Zirconium-boron-silicon laser protective coating and preparation method thereof

Abstract

The present invention discloses a zirconium-boron-silicon laser protective coating and a preparation method thereof, wherein the coating is made of a zirconium-boron-silicon hybrid resin, a zirconium oxide / hollow microsphere composite material, a zirconium oxide nanofiber, and a characteristic filler. The present invention optimizes the design for the special threat properties of laser weapons through absorption, scattering, reflection, and prevention of heat transfer and other mechanisms, and develops a zirconium-boron-silicon laser protective coating that is lightweight, high-strength, high-temperature stable, corrosion-resistant, and resistant to high-energy laser ablation. The coating has a simple preparation process and can be directly applied to the surface of the protected substrate material. The process stability is good, and the coating can effectively prevent the erosion of high temperature and high-energy particles, thereby protecting the integrity and functionality of the base material. The coating is suitable for the surfaces of materials such as aluminum and steel for aerospace and military use, and can meet the needs of high-energy continuous laser protection.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-energy strong laser protection, and relates to a laser protective coating and a preparation method thereof, and specifically relates to a composite protective coating for surface resistance to laser ablation and a preparation method thereof. Background Art

[0002] With the continuous development of human science and technology, laser weapons have become an important military equipment and have also been widely used in the fields of medicine, communications, material processing, etc. But at the same time, due to the characteristics of high energy density, high power, and high temperature, laser weapons can instantly heat and penetrate the surface or interior of the target in a very short time. Laser weapons pose a considerable threat to both the military and aerospace. In the military, laser weapons can be used to kill enemy personnel, destroy enemy ships and missiles, and attack enemy facilities; in aerospace, laser weapons can threaten various facilities and systems installed on satellites and aircraft in space. Therefore, the development of a protective coating that can effectively resist laser ablation is crucial to protecting the safety of the human body and equipment. Summary of the invention

[0003] The purpose of the present invention is to provide a zirconium-boron-silicon laser protective coating and a preparation method thereof which can be prepared at low temperature and has excellent performance. The anti-laser ablation coating has excellent high temperature stability and high reflectivity and can resist high power density laser ablation.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] A zirconium-boron-silicon laser protective coating is made of the following components: 40 to 60 parts by weight of a zirconium-boron-silicon hybrid resin, 1 to 30 parts by weight of a zirconium oxide / hollow microsphere composite material, 1 to 5 parts by weight of zirconium oxide nanofibers, and 5 to 30 parts by weight of a characteristic filler, wherein:

[0006] The zirconium-boron-silicon hybrid resin is a zirconium-boron modified silicone resin synthesized from siloxane, boric acid and zirconium polyacetylacetonate as raw materials. In the zirconium-boron modified silicone resin, the molar ratio of boron atoms to zirconium atoms is 2:1, and the molar ratio of zirconium atoms to silicon atoms is 1:1-20. The siloxane is one or more of dimethyldiethoxysilane, methyltriethoxysilane, methylphenyldiethoxysilane, phenyltriethoxysilane and diphenyldiethoxysilane.

[0007] The zirconium oxide / hollow microsphere composite material is prepared from zirconium oxide and hollow microspheres as raw materials, and the mass ratio of the zirconium oxide to the hollow microspheres is 1:0.5-5; the hollow microspheres can be one or both of glass hollow microspheres and ceramic hollow microspheres, and the density is ≤0.25g / cm -3 ;

[0008] The diameter of the zirconium oxide nanofiber is 100nm to 1μm;

[0009] The characteristic filler is one or more of silicon carbide, aluminum oxide, silicon dioxide, silicon powder, boron nitride, TaSi2, and MoSi2, with a particle size of 1 to 50 μm and excellent dispersibility.

[0010] A method for preparing the above-mentioned zirconium-boron-silicon laser protective coating comprises the following steps:

[0011] Step 1: Synthesize zirconium-boron-silicon hybrid resin using polyacetylacetonate zirconium, boric acid and siloxane as raw materials. The specific synthesis steps are as follows:

[0012] Step 11, dissolving boric acid in methanol to prepare a boric acid solution;

[0013] Step 1 and 2, after the siloxane and the boric acid solution are evenly mixed, poly(zirconium acetylacetonate) is added while stirring;

[0014] Step 13, add hydrochloric acid and heat to 60-70°C;

[0015] Step 14: add water and react at 60-70° C. for 2-4 hours to obtain zirconium-boron-silicon hybrid resin;

[0016] Step 2: Using zirconium oxide and hollow microspheres as raw materials to prepare a zirconium oxide / hollow microsphere composite material, the specific preparation steps are as follows:

[0017] Step 21: Prepare zirconium oxychloride into a zirconium oxychloride aqueous solution;

[0018] Step 22: Add hollow microspheres to the zirconium oxychloride aqueous solution prepared in step 21, mix and stir evenly, and adjust the pH value to 9-11 with ammonia water;

[0019] Step 23, add glycerol, put it into a hydrothermal reactor and react at 180-200° C. for 10-15 hours, and control the amount of glycerol added to be 0.5-1.5% of the total mass of the zirconium oxychloride aqueous solution and the hollow microspheres;

[0020] Step 24: After natural cooling, take out the product, wash it three times with deionized water, and dry it in an oven at 60-80° C. for 10-15 hours to obtain a zirconium oxide / hollow microsphere composite material;

[0021] Step 3: using an ethanol solution containing a silane coupling agent to perform surface modification on the zirconium oxide nanofibers, the characteristic filler and the substrate, wherein:

[0022] The modification treatment method of the substrate surface is as follows: first remove the oil stains on the substrate surface, then polish the substrate surface with 100 mesh and 400 mesh sandpaper in turn, and finally soak it in an ethanol solution containing 5-10% by mass of a silane coupling agent for 1-2 hours, and then take it out and dry it;

[0023] The modification method of the zirconia nanofiber and the characteristic filler is as follows: the zirconia nanofiber and the characteristic filler are respectively placed in an ethanol solution containing 5-10% by mass of a silane coupling agent, stirred in a constant temperature water bath at 60° C. for 120-180 minutes, and then filtered, dried, and ground and dispersed;

[0024] The silane coupling agent is one or more of KH550, KH560, KH570 and KH590;

[0025] Step 4: adding the zirconium oxide / hollow microsphere composite material obtained in step 2 and the modified zirconium oxide nanofiber and characteristic filler obtained in step 3 to the zirconium-boron-silicon hybrid resin obtained in step 1, mixing, and stirring to obtain a composite coating, wherein: the zirconium oxide / hollow microsphere composite material, the modified zirconium oxide fiber and the characteristic filler are added to the zirconium-boron-silicon hybrid resin in small amounts and multiple times and stirred at high speed;

[0026] Step 5: coating the composite coating obtained in step 4 on the substrate treated in step 3, and curing in an oven at 60-80° C. for 45-50 hours;

[0027] Step 6: Repeat step 5 until the desired coating thickness is reached, thereby obtaining a zirconium-boron-silicon laser protective coating, wherein the thickness of the zirconium-boron-silicon laser protective coating is about 1 to 2 mm, and the coating thickness does not exceed 0.5 mm each time.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] 1. The present invention uses zirconium polyacetylacetonate, boric acid and siloxane as raw materials to synthesize zirconium-boron-silicon hybrid resin. The resin has Si-O-Si as the main chain, contains Zr-O bonds and BO bonds, and has good thermal stability. The resin can undergo a ceramic transformation at high temperatures to form ceramic phases such as ZrO2, ZrB2, ZrC, SiC, etc. with high strength, high hardness, high temperature tolerance and chemical stability. Therefore, the coating has good heat resistance and stability, and its advantages are more obvious at higher temperatures; the main chain has no carbon atoms, and no carbon layer is formed at high temperatures, which effectively reduces the absorption of heat and overcomes the problem that traditional organic resins have a sharp temperature rise after carbonization and thus cause structural failure.

[0030] 2. Zirconia has good reflectivity (the average reflectivity of visible light is about 85%, and the reflectivity in the near-infrared band can reach more than 90%), which can effectively reflect the heat released by high-energy laser ablation. The hollow structure of hollow microspheres can reduce the density of the material. The hollow microspheres can also be used as laser scatterers to scatter and absorb laser energy in laser protection materials. The hollow microspheres have low thermal conductivity and can block the transmission and diffusion of thermal energy. The zirconium oxide / hollow microsphere composite material prepared by coating the hollow microspheres with zirconium oxide particles can not only reduce the density of the material, but also block the transmission and diffusion of thermal energy and scatter laser energy. Zirconia fiber and zirconia / hollow microsphere composite materials have good reflectivity and can effectively reflect the heat released by high-energy laser ablation. Zirconia has a very high melting point and density. When the surface of zirconia is irradiated by high-energy laser, an oxide film will be formed, which can further prevent oxidation and ablation. Some characteristic fillers have a high absorption capacity for lasers, which can convert laser energy into heat energy and dissipate it. They also have a certain scattering or reflection capacity for lasers. Some characteristic fillers have high hardness, high temperature stability, and can enhance the service life of the coating. The present invention strengthens the protective effect of the composite coating against high-energy lasers through various mechanisms such as absorption, scattering, and reflection, and is widely used in various fields.

[0031] 3. The present invention optimizes the design according to the special threat nature of laser weapons through various mechanisms such as absorption, scattering, reflection, and prevention of heat transfer, and has developed a new zirconium-boron-silicon laser protective coating that is lightweight, high-strength, stable at high temperatures, has good corrosion resistance, and is resistant to high-energy laser ablation. The preparation process of the coating is simple and can be directly applied to the surface of the protected substrate material. The process stability is good, and the coating can effectively prevent the erosion of high-temperature and high-energy particles, thereby protecting the integrity and functionality of the base material. It is suitable for the surfaces of aluminum, steel and other materials for aerospace and military use, and can meet the needs of high-energy continuous laser protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is the infrared spectrum of the zirconium-boron-silicon resin obtained in Example 1;

[0033] Figure 2 This is the infrared spectrum of the zirconium oxide / hollow microsphere composite material obtained in Example 1;

[0034] Figure 3 This is the EDS image of the zirconium oxide / hollow microsphere composite material obtained in Example 1;

[0035] Figure 4 This is the XRD pattern of the zirconium oxide / hollow microsphere composite material obtained in Example 1 after being treated at 1200°C;

[0036] Figure 5The morphology of the coating obtained in Example 1, (a) macroscopic image, (b) SEM image;

[0037] Figure 6 The morphology of the coating obtained in Example 1 after oxyacetylene flame ablation: (a) macroscopic image, (b) SEM image. DETAILED DESCRIPTION

[0038] The technical solution of the present invention is further described below in conjunction with the accompanying drawings, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be included in the protection scope of the present invention.

[0039] Example 1

[0040] Step 1: Take 2.43g of boric acid and dissolve it in 9.72g of methanol to prepare a boric acid solution, put 26.745g of methyltriethoxysilane, 14.828g of dimethyldiethoxysilane and the boric acid solution into a three-necked flask with a condenser, mix them evenly, add polyacetylacetonate zirconium with a dropping funnel while stirring, and finally add 0.5ml of 1mol / L hydrochloric acid, heat to 65°C, add 7.02g of water with a dropping funnel, react at 65°C for 3 hours, cool naturally and take out the product to obtain a zirconium-boron-silicon hybrid resin;

[0041] Step 2, 1.78g of zirconium oxychloride was prepared into a 0.1mol / L aqueous solution, 1g of hollow silica microspheres was added to the aqueous solution and mixed and stirred evenly, the pH was adjusted to 10 with ammonia water, and finally 1wt% of propylene glycol was added, and the mixture was placed in a hydrothermal reactor and reacted at 180°C for 12h, and the product was taken out after natural cooling, washed three times with deionized water, and dried in an oven at 60°C for 12h to obtain a zirconium oxide / hollow microsphere composite material;

[0042] Step 3, first remove the oil stains on the surface of the substrate, then polish the surface of the substrate with 100 mesh and 400 mesh sandpaper in turn, and finally soak it in an ethanol solution containing 10% KH550 by mass for 2 hours, take it out and dry it in a vacuum drying oven at 120°C for 80 minutes; put the zirconium oxide nanofiber into an ethanol solution containing 10% KH550 by mass, stir it in a constant temperature water bath at 60°C for 120 minutes, filter, dry and grind it to disperse; 2 parts by weight of silicon carbide, 1 part by weight of aluminum oxide and 3 parts by weight of zirconium boride are mixed and ground evenly, put it into an ethanol solution containing 10% KH550 by mass, stir it in a constant temperature water bath at 60°C for 120 minutes, filter, dry and grind it to disperse;

[0043] Step 4: Add 5 parts by weight of the zirconium oxide / hollow microsphere composite material obtained in step 2, 5 parts by weight of the zirconium oxide nanofibers obtained in step 3, and 30 parts by weight of the characteristic filler to 60 parts by weight of the zirconium-boron-silicon hybrid resin obtained in step 1 in small amounts several times and stir at high speed to obtain a uniformly dispersed composite coating;

[0044] Step 5. Apply the composite coating obtained in step 4 on the substrate treated in step 3, cure it in an oven at 60°C for 48 hours, and repeat the above operation until the desired coating thickness (2 mm) is reached to obtain a zirconium-boron-silicon laser protective coating resistant to high-energy laser ablation.

[0045] Depend on Figure 1 It can be seen that zirconium and boron elements were successfully introduced into silicone resin; Figure 2 and Figure 3 It can be seen that zirconium element is introduced into the hollow microspheres, and zirconium is introduced into the system by chemical bonding; Figure 4 It can be seen that after high temperature treatment, the zirconium oxide / hollow microsphere composite material generates a crystalline phase of zirconium oxide, which has a high reflectivity and effectively enhances the reflection ability of laser. Figure 5 It can be seen that the coating has a dense surface structure; Figure 6 It can be seen that after oxyacetylene flame treatment, the coating structure remains basically intact and the ablated area still has good density.

[0046] Example 2

[0047] Step 1: Take 2.43g of boric acid and dissolve it in 9.72g of methanol to prepare a boric acid solution, put 26.745g of methyltriethoxysilane, 14.828g of dimethyldiethoxysilane and the boric acid solution into a three-necked flask with a condenser, mix them evenly, add 9.954g of polyacetylacetonate zirconium with a dropping funnel while stirring, and finally add 0.5ml of 1mol / L hydrochloric acid, heat to 65°C, add 7.02g of water with a dropping funnel, react at 65°C for three hours, cool naturally and take out the product to obtain a zirconium-boron-silicon hybrid resin;

[0048] Step 2, 0.89g of zirconium oxychloride is prepared into a 0.05mol / L aqueous solution, 1g of hollow silica microspheres is added to the aqueous solution and mixed and stirred evenly, the pH is adjusted to 10 with ammonia water, and finally 1wt% of propylene glycol is added, and the mixture is placed in a hydrothermal reactor and reacted at 180°C for 12h, and the product is taken out after natural cooling, washed three times with deionized water, and dried in an oven at 60°C for 12h to obtain a zirconium oxide / hollow microsphere composite material;

[0049] Step 3, first remove the oil stains on the surface of the substrate, then polish the surface of the substrate with 100 mesh and 400 mesh sandpaper in turn, and finally soak it in an ethanol solution containing 10% KH560 by mass for 1.5 hours, take it out and dry it in a vacuum drying oven at 120°C for 60 minutes; put the zirconium oxide nanofiber into an ethanol solution containing 10% KH560 by mass, stir it in a constant temperature water bath at 60°C for 120 minutes, filter, dry and grind it to disperse; 2 parts by weight of silicon carbide, 1 part by weight of aluminum oxide and 3 parts by weight of zirconium boride are mixed and ground evenly, put it into an ethanol solution containing 10% KH560 by mass, stir it in a constant temperature water bath at 60°C for 120 minutes, filter, dry and grind it to disperse;

[0050] Step 4: Add 5 parts by weight of the zirconium oxide / hollow microsphere composite material obtained in step 2, 3 parts by weight of zirconium oxide nanofibers obtained in step 3, and 30 parts by weight of characteristic fillers to 60 parts by weight of the zirconium-boron-silicon hybrid resin obtained in step 1 in small amounts several times and stir at high speed to obtain a uniformly dispersed composite coating;

[0051] Step 5: Apply the composite coating obtained in step 4 on the substrate treated in step 3, cure it in an oven at 60°C for 48 hours, and repeat the above operation until the desired coating thickness (2 mm) is reached to obtain a zirconium-boron-silicon laser protective coating.

[0052] Example 3

[0053] Step 1: Take 2.43g of boric acid and dissolve it in 9.72g of methanol to prepare a boric acid solution, put 26.745g of methyltriethoxysilane, 29.626g of dimethyldiethoxysilane and the boric acid solution into a three-necked flask with a condenser, mix them evenly, add 9.954g of polyacetylacetonate zirconium with a dropping funnel while stirring, and finally add 0.5ml of 1mol / L hydrochloric acid, heat to 65°C, add 9.18g of water with a dropping funnel, react at 65°C for three hours, cool naturally and take out the product to obtain a zirconium-boron-silicon hybrid resin;

[0054] Step 2, 1.78g of zirconium oxychloride was prepared into a 0.1mol / L aqueous solution, 1g of hollow silica microspheres was added to the aqueous solution and mixed and stirred evenly, the pH was adjusted to 10 with ammonia water, and finally 1wt% of propylene glycol was added, and the mixture was placed in a hydrothermal reactor and reacted at 180°C for 12h, and the product was taken out after natural cooling, washed three times with deionized water, and dried in an oven at 60°C for 12h to obtain a zirconium oxide / hollow microsphere composite material;

[0055] Step 3, first remove the oil stains on the surface of the substrate, then polish the surface of the substrate with 100 mesh and 400 mesh sandpaper in turn, and finally soak it in an ethanol solution containing 10% KH550 by mass for 1.5 hours, take it out and dry it in a vacuum drying oven at 120°C for 60 minutes; put the zirconium oxide nanofiber into an ethanol solution containing 10% KH550 by mass, stir it in a constant temperature water bath at 60°C for 120 minutes, filter, dry and grind it to disperse; 2 parts by weight of silicon carbide, 1 part by weight of aluminum oxide and 3 parts by weight of zirconium boride are mixed and ground evenly, put it into an ethanol solution containing 10% KH550 by mass, stir it in a constant temperature water bath at 60°C for 120 minutes, filter, dry and grind it to disperse;

[0056] Step 4: Add 5 parts by weight of the zirconium oxide / hollow microsphere composite material obtained in step 2, 5 parts by weight of the zirconium oxide nanofibers obtained in step 3, and 20 parts by weight of the characteristic filler to 40 parts by weight of the zirconium-boron-silicon hybrid resin obtained in step 1 in small amounts several times and stir at high speed to obtain a uniformly dispersed composite coating;

[0057] Step 5: Apply the composite coating obtained in step 4 on the substrate treated in step 3, cure it in an oven at 60°C for 48 hours, and repeat the above operation until the desired coating thickness (2 mm) is reached to obtain a zirconium-boron-silicon laser protective coating.

Claims

1. A method for preparing a zirconium-boron-silicon laser protective coating, characterized in that The method comprises the following steps: Step 1: Synthesize zirconium-boron-silicon hybrid resin using polyacetylacetonate zirconium, boric acid and siloxane as raw materials. The specific synthesis steps are as follows: Step 11, dissolving boric acid in methanol to prepare a boric acid solution; Step 1 and 2, after the siloxane and the boric acid solution are evenly mixed, poly(zirconium acetylacetonate) is added while stirring; Step 13, add hydrochloric acid and raise the temperature to 60~70℃; Step 14: add water and react at 60-70°C for 2-4 hours to obtain zirconium-boron-silicon hybrid resin; Step 2: Using zirconium oxide and hollow microspheres as raw materials to prepare a zirconium oxide / hollow microsphere composite material, the specific preparation steps are as follows: Step 21: Prepare zirconium oxychloride into a zirconium oxychloride aqueous solution; Step 22: Add hollow microspheres to the zirconium oxychloride aqueous solution prepared in step 21, mix and stir evenly, and adjust the pH to 9-11 with ammonia water; Step 2-3, add glycerol, put it into a hydrothermal reactor and react at 180-200° C. for 10-15 hours, and control the amount of glycerol added to be 0.5-1.5% of the total mass of the zirconium oxychloride aqueous solution and the hollow microspheres; Step 24: After natural cooling, take out the product, wash it three times with deionized water, and dry it in an oven at 60-80° C. for 10-15 hours to obtain a zirconium oxide / hollow microsphere composite material; Step 3: using an ethanol solution containing a silane coupling agent to perform surface modification treatment on the zirconium oxide nanofibers, the characteristic filler and the substrate, wherein the characteristic filler is one or more of silicon carbide, aluminum oxide, silicon dioxide, silicon powder, boron nitride, TaSi2, and MoSi2; Step 4: adding the zirconium oxide / hollow microsphere composite material obtained in step 2 and the modified zirconium oxide nanofibers and characteristic fillers obtained in step 3 to the zirconium-boron-silicon hybrid resin obtained in step 1, mixing, and stirring to obtain a composite coating; Step 5: coating the composite coating obtained in step 4 on the substrate treated in step 3, and curing in an oven at 60-80° C. for 45-50 hours; Step 6. Repeat step 5 until the desired coating thickness is reached to obtain a zirconium-boron-silicon laser protective coating, which is made of the following components: 40 to 60 parts by weight of a zirconium-boron-silicon hybrid resin, 1 to 30 parts by weight of a zirconium oxide / hollow microsphere composite material, 1 to 5 parts by weight of zirconium oxide nanofibers, and 5 to 30 parts by weight of a characteristic filler.

2. The method for preparing the zirconium-boron-silicon laser protective coating according to claim 1, characterized in that The zirconium-boron-silicon hybrid resin is a zirconium-boron modified silicone resin synthesized from siloxane, boric acid and zirconium polyacetylacetonate as raw materials. In the zirconium-boron modified silicone resin, the molar ratio of boron atoms to zirconium atoms is 2:1, and the molar ratio of zirconium atoms to silicon atoms is 1:1-20.

3. The method for preparing the zirconium-boron-silicon laser protective coating according to claim 2, characterized in that The siloxane is one or more of dimethyldiethoxysilane, methyltriethoxysilane, methylphenyldiethoxysilane, phenyltriethoxysilane and diphenyldiethoxysilane.

4. The method for preparing the zirconium-boron-silicon laser protective coating according to claim 1, characterized in that The zirconia / hollow microsphere composite material is prepared with zirconia and hollow microspheres as raw materials, the mass ratio of the zirconia to the hollow microspheres is 1:0.5-5, and the hollow microspheres are one or both of glass hollow microspheres and ceramic hollow microspheres.

5. The method for preparing the zirconium-boron-silicon laser protective coating according to claim 1, characterized in that The diameter of the zirconium oxide nanofiber is 100 nm to 1 μm.

6. The method for preparing the zirconium-boron-silicon laser protective coating according to claim 1, characterized in that The particle size of the characteristic filler is 1 to 50 μm.

7. The method for preparing the zirconium-boron-silicon laser protective coating according to claim 1, characterized in that The modification treatment method of the substrate surface is as follows: first remove the oil stains on the substrate surface, then polish the substrate surface with 100 mesh and 400 mesh sandpaper in turn, and finally soak it in an ethanol solution containing a silane coupling agent with a mass fraction of 5-10% for 1-2 hours, and then take it out and dry it; the modification treatment method of the zirconia nanofiber and the special filler is as follows: respectively put the zirconia nanofiber and the special filler into an ethanol solution containing a silane coupling agent with a mass fraction of 5-10%, stir it in a constant temperature water bath at 60°C for 120-180 minutes, and then filter, dry and grind and disperse it.

8. The method for preparing the zirconium-boron-silicon laser protective coating according to claim 1 or 2, characterized in that The silane coupling agent is one or more of KH550, KH560, KH570 and KH590.

9. The method for preparing the zirconium-boron-silicon laser protective coating according to claim 1, characterized in that The thickness of the zirconium-boron-silicon laser protective coating is 1 to 2 mm, and the thickness of each coating does not exceed 0.5 mm.

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