Method for rapidly repairing normal-temperature stealth coating system in external field

Abstract

A method for quickly repairing a normal-temperature stealth coating system in an external field comprises the following steps: firstly, prefabricating a whole-system normal-temperature stealth coating patch in a factory building with a controllable temperature and humidity environment in advance, and then applying the prepared whole-system normal-temperature stealth coating patch to a simulated airplane surface damage coating system for repairing. The prepared whole-system normal-temperature stealth coating patch is applied to repairing of a damaged normal-temperature stealth coating system on the surface of a fuselage, various electrical performance tests are conducted on simulated repairing splicing seams, and the test results all meet the standard requirements, so that the prepared whole-system normal-temperature stealth coating patch is applied to repairing of the damaged normal-temperature stealth coating system on the surface of the fuselage, meanwhile, the electrical performance tests are conducted on the repairing splicing seams, and the test results all meet the standard requirements. According to the method, the prefabricated whole-system normal-temperature stealth coating patch is adopted for adhesive repairing in an external field, the repairing construction process is not limited by the external field temperature and humidity environment, the repairing time is shortened to one day from the original half month or above, the coating performance of a repaired area meets the standard requirement, and the repairing efficiency of a stealth coating system is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of room-temperature stealth coating repair, and in particular to a method for rapidly repairing a room-temperature stealth coating system in an out-of-field environment. Background Art

[0002] High stealth performance is an essential tactical technology for fifth-generation fighter jets, requiring the aircraft to possess an all-around low radar cross-section (RCS). Besides design, a complete application of a high-performance stealth coating is essential for achieving this high stealth characteristic on advanced equipment. However, feedback from existing stealth fighter aircraft indicates that during field use, due to its relatively thick coating, the aircraft is prone to bulging, cracking, and shedding at seams, flap edges, and serrated edges at high speeds and sudden temperature fluctuations. This can severely impact the aircraft's stealth performance, necessitating prompt repair of mechanical damage to the stealth coating.

[0003] However, stealth coating systems are usually more complex, with up to several layers, and are difficult to construct. At the same time, after each layer of paint is sprayed, it is necessary to wait for it to dry before the next layer of paint can be sprayed. After the entire coating system is sprayed, it needs to cure for several days to meet normal flight requirements. The repair cycle of the stealth coating system is usually more than half a month, which will seriously affect the aircraft's utilization efficiency and the combat effectiveness of the aircraft in wartime. In addition, the radar-absorbing coating has more stringent requirements on the environmental temperature and humidity during the construction process. The temperature and humidity requirements cannot be guaranteed during the aircraft's stealth coating maintenance in the field, which seriously affects the stealth performance of the repaired coating. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide a method for rapid field repair of a room-temperature stealth coating system, namely, prefabricating a full system of room-temperature stealth coating patches in a factory with controllable temperature and humidity environment, and then gluing the full system of room-temperature stealth coating patches to achieve the purpose of rapid field repair of the room-temperature stealth coating, effectively shortening the repair time, and at the same time ensuring that the quality of the repaired room-temperature stealth coating system meets the standard requirements.

[0005] The technical problem solved by the present invention is achieved by adopting the following technical solutions:

[0006] A method for rapidly repairing a room-temperature stealth coating system in an outdoor environment, comprising the following steps:

[0007] (1) Preparation of full-system room-temperature stealth coating patches

[0008] Attach a release cloth or apply a release agent on a smooth steel plate, then remove the absorbing coating formed by spraying a flexible absorbing paint on the release cloth to form an absorbing patch; spray the first coat on the front of the absorbing patch in reverse order of the coating sequence, wait for the sprayed coating system to dry, and then spray the remaining coat on the back of the absorbing patch until the coating system is completely cured, thus obtaining a full-system room-temperature stealth coating patch;

[0009] (2) Room-temperature stealth coating system for repairing damaged fuselage surfaces

[0010] First, the damaged coating system of the room-temperature stealth coating on the fuselage surface is removed, and the removed area is a regular rectangle; then the full-system room-temperature stealth coating patch prepared in step (1) is glued to the damaged part of the room-temperature stealth coating on the fuselage surface, and at the same time, the electrical performance test of the repaired joint is carried out, and the test results all meet the standard requirements.

[0011] In the present invention, in step (1), the specific steps for preparing the room temperature stealth coating patch of the whole system are as follows:

[0012] (a) Paste the release cloth on the smooth steel plate and keep it flat and wrinkle-free; or apply the release agent by brushing, and the release agent should be applied evenly without omission;

[0013] (b) spraying an absorbing coating to a specified thickness on a smooth steel plate with a release cloth attached to form an absorbing coating;

[0014] (c) After the absorbing coating is cured to a substantially dry state, the absorbing coating is removed from the release cloth to form an absorbing patch;

[0015] (d) polishing the front surface of the absorbing patch produced in step (c) with sandpaper and cleaning with acetone, and after the front surface of the absorbing patch is dried, spraying in reverse order of the coating sequence until the first coating layer is applied;

[0016] (e) Turn the absorbing patch over, sand the back of the absorbing patch with sandpaper, clean it with acetone, wait for the back of the absorbing patch to dry, and then spray the last coat of topcoat in the coating sequence;

[0017] (f) After spraying is completed, all coatings on the absorbing patch are ensured to be completely cured, thereby obtaining a room-temperature stealth coating patch for the entire system;

[0018] (g) Various performance tests were conducted on the prepared full-system room-temperature stealth coating patch, and the results all met the standard requirements.

[0019] In the present invention, in step (2), the room temperature stealth coating system that is damaged on the fuselage surface is repaired, and the specific steps are as follows:

[0020] (i) Cutting a patch of the full-system room-temperature stealth coating of appropriate size, and then sanding and cleaning the primer surface of the area to be repaired on the fuselage surface with sandpaper;

[0021] (ii) Use paper tape to protect the surrounding areas of the room-temperature stealth coating patch on the entire system and the complete coating around the area on the fuselage surface where the room-temperature stealth coating is to be repaired;

[0022] (iii) using a pig bristle brush, evenly apply the adhesive to the area of ​​the fuselage surface where the room temperature stealth coating is to be repaired;

[0023] (iv) affixing the full-system room-temperature stealth coating patch to the area of ​​the fuselage surface where the room-temperature stealth coating is to be repaired, adjusting the affixed position of the full-system room-temperature stealth coating patch, and simultaneously rolling the full-system room-temperature stealth coating patch back and forth with a silicone roller to squeeze out the air contained in the full-system room-temperature stealth coating patch, and removing the paper tape before the adhesive cures;

[0024] (v) Use a heavy object larger than the area of ​​the room-temperature stealth coating to be repaired on the fuselage surface to compact the entire system of room-temperature stealth coating patches, and let it stand for the adhesive to cure;

[0025] (vi) After the adhesive has cured, apply paper tape around the inside and outside of the area to be repaired on the fuselage surface where the room-temperature stealth coating is to be repaired for protection, and seal the edges with edge sealant. After applying the edge sealant, remove the paper tape and wait for the edge sealant to cure.

[0026] (vii) After the edge sealant has cured, reapply wear-resistant tape around the inside and outside of the area on the fuselage surface where the room-temperature stealth coating is to be repaired, and sand the edge sealant with sandpaper to eliminate the step difference of the edge sealant;

[0027] (viii) Then use a wool brush to apply the topcoat to the edge sealant, remove the wear-resistant tape, and wait for the topcoat to cure to complete the repair.

[0028] Beneficial effects:

[0029] 1. This invention effectively improves the repair efficiency of the room-temperature stealth coating system, shortening the repair time from more than half a month to one day;

[0030] 2. The present invention uses prefabricated full-system room-temperature stealth coating patches for repair. The repair construction process is not affected by the environment, and the coating performance of the repaired area 100% meets the standard requirements;

[0031] 3. This invention effectively reduces the manpower and material costs of after-sales stealth coating maintenance, eliminating the need to dispatch personnel to the field for long-term construction.

[0032] 4. The present invention provides a method for coating repair of stealth fighters that is simple in process, easy to operate, fast and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1This is a schematic diagram of the preparation of a full-system room-temperature stealth coating patch in a preferred embodiment of the present invention.

[0034] Figure 2 Schematic diagram of demoulding of the microwave-absorbing coating in a preferred embodiment of the present invention.

[0035] Figure 3 Schematic diagram of the area to be repaired of the room-temperature stealth coating on the fuselage surface in a preferred embodiment of the present invention.

[0036] Figure 4 This is a schematic diagram of the repair process using a full-system room-temperature stealth coating patch in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below with reference to specific illustrations.

[0038] See also Figure 1 A method for rapidly repairing a room-temperature stealth coating system in an outdoor environment, the specific steps are as follows:

[0039] (1) Preparation of full-system room-temperature stealth coating patches

[0040] Paste a release cloth 1 or apply a release agent on the smooth steel plate to ensure that the coated patch can be smoothly torn off from the smooth steel plate. Only a flexible coating can ensure that it will not break when torn off from the release cloth 1. Therefore, when preparing the coated patch, first spray a flexible absorbing coating on the release cloth 1 to form an absorbing coating 2, and then spray the remaining coating system in the reverse order of the spraying sequence. The specific steps are as follows:

[0041] (a) Paste the release cloth 1 on a 40*40cm flat, smooth steel plate, making sure that the release cloth 1 is pasted flat and wrinkle-free; or apply the release agent by brushing, and the release agent should be applied evenly without missing any areas;

[0042] (b) spraying an absorbing coating to a predetermined thickness on the smooth steel plate to which the release cloth 1 is attached, thereby forming an absorbing coating 2;

[0043] (c) After the absorbing coating 2 is cured to a substantially dry state, the absorbing coating 2 is removed from the release cloth 1 to form an absorbing patch 4. Figure 2 As shown;

[0044] (d) Sanding and cleaning the front surface of the absorbing patch 4 produced in step (c) with acetone, spraying the other coatings 3 after the front surface of the absorbing patch 4 is dried, that is, spraying in reverse order of the coating sequence until the first coating layer is applied, such as Figure 1 As shown;

[0045] (e) Turning over the absorbing patch 4, polishing the back side of the absorbing patch 4 with sandpaper and cleaning with acetone, and spraying the back side of the absorbing patch 4 with the last coat of topcoat after it is dry in the coating sequence;

[0046] (f) After spraying is completed, ensure that all coatings on the absorbing patch 4 are completely cured, thereby obtaining a room-temperature stealth coating patch for the entire system;

[0047] (g) Various performance tests were conducted on the prepared full-system room-temperature stealth coating patch, and the results all met the standard requirements;

[0048] (2) Simulation of spraying composite curved surface skin and flat parts

[0049] In order to simulate the repair process of the damaged coating system on the aircraft surface, a stealth coating system consistent with the aircraft surface is sprayed on the composite curved skin;

[0050] At the same time, a 30*30cm flat plate is placed next to the composite curved skin for spraying: the flat plate adopts anodized aluminum alloy plate, and the left half of the flat plate is used for spraying the stealth coating system consistent with the skin, as the "furnace part" of the composite curved skin, and the right half of the flat plate is only sprayed with the first primer, and after the primer is cured, it is protected with kraft paper, until the coating of the stealth coating system on the left half of the flat plate is completely cured, and then the kraft paper protection on the right half of the flat plate is removed, and subsequently the full system room temperature stealth coating patch prepared in step (1) is used to perform adhesive repair on the right half of the flat plate, which is used as the "furnace part" in the composite curved skin repair process;

[0051] Conduct various performance tests on the spray-cured flat panels to ensure that their performance meets the standard requirements;

[0052] (3) Repairing composite curved skins and flat panels

[0053] Create a stealth coating system damage phenomenon on the composite curved surface skin, then remove the damaged coating to ensure that the area to be repaired is rectangular, and then use the full system room temperature stealth coating patch prepared in step (1) to adhesively repair the area to be repaired on the composite curved surface skin and the right half of the flat plate. The specific repair steps are as follows:

[0054] (i) Cut a patch of the full-system room-temperature stealth coating of appropriate size (the length and width of the full-system room-temperature stealth coating patch are both 1 mm smaller than the length and width of the area to be repaired), and then use sandpaper to polish and clean the primer surface of the curved skin area to be repaired;

[0055] (ii) Use paper tape to protect the entire system around the room temperature stealth coating patch and the complete coating around the area where the composite curved surface skin is removed;

[0056] (iii) Use a pig bristle brush to evenly apply the adhesive to the coating of the area to be repaired on the surface of the composite curved skin (note: the adhesive should be applied in an appropriate amount and not too much);

[0057] (iv) pasting the full-system room-temperature stealth coating patch on the area to be repaired on the surface of the composite curved skin, adjusting the pasting position of the full-system room-temperature stealth coating patch, and simultaneously rolling the full-system room-temperature stealth coating patch back and forth with a silicone roller to squeeze out the air contained in the full-system room-temperature stealth coating patch, and removing the paper tape before the adhesive cures;

[0058] (v) Using a weight larger than the area to be repaired, compact the entire system of room temperature stealth coating patches and allow them to stand for the adhesive to cure;

[0059] (vi) After the adhesive has cured, paper tape is applied around the inner and outer sides of the composite curved surface skin to be repaired for protection, and edge sealing is performed around the periphery with edge sealing adhesive. After the edge sealing adhesive is applied, the paper tape is removed and the edge sealing adhesive is allowed to cure.

[0060] (vii) After the edge sealant has solidified, reapply wear-resistant tape around the inside and outside of the area to be repaired, sand the edge sealant with sandpaper, and use a U-shaped spatula to eliminate the edge step;

[0061] (viii) Then use a wool brush to apply the topcoat to the edge sealant, remove the wear-resistant tape, and wait for the topcoat to cure to complete the repair;

[0062] The same method as for repairing the composite curved skin was used to repair the right half of the flat panel. Adhesion tests were performed on the repaired area of ​​the flat panel, and various electrical performance tests were performed on the repaired joints. The test results all met the standard requirements.

[0063] Through the above steps (2) and (3), the repair process of the damaged coating system on the aircraft surface is simulated, and various electrical performance tests are performed on the simulated repair joints. The test results all meet the standard requirements. Therefore, the full-system room-temperature stealth coating patch prepared in step (1) can be applied to the repair of the damaged room-temperature stealth coating system on the fuselage surface;

[0064] (4) Room-temperature stealth coating system for repairing damaged fuselage surfaces

[0065] First, the damaged coating system of the room-temperature stealth coating on the fuselage surface is removed, and the removed area is a regular rectangle; then the full-system room-temperature stealth coating patch prepared in step (1) is glued to the damaged part of the room-temperature stealth coating on the fuselage surface, and the electrical performance test of the repaired joint is carried out at the same time. The test results all meet the standard requirements; the specific repair steps are as follows:

[0066] (i) Cut a patch of the full-system room-temperature stealth coating of appropriate size (the length and width of the full-system room-temperature stealth coating patch are both 1 mm smaller than the length and width of the area 5 of the fuselage surface to be repaired), and then use sandpaper to polish and clean the primer surface of the area 5 of the fuselage surface to be repaired;

[0067] (ii) Use paper tape to protect the entire system's ambient temperature stealth coating patch and the entire coating around the area 5 on the fuselage surface where the ambient temperature stealth coating is to be repaired;

[0068] (iii) Using a pig bristle brush, apply the adhesive evenly to the coating of area 5 of the room-temperature stealth coating to be repaired on the fuselage surface (Note: The adhesive should be applied in an appropriate amount and not too much);

[0069] (iv) affixing the full-system room-temperature stealth coating patch to the area 5 on the fuselage surface where the room-temperature stealth coating is to be repaired, adjusting the affixed position of the full-system room-temperature stealth coating patch, and simultaneously rolling the full-system room-temperature stealth coating patch back and forth with a silicone roller to squeeze out the air contained in the full-system room-temperature stealth coating patch, and removing the paper tape before the adhesive cures;

[0070] (v) Use a weight that is larger than the area of ​​the room-temperature stealth coating to be repaired on the fuselage surface to compact the entire system of room-temperature stealth coating patches, and let it stand for the adhesive to cure;

[0071] (vi) After the adhesive has cured, paper tape is applied around the inside and outside of the five areas of the fuselage surface where the room-temperature stealth coating is to be repaired for protection. Edge sealing adhesive is then applied to the perimeter of the area. After the edge sealing adhesive is applied, the paper tape is removed and the edge sealing adhesive is allowed to cure.

[0072] (vii) After the edge sealant has cured, reapply wear-resistant tape around the inside and outside of the area 5 on the fuselage surface where the room-temperature stealth coating is to be repaired. Sand the edge sealant with sandpaper, and use a U-shaped spatula to eliminate the step difference of the edge sealant.

[0073] (viii) Then use a wool brush to apply the topcoat to the edge sealant, remove the wear-resistant tape, and wait for the topcoat to solidify to complete the repair. The patch repair area 6 is as follows: Figure 4 shown.

Claims

1. A method for rapidly repairing a room-temperature stealth coating system in an outdoor environment, characterized in that: The specific steps are as follows: (1) Preparation of full-system room-temperature stealth coating patch Paste a release cloth on a smooth steel plate, and then remove the absorbing coating formed by spraying a flexible absorbing paint on the release cloth to form an absorbing patch; Spray the first coating layer on the front side of the absorbing patch in reverse order of the coating sequence, and after the sprayed coating system is completely dry, spray the remaining coating layer on the back side of the absorbing patch until the coating system is completely cured, thereby obtaining a full-system room-temperature stealth coating patch; (2) Room-temperature stealth coating system for repairing damaged fuselage surface First, the damaged coating system of the room-temperature stealth coating on the fuselage surface is removed, and the removed area is a regular rectangle; The full-system room-temperature stealth coating patch prepared in step (1) is then glued to the damaged part of the room-temperature stealth coating on the fuselage surface, and the electrical performance test is performed on the repaired joints. The test results all meet the standard requirements.

2. The method for rapid repair of a room temperature stealth coating system in an out-of-field according to claim 1, characterized in that: In step (1), the specific steps for preparing the room temperature stealth coating patch of the whole system are as follows: (a) Paste the release cloth on the smooth steel plate and keep it flat and wrinkle-free; (b) spraying the absorbing paint to a specified thickness on the smooth steel plate with the release cloth attached to form an absorbing coating; (c) After the absorbing coating is cured to a substantially dry state, the absorbing coating is removed from the release cloth to form an absorbing patch; (d) polishing the front side of the absorbing patch produced in step (c) with sandpaper and cleaning with acetone, and after the front side of the absorbing patch is dried, spraying in reverse order of the coating sequence until the first coating layer; (e) Turn over the absorbing patch, sand the back of the absorbing patch with sandpaper, clean it with acetone, wait for the back of the absorbing patch to dry, and then spray the last coat of topcoat in the order of coating; (f) After spraying, ensure that all coatings on the absorbing patch are completely cured, so as to obtain a room temperature stealth coating patch for the entire system; (g) Various performance tests were carried out on the prepared full-system room-temperature stealth coating patch, and the results all met the standard requirements.

3. The method for rapid repair of a room temperature stealth coating system in an out-of-field according to claim 1, characterized in that: In step (2), the damaged room temperature stealth coating system on the fuselage surface is repaired, and the specific steps are as follows: (i) Cut the corresponding size of the full-system room-temperature stealth coating patch, and then use sandpaper to polish and clean the primer surface of the room-temperature stealth coating on the fuselage surface to be repaired; (ii) Use paper tape to protect the surrounding areas of the room-temperature stealth coating patch of the entire system and the complete coating around the area of ​​the room-temperature stealth coating on the fuselage surface to be repaired; (iii) using a pig bristle brush to evenly apply the adhesive to the coating of the area to be repaired of the room temperature stealth coating on the surface of the fuselage; (iv) Paste the full-system room-temperature stealth coating patch on the area of ​​the fuselage surface where the room-temperature stealth coating is to be repaired, adjust the pasting position of the full-system room-temperature stealth coating patch, and use a silicone roller to roll the full-system room-temperature stealth coating patch back and forth to squeeze out the air contained in the full-system room-temperature stealth coating patch, and tear off the paper tape before the adhesive solidifies; (v) Use a heavy object larger than the area of ​​the room-temperature stealth coating to be repaired on the fuselage surface to compact the entire system of room-temperature stealth coating patches, let it stand, and wait for the adhesive to cure; (vi) After the adhesive is cured, paper tape is pasted around the inside and outside of the area to be repaired on the surface of the fuselage where the room temperature stealth coating is to be repaired for protection, and the edge sealing adhesive is used to seal the surrounding area. After the edge sealing adhesive is applied, the paper tape is torn off and the edge sealing adhesive is allowed to cure; (vii) After the edge sealant is cured, abrasion-resistant tape is reapplied around the inside and outside of the area to be repaired of the room-temperature stealth coating on the fuselage surface, and the edge sealant is polished with sandpaper to eliminate the edge seal step difference; (viii) Then use a wool brush to pick up the topcoat and apply it on the edge banding adhesive, remove the wear-resistant tape, and wait for the topcoat to cure. The repair is then complete.

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