Flexible anti-laser patch and preparation method thereof

Abstract

The invention relates to the technical field of laser reinforcement, in particular to a flexible anti-laser patch and a preparation method thereof. The flexible anti-laser patch comprises the following components in percentage by weight: 5-10% of polyurethane, 5-10% of crystalline flake graphite, 10-20% of silicon carbide, 10-20% of high-temperature carbide / high-temperature nitride / high-temperature boride, 5-10% of nano carbon powder / graphene / carbon nanotube powder and the balance of zirconium dioxide / silicon dioxide / titanium dioxide. The total weight ratio of the nano carbon powder and the crystalline flake graphite is not more than 15%, and the total weight ratio of the zirconium dioxide and the silicon carbide is 35-45%. The flexible anti-laser patch and the preparation method thereof aim at solving the problem of how to keep certain anti-laser reinforcement performance and have flexibility at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of laser reinforcement, and in particular to a flexible anti-laser patch and a preparation method thereof. Background Art

[0002] Laser weapons are gradually maturing, posing a new threat to aircraft. Traditional aircraft surface materials such as topcoat, protective paint, skin, absorbing coating, absorbing honeycomb and other materials cannot withstand the strong laser irradiation of laser weapons. It is necessary to use anti-laser reinforcement technology to improve the laser damage threshold of the above materials and structures and extend the tolerance time under strong laser irradiation.

[0003] Typical laser-resistant reinforcement technologies can be roughly divided into two categories. One is ceramic coatings with ceramic as the typical material and plasma spraying as the typical preparation process, such as ZrB2 / SiC coatings, which can withstand 1064nm continuous laser power density of 500W / cm 2 The duration is 30 seconds, at which time the coating is ablated and the substrate is not damaged. This type of anti-laser reinforcement technology mainly uses the inherent high temperature resistance of ceramics combined with the increase in reflectivity caused by the melting of the surface when the strong laser irradiates the coating to resist the instantaneous strong heat of the laser. This type of coating is heavy and usually used once. The other type is a composite coating with boron phenolic resin as the typical resin matrix and modified with inorganic fillers. This type of coating can withstand a 1064nm continuous laser power density of 500W / cm 2 The spot duration is 15 seconds. This type of coating mainly resists laser irradiation based on the ablation mechanism. The modified resin coating is ablated under the strong heat of laser irradiation, and the internal chemical bonds are broken to form residual carbon. The instantaneous high heat of the laser acting on the coating is partially dissipated through the coupling effect of carbon thermal conductivity and infrared emission. These anti-laser reinforcement technologies are thick, heavy, lack flexibility, are easy to break during flight, and are difficult to apply.

[0004] Therefore, the inventor provides a flexible anti-laser patch and a preparation method thereof. Summary of the invention

[0005] (1) Technical issues to be solved

[0006] The embodiment of the present invention provides a flexible anti-laser patch and a preparation method thereof, which solves the technical problem of how to have flexibility while maintaining certain anti-laser reinforcement performance.

[0007] (2) Technical solution

[0008] The first aspect of the present invention provides a flexible anti-laser patch, including polyurethane, flake graphite, high-temperature carbide / high-temperature nitride / high-temperature boride, nano-carbon powder / graphene / carbon nanotube powder, zirconium dioxide / silicon dioxide / titanium dioxide, wherein the weight proportion of the polyurethane is 5-10%, the weight proportion of the flake graphite is 5-10%, the weight proportion of the silicon carbide is 10-20%, the total weight proportion of the nano-carbon powder and the flake graphite is no more than 15%, and the total weight proportion of the zirconium dioxide and the silicon carbide is 35-45%.

[0009] Furthermore, the carbon content of the flake graphite is 99%.

[0010] Furthermore, the diameter of the high temperature carbide / high temperature nitride / high temperature boride is 100 nm to 1 μm.

[0011] Furthermore, the diameter of the nano-carbon powder / graphene / carbon nanotube powder is 20 to 200 mm.

[0012] Furthermore, the D of the zirconium dioxide / silicon dioxide / titanium dioxide 50 1μm.

[0013] Furthermore, the weight ratio of the flake graphite, the nano-carbon powder / graphene / carbon nanotube powder, the high-temperature carbide / high-temperature nitride / high-temperature boride, the zirconium dioxide / silicon dioxide / titanium dioxide and the polyurethane is 1:1:4:4:10.

[0014] Furthermore, the high temperature carbide includes at least one of silicon carbide, zirconium carbide and hafnium carbide.

[0015] Furthermore, the high temperature nitride includes at least one of silicon nitride, zirconium nitride and hafnium nitride.

[0016] Furthermore, the high temperature boride includes at least one of silicon boride, zirconium diboride and hafnium diboride.

[0017] A second aspect of the present invention provides a method for preparing a flexible anti-laser patch, comprising the following steps:

[0018] The polyurethane and the curing agent are uniformly mixed in a weight ratio of 100:(3.2-5.5);

[0019] Mixing flake graphite, high temperature carbide / high temperature nitride / high temperature boride, nano carbon powder / graphene / carbon nanotube powder, zirconium dioxide / silicon dioxide / titanium dioxide and mixed polyurethane according to a set weight ratio;

[0020] The above mixture, 2 to 5 times the weight of ethanol, 2 to 10% by weight of a dispersant and 0.1 to 1% by weight of a defoamer are mixed and stirred;

[0021] The mixture is filtered to obtain a slurry;

[0022] The slurry is scraped onto the aluminum substrate, and the coating is scraped again after drying, until the coating thickness reaches a preset thickness value and then cured at a constant temperature to obtain a flexible anti-laser patch.

[0023] (3) Beneficial effects

[0024] In summary, the present invention prepares a laser-resistant patch by specially designed components and ratios. The patch has a thickness of 2 mm and can withstand a 1064 nm continuous laser power density of 500 W / cm 2 Gaussian spot duration 10s, or 1064nm continuous laser power density 1000W / cm 2 The Gaussian spot duration is 5s, and the center temperature of the back side of the substrate is lower than 230℃. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 It is a schematic flow chart of a method for preparing a flexible anti-laser patch provided by an embodiment of the present invention;

[0027] Figure 2 The embodiment of the present invention provides a flexible anti-laser patch at 1000W / cm 2 Temperature profile of the back side of the laser-irradiated substrate. DETAILED DESCRIPTION

[0028] The following detailed description of the embodiments of the present invention is provided in conjunction with the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention, but cannot be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments.

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] Figure 1A flexible anti-laser patch provided by an embodiment of the present invention includes polyurethane, flake graphite, high-temperature carbide / high-temperature nitride / high-temperature boride, nano-carbon powder / graphene / carbon nanotube powder, zirconium dioxide / silicon dioxide / titanium dioxide, wherein the weight proportion of polyurethane is 5-10%, the weight proportion of flake graphite is 5-10%, the weight proportion of silicon carbide is 10-20%, the total weight proportion of nano-carbon powder and flake graphite is no more than 15%, and the total weight proportion of zirconium dioxide and silicon carbide is 35-45%.

[0031] In the above embodiment, the flexible anti-laser patch can withstand a 1064nm continuous laser power density of 500W / cm when the thickness is 2mm. 2 Gaussian spot duration 10s, or 1064nm continuous laser power density 1000W / cm 2 The Gaussian spot duration is 5s, and the center temperature of the back of the substrate is lower than 230°C. When the thickness of the patch is 2mm, the flexibility is not greater than 6mm, and the volume density of the flexible anti-laser patch is not greater than 2.4g / cm 3 , compared with ceramic anti-laser coatings, it reduces weight by more than 50%.

[0032] Flake graphite is a natural crystalline graphite, which is shaped like fish scales, belongs to the hexagonal system, has a layered structure, and has good high temperature resistance, electrical conductivity, thermal conductivity, lubrication, plasticity, acid and alkali resistance and other properties. Flake graphite is a natural solid lubricant with a layered structure, which is abundant in resources and cheap. The present invention uses a graphite intercalation compound obtained by chemical or electrochemical treatment of flake graphite crystals, called "expandable graphite". The present invention uses expandable graphite with a carbon content of 99% and a sheet size of about 3mm. Expandable graphite with a carbon content of not less than 95% and a sheet size of 50um to 5mm can also be used, with an addition ratio of 5 to 10wt%.

[0033] Furthermore, the diameter of the high temperature carbide / high temperature nitride / high temperature boride is 100nm to 1μm, the diameter of the nano carbon powder / graphene / carbon nanotube powder is 20 to 200mm, and the diameter of the zirconium dioxide / silicon dioxide / titanium dioxide is 50 The high temperature carbide includes at least one of silicon carbide, zirconium carbide and hafnium carbide, the high temperature nitride includes at least one of silicon nitride, zirconium nitride and hafnium nitride, and the high temperature boride includes at least one of silicon boride, zirconium diboride and hafnium diboride.

[0034] In a specific embodiment, the weight ratio of flake graphite, nano-carbon powder / graphene / carbon nanotube powder, high-temperature carbide / high-temperature nitride / high-temperature boride, zirconium dioxide / silicon dioxide / titanium dioxide and polyurethane is 1:1:4:4:10.

[0035] Figure 1is a flow chart of a method for preparing a flexible anti-laser patch provided by an embodiment of the present invention, see Figure 1 , the method may include the following steps:

[0036] S100, uniformly mix the polyurethane and the curing agent at a weight ratio of 100:(3.2-5.5).

[0037] Specifically, when the polyurethane is 100 parts, the curing agent ratio can be between 3.2 and 5.5. Within this range, the curing time decreases as the curing agent ratio increases, that is, the curing is faster.

[0038] S200, mixing flake graphite, high temperature carbide / high temperature nitride / high temperature boride, nano carbon powder / graphene / carbon nanotube powder, zirconium dioxide / silicon dioxide / titanium dioxide and mixed polyurethane according to a set weight ratio.

[0039] S300, mixing the above mixture, 2 to 5 times the weight of ethanol, 2 to 10% by weight of a dispersant and 0.1 to 1% by weight of a defoaming agent, and stirring.

[0040] Specifically, BYK-110 dispersant can be replaced by other copolymer solutions with acidic groups, wherein the solvent can be propylene glycol methyl ether acetate / alkylbenzene or any polar solvent that can be mixed with ethanol, and the addition amount is 2-10wt%. Defom 6800 defoamer can be replaced by other polysiloxane compounds containing hydrophobic particles, and the addition amount is 0.1-1.0wt%. It should be noted that the addition amount of ethanol, dispersant, and defoamer is based on the mixture.

[0041] S400, filtering the mixture to obtain a slurry. Specifically, the mixture can be filtered using a 200-mesh filter.

[0042] S500, scraping the slurry onto the aluminum substrate, scraping the coating again after the coating is dried, and curing the coating at a constant temperature until the coating thickness reaches a preset thickness value to obtain a flexible anti-laser patch.

[0043] Specifically, the surface of the aluminum substrate is wiped clean to be free of oil and impurities, and used as a scraping substrate. The slurry is scraped onto the aluminum substrate with a scraper, the coating speed is 15mm / s, and the single scraping thickness is 0.2mm; the single scraping thickness is 0.1-0.2mm. If it is a single 0.1mm, scrape it 20 times at an angle interval of 0° and 90° until it reaches 2mm. If it is a single 0.2mm, scrape it 10 times in the same way until it reaches 2mm. The coating is dried for no less than 15min. Scrape again and repeat the above steps until the coating thickness reaches the required thickness. The coating is placed at 40°C for constant temperature curing for 24h. The curing temperature cannot be lower than 38°C and cannot be higher than 75°C. The curing time is not less than 24h and not longer than 72h.

[0044] Specifically, the coating is peeled off to obtain a patch, and when in use, glue is applied to the back and pasted to the desired position. Figure 2 As shown, the center temperature of the back side of the substrate with the anti-laser patch attached is lower than 230°C.

[0045] Example 1

[0046] 1. Evenly mix the polyurethane and curing agent in a ratio of 100:4.5 (weight ratio);

[0047] 2. Expanded graphite (carbon content 99.99%, 500-800 mesh), nano carbon powder (D50 = 20nm), silicon carbide

[0048] (D50 = 500 nm), zirconium dioxide (D50 = 1 μm), and the mixed polyurethane were mixed in a ratio of 2:1:4:4:10 (by weight);

[0049] 3. Put the above mixture into a high-speed mixer, add 2 times the weight of ethanol, 10% by weight of BYK-110 dispersant, and 0.8% by weight of Defom6800 defoamer, and stir for 1 to 2 hours;

[0050] 4. Filter the mixture through a 200-mesh filter to obtain a slurry;

[0051] 5. Wipe the surface of the aluminum substrate (2A12T4, thickness 2mm) clean to remove oil stains and impurities, and use it as a scraping substrate;

[0052] 6. Use a scraper to scrape the slurry onto the aluminum substrate at a coating speed of 15 mm / s and a single scraping thickness of 0.2 mm;

[0053] 7. Allow the coating to dry for 0.5h;

[0054] 8. Scrape again and repeat the above steps until the coating thickness reaches the required level;

[0055] 9. The coating is placed at 40°C for constant temperature curing for 24 hours;

[0056] 10. Peel off the coating to get the patch. When using, apply glue on the back and stick it to the required position.

[0057] Anti-laser effect: The patch with a thickness of 2mm can withstand 1064nm continuous laser power density of 500W / cm 2 Gaussian spot duration 12s, or 1064nm continuous laser power density 1000W / cm 2 The Gaussian spot duration is 8s, and the center temperature of the back side of the substrate is lower than 220℃.

[0058] Flexibility effect: When the thickness of the patch is 2mm, the flexibility is no more than 6mm;

[0059] Weight reduction effect: The coating body density is not more than 2.4g / cm 3 , compared with ceramic anti-laser coatings, it reduces weight by more than 50%.

[0060] Example 2

[0061] 1. Evenly mix the polyurethane and curing agent in a ratio of 100:4.5 (weight ratio);

[0062] 2. Mix flake graphite (99% carbon content, size about 3 mm), nano carbon powder (D50 = 20 nm), silicon carbide (D50 = 500 nm), zirconium dioxide (D50 = 1 μm) and the mixed polyurethane in a ratio of 2:1:4:4:10 (weight ratio);

[0063] 3. Put the above mixture into a high-speed mixer, add 2 times the weight of butyl acetate, 10% by weight of BYK-110 dispersant, and 0.8% by weight of Defom6800 defoamer, and stir for 1 to 2 hours;

[0064] 4. Filter the mixture through a 200-mesh filter to obtain a slurry;

[0065] 5. Wipe the surface of the aluminum substrate (2A12T4, thickness 2mm) clean to remove oil stains and impurities, and use it as a scraping substrate;

[0066] 6. Use a scraper to scrape the slurry onto the aluminum substrate at a coating speed of 15 mm / s and a single scraping thickness of 0.2 mm;

[0067] 7. Allow the coating to dry for 0.5h;

[0068] 8. Scrape again and repeat the above steps until the coating thickness reaches the required level;

[0069] 9. The coating is placed at 40°C for constant temperature curing for 24 hours;

[0070] 10. Peel off the coating to get the patch. When using, apply glue on the back and stick it to the required position.

[0071] Anti-laser effect: The patch with a thickness of 2mm can withstand 1064nm continuous laser power density of 500W / cm 2 Gaussian spot duration 10s, or 1064nm continuous laser power density 1000W / cm 2 The Gaussian spot duration is 5s, and the center temperature of the back side of the substrate is lower than 230℃.

[0072] Flexibility effect: When the thickness of the patch is 2mm, the flexibility is no more than 6mm;

[0073] Weight reduction effect: The coating body density is not more than 2.4g / cm 3 , compared with ceramic anti-laser coatings, it reduces weight by more than 50%.

[0074] It should be clear that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. In addition, for the sake of brevity, a detailed description of known methods and technologies is omitted here.

[0075] The above are only embodiments of the present application and are not limited to the present application. For those skilled in the art, the present application may have various changes and variations without departing from the scope of the present invention. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A flexible anti-laser patch, characterized in that: It includes polyurethane, flake graphite, high-temperature carbide / high-temperature nitride / high-temperature boride, nano-carbon powder / graphene / carbon nanotube powder, zirconium dioxide / silicon dioxide / titanium dioxide, wherein the weight proportion of the polyurethane is 5-10%, the weight proportion of the flake graphite is 5-10%, the weight proportion of the silicon carbide is 10-20%, the total weight proportion of the nano-carbon powder and the flake graphite is no more than 15%, and the total weight proportion of the zirconium dioxide and the silicon carbide is 35-45%.

2. The flexible anti-laser patch according to claim 1, characterized in that: The carbon content of the flake graphite is 99%.

3. The flexible anti-laser patch according to claim 1, characterized in that: The diameter of the high temperature carbide / high temperature nitride / high temperature boride is 100 nm to 1 μm.

4. The flexible anti-laser patch according to claim 1, characterized in that: The diameter of the nano-carbon powder / graphene / carbon nanotube powder is 20-200 mm.

5. The flexible anti-laser patch according to claim 1, characterized in that: The zirconium dioxide / silicon dioxide / titanium dioxide D 50 1μm.

6. The flexible anti-laser patch according to claim 1, characterized in that: The weight ratio of the flake graphite, the nano-carbon powder / graphene / carbon nanotube powder, the high-temperature carbide / high-temperature nitride / high-temperature boride, the zirconium dioxide / silicon dioxide / titanium dioxide and the polyurethane is 1:1:4:4:

10.

7. The flexible anti-laser patch according to any one of claims 1 to 6, characterized in that: The high temperature carbide includes at least one of silicon carbide, zirconium carbide and hafnium carbide.

8. The flexible anti-laser patch according to any one of claims 1 to 6, characterized in that: The high temperature nitride includes at least one of silicon nitride, zirconium nitride and hafnium nitride.

9. The flexible anti-laser patch according to any one of claims 1 to 6, characterized in that: The high temperature boride includes at least one of silicon boride, zirconium diboride and hafnium diboride.

10. A method for preparing the flexible anti-laser patch as claimed in claim 1, characterized in that: The method comprises the following steps: The polyurethane and the curing agent are uniformly mixed in a weight ratio of 100:(3.2-5.5); Mixing flake graphite, high temperature carbide / high temperature nitride / high temperature boride, nano carbon powder / graphene / carbon nanotube powder, zirconium dioxide / silicon dioxide / titanium dioxide and mixed polyurethane according to a set weight ratio; The above mixture, 2 to 5 times the weight of ethanol, 2 to 10% by weight of a dispersant and 0.1 to 1% by weight of a defoamer are mixed and stirred; The mixture is filtered to obtain a slurry; The slurry is scraped onto the aluminum substrate, and the coating is scraped again after drying, until the coating thickness reaches a preset thickness value and then cured at a constant temperature to obtain a flexible anti-laser patch.

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