Treatment process of resin-based composite material surface paint layer

Abstract

The invention provides a treatment process for a surface paint layer of a resin-based composite material. The treatment process comprises the following steps: acquiring a thickness distribution model of the surface paint layer of the resin-based composite material; constructing a relational expression among the scanning speed, the pulse frequency and the paint removal depth of the laser based on the thickness distribution model; dynamically adjusting the scanning speed and the pulse frequency based on the relational expression to carry out laser leveling paint removal on the surface of the resin-based composite material; wherein the paint removal depth associates and maps the thickness distribution model. When a laser is used for removing paint in different areas of the surface of the resin-based composite material, laser parameters (scanning speed and pulse frequency) are accurately controlled through a regression equation of a relational expression to realize removal of paint layers with different thicknesses and roughening treatment of a matrix, so that the surface quality of the cleaned resin-based composite material is uniform and consistent; and the effect of cleaning and leveling the resin-based composite material by laser is improved. Laser cleaning is suitable for paint layers of various thicknesses and types and resin-based composite materials of different shapes, and the treatment process has wide applicability.

Description

Technical Field

[0001] The present invention belongs to the field of surface processing of materials, and specifically relates to a processing technology for the surface paint layer of resin-based composites. Background Art

[0002] At present, in the aerospace field, resin-based composites include reinforcing materials such as carbon fiber, glass fiber, aramid fiber, and their fabrics, and thus are widely used due to their advantages such as light weight, high strength, and good rigidity. However, the paint layer on the surface of resin-based composites may gradually lose its protective function during use due to reasons such as wear, aging, and corrosion, which not only affects the appearance but also may pose a threat to the structural safety and reliability. Therefore, it is necessary to repaint the surface of resin-based composites.

[0003] Laser paint removal technology has been widely used in various fields due to its advantages such as high efficiency, environmental protection, non-contact operation, high precision, strong applicability, safety and reliability, and controllability. The laser paint removal speed is fast, which can greatly shorten the paint layer removal time; no chemical solvents are used, reducing the emission of harmful substances, meeting the requirements of green environmental protection. The non-contact laser treatment will not cause mechanical wear and scratches to the resin-based composites, protecting the integrity and mechanical properties of the resin-based composites, and providing ideal surface conditions for subsequent repainting.

[0004] When using the laser process to level the paint on resin-based composites, due to reasons such as initial painting or wear, aging, and corrosion during use, the thickness distribution of the paint layer on the resin-based composites is not uniform. The laser beam generated by the laser under fixed parameters cannot accurately adjust the laser operation parameters during the paint removal process, inevitably damaging the fiber matrix in the resin-based composites, resulting in poor cleaning and leveling effects, and further reducing the overall performance of the resin-based composites. Summary of the Invention

[0005] The object of the present invention is to solve the problem that the existing laser process has poor cleaning and leveling effects on resin-based composites with uneven thickness distribution of the surface paint layer.

[0006] The object of the present invention is achieved by adopting the following technical solutions:

[0007] The present invention provides a processing technology for the surface paint layer of resin-based composites. The processing technology includes: obtaining a thickness distribution model of the surface paint layer of resin-based composites; constructing a relationship among the scanning speed, pulse frequency, and paint removal depth of the laser based on the thickness distribution model; dynamically adjusting the scanning speed and the pulse frequency based on the relationship to perform laser leveling and paint removal on the surface of resin-based composites; wherein, the paint removal depth is associated with and maps the thickness distribution model.

[0008] Preferably, the relationship between the scanning speed, pulse frequency, and paint removal depth of the laser based on the thickness distribution model is constructed as follows:

[0009] The regression equation is f(x, y) = P 00 + P 10 ·x + P 01 ·y + P 20 ·x 2 + P 11 ·x·y + P 02 ·y 2 ; where x is the scanning speed, y is the pulse frequency, f(x, y) is the paint removal depth, and the P 00 、P 10 、P 01 、P 20 、P 11 、P 02 are the coefficients of the regression equation.

[0010] Preferably, the thickness of the paint layer does not exceed 10 μm. Taking the 90% confidence interval as the standard, P 00 = -1.779885×10 -06 , P 10 = 4.505180×10 -06 , P 01 = -8.903932×10 -05 , P 20 = -5.876438×10 -07 , P 11 = 2.252648×10 -04 , P 02 = -4.454218×10 -03 .

[0011] Preferably, the laser leveling and paint removal of the resin matrix composite surface based on the relationship includes: setting a threshold range, comparing the average thickness of the paint layer with the threshold range; if the average thickness is within the threshold range, the scanning speed and pulse frequency of the laser are dynamically adjusted according to the relationship to perform paint removal and leveling operations on the resin matrix composite surface.

[0012] Preferably, the range of the pulse frequency is 20 kHz - 40 kHz.

[0013] Preferably, the range of the scanning speed is 1000 mm / s - 3000 mm / s.

[0014] Preferably, before performing the paint removal and leveling operation on the surface of the resin matrix composite material, an initialization setting operation is performed on the laser. The initialization setting parameters of the laser include:

[0015] The laser wavelength is set to 1064 nm, the laser spot diameter is set to 1 mm, the pulse width is set to 200 ns, the laser power is set to 100 W, the pulse frequency is set to 20 kHz, and the scanning speed is set to 3000 mm / s.

[0016] Preferably, the obtaining of the thickness distribution model of the paint layer on the surface of the resin matrix composite material includes: cleaning and softening the surface of the resin matrix composite material; dividing multiple grids on the surface of the resin matrix composite material; obtaining the thickness data of the paint layer within each grid; and summarizing and calculating the thickness data of each grid to obtain the thickness distribution model of the paint layer.

[0017] Preferably, the obtaining of the thickness data of the paint layer within each grid includes: using an ultrasonic thickness gauge with a double crystal probe and applying glycerol as a coupling agent between the double crystal probe and the paint layer to obtain the thickness data.

[0018] Preferably, the treatment process further includes: during the laser leveling and paint removal process on the surface of the resin matrix composite material, using auxiliary gas to blow away the vaporized paint layer material ablated by the laser to cool and reduce the oxidation reaction on the surface of the resin matrix composite material; the gas flow rate of the auxiliary gas is 10 L / min - 30 L / min, and the auxiliary gas is nitrogen or argon.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] The present invention provides a treatment process for the paint layer on the surface of a resin matrix composite material, including obtaining a thickness distribution model of the paint layer on the surface of the resin matrix composite material; constructing a relationship among the scanning speed, pulse frequency, and paint removal depth of the laser based on the thickness distribution model; dynamically adjusting the scanning speed and pulse frequency based on the relationship to perform laser leveling and paint removal on the surface of the resin matrix composite material; wherein, the paint removal depth is associated with and maps the thickness distribution model. When the laser performs paint removal on different regions of the surface of the resin matrix composite material, the laser parameters (such as scanning speed, pulse frequency) are precisely controlled through the regression equation of the relationship to achieve the removal of paint layers with different thicknesses and the roughening treatment of the matrix, ensuring that the quality of the surface of the resin matrix composite material cleaned is uniform, and improving the effect of laser cleaning and leveling of the resin matrix composite material. Laser cleaning is applicable to paint layers of various thicknesses and types and resin matrix composite materials of different shapes, and this treatment process has wide applicability. Description of the Drawings

[0021] Figure 1This is the main process flow chart of the treatment process for the surface paint layer of the resin matrix composite material of the present invention;

[0022] Figure 2 This is a schematic diagram of the paint layer thickness distribution on the surface of the resin matrix composite material;

[0023] Figure 3 This is the process principle diagram of laser removing the surface paint layer of the resin matrix composite material;

[0024] Figure 4 This is the schematic diagram of the pull-out test principle for the resin matrix composite material after painting;

[0025] Figure 5 This is the schematic diagram of the S-shaped path of the laser spot movement;

[0026] Figure 6 This is the schematic diagram of the spiral path of the laser spot movement;

[0027] Figure 7 This is the schematic diagram of the grid-shaped path of the laser spot movement;

[0028] Figure 8 This is the schematic diagram of the fractal structure path of the laser spot movement.

[0029] Reference numerals: 1 - carbon fiber matrix; 2 - original paint layer; 2a - raised area; 2b - sunken area; 3 - cleaning laser beam; 4 - strengthening laser beam; 5 - surface of the paint layer after cleaning; 6 - fiber-reinforced surface; 7 - vaporized paint layer material; 8 - new paint layer; 9 - adhesive layer; 10 - pull-out rod. Detailed implementation manners

[0030] The preferred implementation manners of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these implementation manners are only used to explain the technical principle of the present invention and are not intended to limit the protection scope of the present invention. Those skilled in the art can make adjustments according to needs to adapt to specific application scenarios. The reinforcing materials in the resin matrix composite material usually include carbon fiber, glass fiber, aramid fiber and their fabrics, etc. The paint layer of the resin matrix composite material is epoxy resin. Although the description in the specification takes the carbon fiber resin matrix composite material as an example, it is obvious that the present invention can also process other resin matrix composite materials such as glass fiber, aramid fiber and their fabrics.

[0031] As Figure 1 shown, the present invention provides a treatment process for the surface paint layer of the resin matrix composite material, including:

[0032] S1. Obtain the thickness distribution model of the surface paint layer of the resin matrix composite material;

[0033] S2. Constructing the relationship between the laser scanning speed, pulse frequency and paint removal depth based on the thickness distribution model;

[0034] S3, dynamically adjusting the scanning speed and pulse frequency based on the relationship to perform laser leveling and paint removal on the surface of the resin-based composite material;

[0035] Among them, the paint removal depth correlation maps the thickness distribution model.

[0036] like Figure 2 As shown, it is understandable that due to the limitation of the carbon fiber painting process, after the carbon fiber surface is painted, the original paint layer 2 inevitably has undulating raised areas 2a and recessed areas 2b. The leveling operation is mainly a process of making the surface of an object flat and without bumps. When a conventional laser beam is used to clean and level the original paint layer 2 on the carbon fiber surface, the paint removal depth of the constant energy laser beam remains constant, which can easily lead to excessive paint removal of the upper recessed area 2b of the original paint layer 2 during the laser cleaning process, thereby damaging the carbon fiber matrix 1 and reducing the overall strength of the carbon fiber material. The upper raised area 2a of the original paint layer 2 is prone to form a residual layer, which reduces the leveling effect of the carbon fiber surface and the mechanical properties after repainting.

[0037] The processing technology of the present invention obtains the thickness distribution model of the paint layer in advance, and constructs the relationship between the laser scanning speed, pulse frequency and paint removal depth based on the thickness distribution model. That is, the laser scanning speed and pulse frequency are dynamically controlled according to the relationship to determine the laser paint removal depth. That is, when cleaning paint layers of different thicknesses, the paint removal depth and the thickness distribution of the paint layer are adaptively correlated and matched, and then the surface of the material is kept smooth after the paint layer is vaporized and cleaned away, thereby improving the cleaning effect of the paint layer with uneven thickness distribution on the carbon fiber surface, and also laying a good quality foundation for repainting.

[0038] Wherein, in step S1, the specific steps include:

[0039] S11, cleaning and softening the surface of the resin-based composite material;

[0040] S12, a plurality of grids divided on the surface of the resin-based composite material;

[0041] S13, obtaining the thickness data of the paint layer in each grid;

[0042] S14, summarizing and calculating the thickness data of each grid to obtain a thickness distribution model of the paint layer.

[0043] Specifically, use a lint-free cloth and alcohol to clean the carbon fiber surface to remove dust, oil stains, and other impurities, ensuring that the carbon fiber surface is clean. Use an ultrasonic thickness gauge to preliminarily measure the thickness of the paint layer on the carbon fiber surface, and then apply a chemical solvent to soften the paint layer. The chemical solvent selected is N-methylpyrrolidone, which performs well as a powerful organic solvent in removing epoxy resin paint layers. Among them, when the paint layer thickness ranges from 25μm to 50μm, the softening time of the paint layer is 5 minutes to 10 minutes; when the paint layer thickness ranges from 50μm to 150μm, the softening time of the paint layer is 10 minutes to 30 minutes; when the paint layer thickness exceeds 150μm, the softening time of the paint layer is at least 30 minutes. After softening the paint layer, use a lint-free cloth to gently wipe the softened paint layer, which can remove most of the loose paint layer, laying a good foundation for laser paint removal and avoiding cracking and delamination during the paint removal process.

[0044] To accurately capture the thickness change of the entire paint layer on the carbon fiber surface, the surface area to be cleaned is divided into multiple regular grids, and the grid size depends on the required accuracy. The processing technology of the present invention uses relatively dense grids, that is, the grid size is equivalent to the spot diameter of the laser.

[0045] Use an ultrasonic thickness gauge to measure and obtain the thickness data of each grid. After collecting the thickness data of all grids, use computer software to draw a three-dimensional model of the paint layer thickness distribution, which is convenient to visually identify the trend and pattern of the paint layer thickness change.

[0046] Among them, the measurement mode of the ultrasonic thickness gauge is selected as the coating mode, and the sound velocity value (2700m / s - 3500m / s) of the carbon fiber material is set as the input to ensure the accuracy of the measurement results. Set the upper and lower limit alarm values of the paint layer thickness so as to detect abnormalities in time during the measurement process. Select an appropriate ultrasonic probe according to the curvature, surface smoothness, paint layer material, and expected thickness range of the carbon fiber thin-walled component. Probes with different frequencies are applicable to different thickness ranges. In the present invention, a double-crystal probe is selected. Apply a coupling agent on the surface of the paint layer to be measured, that is, evenly apply a layer of glycerol on the surface of the pre-divided grid to ensure that there are no bubbles or gaps between the probe and the paint layer surface. Gently press the probe on the grid measurement point coated with glycerol, and keep the probe perpendicular to the surface of the paint layer to be measured to avoid tilting affecting the measurement results. Press the measurement button on the ultrasonic thickness gauge and wait for the stable thickness value to be displayed on the screen, that is, obtain the thickness data of this grid position. Among them, to ensure the accuracy of the measurement result of the paint layer thickness distribution, use a standard test block to calibrate the ultrasonic thickness gauge.

[0047] As Figure 1 shown, in step S2, the constructed relationship is a regression equation, as follows:

[0048] f(x,y) = P 00 + P 10·x + P 01 ·y + P 20 ·x 2 + P 11 ·x·y + P 02 ·y 2 ;

[0049] Wherein, x is the scanning speed, y is the pulse frequency, f(x, y) is the paint removal depth, and P 00 , P 10 , P 01 , P 20 , P 11 , P 02 are the coefficients of the regression equation.

[0050] It can be understood that by adaptively adjusting the scanning speed and pulse frequency of the laser according to the regression equation, the paint removal depth associated with the thickness distribution model of the paint layer can be determined. That is, the laser energy is reduced in the concave area 2b of the original paint layer 2 to form a shallower paint removal depth, and the laser energy is increased in the convex area 2a of the original paint layer 2 to form a deeper paint removal depth. Furthermore, a relatively flat surface can be formed when cleaning paint layers of different thicknesses, improving the surface effect of laser cleaning and leveling the carbon fiber material.

[0051] It should be noted that compared with the linear parameter adjustment method (such as adjusting the laser power), the present processing technology uses the regression equation to adjust the pulse frequency to achieve more precise control of the laser energy for the paint removal depth, thereby reducing the damage to the carbon fiber matrix 1 by the laser.

[0052] As Figure 1 and Figure 2 shown, in step S3, it includes:

[0053] S31. Set a threshold range and compare the average thickness of the paint layer with the threshold range;

[0054] S32. If the average thickness exceeds the set threshold range, the laser performs a paint removal operation on the surface of the resin matrix composite material according to the set value;

[0055] S33. If the average thickness is within the threshold range, the scanning speed and pulse frequency of the laser are dynamically adjusted according to the relationship formula to perform a paint removal and leveling operation on the surface of the resin matrix composite material.

[0056] As Figure 2 and Figure 3 shown, considering the influence of laser energy on the performance of carbon fiber materials, when the laser beam is not suitable for forcibly cleaning the carbon fiber surface at one time, or the thickness (W) of the original paint layer 2 exceeds the laser single - time paint removal depth, to avoid cracking on the surface of the carbon fiber material resin matrix composite material caused by excessive laser energy, first perform the first cleaning on the original paint layer 2 ( Figure 3In the medium cleaning laser beam 3), that is, the laser reduces the thickness of the paint layer according to the set value to form a paint layer cleaning surface 5 while keeping the undulating distribution pattern of the paint layer surface unchanged. Among them, the average thickness of the paint layer is directly calculated through the three-dimensional model of the thickness distribution.

[0057] In step S32, when the remaining paint layer after being processed in step S32, or the original average thickness of the paint layer is within the threshold range, the scanning speed and pulse frequency of the laser are adjusted according to the regression equation to directly clean and level the paint layer.

[0058] Among them, when the average thickness of the paint layer does not exceed 10μm, taking the 90% confidence interval as the standard, the coefficients of the regression equation are set: P 00 =-1.779885×10 -06 , P 10 =4.505180×10 -06 , P 01 =-8.903932×10 -05 , P 20 =-5.876438×10 -07 , P 11 =2.252648×10 -04 , P 02 =-4.454218×10 -03 .

[0059] As Figure 2 and Figure 3 shown, the parameter values are set according to the above regression equation coefficients to control and adjust the output of the enhanced laser beam 4 of the laser, that is, the paint removal depth of the laser is greater than the thickness of the paint layer, which can make the paint layer roughen the surface of the carbon fiber matrix 1 synchronously during the cleaning and leveling process to form a fiber-reinforced surface 6. That is, the cleaning of the paint layer by the laser beam and the strengthening and leveling of the carbon fiber matrix 1 are completed synchronously, improving the efficiency of the laser treatment process.

[0060] In step S3, before the paint removal and leveling operation on the carbon fiber surface, it is also necessary to perform secondary cleaning on the surface of the resin-based composite material to remove the glycerol applied in the measurement state and perform initialization settings on the laser.

[0061] Specifically, the laser uses a fiber pulse laser, and the main parameter ranges of the selected laser are as follows:

[0062] Scanning speed: 1000 mm / s - 5000 mm / s, pulse width: 10 ns - 1000 ns, laser power: 0 W - 100 W, pulse frequency: 1 kHz - 500 kHz. It should be noted that the range of the pulse frequency of the laser in the working state is 20 kHz - 40 kHz, the range of the scanning speed is 1000 mm / s - 3000 mm / s, and the spot overlap rate is 50% - 90%.

[0063] Among them, in the initial state, the initial settings of the laser are as follows:

[0064] The wavelength of the laser is set to 1064 nm, the spot diameter of the laser is set to 1 mm, the pulse width is set to 200 ns, the laser power is set to 100 W, the pulse frequency is set to 20 kHz, the scanning speed is set to 3000 mm / s, the spot overlap rate is 90% (can be adjusted according to the paint layer thickness), and the scanning pitch is set to 0.5 mm to ensure rapid heating and evaporation of the paint layer material. The laser wavelength of 1064 nm has a good absorption effect on most paint layer materials and has little impact on resin-based carbon fiber materials.

[0065] In the laser cleaning process, the spot movement trajectory mainly includes the following five typical scanning modes: linear reciprocating path, S-shaped path, spiral path, grid path, and fractal structure path. These movement trajectories can significantly improve the cleaning uniformity and processing efficiency by optimizing the energy distribution and heat accumulation effect.

[0066] Among them, during the laser cleaning process, the laser scanning mode can be adjusted according to the different matrix shapes and different sizes of resin-based composite materials.

[0067] Such as Figure 5 shown, the S-shaped path of the laser scanning mode is suitable for surfaces with a relatively large area and a relatively regular shape. It has a wide coverage area and is suitable for large-area cleaning. It has good continuity, reduces the number of pauses, and can improve efficiency. The S-shaped scanning path can effectively cover the entire area and ensure that the paint layer is evenly removed. For large-area surfaces with a certain curvature, the S-shaped path can adapt to the curvature change and ensure the cleaning effect.

[0068] Such as Figure 6 shown, the spiral path of the laser scanning mode is a scanning path of a continuous spiral curve. The spiral scanning path usually starts from a central point and gradually expands its trajectory outward in a spiral form. This process can be equidistant or adjusted according to the specific application requirements. A common form of the spiral is the Archimedean spiral, which is characterized in that as the radius increases, the distance between the spirals remains constant. The spiral path helps to achieve a more uniform energy distribution because it can effectively cover the entire surface without passing through the same point too many times. It is suitable for circular or elliptical areas and is used for larger areas that require uniform paint removal.

[0069] As Figure 7 shown, the grid-shaped path of the laser scanning mode is a crisscrossing network structure scanning path, which is applicable to small-area regions that require fine processing. It has high fineness and is suitable for the processing of small areas and local regions. It can ensure that each point can be irradiated by the laser, avoiding omission. For small complex parts, such as sensor housings, the grid-shaped path can provide higher resolution and finer cleaning effects.

[0070] As Figure 8 shown, the fractal-shaped path of the laser scanning mode, this fractal shape is based on the concept of fractal geometry in mathematics, generating self-similar complex patterns, and is applicable to highly irregular surfaces. It has strong adaptability, can adapt to extremely complex surface morphologies, and provides higher flexibility and coverage. It is applicable to parts with complex geometric shapes: for parts with highly complex shapes, such as special structural parts of some spacecraft, the fractal-shaped path can provide the best coverage effect. For surfaces with multiple dimensions and complex curvatures, the fractal path can better adapt to the surface morphology and ensure full coverage.

[0071] In step S3, during the process of laser leveling and paint removal on the surface of the resin matrix composite material, the auxiliary gas is used to blow away the vaporized paint layer material 7 ablated by the laser to cool and reduce the oxidation reaction on the surface of the resin matrix composite material;

[0072] The gas flow rate of the auxiliary gas is 10 L / min - 30 L / min, the auxiliary gas is nitrogen or argon, and the tool uses a blowing fan. Among them, the gas flow rate in the initial state is 20 L / min.

[0073] It should be noted that the processing technology of the present invention is also equipped with a real-time monitoring system, and this real-time monitoring system includes monitoring devices such as high-speed cameras, infrared thermal imagers, and spectral detectors to monitor the laser paint removal process to ensure that the paint removal reaches the best processing effect.

[0074] Specifically, the laser processing process is monitored through cameras and sensors, the temperature change of the material surface during the cleaning process is monitored by an infrared thermal imager, the change state of the material surface during the cleaning process is recorded by a high-speed camera, and the specific composition of the surface material is determined by a spectral detector. Through the above monitoring methods, the corresponding laser parameters can be dynamically adjusted in a timely manner according to the monitoring results to ensure the best processing effect and avoid over-processing or under-processing of the laser.

[0075] The advantages of the processing technology of the present invention compared with the traditional laser cleaning technology are as follows:

[0076] 1. The laser paint removal technology and the laser strengthening technology are combined and integrated for treatment. By combining the laser paint removal and the laser strengthening technology, the dual goals of removing the paint layer and improving the matrix performance are achieved in one treatment. This not only improves the treatment efficiency but also reduces the complexity and cost brought by multiple treatments. By optimizing the laser parameter settings, the laser paint removal and the laser strengthening processes can promote each other to achieve better comprehensive effects.

[0077] 2. The multi-pulse technology is adopted. Through multiple low-energy laser irradiations, more precise control is achieved, and substrate damage is reduced. This method can better protect the structural integrity of the carbon fiber composite material.

[0078] 3. The laser treatment is non-contact and will not cause abrasion and scratches to the substrate, protecting the integrity and mechanical properties of the carbon fiber composite material. Compared with the traditional sandblasting paint removal method, the laser paint removal reduces the risk of delamination between carbon fiber layers, improves the safety and reliability of the structure, and does not introduce other substances such as grit.

[0079] 4. The laser parameters (such as scanning speed, pulse frequency, etc.) are precisely controlled through the regression equation to achieve the removal of paint layers with different thicknesses and the roughening treatment of the substrate, ensuring that the quality of the cleaned surface is uniform. Laser cleaning is applicable to paint layers of various thicknesses and types, as well as resin matrix composites with thin-walled structures of different shapes, and has wide applicability.

[0080] In addition, the combination of chemical solvents and laser cleaning will not cause abrasion and scratches to the carbon fiber substrate, protecting the integrity and mechanical properties of the carbon fiber composite material. The laser paint removal reduces the risk of cracking and delamination between carbon fiber layers, and the combination of chemical solvents and laser cleaning for paint removal is fast and efficient, significantly shortening the paint removal time.

[0081] Result Detection

[0082] According to the treatment process of the surface paint layer of the resin matrix composite material of the present invention, 5 groups of specimens with different paint layer thicknesses are selected, and the surface paint layers are subjected to laser leveling and strengthening treatment for roughness detection. Among them, the laser spot movement trajectory adopts a linear reciprocating path.

[0083] As Figure 4 shown, 5 specimens with different paint removal thicknesses after treatment are taken. A new paint layer 8 with a thickness of 10 μm is re-sprayed on both sides of each specimen. An adhesive layer 9 is formed by applying glue on the surface of the new paint layer 8 for fixing the two-sided pull rods 10. The two-sided pull rods 10 are installed on a tensile testing machine to pull the specimens for adhesion force detection.

[0084] Table 1 is a comparison table of the roughness and adhesion inspection results of 5 groups of specimens after the laser treatment process.

[0085] Table 1

[0086]

[0087]

[0088] After strengthening by laser cleaning, the surface roughness of the carbon fiber matrix 1 is improved, the adhesion of the re-sprayed paint layer is increased, and an ideal effect is achieved. Among them, the highest surface roughness of Specimen 1 is detected to be 4.28 μm, and its adhesion force reaches 9.91 MPa after re-spraying.

[0089] The treatment process of the surface paint layer of the resin matrix composite material of the present invention is used to detect the paint removal and strengthening of four groups of specimens respectively by using different spot movement trajectories, as shown in Table 2.

[0090] Table 2

[0091]

[0092] Table 2 is a comparison table of the roughness and adhesion inspection results of 4 groups of specimens after laser treatment with different scanning paths. It can be seen from the comparison that using the grid-shaped path has the best paint removal and strengthening effect on the surface of the carbon fiber material (the surface roughness reaches 4.56 μm), and the adhesion force after re-coating the coating reaches 10.12 MPa.

[0093] The above are only examples of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention are included in the scope of the claims of the present invention pending approval.

Claims

1. A treatment process for the surface paint layer of a resin-based composite material, characterized in that, The processing technology includes: Obtaining the thickness distribution model of the paint layer on the surface of the resin matrix composite material; Constructing the relationship among the scanning speed, pulse frequency, and paint removal depth of the laser based on the thickness distribution model; Dynamically adjusting the scanning speed and the pulse frequency based on the relationship to perform laser leveling and paint removal on the surface of the resin matrix composite material; Among them, the paint removal depth is associated with and maps the thickness distribution model.

2. The treatment process of the resin-based composite material surface paint layer according to claim 1, characterized in that, The constructing the relationship among the scanning speed, pulse frequency, and paint removal depth of the laser based on the thickness distribution model includes: The regression equation is f(x,y) = P 00 + P 10 · x + P 01 · y + P 20 · x 2 + P 11 · x · y + P 02 · y 2 ; Among them, x is the scanning speed, y is the pulse frequency, f(x, y) is the paint removal depth, and P 00 , P 10 , P 01 , P 20 , P 11 , P 02 are the coefficients of the regression equation.

3. The treatment process of the surface paint layer of the resin-based composite material according to claim 2, characterized in that, The thickness of the paint layer does not exceed 10 μm. Taking the 90% confidence interval as the standard, P 00 =-1.779885×10 -06 , P 10 =4.505180×10 -06 , P 01 =-8.903932×10 -05 , P 20 =-5.876438×10 -07 , P 11 =2.252648×10 -04 , P 02 =-4.454218×10 -03 .

4. The treatment process of the surface paint layer of the resin-based composite material according to claim 1, characterized in that, The dynamically adjusting the scanning speed and pulse frequency based on the relationship to perform laser leveling and paint removal on the surface of the resin matrix composite material includes: Setting a threshold range and comparing the average thickness of the paint layer with the threshold range; If the average thickness exceeds the threshold range, the laser performs paint removal operation on the surface of the resin matrix composite material according to the set value; If the average thickness is within the threshold range, the scanning speed and the pulse frequency of the laser are dynamically adjusted according to the relationship to perform paint removal and leveling operation on the surface of the resin matrix composite material.

5. The treatment process of the surface paint layer of the resin-based composite material according to claim 4, characterized in that, The range of the pulse frequency is 20 kHz - 40 kHz.

6. The processing technology of the surface paint layer of the resin matrix composite material according to claim 5, characterized in that, The range of the scanning speed is 1000 mm / s - 3000 mm / s.

7. The treatment process of the surface paint layer of the resin matrix composite material according to claim 6, characterized in that, Before performing the paint removal and leveling operation on the surface of the resin matrix composite material, an initialization setting operation is performed on the laser. The initialization setting parameters of the laser include: The laser wavelength is set to 1064 nm, the laser spot diameter is set to 1 mm, the pulse width is set to 200 ns, the laser power is set to 100 W, the pulse frequency is set to 20 kHz, and the scanning speed is set to 3000 mm / s.

8. The treatment process of the surface paint layer of the resin matrix composite material according to claim 1, characterized in that, The obtaining the thickness distribution model of the paint layer on the surface of the resin matrix composite material includes: Performing cleaning and softening treatment on the surface of the resin matrix composite material; Dividing a plurality of grids on the surface of the resin matrix composite material; Obtaining the thickness data of the paint layer in each grid; Summarizing and calculating the thickness data of each grid to obtain the thickness distribution model of the paint layer.

9. The processing technology of the surface paint layer of the resin matrix composite material according to claim 8, characterized in that, The obtaining the thickness data of the paint layer in each grid includes: Using an ultrasonic thickness gauge with a double-crystal probe and applying glycerol as a coupling agent between the double-crystal probe and the paint layer to obtain the thickness data.

10. The processing technology of the surface paint layer of the resin matrix composite material according to claim 1, characterized in that, The processing technology further includes: During the process of performing laser leveling and paint removal on the surface of the resin matrix composite material, using auxiliary gas to blow away the vaporized paint layer material ablated by the laser to cool and reduce the oxidation reaction on the surface of the resin matrix composite material; The gas flow rate of the auxiliary gas is 10 L / min - 30 L / min, and the auxiliary gas is nitrogen or argon.

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