A laser protective coating and its preparation method

Abstract

This invention relates to the field of laser protection technology, specifically to a laser protection coating and its preparation method. The laser protection coating comprises a reflective ceramic layer, a heat-insulating ceramic layer, and at least three gradient ceramic layers located between the reflective and heat-insulating ceramic layers. The reflective ceramic layer comprises barium titanate and its doped system, and / or pyrochlore and its doped system; the heat-insulating ceramic layer comprises yttrium-stabilized zirconium oxide and its doped system, and / or rare-earth tantalates and their doped systems. The purpose of this laser protection coating and its preparation method is to address the problem of low optical reflectivity in existing laser-resistant materials.

Description

Technical Field

[0001] This invention relates to the field of laser protection technology, specifically to a laser protection coating and its preparation method. Background Technology

[0002] When the laser power density irradiating a target exceeds the material's damage threshold, the target suffers damage such as melting, pyrolysis, vaporization, and cracking. When a laser with sufficient energy irradiates the surface of a protective coating, some energy is reflected / scattered, and the deposited energy generates a secondary heat source at the skin depth and propagates inward. During this process, the heat decreases geometrically according to the Lambert-Beer-Bouguer law. Clearly, the protective coating's ability to resist laser irradiation depends on both energy deposition and heat transfer processes. High reflectivity can reduce deposited energy, lower the heating rate, and increase the surface melting and vaporization thresholds; while low thermal conductivity can reduce the rate of heat transfer to the substrate, increasing the aircraft's dwell time and achieving the goal of resisting laser damage. Therefore, developing protective coatings with low thermal conductivity and high reflectivity is key to resisting laser hard-kill damage.

[0003] Currently, one type of laser-resistant coating is a ceramic coating. However, ceramics have a large band gap between their conduction and valence bands, resulting in a significantly lower electron density compared to metals, making it difficult for ceramics to achieve high optical reflectivity. Therefore, combining reflective ceramics with low thermal conductivity ceramics can achieve a coupling of these two functions. However, the thermal expansion coefficients of the two types of ceramics are mismatched, making it difficult to obtain a complete coating simply by physically combining them.

[0004] Therefore, the inventors provide a laser protective coating and its preparation method. Summary of the Invention

[0005] (1) Technical problems to be solved

[0006] This invention provides a laser protective coating and its preparation method, which solves the technical problem of low optical reflectivity of existing anti-laser materials.

[0007] (2) Technical solution

[0008] This invention provides a laser protective coating, comprising a reflective ceramic layer, a heat-insulating ceramic layer, and at least three gradient ceramic layers located between the reflective ceramic layer and the heat-insulating ceramic layer; wherein,

[0009] The reflective ceramic layer includes barium titanate and its doped system, and / or pyrochlore and its doped system;

[0010] The heat-insulating ceramic layer includes yttrium-stabilized zirconium oxide and its doped system, and / or rare earth tantalates and their doped systems.

[0011] Furthermore, the gradient ceramic layer is a hybrid coating of reflective ceramic and heat-insulating ceramic.

[0012] Furthermore, the mixing ratio of reflective ceramic and heat-insulating ceramic in the gradient ceramic layer is gradient-distributed according to the spraying sequence of the multiple gradient ceramic layers.

[0013] Furthermore, strontium is doped into the barium titanate doping system.

[0014] Furthermore, the strontium doping amount in the barium titanate doped system is 5–15 mol%.

[0015] Furthermore, strontium is doped into the pyrochlore doping system.

[0016] Furthermore, the strontium doping amount in the pyrochlore doped system is 5–15 mol%.

[0017] This invention also provides a method for preparing a laser protective coating, comprising the following steps:

[0018] The base material is placed in the processing position, and the surface of the base material is sandblasted.

[0019] An adhesive layer is prepared on the surface of the sandblasted substrate material, and a heat-insulating ceramic coating is sprayed onto the surface of the adhesive layer.

[0020] At least three layers of gradient ceramic coating are sequentially sprayed onto the surface of the heat-insulating ceramic coating, wherein the mixing ratio of reflective ceramic and heat-insulating ceramic in each layer of gradient ceramic coating is gradient distributed.

[0021] A reflective ceramic coating is sprayed onto the surface of the top gradient ceramic coating.

[0022] Furthermore, after each layer of spray coating is applied, a surface smoothing treatment is performed, and the surface roughness is less than 5μm.

[0023] Furthermore, the thickness of each spray coating layer is less than 0.5 mm.

[0024] (3) Beneficial effects

[0025] In summary, this invention prepares a gradient ceramic layer by mixing reflective ceramics and heat-insulating ceramics in different proportions. By matching the mixing ratios between the layers, a good interfacial bond between the reflective ceramics and the heat-insulating ceramics is achieved, forming a complete laser protective coating. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of a laser protective coating provided in an embodiment of the present invention;

[0028] Figure 2 This is a schematic flowchart of a method for preparing a laser protective coating provided in an embodiment of the present invention.

[0029] In the picture:

[0030] 1-Reflective ceramic layer; 2-Insulating ceramic layer; 3-Gradient ceramic layer; 301-First gradient ceramic layer; 302-Second gradient ceramic layer; 303-Third gradient ceramic layer. Detailed Implementation

[0031] The embodiments of the present invention will be further described in detail below with reference to 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 by way of example, but should not be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments.

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] Figure 1This is a schematic diagram of a laser protective coating provided in an embodiment of the present invention, including a reflective ceramic layer 1, a heat-insulating ceramic layer 2, and at least three gradient ceramic layers 3 located between the reflective ceramic layer and the heat-insulating ceramic layer. The reflective ceramic layer 1 includes barium titanate (BaTiO3) and its doped system, and / or pyrochlore (Gd2Zr2O7) and its doped system; the heat-insulating ceramic layer 2 includes yttrium-stabilized zirconium oxide (YSZ) and its doped system, and / or rare earth tantalates (including but not limited to SmTaO4, DyTaO4) and their doped systems.

[0035] In the above embodiments, the gradient ceramic layer 3 is a mixed coating of reflective ceramic and heat-insulating ceramic, and the mixing ratio of reflective ceramic and heat-insulating ceramic in the gradient ceramic layer 3 is gradient-distributed according to the spraying sequence of the multi-layer gradient ceramic layers. Taking a three-layer gradient ceramic layer 3 as an example, it includes a first gradient ceramic layer 301, a second gradient ceramic layer 302, and a third gradient ceramic layer 303, as follows. Figure 1 As shown, the heat-insulating ceramic layer 2, the third gradient ceramic layer 303, the second gradient ceramic layer 302, the first gradient ceramic layer 301, and the reflective ceramic layer 1 are sprayed and bonded sequentially from bottom to top.

[0036] In the barium titanate doping system, strontium is doped with a doping amount of 5–15 mol%. In the pyrochlore doping system, strontium is doped with a doping amount of 5–15 mol%. After testing, it was found that the reflectivity of the reflective ceramic layer 1 was significantly improved after strontium doping.

[0037] The reflectivity of the coating was measured using a spectrophotometer. After treatment, the laser reflectivity of the coating in the 355nm–10.6μm wavelength range was above 90%. The coating also exhibited reflectivity at 1064nm and 2000W / cm². 2 No visible damage was observed after 15 seconds of continuous laser irradiation with a 1cm spot, while the coating without a gradient layer, where barium titanate (0.5mm) was directly sprayed onto a zirconia layer (1mm), cracked after 5 seconds of irradiation with the same level of laser. The adhesion between the coating and the substrate material was not less than 8MPa.

[0038] Figure 2 This is a schematic flowchart of a method for preparing a laser protective coating according to an embodiment of the present invention. The method may include the following steps:

[0039] S100. Place the base material in the processing position and sandblast the surface of the base material.

[0040] S200. An adhesive layer is prepared on the surface of the sandblasted substrate material, and a heat-insulating ceramic coating is sprayed onto the surface of the adhesive layer.

[0041] S300. At least three layers of gradient ceramic coating are sequentially sprayed onto the surface of the heat-insulating ceramic coating, wherein the mixing ratio of reflective ceramic and heat-insulating ceramic in each layer of gradient ceramic coating is gradient distributed.

[0042] S400: A reflective ceramic coating is sprayed onto the surface of the top gradient ceramic coating.

[0043] In the above embodiments, the substrate material is cleaned with ethanol, and after each layer of spray coating is applied, a surface smoothing treatment is performed, with a surface roughness of less than 5 μm. The thickness of each layer of spray coating is less than 0.5 mm.

[0044] Example 1 (The substrate material is T800 carbon fiber composite)

[0045] 1. Place the base material in the processing position. The base material is T800 carbon fiber composite with a thickness of 5mm. Clean the processing surface of the plate with ethanol and place it in the processing position with the fixture.

[0046] 2. Sandblasting the surface of the board;

[0047] 3. Prepare an adhesive layer on the surface of the sandblasted board;

[0048] 4. The adhesive layer surface is plasma-sprayed with a YSZ coating, with a coating thickness of 0.5mm;

[0049] 5. Grind the YSZ coating surface until it is smooth, with a surface roughness of less than 5μm;

[0050] 6. Plasma spray a mixed coating of YSZ and BaTiO3 onto the YSZ coating surface, with a mixing ratio of 7:3 (wt%) and a mixed coating thickness of 0.3 mm.

[0051] 7. Grind the surface of the mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0052] 8. Plasma spray a second mixed coating of YSZ and BaTiO3 onto the surface of the mixed coating, with a mixing ratio of 5:5 (wt%) and a thickness of 0.3 mm.

[0053] 9. Grind the surface of the second mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0054] 10. Plasma-spray a third mixed coating of YSZ and BaTiO3 onto the surface of the second mixed coating, with a mixing ratio of 3:7 (wt%) and a mixed coating thickness of 0.3 mm.

[0055] 11. Grind the surface of the third mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0056] 12. Plasma spray BaTiO3 onto the surface of the third mixed coating, with a coating thickness of 0.5 mm;

[0057] 13. Polish the BaTiO3 coating until it is smooth, with a surface roughness of less than 5μm, to complete the coating preparation.

[0058] In this embodiment, the laser reflectivity of the treated coating in the 355nm–10.6μm wavelength range is above 88%, and the interfacial adhesion is 8.3MPa. The coating at 1064nm and 2000W / cm²... 2 No visible damage was observed when a 1cm spot of continuous laser irradiation was applied for 16s. However, without a gradient layer, the coating of BaTiO3 (0.5mm) directly sprayed onto the YSZ layer (1mm) cracked after 5s under the same level of laser irradiation.

[0059] Example 2 (The base material is TC4 titanium alloy sheet)

[0060] 1. Place the base material in the processing position. The base material is TC4 titanium alloy sheet with a thickness of 3mm. Clean the processing surface of the sheet with ethanol and place it in the processing position using a fixture.

[0061] 2. Sandblasting the surface of the board;

[0062] 3. Prepare an adhesive layer on the surface of the sandblasted board;

[0063] 4. The adhesive layer surface is plasma-sprayed with a YSZ coating, with a coating thickness of 0.5mm;

[0064] 5. Grind the YSZ coating surface until it is smooth, with a surface roughness of less than 5μm;

[0065] 6. Plasma-spray a mixed coating of YSZ and Sr-doped BaTiO3 onto the YSZ coating surface, with a mixing ratio of 7:3 (wt%) and a mixed coating thickness of 0.2 mm.

[0066] 7. Grind the surface of the mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0067] 8. Plasma-spray a second mixed coating of YSZ and Sr-doped BaTiO3 onto the surface of the mixed coating, with a mixing ratio of 6:4 (wt%) and a thickness of 0.2 mm.

[0068] 9. Plasma spray a second mixed coating of YSZ and Sr-doped BaTiO3 onto the surface of the mixed coating, with a mixing ratio of 4:6 (wt%) and a thickness of 0.2 mm.

[0069] 10. Grind the surface of the second mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0070] 11. Plasma spray a third mixed coating of YSZ and Sr-doped BaTiO3 onto the surface of the mixed coating, with a mixing ratio of 6:4 (wt%) and a thickness of 0.2 mm.

[0071] 12. Grind the surface of the second mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0072] 13. Plasma-spray a fourth mixed coating of YSZ and Sr-doped BaTiO3 onto the surface of the second mixed coating, with a mixing ratio of 3:7 (wt%) and a mixed coating thickness of 0.2 mm.

[0073] 14. Grind the surface of the third mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0074] 15. Plasma-spray Sr-doped BaTiO3 onto the surface of the third hybrid coating, with a coating thickness of 0.5 mm;

[0075] 16. Polish the Sr-doped BaTiO3 coating until it is smooth, with a surface roughness of less than 5 μm, to complete the coating preparation.

[0076] In this embodiment, the laser reflectivity of the treated coating in the 355nm–10.6μm wavelength range is above 91%, and the interfacial adhesion is 7.8MPa. The coating at 1064nm has a wavelength of 2000W / cm². 2 No visible damage was observed when a 1cm spot of continuous laser irradiation was applied for 20s. However, without a gradient layer, the coating of BaTiO3 (0.5mm) directly sprayed onto the YSZ layer (1mm) cracked after 5s under the same level of laser irradiation.

[0077] Example 3 (The substrate material is T800 carbon fiber composite)

[0078] 1. Place the base material in the processing position. The base material is T800 carbon fiber composite with a thickness of 10mm. Clean the processing surface of the plate with ethanol and place it in the processing position with the fixture.

[0079] 2. Sandblasting the surface of the board;

[0080] 3. Prepare an adhesive layer on the surface of the sandblasted board;

[0081] 4. Plasma-sprayed SmTaO4 coating is applied to the surface of the adhesive layer, with a coating thickness of 0.5mm;

[0082] 5. Grind the SmTaO4 coating surface until it is smooth, with a surface roughness of less than 5μm;

[0083] 6. Plasma-spray a mixed coating of SmTaO4 and Sr-doped BaTiO3 onto the SmTaO4 coating surface, with a mixing ratio of 7:3 (wt%) and a mixed coating thickness of 0.2 mm.

[0084] 7. Grind the surface of the mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0085] 8. Plasma-spray a second mixed coating of SmTaO4 and Sr-doped BaTiO3 onto the surface of the mixed coating, with a mixing ratio of 6:4 (wt%) and a thickness of 0.2 mm.

[0086] 9. Grind the surface of the second mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0087] 10. Plasma spray a second mixed coating of SmTaO4 and Sr-doped BaTiO3 onto the surface of the mixed coating, with a mixing ratio of 4:6 (wt%) and a thickness of 0.2 mm.

[0088] 11. Grind the surface of the second mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0089] 12. Plasma-spray a third mixed coating of SmTaO4 and Sr-doped BaTiO3 onto the surface of the second mixed coating, with a mixing ratio of 3:7 (wt%) and a mixed coating thickness of 0.2 mm.

[0090] 13. Grind the surface of the third mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0091] 14. Plasma-spray Sr-doped BaTiO3 onto the surface of the third hybrid coating, with a coating thickness of 0.5 mm;

[0092] 15. Polish the Sr-doped BaTiO3 coating until it is smooth, with a surface roughness of less than 5 μm, to complete the coating preparation.

[0093] In this embodiment, the laser reflectivity of the treated coating in the 355nm–10.6μm wavelength range is above 89%, and the interfacial adhesion is 8.2MPa. The coating at 1064nm has a wavelength of 2000W / cm². 2 No visible damage was observed when a 1cm spot of continuous laser irradiation was applied for 17s. However, the coating without a gradient layer, on which BaTiO3 (0.5mm) was directly sprayed onto the YSZ layer (1mm), cracked after 5s under the same level of laser irradiation.

[0094] Example 4 (The substrate material is TC4 board)

[0095] 1. Place the base material in the processing position. The base material is TC4 sheet with a thickness of 5mm. Clean the processing surface of the sheet with ethanol and place it in the processing position using a fixture.

[0096] 2. Sandblasting the surface of the board;

[0097] 3. Prepare an adhesive layer on the surface of the sandblasted board;

[0098] 4. The adhesive layer surface is plasma-sprayed with a YSZ coating, with a coating thickness of 0.5mm;

[0099] 5. Grind the YSZ coating surface until it is smooth, with a surface roughness of less than 5μm;

[0100] 6. Plasma-spray a mixed coating of YSZ and Gd2Zr2O7 onto the YSZ coating surface, with a mixing ratio of 73 (wt%) and a mixed coating thickness of 0.2 mm.

[0101] 7. Grind the surface of the mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0102] 8. Plasma spray a second mixed coating of YSZ and Gd2Zr2O7 onto the surface of the mixed coating, with a mixing ratio of 6:4 (wt%) and a thickness of 0.2 mm.

[0103] 9. Grind the surface of the second mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0104] 10. Plasma-spray a third mixed coating of YSZ and Gd2Zr2O7 onto the surface of the second mixed coating, with a mixing ratio of 4:6 (wt%) and a mixed coating thickness of 0.2 mm.

[0105] 11. Grind the surface of the third mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0106] 12. Plasma spray a fourth mixed coating of YSZ and Gd2Zr2O7 onto the surface of the third mixed coating, with a mixing ratio of 3:7 (wt%) and a mixed coating thickness of 0.2 mm.

[0107] 13. Plasma-spray a Gd2Zr2O7 coating onto the surface of the third mixed coating, with a coating thickness of 0.5 mm;

[0108] 14. Polish the Gd2Zr2O7 coating until it is smooth, with a surface roughness of less than 5μm, to complete the coating preparation.

[0109] In this embodiment, the laser reflectivity of the treated coating in the 355nm–10.6μm wavelength range is above 92%, and the interfacial adhesion is 7.5MPa. The coating at 1064nm and 2000W / cm²... 2 No visible damage was observed when a 1cm spot of continuous laser irradiation was applied for 20s. However, in the case of a coating without a gradient layer, BaTiO3 (0.5mm) was directly sprayed onto the YSZ layer (1mm). In this example, the coating on the coating cracked after 5s under the same level of laser irradiation.

[0110] Example 5 (The substrate material is T800 composite)

[0111] 1. Place the base material in the processing position. The base material is T800 composite material with a thickness of 5mm. Clean the processing surface of the board with ethanol and place it in the processing position with the fixture.

[0112] 2. Sandblasting the surface of the board;

[0113] 3. Prepare an adhesive layer on the surface of the sandblasted board;

[0114] 4. The adhesive layer surface is plasma-sprayed with a YSZ coating, with a coating thickness of 0.5mm;

[0115] 5. Grind the YSZ coating surface until it is smooth, with a surface roughness of less than 5μm;

[0116] 6. Plasma-spray a mixed coating of YSZ and Eu-doped Gd2Zr2O7 onto the YSZ coating surface, with a mixing ratio of 9:1 (wt%) and a mixed coating thickness of 0.2 mm.

[0117] 7. Grind the surface of the mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0118] 8. Plasma spray a second mixed coating of YSZ and Eu-doped Gd2Zr2O7 onto the surface of the mixed coating, with a mixing ratio of 6:4 (wt%) and a thickness of 0.2 mm.

[0119] 9. Grind the surface of the second mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0120] 10. Plasma-spray a third mixed coating of YSZ and Eu-doped Gd2Zr2O7 onto the surface of the second mixed coating, with a mixing ratio of 4:6 (wt%) and a mixed coating thickness of 0.2 mm.

[0121] 11. Grind the surface of the third mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0122] 12. Plasma spray a fourth mixed coating of YSZ and Eu-doped Gd2Zr2O7 onto the surface of the third mixed coating, with a mixing ratio of 1:9 (wt%) and a mixed coating thickness of 0.2 mm.

[0123] 13. Grind the surface of the fourth mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0124] 14. Plasma-spray an Eu-doped Gd2Zr2O7 coating with a thickness of 0.3 mm onto the surface of the fourth mixed coating.

[0125] 15. Polish the Eu-doped Gd2Zr2O7 coating until it is smooth, with a surface roughness of less than 5μm, to complete the coating preparation.

[0126] In this embodiment, the laser reflectivity of the treated coating in the 355nm–10.6μm wavelength range is above 95%, and the interfacial adhesion is 7.6MPa. The coating at 1064nm and 2000W / cm²... 2 No visible damage was observed when a 1cm spot of continuous laser irradiation was applied for 23s. However, the coating without a gradient layer, where BaTiO3 (0.5mm) was directly sprayed onto the YSZ layer (1mm), cracked after 5s under the same level of laser irradiation.

[0127] Example 6 (The substrate material is TC4 board)

[0128] 1. Place the base material in the processing position. The base material is TC4 sheet with a thickness of 5mm. Clean the processing surface of the sheet with ethanol and place it in the processing position using a fixture.

[0129] 2. Sandblasting the surface of the board;

[0130] 3. Prepare an adhesive layer on the surface of the sandblasted board;

[0131] 4. Plasma-sprayed SmTaO4 coating is applied to the surface of the adhesive layer, with a coating thickness of 0.5mm;

[0132] 5. Grind the SmTaO4 coating surface until it is smooth, with a surface roughness of less than 5μm;

[0133] 6. Plasma spray a mixed coating of SmTaO4 and Gd2Zr2O7 onto the SmTaO4 coating surface, with a mixing ratio of 7:3 (wt%) and a mixed coating thickness of 0.2 mm.

[0134] 7. Grind the surface of the mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0135] 8. Plasma spray a second mixed coating of SmTaO4 and Gd2Zr2O7 onto the surface of the mixed coating, with a mixing ratio of 6:4 (wt%) and a thickness of 0.2 mm.

[0136] 9. Grind the surface of the second mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0137] 10. Plasma-spray a third mixed coating of SmTaO4 and Gd2Zr2O7 onto the surface of the second mixed coating, with a mixing ratio of 4:6 (wt%) and a mixed coating thickness of 0.2 mm.

[0138] 11. Grind the surface of the third mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0139] 12. Plasma spray a fourth mixed coating of SmTaO4 and Gd2Zr2O7 onto the surface of the third mixed coating, with a mixing ratio of 3:7 (wt%) and a mixed coating thickness of 0.2 mm.

[0140] 13. Grind the surface of the fourth mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0141] 14. Plasma-spray a Gd2Zr2O7 coating onto the surface of the fourth mixed coating, with a coating thickness of 0.2 mm;

[0142] 15. Polish the Gd2Zr2O7 coating until it is smooth, with a surface roughness of less than 5μm, to complete the coating preparation.

[0143] In this embodiment, the laser reflectivity of the treated coating in the 355nm–10.6μm wavelength range is above 94%, and the interfacial adhesion is 9.0MPa. The coating at 1064nm has a wavelength of 2000W / cm². 2 No visible damage was observed when a 1cm spot of continuous laser irradiation was applied for 21s. However, without a gradient layer, the coating of BaTiO3 (0.5mm) directly sprayed onto the YSZ layer (1mm) cracked after 5s under the same level of laser irradiation.

[0144] Example 7 (The substrate material is T800 composite)

[0145] 1. Place the base material in the processing position. The base material is T800 composite material with a thickness of 5mm. Clean the processing surface of the board with ethanol and place it in the processing position with the fixture.

[0146] 2. Sandblasting the surface of the board;

[0147] 3. Prepare an adhesive layer on the surface of the sandblasted board;

[0148] 4. The adhesive layer surface is plasma-sprayed with a DyTaO4 coating, with a coating thickness of 0.5mm;

[0149] 5. Grind the DyTaO4 coating surface until it is smooth, with a surface roughness of less than 5μm;

[0150] 6. Plasma-spray a mixed coating of DyTaO4 and Sr-doped Gd2Zr2O7 onto the DyTaO4 coating surface, with a mixing ratio of 9:1 (wt%) and a mixed coating thickness of 0.2 mm.

[0151] 7. Grind the surface of the mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0152] 8. Plasma-spray a second mixed coating of DyTaO4 and Sr-doped Gd2Zr2O7 onto the surface of the mixed coating, with a mixing ratio of 6:4 (wt%) and a thickness of 0.2 mm.

[0153] 9. Grind the surface of the second mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0154] 10. Plasma-spray a third mixed coating of DyTaO4 and Sr-doped Gd2Zr2O7 onto the surface of the second mixed coating, with a mixing ratio of 4:6 (wt%) and a mixed coating thickness of 0.2 mm.

[0155] 11. Grind the surface of the third mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0156] 12. Plasma spray a fourth mixed coating of DyTaO4 and Sr-doped Gd2Zr2O7 onto the surface of the third mixed coating, with a mixing ratio of 1:9 (wt%) and a mixed coating thickness of 0.2 mm.

[0157] 13. Grind the surface of the fourth mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0158] 14. Plasma-spray Sr-doped Gd2Zr2O7 coating with a thickness of 0.4 mm is applied to the surface of the fourth mixed coating.

[0159] 15. Polish the Sr-doped Gd2Zr2O7 coating until it is smooth, with a surface roughness of less than 5μm, to complete the coating preparation.

[0160] In this embodiment, the treated coating exhibits a laser reflectivity exceeding 87% in the 355nm–10.6μm wavelength range and an interfacial adhesion of 9.3MPa. The coating at 1064nm and 2000W / cm²... 2 No visible damage was observed when a 1cm spot of continuous laser irradiation was applied for 15s. However, without a gradient layer, the coating of BaTiO3 (0.5mm) directly sprayed onto the YSZ layer (1mm) cracked after 5s under the same level of laser irradiation.

[0161] Example 8 (The substrate material is T800 composite)

[0162] 1. Place the base material in the processing position. The base material is T800 composite material with a thickness of 5mm. Clean the processing surface of the board with ethanol and place it in the processing position with the fixture.

[0163] 2. Sandblasting the surface of the board;

[0164] 3. Prepare an adhesive layer on the surface of the sandblasted board;

[0165] 4. The adhesive layer surface is plasma-sprayed with a DyTaO4 coating, with a coating thickness of 0.5mm;

[0166] 5. Grind the DyTaO4 coating surface until it is smooth, with a surface roughness of less than 5μm;

[0167] 6. Plasma spray a mixed coating of DyTaO4 and CNT mixed with ZrB2 onto the DyTaO4 coating surface, with a mixing ratio of 9:1 (wt%) and a mixed coating thickness of 0.2 mm.

[0168] 7. Grind the surface of the mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0169] 8. Plasma spray a second mixed coating of DyTaO4 and CNT mixed with ZrB2 onto the surface of the mixed coating, with a mixing ratio of 6:4 (wt%) and a thickness of 0.2 mm.

[0170] 9. Grind the surface of the second mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0171] 10. Plasma spray a third mixed coating of DyTaO4 and CNT mixed with ZrB2 onto the surface of the second mixed coating, with a mixing ratio of 4:6 (wt%) and a mixed coating thickness of 0.2 mm.

[0172] 11. Grind the surface of the third mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0173] 12. Plasma spray a fourth mixed coating of DyTaO4 and CNT mixed with ZrB2 onto the surface of the third mixed coating, with a mixing ratio of 1:9 (wt%) and a mixed coating thickness of 0.2 mm.

[0174] 13. Grind the surface of the fourth mixed coating until it is smooth, with a surface roughness of less than 5μm;

[0175] 14. Plasma-spray a CNT-mixed ZrB2 coating onto the surface of the fourth mixed coating, with a coating thickness of 0.3 mm;

[0176] 15. Polish the Sr-doped Gd2Zr2O7 coating until it is smooth, with a surface roughness of less than 5μm, to complete the coating preparation.

[0177] In this embodiment, the laser reflectivity of the treated coating in the 355nm–10.6μm wavelength range is above 77%, and the interfacial adhesion is 5.6MPa. The coating at 1064nm and 2000W / cm²... 2 No visible damage was observed when a 1cm spot of continuous laser irradiation was applied for 17s. However, the coating without a gradient layer, on which BaTiO3 (0.5mm) was directly sprayed onto the YSZ layer (1mm), cracked after 5s under the same level of laser irradiation.

[0178] It should be noted 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 mutually. Each embodiment focuses on describing the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. Furthermore, for the sake of brevity, detailed descriptions of known methods and techniques are omitted here.

[0179] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art without departing from the scope of the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A laser protective coating, characterized in that, It includes a reflective ceramic layer, a heat-insulating ceramic layer, and at least three gradient ceramic layers located between the reflective ceramic layer and the heat-insulating ceramic layer; wherein, The reflective ceramic layer includes barium titanate and its doped system, and / or pyrochlore and its doped system; The thermally insulating ceramic layer includes yttrium-stabilized zirconium oxide and its doped system, and / or rare earth tantalates and their doped systems; The gradient ceramic layer is a mixed coating of reflective ceramic and heat-insulating ceramic, and the mixing ratio of reflective ceramic and heat-insulating ceramic in the gradient ceramic layer is distributed in a gradient according to the spraying sequence of the multiple gradient ceramic layers.

2. The laser protective coating according to claim 1, characterized in that, Strontium is doped into the barium titanate doping system.

3. The laser protective coating according to claim 2, characterized in that, The strontium doping amount in the barium titanate doped system is 5–15 mol.

4. The laser protective coating according to claim 1, characterized in that, Strontium is doped into the pyrochlore doping system.

5. The laser protective coating according to claim 4, characterized in that, The strontium doping amount in the pyrochlore doped system is 5–15 mol.

6. A method for preparing a laser protective coating as described in any one of claims 1-5, characterized in that, The method includes the following steps: The base material is placed in the processing position, and the surface of the base material is sandblasted. An adhesive layer is prepared on the surface of the sandblasted substrate material, and a heat-insulating ceramic coating is sprayed onto the surface of the adhesive layer. At least three layers of gradient ceramic coating are sequentially sprayed onto the surface of the heat-insulating ceramic coating, wherein the mixing ratio of reflective ceramic and heat-insulating ceramic in each layer of gradient ceramic coating is gradient distributed. A reflective ceramic coating is sprayed onto the surface of the top gradient ceramic coating.

7. The method for preparing the laser protective coating according to claim 6, characterized in that, After each layer of spray coating is applied, the surface is smoothed and the surface roughness is less than 5μm.

8. The method for preparing the laser protective coating according to claim 6, characterized in that, Each layer of the spray coating is less than 0.5 mm thick.

Images