Method for repairing through holes in metal parts with removable gauze

Abstract

The present application relates to a method for repairing a through hole of a metal component by means of a detachable gauze, comprising a polishing step and a surface treatment step on the periphery of the through hole of the metal component, a step of fixing a flexible and dense gauze on the metal surface on one side of the through hole of the metal component by means of a high-temperature-resistant adhesive tape as an effective deposition matrix for the next step of repairing powder, a step of spraying and repairing the repairing powder from the opening on the other side of the through hole of the metal component by means of a spraying process with a gas inlet temperature of 400-550 DEG C, a gas pressure of 110-130 psi, a powder feeding amount of 12-15 g / min and a spraying distance of 10-25 mm, and a polishing step. The method overcomes the problem that the support plate and the repaired component are difficult to detach in the current cold spraying repair method. The unique design of the gauze makes it easy to remove the support after the repair is completed, and no additional heat treatment is required. The method is suitable for on-site repair of complex holes of various metal components and has wide application potential, especially in the aviation, automobile and construction industries.

Description

Technical Field

[0001] This invention relates to the fields of surface engineering and additive manufacturing, and specifically to a method for repairing through holes in metal parts using easily removable mesh. Background Technology

[0002] Cold spraying is a solid-state deposition process that uses high-speed gas flow to accelerate micron-sized metal particles to 300-1200 m / s, allowing them to impact the substrate surface in their unmelted state and form a deposition layer. Compared to traditional thermal spraying and welding methods, cold spraying offers significant advantages in several aspects. Its low-temperature characteristics avoid problems such as oxidation, porosity, and component segregation that can occur during material melting, thus achieving an oxidation-free, high-density deposition structure. Simultaneously, due to its small heat-affected zone, cold spraying effectively preserves the physical and chemical properties of the substrate, avoiding the risks of substrate deformation and microstructural damage during thermal processing. Because of these advantages, cold spraying technology has been widely used in the repair and additive manufacturing of metal parts, particularly valuable in large-area repair and the processing of irregularly shaped structural components.

[0003] In the practical application of cold spraying technology, the repair of through-holes in metal parts (such as penetrating defects or damage in mechanical components) remains a technical challenge. The shape and size of through-holes are often highly irregular, causing sprayed powder particles to easily penetrate through the holes and preventing uniform filling, thus affecting the density and strength of the deposited layer. Currently, conventional methods for repairing through-holes typically require placing support material or filling structures on the back of the hole to provide auxiliary support. However, the support materials in existing technologies are usually inseparably bonded to the component being repaired. This inseparability not only reduces the quality of the repaired component but may also adversely affect its performance and subsequent processing.

[0004] To address the aforementioned issues, some studies have proposed designs for detachable support structures. However, these support structures often face numerous limitations in practical operation. For example, some designs, due to their structural complexity, make the positioning and fixing of the support device on the back of the through hole extremely cumbersome. Furthermore, to disassemble the support material, specialized tools or additional machining steps may be required after repair, significantly increasing process costs and repair time, and potentially causing secondary damage to the integrity and performance of the repaired area. Developing a through hole repair support that is easy to operate, performs stably, and is readily detachable remains a challenge in cold spray repair technology, which is the objective of this invention. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a simple, low-cost, and effective method for repairing through holes in metal parts using an easily removable mesh.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a method for repairing through holes in metal parts using easily removable mesh, comprising the following steps:

[0007] Step 1: Grind and surface treat the area around the through holes on the metal parts to enhance the adhesion between the repair powder and the substrate;

[0008] Step 2: Use high-temperature resistant tape to fix the flexible dense mesh to the surface of the metal part on one side of the through hole. The flexible dense mesh and the hole form an effective deposition matrix for the repair powder.

[0009] Step 3: Fix the metal parts on the tooling fixture. Under the condition that the spraying gas source is pure helium, use a spraying process with an inlet temperature of 400-550℃, a pressure of 110-130psi, a powder feed rate of 12-15 g / min, and a spraying distance of 10-25 mm to spray the repair powder through the through hole opening of the deposited substrate. The nozzle diameter of the spray gun of the spraying equipment should not be larger than the diameter of the through hole.

[0010] During spray repair, keep the nozzle of the spray gun at a 90° angle to the inner wall of the through hole opening. Spray from the inner wall edge near the through hole at a uniform speed in a spiral pattern to the center of the hole. After 2-3 sprays in this manner, a cone-shaped protrusion with a apex angle of 10-20° will be formed in the center of the hole. The area around the protrusion is the spray dead zone, where repair powder cannot be deposited. At this point, grind the protrusion until it is flush with the lowest point of the repair layer. After grinding, spray again in a spiral pattern to the center of the hole. If a protrusion forms again, grind it until it is flush with the lowest point of the repair layer. Repeat this process until the repair is complete.

[0011] Step 4: After spraying, remove the mesh and sand the coating surface to ensure a smooth transition between the filler layer and the surface of the metal part.

[0012] Furthermore, in step one, the grinding process involves grinding the inner wall surface of the through hole at both sides of the opening into a bevel with an angle of 70-80° to facilitate the repair of powder deposition.

[0013] The surface treatment involves sandblasting or laser scanning the metal surface around the through hole in the metal component to remove impurities or oxide film from the surface of the metal component.

[0014] Furthermore, in step two, the flexible dense mesh is made of high-temperature resistant and highly oxidation-resistant metal fiber or alloy fiber material; the thickness of the flexible dense mesh is 0.5-2mm, the wire diameter is 0.1-0.3mm, the mesh size is at least 1200 mesh, and the particle size of the repair powder is 23-50μm. This ensures that the flexible dense mesh can prevent the repair powder from being directly sprayed out of the through holes under spraying pressure and airflow conditions, while facilitating airflow without causing reverse pressure, ensuring uniform powder flow within the through holes, and improving the deposition effect.

[0015] Specifically, if the mesh is too thin, it may not effectively block the powder during the spraying process, especially under high airflow and spraying pressure, causing the powder to leak out from behind the holes and affecting the repair effect. Mesh damage: Thin mesh may be easily damaged by impact under high spraying pressure, causing the mesh to fail during the spraying process, thus affecting the repair quality.

[0016] However, when the mesh is too thick, especially when using a coarse material, it may create excessive resistance to airflow, preventing smooth airflow and affecting the uniformity of spraying and the quality of powder deposition. It can also reduce coating adhesion; an excessively thick mesh may cause uneven powder flow during spraying, resulting in poor coating deposition and affecting the quality of the repair layer. Furthermore, it increases operational difficulty; a thick mesh can easily create greater back pressure, potentially requiring higher airflow pressure during spraying, which may increase operational complexity and consume more gas and energy.

[0017] Furthermore, the metal fiber material is stainless steel fiber, nickel fiber, or titanium fiber; the alloy fiber material is iron-chromium-aluminum alloy fiber, constantan fiber, or Incol nickel alloy fiber.

[0018] Furthermore, in step three, the spraying powder material used in the spraying process is a metal or a metal-ceramic mixed powder; the metal is Al and Al alloys, Mg and Mg alloys, Cu and Cu alloys, Ti and Ti alloys, and the ceramic is Al2O3, SiC, or TiN.

[0019] Furthermore, the material of the metal component is a metal and its alloy or a ceramic-metal matrix composite; the metal and alloy are Al and Al alloy, Mg and Mg alloy, Cu and Cu alloy, Ti and Ti alloy; the ceramic-metal matrix composite is Al2O3 reinforced metal matrix composite, SiC reinforced metal matrix composite, or TiN reinforced metal matrix composite.

[0020] Furthermore, the depth of the through hole on the metal component is 3-15mm, and the radius is 3-10mm.

[0021] Specifically, when the depth of the through hole is less than 3 mm, the spraying process can cause the local temperature of the metal parts to become too high, which can lead to deformation or warping; when the depth is greater than 15 mm, it is difficult for the repair powder to adhere evenly, which may cause the repair layer to fall off.

[0022] Meanwhile, when the radius of the through hole is less than 3 mm, the repair powder cannot completely cover the inner edge area of ​​the hole; when the radius is greater than 10 mm, the repair powder can only adhere to the edge of the hole and is difficult to fill the central area of ​​the hole, thus forming a gap.

[0023] Furthermore, the spraying equipment is a handheld cold spraying device or a path-programmed mechanical spraying device, and the tool used for polishing is a small rotary polishing pen.

[0024] Furthermore, the high-temperature resistant tape is a polyimide tape, model 5406, manufactured by 3M Company of the United States; the helium gas is high-purity helium gas with a purity of 99.99%.

[0025] Furthermore, in step three, when the repair powder is aluminum powder and the metal part being repaired is an aluminum part, the process parameters are: gas inlet temperature of 450℃, gas pressure of 110psi, powder feed rate of 13.45g / min, and spraying distance of 10-25mm.

[0026] The beneficial effects of this invention are as follows: Compared with traditional rigid support materials, this invention exhibits significant technical advantages in terms of ease of operation and material adaptability. This invention utilizes a flexible mesh with excellent high-temperature resistance to closely conform to the irregular surface of the hole, providing stable support during the cold spraying process, ensuring uniform deposition and dense filling of metal powder, while reducing the risk of powder waste. The mesh is easy to disassemble, solving a key technical problem in the repair of through holes. It is applicable to the repair of holes of various shapes and sizes, and has wide application value in aerospace, automotive, and construction fields, providing a practical and feasible solution for the efficient and economical repair of metal structural components. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the polishing process involved in step one of the present invention;

[0028] Figure 2 This is a schematic diagram of step two of the present invention;

[0029] Figure 3 This is a schematic diagram of a handheld spray gun used to repair holes in Embodiment 1 of the present invention.

[0030] Figure 4 Photograph of the hole repaired in Example 1 of the present invention;

[0031] Figure 5Photographs of holes repaired according to Comparative Example 1 of the present invention;

[0032] Figure 6 This is a photograph of the hole repaired in Comparative Example 2 of the present invention. Detailed Implementation

[0033] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0034] To achieve the above objectives, the present invention provides the following specific embodiments:

[0035] Example 1: As Figure 1 , Figure 2 , Figure 3 As shown, a method for repairing through holes in metal parts using easily removable mesh includes the following steps:

[0036] Step 1: Grind and surface treat the area around the through hole on the metal part to enhance the adhesion between the repair powder and the substrate; the depth of the through hole on the metal part is 3-15mm and the radius is 3-10mm.

[0037] Among them, such as Figure 1 As shown, the grinding process involves grinding the inner wall of the through hole at both sides of the opening into a bevel with an angle of 70-80° to facilitate the repair of powder deposits; the bevel treatment in the figure points to the grinding bevel.

[0038] Surface treatment involves sandblasting or laser scanning the metal surface around the through hole in a metal part to remove impurities or oxide film from the surface of the metal part.

[0039] Step Two: As Figure 2 As shown, a flexible dense mesh is fixed to the surface of the metal part on one side of the through hole of the metal part using high-temperature resistant tape. The flexible dense mesh and the hole form an effective deposition matrix for the repair powder.

[0040] The flexible dense mesh is made of high-temperature resistant and highly oxidation-resistant metal fiber or alloy fiber material; the thickness of the flexible dense mesh is 0.5-2mm, the wire diameter is 0.1-0.3mm, the mesh size is at least 1200 mesh, and the particle size of the repair powder is 23-50μm. This ensures that the flexible dense mesh can prevent the repair powder from being directly sprayed out of the through holes under spraying pressure and airflow conditions. At the same time, it facilitates airflow without causing reverse pressure, ensuring uniform powder flow in the through holes and improving the deposition effect.

[0041] Step 3: As Figure 3As shown, the metal parts are fixed on the tooling fixture. Under the condition that the spraying gas source is pure helium, the spraying process is carried out with the inlet temperature of the spraying gas being 400-550℃, the pressure being 110-130psi, the powder feeding rate being 12-15 g / min, and the spraying distance being 10-25 mm. The repair powder is sprayed to repair the through hole opening of the deposited substrate. The nozzle diameter of the spray gun of the spraying equipment is not greater than the diameter of the through hole.

[0042] The powder material used in the spraying process is metal or metal-ceramic mixed powder; the material of the metal parts is metal and its alloys or ceramic-metal matrix composite material; the spraying equipment is a handheld cold spraying device or a path-programmed mechanical spraying device; and the tool used for polishing is a small rotary polishing pen.

[0043] During spray repair, keep the nozzle of the spray gun at a 90° angle to the inner wall of the through hole opening. Spray from the inner wall edge near the through hole at a uniform speed in a spiral pattern to the center of the hole. After 2-3 sprays in this manner, a cone-shaped protrusion with a apex angle of 10-20° will be formed in the center of the hole. The area around the protrusion is the spray dead zone, where repair powder cannot be deposited. At this point, grind the protrusion until it is flush with the lowest point of the repair layer. After grinding, spray again in a spiral pattern to the center of the hole. If a protrusion forms again, grind it until it is flush with the lowest point of the repair layer. Repeat this process until the repair is complete.

[0044] Step 4: After spraying, remove the mesh and sand the coating surface to ensure a smooth transition between the filler layer and the surface of the metal part.

[0045] Example 2: Same as Example 1, except that in step three, when the repair powder is aluminum powder and the metal part being repaired is aluminum, the process parameters are: gas inlet temperature is 450℃, gas pressure is 110psi, powder feed rate is 13.45g / min, and spraying distance is 10-25mm.

[0046] Example 3: Same as Example 1, except that the flexible dense mesh uses stainless steel fiber, nickel fiber, and titanium fiber as the metal fiber material; and iron-chromium-aluminum alloy fiber, constantan fiber, and Inco nickel alloy fiber as the alloy fiber material.

[0047] The powder materials used in the spraying process are Al and Al alloys, Mg and Mg alloys, Cu and Cu alloys, and Ti and Ti alloys; the ceramics are Al2O3, SiC, and TiN.

[0048] The materials for the metal parts are Al and Al alloys, Mg and Mg alloys, Cu and Cu alloys, Ti and Ti alloys; or ceramic-metal matrix composites are Al2O3 reinforced metal matrix composites, SiC reinforced metal matrix composites, and TiN reinforced metal matrix composites.

[0049] Example 4: Same as Example 1, except that the high-temperature resistant tape is polyimide tape model 5406 manufactured by 3M Company of the United States; the helium gas is high-purity helium gas with a purity of 99.99%.

[0050] like Figure 4 , Figure 5 , Figure 6 To further illustrate the technical solution and technical effects of the present invention, the following specific examples are provided:

[0051] Specific example 1:

[0052] like Figure 1-3 A method for repairing through holes in metal parts using easily removable mesh includes the following steps:

[0053] Step 1: Beveling the inner wall of the through hole opening in the aluminum component, and laser scanning the surrounding metal surface twice to remove impurities or oxide film, thereby enhancing the adhesion between the repair powder and the substrate. The through hole depth is 7 mm; radius is 5 mm; beveling angle is 80°; laser scanning parameters for removing the oxide layer from the aluminum component surface are: speed 2000 mm / s, power: 100%, frequency: 70 kHz, pulse width: 500 ns, line spacing: 0.05 mm, ring spacing: 0.05 mm, on-time delay: 300 μs, off-time delay: 100 μs, end delay: 300 μs, corner delay: 100 μs.

[0054] Step 2: Use a 1200-mesh flexible dense mesh made of stainless steel fiber material with a thickness of 0.5 mm and a wire diameter of 0.1 mm to seal the metal surface on one side of the through hole of the aluminum component, as an effective deposition substrate for the next step of repair powder; the specific sealing method is to use 3M high temperature resistant tape to stick to the metal surface on one side of the through hole of the aluminum component.

[0055] Step 3: Fix the aluminum component onto a specialized tooling fixture. Using a specific spraying process, repair the hole by spraying with a handheld cold spraying device from the front of the through hole in the aluminum component, gradually filling the hole. The parameters of the spraying process are: using 99.99% pure helium as the gas source; gas inlet temperature of 450 ℃; gas pressure of 110 psi; powder feed rate of 13.45 g / min; and spraying distance of 10-25 mm. mm; The step-by-step filling of the hole is specifically as follows: the nozzle of the spray gun should be kept at 90° to the inner wall of the through hole opening, and the spray should be applied at a uniform speed in a spiral path from the inner wall edge near the through hole to the center of the hole. After 2-3 sprays in this manner, a conical protrusion with a apex angle of 10-20° will be formed in the center of the hole. A spray dead zone will be formed around the protrusion, and the repair powder cannot be deposited. At this time, a small rotating grinding pen is needed to grind the protrusion until it is flush with the lowest point of the repair layer. After grinding, spraying is carried out again in the above manner. If a protrusion is formed again, grinding is required again. This process is repeated until the repair is completed. The repair powder is spherical Al powder with a particle size of 30-35 μm.

[0056] Step 4: After spraying, remove the mesh and sand the coating surface to ensure a smooth transition between the filler layer and the surface of the copper component.

[0057] Repair effect as Figure 4 As shown, the powder deposition effect is very good and can complete the repair of through holes.

[0058] Specific Example 2: Repairing a copper metal component using a flexible, dense mesh made of titanium fiber. The method for repairing a through hole in the metal component using this easily removable mesh includes the following steps:

[0059] Step 1: Beveling the inner wall of the through hole opening in the copper component, and laser scanning the surrounding metal surface twice to remove impurities or oxide film, thereby enhancing the adhesion between the repair powder and the substrate. The through hole depth is 10 mm; radius is 8 mm; beveling angle is 80°; laser scanning parameters for removing the oxide layer from the copper component surface are: speed 2000 mm / s, power: 100%, frequency: 70 kHz, pulse width: 500 ns, line spacing: 0.05 mm, ring spacing: 0.05 mm, on-time delay: 300 μs, off-time delay: 100 μs, end delay: 300 μs, corner delay: 100 μs.

[0060] Step 2: Use a 1 mm thick, 0.1 mm diameter, 1500-mesh flexible dense mesh made of titanium fiber to seal the metal surface on one side of the through hole of the copper component, as an effective deposition substrate for the next step of repair powder; the specific sealing method is to use 3M high temperature resistant tape to stick to the metal surface on one side of the through hole of the copper component.

[0061] Step 3: Fix the copper component onto a specialized tooling fixture. Using a specific spraying process, repair the hole by spraying with a handheld cold spraying device from the front of the through hole in the copper component, gradually filling the hole. The parameters of the spraying process are: using 99.99% pure helium as the gas source; gas inlet temperature of 500 ℃; gas pressure of 120 psi; powder feed rate of 15.01 g / min; and spraying distance of 10-25 mm. mm; The step-by-step filling of the hole is specifically as follows: the nozzle of the spray gun should be kept at 90° to the inner wall of the through hole opening, and the spray should be applied at a uniform speed in a spiral path from the inner wall edge near the through hole to the center of the hole. After 2-3 sprays in this manner, a conical protrusion with an apex angle of 10-20° will be formed in the center of the hole. A spray dead zone will be formed around the protrusion, and the repair powder cannot be deposited. At this time, a small rotating grinding pen is needed to grind the protrusion until it is flush with the lowest point of the repair layer. After grinding, spraying is carried out again in the above manner. If a protrusion is formed again, grinding is required again. This process is repeated until the repair is completed. The repair powder is spherical Cu powder with a particle size of 25-30μm.

[0062] Step 4: After spraying, remove the mesh and sand the coating surface to ensure a smooth transition between the filler layer and the surface of the copper component.

[0063] Compare with Example 1: Figure 5 As shown, the process is the same as in Specific Example 1, except that a metal plate is used to seal the through hole, which is step two: a metal plate is used to seal the metal surface on one side of the through hole of the aluminum component, serving as an effective deposition substrate for the next step of repair powder.

[0064] See the repair result image. Figure 5 As shown in the image, the repair powder only deposits at the edges of the holes, clearly failing to fill them completely, indicating a poor powder deposition effect. The specific reason is that, in Comparative Example 1, a metal plate was used instead of the aforementioned mesh as the substrate for the repair powder. Since the metal plate lacks good deformation capacity, and the through holes are often formed on irregular planes or are themselves irregular, it cannot effectively encapsulate the through holes. Consequently, the repair powder leaks from the gaps between the metal plate and the edges of the through holes, failing to deposit effectively.

[0065] Furthermore, the metal plate creates excessive resistance to airflow, preventing it from passing smoothly and affecting the uniformity of the coating and the quality of powder deposition. Excessive airflow pressure, in addition to affecting the coating effect, can also cause deformation or displacement of the metal plate, further impacting the coating process.

[0066] Compare with Example 2: Figure 6 As shown, the method is the same as in Specific Example 1, except that a thinner mesh is used to seal the through hole.

[0067] In step two, a 1200-mesh flexible dense mesh made of stainless steel fiber material with a thickness of 0.3 mm and a wire diameter of 0.1 mm is used to seal the metal surface on one side of the through hole of the aluminum component, serving as an effective deposition substrate for the repair powder in the next step. The specific sealing method is to use 3M high-temperature resistant tape to stick to the metal surface on one side of the through hole of the aluminum component.

[0068] See repair results Figure 6 As shown in the image, the filling is clearly incomplete, with blind holes remaining. This indicates that the repair powder deposition effect is unsatisfactory. The specific reason is that the mesh thickness used in Control Example 2 was only 0.3 mm. During the spraying process, there is a high airflow, and the mesh being too thin cannot effectively block the repair powder, causing the powder to leak from behind the holes, affecting the repair effect. In addition, a mesh that is too thin is easily damaged by impact under high spraying pressure, thus affecting the repair quality.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of repairing a through hole in a metal part with the aid of a removable gauze, characterized in that, It comprises the following steps: Step one: polishing and surface treatment on the surrounding of the through hole of the metal part to enhance the bonding force between the repair powder and the substrate; Step two: using high-temperature-resistant adhesive tape to fix the flexible and dense gauze on the surface of the metal part on one side of the through hole of the metal part, and the flexible and dense gauze and the hole body form an effective deposition substrate for the repair powder; Step three: fixing the metal part on the fixture, under the condition that the spraying gas source is pure helium, the inlet temperature of the spraying gas is 400-550℃, the pressure is 110-130psi, the spraying powder amount is 12-15 g / min, and the spraying distance is 10-25mm, the repair powder is sprayed from the through hole opening of the deposition substrate to repair; the caliber of the nozzle of the spraying gun is not greater than the diameter of the through hole; During spraying repair, the nozzle of the spraying gun is uniformly sprayed in a spiral route from the edge of the inner wall of the through hole to the center of the hole, and after 2-3 times of spraying, a conical protrusion with an apex angle of 10-20° is formed at the center of the hole, and around the protrusion is a dead zone where the repair powder cannot be deposited, at this time, the protrusion is polished to be flush with the lowest part of the repair layer, after polishing, the method of gradually spraying to the center of the hole in a spiral route is used again, and the protrusion is polished to be flush with the lowest part of the repair layer again, and the process is repeated until the repair is completed; Step four: after spraying is completed, remove the gauze and polish the surface of the coating to ensure smooth transition between the filling layer and the surface of the metal part.

2. The method of repairing a through hole in a metal part with a removable gauze according to claim 1, wherein, In step one, the polishing treatment is to polish the inner wall of the through hole at both openings to a bevel with an angle of 70-80° to facilitate the deposition of the repair powder; The surface treatment is to perform sand blasting treatment or laser scanning on the metal surface around the opening of the metal part to remove impurities or oxide film on the surface of the metal part.

3. The method of repairing a through hole in a metal part with a removable gauze according to claim 1, wherein, In step two, the flexible and dense gauze is made of metal fiber material or alloy fiber material with high temperature resistance and strong oxidation resistance; the thickness of the flexible and dense gauze is 0.5-2mm, the wire diameter is 0.1-0.3mm, the mesh number is at least 1200, and the particle size of the repair powder is 23-50μm, which ensures that the flexible and dense gauze can prevent the repair powder from being directly sprayed out of the through hole under the conditions of spraying pressure and airflow, at the same time, it is convenient for airflow to pass through without causing reverse pressure, ensuring uniform flow of powder in the through hole and improving deposition effect.

4. The method of repairing a through hole in a metal part with a removable gauze according to claim 3, wherein, The metal fiber material is stainless steel fiber, nickel fiber, and titanium fiber; the alloy fiber material is iron-chromium-aluminum alloy fiber, constantan fiber, and inco nickel alloy fiber.

5. The method of repairing a through hole in a metal part with a removable gauze according to claim 1, wherein, In step three, the spraying powder material used in the spraying process is metal or metal-ceramic mixed powder; the metal is Al and Al alloy, Mg and Mg alloy, Cu and Cu alloy, Ti and Ti alloy, and the ceramic is Al2O3, SiC, and TiN.

6. The method of repairing a through hole in a metal part with a removable gauze of claim 1, wherein, The material of the metal part is metal and its alloy or ceramic-metal matrix composite material; the metal and alloy are Al and Al alloy, Mg and Mg alloy, Cu and Cu alloy, Ti and Ti alloy; the ceramic-metal matrix composite material is Al2O3 reinforced metal matrix composite material, SiC reinforced metal matrix composite material and TiN reinforced metal matrix composite material.

7. The method of repairing a through hole in a metal part with a removable screen of claim 1, wherein, The depth of the through hole on the metal part is 3-15 mm, and the radius is 3-10 mm.

8. The method of repairing a through hole in a metal part with a removable screen of claim 1, wherein, The spraying equipment is a handheld cold spraying device or a mechanical spraying device based on path programming, and the tool used during polishing is a small head carving pen.

9. The method of repairing a through hole in a metal part with a removable screen of claim 1, wherein, The high-temperature-resistant adhesive tape is a polyimide adhesive tape produced by the American 3M Company, with the model number 5406; and the helium is high-purity helium with a purity of 99.99%.

10. A method of repairing a through hole in a metal part with the aid of a readily detachable gauze according to any one of claims 1-9, characterized in that, In step three, when the repair powder is aluminum powder and the repaired metal part is an aluminum part, the process parameters are: the gas inlet temperature is 450 DEG C, the gas pressure is 110 psi, the powder feeding amount is 13.45 g / min, and the spraying distance is 10-25 mm.

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