope of equivalents.

Claims (7)

1. A KDP surface microdefect profiling deliquescence repair device is characterized by comprising a profiling polishing head (8) and a machine vision system (7); a micro water mist channel (5) and a micro cold plasma channel (6) are formed in the middle of the profiling polishing head (8), and a plurality of negative pressure holes (4) are formed in the periphery of the profiling polishing head (8); the negative pressure hole (4) is communicated with a negative pressure device (3);

the machine vision system (7) is used for identifying and locating microdefects on the surface of the KDP crystal (1);

the micro cold plasma channel (6) is used for introducing micro cold plasma to carry out super-hydrophilic modification on the micro defects of the KDP crystal (1);

the micro water mist channel (5) is used for introducing micro water mist to deliquesce the micro defects on the surface of the KDP crystal (1) subjected to super-hydrophilic modification;

the negative pressure hole (4) is used for forming negative pressure so as to limit the spreading of the micro cold plasma and the micro water mist in the aging area; the machine vision system (7) collects microdefect patterns on the surface of the KDP crystal (1) as training data, and a microdefect identification model is constructed by adopting a deep learning method; then, comparing the acquired KDP surface image to be repaired with the micro-defects with training data, constructing the mapping relation between the micro-defect type, the micro-defect scale and the copying polishing head and the repair contour, and assisting in deciding the selection scheme of the shape and the width-depth ratio of the copying polishing head to realize the identification and the positioning of the micro-defects and the selection of the copying polishing head; during repair, after accurate tool setting is realized, micro water mist and micro cold plasma enter a profiling polishing head corresponding to a repair contour through the micro water mist channel and the micro cold plasma channel, and are conveyed to a micro defect to-be-repaired interface of the KDP crystal (1) for repair.

2. The KDP surface microdefect profiling deliquescence repair device according to claim 1, wherein the machine vision system (7) is further adapted to determine the shape and size of the selected profiling polishing head (8) and the vacuum value of each vacuum hole (4) based on the shape of microdefects on the surface of the KDP crystal (1).

3. The KDP surface microdefect profiling deliquescence repair device according to claim 1, wherein the profiling polishing head (8) is mounted on a machine tool through a connection structure (2).

4. The KDP surface microdefect profiling deliquescence repair device according to claim 1, wherein the microdefects of the KDP crystal (1) surface comprise micro-pits, bumps, cracks, scratches, fractures and burns.

5. The KDP surface microdefect profiling deliquescence repair device of claim 1, wherein the mapping relationship is obtained by: firstly, a machine vision system (7) acquires the shape contour of the KDP surface microdefect to be repaired, and the microdefect type is determined; because the depths of the areas to be repaired are different due to different types of defects, a series of profiling polishing heads taking the width-depth ratio as the dividing requirement are designed according to different defect types; after the micro-defect type is determined, a machine vision system is used for fitting to obtain a minimum circumscribed circle of the shape outline of the micro-defect, and finally, spherical and Gaussian curved surface profiling polishing heads with the same specification are selected according to the size of the micro-defect type and the circumscribed circle of the area to be repaired, so that the repairing area of the KDP crystal is minimized.

6. The profiling deliquescence repair device for the KDP surface microdefects, as claimed in claim 5, wherein when the width-to-depth ratio of the KDP surface microdefects to be repaired is between 5 and 10, a spherical profiling polishing head is selected; selecting a Gaussian profiling polishing head when the width-depth ratio of the KDP surface micro-defects to be repaired is more than 10; the parameters of the Gaussian profiling polishing head comprise a maximum diameter, a median diameter and an arc diameter, and the scale range of the micro defects on the KDP surface to be repaired is 10 mu m-2 mm magnitude.

7. The profiling deliquescence repair device for the KDP surface micro-defects as claimed in claim 1, wherein the fine cold plasma channel (6) is communicated with a fine cold plasma supply device; the micro water mist channel (5) is communicated with a micro water mist supply device; the micro-fine cold plasma channel (6) utilizes the micro-fine cold plasma to carry out real-time super-hydrophilic modification between the KDP surface micro-defect and the profiling polishing head, and the micro-defect interface after the super-hydrophilic modification absorbs micro-water mist to realize profiling deliquescence; the moisture content is adjusted and controlled by controlling the supply flow of the micro water mist and the gap between the profiling polishing head and the workpiece, and the trace moisture is limited in a profiling deliquescence area by the negative pressure device, so that controllable profiling deliquescence is realized.

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