Protective glue, application thereof and protection method of gas film hole

Abstract

The invention provides protective glue, application thereof and a protective method of an air film hole, and belongs to the technical field of coating protection. The protective glue provided by the invention comprises the following components in percentage by mass: 20%-55% of polyurethane resin, 35%-55% of an acrylate monomer, 1%-6% of a photoinitiator, 0.1%-3% of a coupling agent, 0.2%-2% of an accelerant and 5%-30% of inorganic filler. Through specific composition and components, the protective glue has certain flexibility, is not liable to volatilize at the instantaneous high temperature of 600-800 DEG C, can be completely burnt at the temperature of 450 DEG C or above, and has an excellent protective effect. The result of the embodiment shows that the gas film hole protected by the protective glue is complete and free of shrinkage cavity, and the coating near the gas film hole is complete and continuous and free of crack and block collapse phenomena.

Description

Technical Field

[0001] The invention relates to the technical field of coating protection, and in particular to a protective adhesive and application thereof and a protective method for air film holes. Background Art

[0002] Space engines are the core component of aerospace technology. They have the advantages of strong thrust, high impulse ratio, high reliability and reusability. They play an important role in launching spacecraft, orbit adjustment and attitude control, deep space exploration and extending the life of satellites, and provide strong power support for human space exploration and development. It is precisely because of the application of aerospace engines in space exploration and development that they will experience extreme conditions such as high temperature and high pressure. In order to ensure the normal operation of aerospace engines and extend their service life, coatings are usually sprayed on the surface of aerospace engines and components to protect them.

[0003] It should be noted that there are air film holes on the turbine blades of aerospace engines. When using coatings to protect them, the air film holes need to be protected at the same time to avoid blockage and collapse of the air film holes. Usually, tooling is used to protect the air film holes, or the parts are laser-drilled for air film holes after the coating is sprayed. However, for complex parts such as stabilizers, there are many air film holes on the parts and they are densely distributed, so it is difficult for tooling to achieve effective protection of the air film holes; and laser drilling of air film holes on parts after the coating is sprayed will destroy the integrity of the metal bonding layer, causing local oxidation of parts during subsequent service, and reducing service life. For example, the prior art CN116393847A provides a technical solution for laser processing of air film holes after coating a thermal barrier coating on a metal substrate. Although it reduces the impact time of the thermal barrier coating during the hole making process through a two-stage femtosecond laser, due to the very high hardness of the high-temperature protective coating, there is still a possibility of coating damage during the laser drilling process, and its protection of air film holes still cannot meet the needs of practical applications. Summary of the invention

[0004] The purpose of the present invention is to provide a protective glue and its application and a method for protecting air film holes. The protective glue provided by the present invention can effectively protect the air film holes, avoid blockage and shrinkage of the air film holes, and will not damage the spray coating, thereby extending the service life of the coating.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The invention provides a protective adhesive, comprising the following components in percentage by mass: 20% to 55% of polyurethane resin, 35% to 55% of acrylate monomer, 1% to 6% of photoinitiator, 0.1% to 3% of coupling agent, 0.2% to 2% of accelerator and 5% to 30% of inorganic filler.

[0007] Preferably, the protective adhesive comprises the following components in percentage by mass: 25% to 50% polyurethane resin, 40% to 50% acrylate monomer, 2% to 5% photoinitiator, 0.5% to 2% coupling agent, 0.5% to 1.5% accelerator, and 10% to 25% inorganic filler.

[0008] Preferably, the protective adhesive comprises the following components in percentage by mass: 30% to 40% polyurethane resin, 42% to 45% acrylate monomer, 3% to 4% photoinitiator, 1% to 1.5% coupling agent, 0.8% to 1.2% accelerator, and 15% to 20% inorganic filler.

[0009] Preferably, the photoinitiator is one of 2-hydroxy-2-methyl-1-phenylpropanone, 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone and benzoin methyl ether.

[0010] Preferably, the coupling agent is one of γ-propyl methacrylate trimethoxysilane and γ-aminopropyl triethoxysilane.

[0011] Preferably, the accelerator is one or two of polyester phosphate modified accelerators.

[0012] The present invention also provides the use of the protective glue described in the above technical solution in the protection of non-coating areas during thermal spraying.

[0013] The present invention also provides a method for protecting air film holes, comprising the following steps:

[0014] Inject glue into the air film holes of the part to be sprayed and then solidify to obtain a protective part; the glue used for the injection is the protective glue according to any one of claims 1 to 7;

[0015] spraying a target coating on the surface of the protective part and then trimming it to obtain a coated part;

[0016] The coated part is subjected to heat treatment to remove the glue.

[0017] Preferably, after the glue is injected, the surface of the glue in the air film hole is concave.

[0018] Preferably, when the thickness of the target coating is greater than 1 mm, the spraying is performed in sections, and trimming is performed after each section of spraying.

[0019] The present invention provides a protective glue, comprising the following components in percentage by mass: 20% to 55% polyurethane resin, 35% to 55% acrylate monomer, 1% to 6% photoinitiator, 0.1% to 3% coupling agent, 0.2% to 2% accelerator, and 5% to 30% inorganic filler. The polyurethane resin in the protective glue provided by the present invention has a certain flexibility. The acrylate monomer can be cross-linked during the curing process to form a cross-linked structure to improve the flexibility of the protective glue. The coupling agent improves the interface bonding force between the inorganic filler and the organic resin, so that a strong chemical bond is formed between the two, so that the external force is smoothly transmitted between the inorganic filler and the organic resin, and the flexibility of the protective glue is further improved; thus, under the joint action of the above-mentioned multiple raw materials, a protective glue with good flexibility is obtained, thereby ensuring that the protective glue can effectively resist external forces when acting in the air film hole, realize effective protection of the air film hole, and avoid blockage and collapse of the air film hole; the use of polyurethane resin can ensure that when facing the spray 6 When the instantaneous high temperature is between 100 and 800°C, the surface can be carbonized in time to form a shielding layer, avoiding the volatilization of the internal protective glue, and further improving the protective effect of the protective glue; by adding acrylate monomers, it can be ensured that the protective glue can be completely burned at a temperature of 450°C and above, and there is no residue in the protection area, thereby ensuring the integrity of the coating and extending the service life of the coating and parts; using highly reactive acrylate monomers for polymerization to obtain a mesh structure, and using a photoinitiator with a faster reaction speed to initiate the polymerization reaction, effectively shortening the curing process of the protective glue; the curing reaction is further accelerated by the accelerator, thereby further shortening the curing time, so that the protective glue can be quickly cured in a short time. The results of the embodiment show that the curing time of the protective glue of the present invention can be as low as 30s, the air film holes protected by it are complete and free of shrinkage holes, and the coating near the air film holes is complete and continuous, without cracks and collapse. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The macroscopic photographs are the test results of the fluidity performance of the type 4 protective glue of Example 1 and the type 6 protective glue of Example 2 of the present invention;

[0021] Figure 2 It is a structural schematic diagram of the special glue dispensing machine used in Application Example 1 and Application Example 2;

[0022] Figure 3 This is a macroscopic photograph of an air film hole part obtained by using the protection method of Application Example 1 of the present invention;

[0023] Figure 4 A macroscopic photograph of an air film hole part obtained by using the protection method of Application Example 2 of the present invention;

[0024] Figure 5This is a macroscopic photograph of an air film hole part obtained by the protection method of comparative application example 1 of the present invention;

[0025] Figure 6 This is a macroscopic photograph of an air film hole part obtained by the protection method of comparative application example 2 of the present invention;

[0026] Figure 7 The metallographic structure diagram of the coating around the air film hole after the air film hole part obtained by the protection method of application example 1 and the air film hole part protected by the protection method of comparative application example 3 were subjected to air cooling thermal shock cycle test;

[0027] Figure 8 These are macroscopic photographs of the air film hole parts protected by the protection method of Application Example 1 and the air film hole parts protected by the protection method of Comparative Application Example 3 after air cooling thermal shock cycle testing. DETAILED DESCRIPTION

[0028] The invention provides a protective adhesive, comprising the following components in percentage by mass: 20% to 55% of polyurethane resin, 35% to 55% of acrylate monomer, 1% to 6% of photoinitiator, 0.1% to 3% of coupling agent, 0.2% to 2% of accelerator and 5% to 30% of inorganic filler.

[0029] In terms of mass percentage, the protective glue provided by the present invention includes 20% to 55% of polyurethane resin. As an embodiment, the polyurethane resin can be 25% to 50%, or 30% to 40%; in an embodiment of the present invention, the polyurethane resin can be specifically 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 45%, 50%, 53% or 55%. As an embodiment of the present invention, the polyurethane resin can be polyurethane acrylate. In the present invention, the polyurethane resin itself has a certain flexibility, which can improve the flexibility of the protective glue to a certain extent; at the same time, the type and amount of the polyurethane resin are limited, and the use of a polyurethane resin with a high carbon content can ensure that the protective glue can be carbonized in time when facing an instantaneous high temperature of 600 to 800°C during spraying to form a shielding layer to avoid the volatilization of the internal protective glue; and the polyurethane resin itself has a certain fluidity, which can improve the fluidity of the protective glue to a certain extent, which is conducive to the protective glue forming a concave shape in the air film hole, and is not easy to overflow and splash, further improving the protective effect of the protective glue.

[0030] In terms of mass percentage, the protective glue provided by the present invention includes 35% to 55% of acrylate monomers. As an embodiment, the acrylate monomers can be 40% to 50%, or 42% to 45%; in an embodiment of the present invention, the acrylate monomers can be specifically 35%, 38%, 40%, 42%, 43%, 45%, 48%, 50%, 53% or 55%. As an embodiment of the present invention, the acrylate monomers can be one or more of isobornyl acrylate, trimethylolpropane triacrylate, hydroxypropyl methyl acrylate, vinyl acrylate monomer, diallyl phthalate and methyl methacrylate. In the present invention, the acrylate monomer can form a cross-linked structure during the curing process, and the cross-linked network structure can further improve the flexibility of the protective glue; at the same time, it can ensure that the protective glue is completely burned at a temperature of 450°C or above, and there is no residue in the protection area, thereby ensuring the integrity of the coating and extending the service life of the coating and parts; by limiting the amount and type of acrylate monomers, the integrity of its cross-linked network structure is further improved, and the protective effect is further improved.

[0031] In terms of mass percentage, the protective glue provided by the present invention includes 1% to 6% of a photoinitiator. As an embodiment, the photoinitiator may be 2% to 5%, or 3% to 4%. As an embodiment of the present invention, the photoinitiator may be one of 2-hydroxy-2-methyl-1-phenylpropanone, 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone and benzoin methyl ether. In the present invention, by limiting the amount and type of the photoinitiator, the polymerization reaction of the acrylate monomer is smoothly initiated, ensuring that the cross-linked structure can be smoothly formed, and further improving the flexibility and protective effect of the protective glue.

[0032] In terms of mass percentage, the protective glue provided by the present invention includes 0.1% to 3% of a coupling agent. As an embodiment, the coupling agent may be 0.5% to 2%, or 1% to 1.5%. As an embodiment of the present invention, the coupling agent may be γ-methacrylate propyltrimethoxysilane (KH-570) or γ-aminopropyltriethoxysilane (KH-550). In the present invention, the coupling agent is used to improve the interfacial bonding force between the inorganic filler and the organic resin, so that a strong chemical bond is formed between the two, so that the external force is smoothly transmitted between the inorganic filler and the organic resin, and the flexibility of the protective glue is further improved; at the same time, the coupling agent improves the dispersibility of the inorganic filler in the organic resin, avoids the agglomeration of the protective glue components, and further improves the fluidity; by limiting the amount and type of the coupling agent, the interaction force between the inorganic filler and the organic resin is improved, and the flexibility, fluidity and protective effect of the protective glue are further improved.

[0033] In terms of mass percentage, the protective glue provided by the present invention includes 0.2% to 2% of the accelerator. As an embodiment, the accelerator can be 0.5% to 1.5%, or 0.8% to 1.2%. As an embodiment of the present invention, the accelerator can be one or two of the polyester phosphate modified accelerators. In an embodiment of the present invention, the accelerator can be specifically tetraisopropyl di(dioctylphosphite) titanate 9051. In the present invention, the accelerator can further promote the initiation of the photoinitiator and the polymerization reaction of the acrylate monomer, thereby further improving the protective effect.

[0034] In terms of mass percentage, the protective glue provided by the present invention includes 5% to 30% of inorganic filler. As an embodiment, the inorganic filler can be 10% to 25%, or 15% to 20%; in an embodiment of the present invention, the inorganic filler can be specifically 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28% or 30%. As an embodiment of the present invention, the inorganic filler can be one or more of magnesium oxide, mica powder and calcium carbonate. As an embodiment of the present invention, the particle size of the inorganic filler can be less than 20μm; in an embodiment of the present invention, the particle size of the inorganic filler can be specifically 5μm, 8μm, 10μm, 12μm, 15μm or 18μm. In the present invention, the heat resistance stability of the protective glue can be effectively improved by adding inorganic fillers, so as to avoid the melting of the protective glue during the spraying process, which causes the coating to enter the air film pores, and further improve the protective effect.

[0035] The protective glue provided by the present invention has specific components and compositions, so that the obtained protective glue has a certain fluidity, which helps to form a concave surface, avoids overflow or splashing, and can effectively protect the air film holes. At the same time, the protective glue with a certain flexibility can be tightly combined with the air film holes, so that the spray coating will not enter the air film holes. At the same time, the protective glue can be completely burned at a temperature of 450°C or above, avoiding the blockage and shrinkage of the air film holes, and will not be damaged during the spray coating process, avoiding the clogging of the air film holes by the coating; moreover, the protective glue is easy to remove, will not damage the spray coating, and can extend the service life of the coating.

[0036] The present invention also provides the use of the protective glue described in the above technical solution in the protection of non-coating areas during thermal spraying.

[0037] As an embodiment of the present invention, the non-coating area may be an air film hole, an air film hole edge or a functional gap.

[0038] The present invention also provides a method for protecting air film holes, comprising the following steps:

[0039] Inject glue into the air film holes of the part to be sprayed and then solidify to obtain a protective part; the glue used in the injection is the protective glue described in the above technical solution;

[0040] spraying a target coating on the surface of the protective part and then trimming it to obtain a coated part;

[0041] The coated part is subjected to heat treatment to remove the glue.

[0042] The invention injects glue into the air film holes of the part to be sprayed and then solidifies the glue to obtain the protective part.

[0043] In the present invention, the surface of the glue in the air film hole after the glue injection is preferably concave. In the present invention, by limiting the surface shape of the glue in the air film hole after the glue injection, the deposition direction of the coating in the air film hole can be controlled, and it is easier to observe the hole shape and find the force point in the subsequent steps of trimming the hole shape and removing the coating on the air film hole, and it is not easy to slip, so that the coating at the edge of the air film hole is not easy to collapse, and it is not easy to damage the coating in other places.

[0044] As an embodiment of the present invention, the glue injection device may be a glue dispenser. In the present invention, glue dispensing by the glue dispenser can achieve accurate glue injection to the air film hole, and is conducive to controlling the surface shape of the glue in the air film hole, further improving the protection effect.

[0045] As an embodiment of the present invention, the curing method is UV lamp curing. As an embodiment of the present invention, the wavelength of the UV lamp for curing can be 365-405nm; in the embodiment of the present invention, the wavelength of the UV lamp for curing can be specifically 365nm, 395nm or 405nm; the curing time can be 30-60s, or 40-50s; the distance between the curing light source or heat source and the air film hole can be 20-30cm, or 12-16cm. In the present invention, by limiting the curing method and curing process parameters of the protective glue, it is ensured that the protective glue can be completely cured in a short time, so as to achieve strict protection of the air film holes, further improve the protection effect, and avoid the occurrence of blockage, shrinkage and other phenomena.

[0046] As an embodiment of the present invention, the protective part can be tested by sandblasting to observe whether the cured protective glue can withstand the sandblasting pressure and ensure that the glue in the air film hole is not sprayed away during sandblasting. As an embodiment of the present invention, the medium for sandblasting can be 46 mesh white corundum; the pressure of sandblasting can be 0.4-0.5MPa, or 0.43-0.46MPa; in an embodiment of the present invention, the pressure of sandblasting can be specifically 0.4MPa, 0.43MPa, 0.43MPa, 0.45MPa, 0.46MPa, 0.48MPa or 0.5MPa; the sandblasting distance can be 100-150mm, or 120-135mm; in an embodiment of the present invention, the sandblasting distance can be specifically 100mm, 110mm, 120mm, 125mm, 130mm, 135mm, 140mm or 150mm. In the present invention, by controlling the process parameters of sandblasting, it is ensured that the sandblasting can effectively detect the cured protective glue, ensure that the protective glue can be tightly combined with the air film hole without gaps, and will not enter the air film hole during the subsequent spray coating process, thereby avoiding the occurrence of hole blockage.

[0047] After obtaining the protective part, the present invention sprays the target coating on the surface of the protective part and then performs trimming to obtain a coated part.

[0048] As an embodiment of the present invention, the power of the spraying can be 20-40KW, or 25-30KW; in an embodiment of the present invention, the power of the spraying can be specifically 20KW, 23KW, 25KW, 28KW, 30KW, 35KW or 40KW; the speed of the spraying gun can be 300-600mm / s, or 400-500mm / s; in an embodiment of the present invention, the power of the spraying can be specifically 300mm / s, 350mm / s, 400mm / s, 450mm / s, 500mm / s, 550mm / s or 600mm / s. In the present invention, by limiting the process parameters of spraying the target coating, the uniform spraying of the target coating is achieved, and at the same time, the protective glue will not be damaged, and the effective protection of the air film holes is further achieved.

[0049] In the present invention, when the thickness of the target coating is less than 1 mm, no trimming is required during the spraying stage; when the thickness of the target coating is greater than 1 mm, the spraying is preferably performed in sections, and trimming is performed after each section of spraying. In the present invention, when the thickness of the target coating is 1 to 2 mm, trimming is performed once during the spraying process; when the thickness of the target coating is greater than 2 mm, the target coating is trimmed 2 to 3 times. In the present invention, the timing of the trimming is to evenly divide the thickness of the target coating according to the number of trimmings. In the present invention, by limiting the corresponding relationship between the target coating thickness and the number of trimmings, the air film holes can be clearly seen throughout the spraying process, thereby achieving precise protection of the air film holes; at the same time, it can prevent the coating at the edge of the air film holes from being too thick and difficult to handle, and avoid the collapse of the coating at the edge of the hole.

[0050] As an embodiment of the present invention, the trimming may be to use a grinder to grind the air film holes of the spray target coating until the hole shape can be clearly seen, but the hole is not ground through; the trimming angle may be 10 to 20 degrees, or 13 to 16 degrees. The present invention is not particularly limited to the grinder, and the diameter of the grinder can be smaller than the aperture of the air film hole.

[0051] After obtaining the coated part, the present invention performs heat treatment on the coated part to remove the glue.

[0052] As an embodiment of the present invention, the temperature of the heat treatment degumming can be 450-500°C, or 450-475°C; the time of the heat treatment degumming can be 4-5h, or 4h-4.5h. In the present invention, by limiting the process parameters of the heat treatment degumming, it is ensured that the protective glue in the air film hole can be fully removed and the air film hole will not be blocked.

[0053] After the heat treatment to remove the adhesive, as an implementation mode, the air film holes of the coating part after the heat treatment to remove the adhesive can be trimmed to fully remove the protective adhesive in the air film holes.

[0054] As an implementation method, the trimming time of each air film hole can be 2 to 3 minutes, or 2.4 to 2.8 minutes; the trimming angle can be 10 to 20 degrees, or 13 to 16 degrees. In the present invention, by limiting the process parameters of the trimming process, the removal effect of the protective glue is further improved.

[0055] The protection method provided by the present invention can firmly combine the protective glue with the air film hole to achieve effective protection of the inside of the air film hole; at the same time, the integrity of the coating is ensured by trimming, thereby avoiding the collapse of the coating.

[0056] In order to further illustrate the present invention, the liquid fiber toughening material provided by the present invention and its preparation method and application are described in detail below in combination with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0057] Example 1

[0058] A protective adhesive type 4 is composed of the following components in percentage by mass: 30.00% of polyurethane acrylate, 45.00% of vinyl acrylate monomer, 5.00% of 2-hydroxy-2-methyl-1-phenylpropanone, 2.00% of KH570, 11.00% of 905, and 17.00% of calcium carbonate.

[0059] Example 2

[0060] A protective adhesive type 6 is composed of the following components in percentage by mass: 32.00% of polyurethane acrylate, 20.00% of vinyl acrylate monomer, 23.00% of methyl methacrylate, 4.50% of 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, 1.50% of KH550, 11.00% of 905, and 18.00% of mica powder.

[0061] The flowability performance of the type 4 protective glue of Example 1 and the type 6 protective glue of Example 2 were tested respectively. The specific testing method was to inject the type 4 protective glue of Example 1 and the type 6 protective glue of Example 2 onto the surface of the substrate respectively, and the glue did not need to be cured. The substrate was placed upright to obtain a macroscopic photograph after the glue was injected into the air film hole part. Figure 1 As shown. Figure 1 It can be seen that the uncured protective glue will adhere to the surface of the part and will not flow downward. After the protective glue enters the air film hole, the surface tension between the protective glue and the air film hole wall and the gravity of the protective glue itself will cause the glue to sink downward to form a concave surface, but it will not flow directly or splash to other parts of the part.

[0062] Application Example 1

[0063] A protection method consisting of the following steps:

[0064] use Figure 2 The special glue dispensing machine shown injects the type 4 protective glue of Example 1 into the parts with air film holes of 0.8mm and 2mm diameters and a hole inclination angle of 20° along the hole wall. During the glue injection process, it should be noted that the glue should not overflow, and the surface of the protective glue in the air film hole is concave; after the glue injection is completed, it is cured under a LED lamp with a wavelength of 365nm, the curing distance is 25cm, and the curing time is 30s to obtain a protective part;

[0065] The protective part is placed on a dry sandblasting machine for sandblasting. The sandblasting medium is 46 mesh white corundum, the sandblasting pressure is 0.4 MPa, and the sandblasting distance is 120 mm. After sandblasting, the protective glue solidified in the air film hole of the part can withstand the sandblasting pressure without glue falling off.

[0066] The sandblasted protective part is clamped with a tooling and placed on the turntable of the APS plasma spraying equipment. The target coating is sprayed under the conditions of a spraying efficiency of 25KW and a spraying gun speed of 600mm / s. The thickness of the target coating is 1.3mm. When the thickness of the sprayed target coating is 0.6mm, a diamond grinding head smaller than the aperture of the air film hole is used to align the air film hole at a hole inclination angle of 15° to trim the hole shape, but the air film hole is not penetrated; then spraying is performed to 1.3mm to obtain a coated part;

[0067] The coated parts were placed in a tubular furnace and heat treated at 450°C for 4 hours to remove the glue. The protective glue after heat treatment was in the form of carbonized ash, which was blown off with an air gun. The air film holes were trimmed with a diamond grinding head. The average trimming time for each hole was 2.5 minutes, and the relative inclination angle between the diamond grinding head and the air film hole was 15°.

[0068] The macroscopic photograph of the air film hole part obtained by the protection method of Application Example 1 is as follows: Figure 3 As shown. Figure 3 It can be seen that the actual measured diameter of the air film holes is still 0.8mm and 2mm, that is, the air film holes after protection by type 4 protective glue are complete, without shrinkage or collapse, and the coating around the air film holes is continuous and complete, without cracks or collapse.

[0069] Application Example 2

[0070] A protection method consisting of the following steps:

[0071] A special glue dispensing machine is used to inject the type 6 protective glue of Example 2 into the parts with air film holes of 0.8 mm and 2 mm in diameter and a hole inclination angle of 20° along the hole wall. During the glue injection process, it should be noted that the glue should not overflow, and the surface of the protective glue in the air film hole is concave; after the glue injection is completed, it is cured under a LED lamp with a wavelength of 365 nm, the curing distance is 25 cm, and the curing time is 30 s to obtain a protective part;

[0072] The protective part is placed on a dry sandblasting machine for sandblasting. The sandblasting medium is 46 mesh white corundum, the sandblasting pressure is 0.4 MPa, and the sandblasting distance is 120 mm. After sandblasting, the protective glue solidified in the air film hole of the part can withstand the sandblasting pressure without glue falling off.

[0073] The sandblasted protective part is clamped with a tooling and placed on the turntable of the APS plasma spraying equipment. The target coating is sprayed under the conditions of a spraying efficiency of 25KW and a spraying gun speed of 600mm / s. The thickness of the target coating is 1.3mm. When the thickness of the sprayed target coating is 0.6mm, a diamond grinding head smaller than the aperture of the air film hole is used to align the air film hole at a hole inclination angle of 15° to trim the hole shape, but the air film hole is not penetrated; then spraying is performed to 1.3mm to obtain a coated part;

[0074] The coated parts were placed in a tubular furnace and heat treated at 450°C for 4 hours to remove the glue. The protective glue after heat treatment was in the form of carbonized ash, which was blown off with an air gun. The air film holes were trimmed with a diamond grinding head. The average trimming time for each hole was 2.5 minutes, and the relative inclination angle between the diamond grinding head and the air film hole was 15°.

[0075] The macroscopic photograph of the air film hole part obtained by the protection method of Application Example 2 is as follows: Figure 4 As shown. Figure 4 It can be seen that the actual measured diameter of the air film holes is still 0.8mm and 2mm, that is, the air film holes after protection by type 6 protective glue are complete, without shrinkage or collapse, and the coating around the air film holes is continuous and complete, without cracks or collapse.

[0076] Comparative Example 1

[0077] A UV glue, composed of the following components in percentage by mass:

[0078] Epoxy acrylate 45%, isooctyl acrylate 40%, benzophenone 1%, KH5502%, hydroquinone 1%, silica 11%.

[0079] Comparative Example 2

[0080] An epoxy AB glue is composed of the following components in percentage by mass:

[0081] Component A is 42.0% bisphenol A epoxy resin, 54.0% calcium silicate, 1% KH560 coupling agent, and 3.0% silicon dioxide;

[0082] Component B is 30.0% methyltetrahydrophthalic anhydride, 60.0% calcium silicate, 1.5% aminoethylpiperazine, 7.0% polyester polyurethane, and 1.5% BHT;

[0083] The mass ratio of component A to component B is 2.5:1.

[0084] Comparative application example 1

[0085] The difference between comparative application example 1 and application example 1 is that the type 4 protective glue of embodiment 1 is replaced by the UV glue of comparative example 1.

[0086] The macroscopic photo of the air film hole part obtained by UV glue protection in comparative example 1 is as follows Figure 5 As shown, from Figure 5 It can be seen that the UV glue of comparative example 1 does not have high temperature protection performance. During the spraying process, the glue will melt due to the high temperature, causing the coating to be deposited in the holes, and the purpose of protecting the air film holes cannot be achieved.

[0087] Comparative Application Example 2

[0088] The difference between comparative application example 2 and application example 1 is that the type 4 protective adhesive in embodiment 1 is replaced by the epoxy AB adhesive in comparative example 2, and the epoxy AB adhesive is cured in an oven at 80° C. for 1 hour. .

[0089] The macroscopic photo of the air film hole parts obtained after epoxy AB glue protection is as follows Figure 6 As shown, from Figure 6 It can be seen that the epoxy AB glue is relatively viscous, difficult to inject, unable to maintain the concave structure of the injected surface, and easily contaminates the surface of the substrate and is difficult to clean. The epoxy AB glue cannot achieve the purpose of protecting the air film holes of the parts.

[0090] Comparative Application Example 3

[0091] The difference between Comparative Application Example 3 and Application Example 1 is that the protective glue is not injected into the air film hole, and then cured and subsequently removed, and the target coating is directly sprayed onto the air film hole part.

[0092] The air film hole parts obtained by the protection method of application example 1 and the air film hole parts of comparative application example 3 were subjected to air cooling thermal shock cycle test under the conditions of 1100℃ and air cooling for 5 minutes. The metallographic structure of the coating around the air film hole is as follows: Figure 7 As shown, the macroscopic photos of the parts after testing are as follows Figure 8 As shown. Figure 7 It can be seen that there is no difference in the metallographic structure of the coating around the air film hole with and without injection, indicating that there is no foreign matter diffusion and carbon deposition in the coating and substrate structure; Figure 8 It can be seen that the coating around the air film holes without glue injection fell off as a whole after two cycle experiments, while the coating around the air film holes with glue injection can still remain intact after seven cycle experiments, indicating that the protective glue provided by the present invention achieves effective protection of the air film holes and can ensure the integrity of the coating around the air film holes without collapse or falling off.

[0093] In summary, the protective glue provided by the present invention can effectively protect the air film holes and avoid the blockage and shrinkage of the air film holes. At the same time, it will not damage the spray coating. The coating is complete without cracks or collapse, which can effectively extend the service life of the coating.

Claims

1. A protective adhesive comprising the following components in percentage by mass: 20% to 55% of polyurethane resin, 35% to 55% of acrylate monomer, 1% to 6% of photoinitiator, 0.1% to 3% of coupling agent, 0.2% to 2% of accelerator, and 5% to 30% of inorganic filler.

2. The protective glue according to claim 1, characterized in that: The invention comprises the following components in percentage by mass: 25% to 50% of polyurethane resin, 40% to 50% of acrylate monomer, 2% to 5% of photoinitiator, 0.5% to 2% of coupling agent, 0.5% to 1.5% of accelerator and 10% to 25% of inorganic filler.

3. The protective glue according to claim 2, characterized in that: The invention comprises the following components in percentage by mass: 30% to 40% of polyurethane resin, 42% to 45% of acrylate monomer, 3% to 4% of photoinitiator, 1% to 1.5% of coupling agent, 0.8% to 1.2% of accelerator and 15% to 20% of inorganic filler.

4. The protective glue according to any one of claims 1 to 3, characterized in that: The photoinitiator is one of 2-hydroxy-2-methyl-1-phenylpropanone, 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone and benzoin methyl ether.

5. The protective glue according to any one of claims 1 to 3, characterized in that: The coupling agent is one of γ-methacrylate propyltrimethoxysilane and γ-aminopropyltriethoxysilane.

6. The protective glue according to any one of claims 1 to 3, characterized in that: The accelerator is one or two of polyester phosphate modified accelerators.

7. Use of the protective adhesive according to any one of claims 1 to 6 in protecting non-coating areas during thermal spraying.

8. A method for protecting air film holes, comprising the following steps: Inject glue into the air film holes of the part to be sprayed and then solidify to obtain a protective part; the glue used for the injection is the protective glue according to any one of claims 1 to 7; spraying a target coating on the surface of the protective part and then trimming it to obtain a coated part; The coated part is subjected to heat treatment to remove the glue.

9. The protection method according to claim 8, characterized in that: After the glue is injected, the surface of the glue in the air film hole is concave.

10. The protection method according to claim 8, characterized in that: When the target coating has a thickness of more than 1 mm, the spraying is performed in sections, and trimming is performed after each section of spraying.

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