A method for repairing and protecting the surface of iron metal cultural relics

Abstract

The present invention discloses a method for repairing and protecting the surface of ferrous metal artifacts, comprising the following steps: depositing a material for repairing ferrous metal artifacts on the surface of the artifact by cold spraying; processing the surface of the cold sprayed deposited layer to the original dimensional accuracy and surface roughness of the artifact, thereby completing the repair; the material for repairing the ferrous metal artifact comprises, by mass percentage, 50% to 95% micron iron-based amorphous alloy powder and 5% to 50% submicron ceramic powder. The present invention innovatively utilizes advanced low-temperature solid-state deposition cold spraying technology to prepare a coating material suitable for ferrous metal artifact substrates, providing reliable theoretical and technical support for the practical application of surface coatings on ferrous metal artifact substrates.

Description

Technical Field

[0001] The present invention relates to the technical field of methods for repairing and protecting the surfaces of ferrous metal cultural relics, and in particular to a method for repairing and protecting ferrous metal cultural relics that have been corroded and have lost size, and specifically to the density, bonding strength, and antioxidant properties of the repair layer. Background Art

[0002] Metal artifacts are rare and precious cultural heritage, imbued with rich humanistic sentiments and representing the spiritual values of our ancestors. Cultural relics epitomize and represent an era. Research indicates that the majority of existing metal artifacts are made of iron and bronze, such as the Shaanxi Thousand Buddha Pagoda, the Cangzhou Iron Lion, and various bronze artifacts. However, due to their centuries or even millennia of exposure to natural environments, these metal artifacts are subject to severe corrosion, which impacts their lifespan. Therefore, the challenge of preserving these metal artifacts remains urgent.

[0003] At present, most of the traditional methods for protecting metal cultural relics are welding, corrosion inhibitor sealing, desalination protection and surface sealing. For example, Zhang Ming et al. used spot welding technology to repair a Yaqiang Fuyi Lei from the Western Zhou Dynasty unearthed from the tomb of a nobleman in Shigu Mountain, Baoji City, Shaanxi Province, with good repair results. Hollner et al. used HC 10 +H2O2 water-ethanol mixed solution was applied to the iron anchor of the National Maritime Museum in Paris, and it was found that the corrosion inhibitor had a long-term protective effect and was suitable for the long-term preservation of iron cultural relics; Wu Gengfeng et al. used the immersion desalination method to treat the "Lugangjiao" iron bell of the Qing Dynasty. The immersion liquid was a compound alkaline solution composed of sodium hydroxide, sodium molybdate, sodium silicate and surfactants. The desalination effect was good. No new rust was found on the surface of the iron bell during the whole process of immersion desalination; He Haiping et al. modified the polyester polyurethane emulsion by adding nano-TiO2 and SiO2 as a composite sealing agent for iron cultural relics. It not only solved the damage of the dispersed medium water to the iron cultural relic matrix, but also improved the aging resistance and corrosion resistance of the sealing agent film.

[0004] Treatment techniques such as welding and chemical treatments with corrosion inhibitors can sometimes cause surface defects such as pitting and oxidation, which can irreversibly damage the metal substrate. Furthermore, some chemical agents can also have environmental impacts. Therefore, new methods are urgently needed to repair and protect the surfaces of ferrous metal artifacts. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a method for repairing and protecting the surface of ferrous metal cultural relics. The present invention innovatively adopts advanced low-temperature solid-state deposition cold spray technology to prepare coating materials suitable for ferrous metal cultural relic substrates, providing reliable theoretical and technical support for the practical application of surface coatings on ferrous metal cultural relic substrates.

[0006] The technical solution adopted in the present invention is as follows:

[0007] A method for repairing and protecting the surface of iron metal cultural relics, comprising the following steps:

[0008] The material used to repair the iron metal cultural relic is deposited on the part to be repaired of the iron metal cultural relic by cold spraying, forming a cold spray deposition layer on the surface of the part to be repaired, and the cold spray deposition layer is processed to the original dimensional accuracy and surface roughness of the iron metal cultural relic to be repaired, and the repair is completed;

[0009] Calculated by mass percentage, the material for repairing iron metal cultural relics includes: 50% to 95% of micron iron-based metal powder and 5% to 50% of submicron ceramic powder.

[0010] Preferably, the particle size of the micron iron-based metal powder is 5 μm to 30 μm, and the particle size of the submicron ceramic powder is 30 μm to 100 μm.

[0011] Preferably, the micron iron-based metal powder is iron-based amorphous particles, and the submicron ceramic particles are Al2O3 powder, which is a powder formed by agglomeration of fine lamellar aluminum oxide with a particle size of 1 to 10 μm.

[0012] Preferably, the chemical composition of the micron iron-based metal powder is as shown in Table 1:

[0013] Table 1

[0014]

[0015] The volume ratio is the volume ratio measured by scanning electron microscope energy spectrum analysis.

[0016] Preferably, the thickness of the cold spray deposition layer is 1000 μm to 5000 μm.

[0017] Preferably, when the material for repairing the iron metal cultural relic is deposited on the part to be repaired of the iron metal cultural relic by cold spraying:

[0018] The parameters of cold spraying include: carrier gas pressure of 2.5-4.5 MPa, spraying distance of 5-30 mm, spray gun moving speed of 5-30 mm / s, spraying temperature of 100-500°C, and powder feeding speed of 0.5 r / min-2.0 r / min.

[0019] Preferably, when the material for repairing the iron metal cultural relic is deposited on the part to be repaired of the iron metal cultural relic by cold spraying:

[0020] When the carrier gas pressure is 2.5-3 MPa, the spraying temperature is 400-500°C, the spraying distance is 5-10 mm, the spray gun moving speed is 10-20 mm / s, and the powder feeding speed is 1.0-2.0 r / min;

[0021] When the carrier gas pressure is 3-3.5 MPa, the spraying temperature is 300-400°C, the spraying distance is 10-20 mm, the spray gun moving speed is 20-30 mm / s, and the powder feeding speed is 0.8-1.5 r / min;

[0022] When the carrier gas pressure is 3.5-4 MPa, the spraying temperature is 200-300°C, the spraying distance is 15-25 mm, the spray gun moving speed is 30-40 mm / s, and the powder feeding speed is 0.5-1.0 r / min;

[0023] When the carrier gas pressure is 4-4.5 MPa, the spraying temperature is 100-250°C, the spraying distance is 10-30 mm, the spray gun moving speed is 40-50 mm / s, and the powder feeding speed is 0.5-0.8 r / min.

[0024] Preferably, before the material for repairing the iron metal cultural relic is deposited on the part to be repaired of the iron metal cultural relic by cold spraying, the notch or crack of the part to be repaired of the iron metal cultural relic is firstly sanded with water sandpaper, cleaned with laser and sandblasted in sequence, and then the cold spraying deposition is performed;

[0025] Among them, sandblasting makes the surface roughness of the structural parts reach Ra60μm~80μm. During the sandblasting process, the sand is brown corundum with a particle size of 400~700μm, and the compressed air pressure during sandblasting is 0.5~0.7MPa;

[0026] After the cold spray deposited layer is processed to the original dimensional accuracy and surface roughness of the iron metal cultural relic to be repaired, the iron metal cultural relic to be repaired with the cold spray deposited layer is ultrasonically cleaned and dried using ethanol as a solution.

[0027] Preferably, the angle of the notch is 90° to 120°.

[0028] Preferably, the material of the ferrous metal cultural relic to be repaired is an iron-based metal material, and the micron iron-based metal powder is an iron-based amorphous alloy powder.

[0029] The present invention has the following beneficial effects:

[0030] This invention uses low-temperature solid-state deposition cold spray technology to produce a cold-spray coating on the surface of ferrous metal cultural relics. By adjusting parameters, the density, corrosion resistance, and friction resistance of the repaired layer are enhanced compared to the original ferrous metal cultural relics to be repaired, thereby protecting the ferrous metal cultural relics and extending their shelf life. This invention integrates cultural relic protection with fields such as metallurgy, materials, engineering, and information technology to further reveal the historical, artistic, and scientific value of cultural relics, thereby effectively protecting and preserving them. This will greatly promote the scientific understanding and protection of cultural relics in my country, achieve new breakthroughs in development, and create a new era for development. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a process flow chart of the method for repairing and protecting the surface of ferrous metal cultural relics of the present invention;

[0032] Figure 2 Schematic diagram of the cold spraying equipment used in the present invention;

[0033] Figure 3 A schematic diagram of the structure of the notch designed for the present invention;

[0034] Figure 4 This is a micrograph of the repaired portion (notch) of the iron metal cultural relic after the repair is completed in Example 1 of the present invention;

[0035] Figure 5 This is a micrograph of the repaired portion (notch) of the iron metal cultural relic after the repair is completed in Example 2 of the present invention;

[0036] Figure 6 This is a micrograph of the micronized iron-based amorphous alloy powder used in the embodiments of the present invention;

[0037] Figure 7 This is a micrograph of the morphology of the lamellar Al2O3 powder used in the embodiments of the present invention;

[0038] In the figure, 1-gas container, 2-powder feeder, 3-spray gun, 4-substrate. DETAILED DESCRIPTION

[0039] The present invention will be described below with reference to the accompanying drawings and embodiments.

[0040] The purpose of this invention is to use remanufacturing technology to repair iron metal cultural relics with wear phenomena such as gaps or cracks. Figure 6 ) doped submicron ceramic particles (see Figure 7 ) composite powder is used as the repair powder, and cold spray deposition is used as the main repair technology. By controlling the process parameters, a dense and high-bonding-strength cold spray deposition coating is prepared on the gap of the iron metal cultural relic to be repaired.

[0041] The overall idea of the technical solution of the present invention is as follows: the material used to repair defects such as notches and cracks is cold-sprayed on the surface of the iron metal cultural relic to be repaired, forming a cold-sprayed deposition layer on the surface of the iron metal cultural relic to be repaired, and the repaired coating surface is mechanically processed and polished to the original dimensional accuracy and surface roughness.

[0042] Specifically, refer to Figure 1 The present invention provides a method for repairing and protecting the surface of ferrous metal cultural relics, comprising the following steps:

[0043] Step 1: Mix the micron iron-based amorphous powder and the submicron ceramic powder, and then place the obtained mixed raw material in a mixer for mixing. After ensuring that it is fully mixed, take out the mixed powder; wherein, in terms of mass percentage, the mixed raw material contains 50% to 95% of the micron iron-based amorphous powder and 5% to 50% of the submicron ceramic powder. The submicron ceramic particles are Al2O3 powder, refer to Figure 7 The Al2O3 powder is agglomerated from fine lamellar aluminum oxide, and the particle size of the fine lamellar powder is 1 to 10 μm.

[0044] Step 2: drying the mixed powder obtained in step 1 in a vacuum drying oven at 60-100° C. for 5-8 hours;

[0045] Step 3: Place the iron metal artifacts to be repaired ( Figure 2 The base 4) shown is simplified to a ferrous metal artifact to be repaired with a gap, such as Figure 3 As shown, the surface of the cracks or notches of the iron metal cultural relics to be repaired is polished with water sandpaper until it is easy to repair. Specifically, the surface of the structural parts to be repaired is polished flat with 80 mesh, 200 mesh, 1000 mesh, 1500 mesh, and 2000 mesh water sandpaper in sequence and then ultrasonically cleaned. After cleaning, sandblasting is performed.

[0046] Step 4: Use cold spraying to spray the dried mixed powder onto the surface of the gap that has been sandblasted to form a cold spray deposition coating with a thickness of 1000μm to 5000μm. The cold spray is perpendicular to the part to be repaired. The repaired reference Figure 4 and Figure 5 ;like Figure 3 As shown, in the present invention, a 90° to 120° notch design is used for pre-setting the notches. SEM observation shows that the coating has low porosity and good coating quality. During the cold spray deposition process, the carrier gas pressure is 2.5 to 4.5 MPa, the spraying distance is 5 to 30 mm, the spray gun movement speed is 5 to 30 mm / s, the spraying temperature is 100 to 500°C, and the powder feed rate is 0.5 to 2.0 r / min.

[0047] The iron metal artifacts to be restored are iron-based alloys. The cold spray deposition method uses nitrogen, helium, or compressed air as the carrier gas. The sand used for sandblasting the iron-based alloy surface is brown corundum with a particle size of 400-700μm, and the blasting pressure is 0.5-0.7MPa.

[0048] During the cold spray deposition process, the spray parameters are matched according to the parameters in Table 2:

[0049] Table 2

[0050]

[0051] Step 5, size restoration: The cold spray deposited layer is mechanically processed, such as using wire cutting technology, and the surface of the supersonic laser deposited layer is polished using water-jet sandpaper of different particle sizes. The surface after supersonic laser deposition is then polished using a diamond polishing agent with a particle size of 0.5 microns to restore the iron metal artifact to its original size after repair. The surface roughness after treatment is Ra0.2. Then, using ethanol as a solution, the structural iron metal artifact with the cold spray deposited layer is placed in an ultrasonic cleaning chamber for ultrasonic cleaning. After cleaning, it is placed in a drying oven for drying at a temperature of 80°C and a drying time of 1 hour.

[0052] In the process of repairing iron metal cultural relics, the present invention needs to design an appropriate powder particle size to achieve good results. The selection of powder particle size is related to the density of the material. Because the cold spraying technology uses high-pressure gas as a power source, the high-pressure gas reaches supersonic speed after passing through the Raoult tube during the spraying process. The supersonic gas will form a shock wave on the surface of the substrate, hindering the particles from colliding with the substrate. Therefore, when the mass of the powder particles is too small, it will be difficult to overcome the shock wave, and effective deposition cannot be achieved. However, when the powder particles are too large, the gas has a poor acceleration effect on them, and the particle speed cannot meet the deposition requirements, and effective deposition cannot be achieved. In the present invention, after reasonable experimental design, it is concluded that the particle size of the iron-based alloy powder is 5μm to 30μm, and the particle size of the submicron ceramic powder is 30μm to 100μm.

[0053] During implementation of the present invention's surface restoration and protection method for ferrous metal artifacts, the material used to repair ferrous metal artifacts is cold-sprayed onto the surface of an iron-based alloy, restoring the damaged ferrous metal artifact to its original dimensions. The cold spraying process, performed at temperatures far below the melting point of the original powdered material, effectively avoids adverse effects such as oxidation, phase transformation, and thermal cracking caused by high temperatures. Furthermore, the high-speed impact of the sprayed particles on the substrate or the deposited particles creates a denser structure and improved bonding strength.

[0054] Prior to cold spray deposition, the surface of the iron metal artifact to be repaired is sandblasted, and then supersonic laser deposition is performed on the sandblasted surface of the repaired part. During sandblasting, the sand is brown corundum with a particle size of 400μm to 700μm, and the compressed air pressure during sandblasting is 0.5MPa to 0.7MPa. Before preparing the repair layer, the surface of the repaired part must first be sandblasted to achieve a roughened surface, increase the contact area between the particles and the substrate, and improve the bonding strength between the coating and the substrate. For iron-based alloy substrates, using brown corundum with a particle size of 400μm to 700μm and a compressed air pressure of 0.5MPa to 0.7MPa during sandblasting can effectively roughen the surface and achieve a high bonding strength between the coating and the substrate.

[0055] The present invention's surface restoration process for ferrous metal artifacts integrates powder selection to maximize the functionality and potential of the original powder material. This method effectively completes the restoration of ferrous metal artifacts, leveraging the inherent advantages of cold spray deposition methods and providing a scientific approach to repair damaged ferrous metal artifacts at the lowest cost.

[0056] The material of the iron metal cultural relic to be repaired is iron-based material, which does not protect the historicity and material of the iron cultural relic. The repair material should be similar to the iron metal cultural relic to be repaired.

[0057] The chemical composition of the micron iron-based metal powder used in the following examples of the present invention is shown in Table 1:

[0058] Table 1

[0059]

[0060] The volume ratio is the volume ratio measured by scanning electron microscope energy spectrum analysis.

[0061] Example 1

[0062] The surface restoration and protection method of ferrous metal cultural relics in this embodiment includes the following steps:

[0063] Step 1: Weigh 350g of Al2O3 powder and 700g of iron-based amorphous alloy powder respectively, wherein the particle size of the iron-based amorphous alloy powder is 5μm to 30μm, and the average particle size is 20μm; the particle size of the Al2O3 powder is 30μm to 100μm, and the average particle size is 50μm.

[0064] Step 2: Mix the Al2O3 powder and the iron-based amorphous alloy powder weighed in step 1, and then place them in a mixer for mixing. Take them out after mixing for 2 hours;

[0065] Step 3: Dry the mixed powder obtained in step 2 in a vacuum drying oven at 80° C. and take it out after keeping the temperature for 6 hours.

[0066] Step 4: polish the surface of the simplified iron metal cultural relic to be repaired with 80 mesh, 200 mesh, 1000 mesh, 1500 mesh, and 2000 mesh water sandpaper in sequence, then perform ultrasonic cleaning, and then perform sandblasting;

[0067] Step 5: Use supersonic laser deposition to spray the mixed powder dried in step 3 onto the surface of the iron metal cultural relic that has been sandblasted (with a notch angle of 120°) to form a cold spray deposition layer with a thickness of 2000 μm; wherein, during the cold spraying, the carrier gas used is nitrogen, the carrier gas pressure is 3.0 MPa, the spraying distance is 12 mm, the spray gun speed is 25 mm / s, the spraying temperature is 400°C, and the powder feeding rate is 1.5 r / min. The sand used for sandblasting the surface of the iron metal cultural relic to be repaired is brown corundum with a particle size of 400 to 700 μm, and the sandblasting pressure is 0.6 MPa.

[0068] Step 6: The cold spray deposited layer is mechanically processed, such as using wire cutting technology, and the surface of the supersonic laser deposited layer is polished using water sandpaper of different particle sizes. The surface after supersonic laser deposition is then polished using a diamond polishing agent with a particle size of 0.5 microns to restore the iron metal artifact to its original size after repair. The surface roughness after treatment is Ra0.2. Then, using ethanol as a solution, the structural iron metal artifact with the cold spray deposited layer is placed in an ultrasonic cleaning chamber for ultrasonic cleaning. After cleaning, it is placed in a drying oven for drying at a drying temperature of 80°C and a drying time of 1 hour.

[0069] Step 7: The porosity and electrochemical corrosion tests were conducted on the repaired iron metal cultural relic repair layer. The coating porosity was 0.45%, as shown in the following figure. Figure 4 As shown, the coating has good density. Electrochemical corrosion tests found that the pitting corrosion resistance of the repaired coating was enhanced, proving that the cold-sprayed iron-based amorphous coating restored the size of the damaged iron metal artifacts while increasing their corrosion resistance, thus playing a protective role in the iron metal artifacts.

[0070] Example 2

[0071] The surface restoration and protection method of ferrous metal cultural relics in this embodiment includes the following steps:

[0072] Step 1: Weigh 400g of Al2O3 powder and 800g of iron-based amorphous alloy powder respectively, wherein the particle size of the iron-based amorphous alloy powder is 5μm to 30μm, and the average particle size is 20μm; the particle size of the Al2O3 powder is 30μm to 100μm, and the average particle size is 50μm.

[0073] Step 2: Mix the Al2O3 powder and the iron-based amorphous alloy powder weighed in step 1, and then place them in a mixer for mixing. Take them out after mixing for 2 hours;

[0074] Step 3: Dry the mixed powder obtained in step 2 in a vacuum drying oven at 80° C. and take it out after keeping the temperature for 6 hours.

[0075] Step 4: polish the surface of the simplified iron metal cultural relic to be repaired with 80 mesh, 200 mesh, 1000 mesh, 1500 mesh, and 2000 mesh water sandpaper in sequence, then perform ultrasonic cleaning, and then perform sandblasting;

[0076] Step 5: Use supersonic laser deposition to spray the mixed powder dried in step 3 onto the surface of the iron metal cultural relic (with a notch angle of 120°) that has been sandblasted to form a cold spray deposition layer with a thickness of 2000 μm; wherein, during the cold spraying, the carrier gas used is nitrogen, the carrier gas pressure is 3.5 MPa, the spraying distance is 18 mm, the spray gun speed is 25 mm / s, the spraying temperature is 350°C, and the powder feeding rate is 1.5 r / min. The sand used for sandblasting the surface of the iron metal cultural relic to be repaired is brown corundum with a particle size of 400 to 700 μm, and the sandblasting pressure is 0.6 MPa.

[0077] Step 6: The cold spray deposited layer is mechanically processed, such as using wire cutting technology, and the surface of the supersonic laser deposited layer is polished using water sandpaper of different particle sizes. The surface after supersonic laser deposition is then polished using a diamond polishing agent with a particle size of 0.5 microns to restore the iron metal artifact to its original size after repair. The surface roughness after treatment is Ra0.2. Then, using ethanol as a solution, the structural iron metal artifact with the cold spray deposited layer is placed in an ultrasonic cleaning chamber for ultrasonic cleaning. After cleaning, it is placed in a drying oven for drying at a drying temperature of 80°C and a drying time of 1 hour.

[0078] Step 7: The porosity and electrochemical corrosion tests were conducted on the repaired iron metal cultural relic repair layer. The coating porosity was 0.38%, as shown in the following figure. Figure 5 As shown, the coating has good density. Electrochemical corrosion tests found that the pitting corrosion resistance of the repaired coating was enhanced, proving that the cold-sprayed iron-based amorphous coating restored the size of the damaged iron metal artifacts while increasing their corrosion resistance, thus playing a protective role in the iron metal artifacts.

[0079] Example 3

[0080] The surface restoration and protection method of ferrous metal cultural relics in this embodiment includes the following steps:

[0081] Step 1: Weigh 80g of Al2O3 powder and 1600g of iron-based amorphous alloy powder respectively, wherein the particle size of the iron-based amorphous alloy powder is 5μm to 30μm, and the average particle size is 20μm; the particle size of the Al2O3 powder is 30μm to 100μm, and the average particle size is 50μm.

[0082] Step 2: Mix the Al2O3 powder and the iron-based amorphous alloy powder weighed in step 1, and then place them in a mixer for mixing. Take them out after mixing for 2 hours;

[0083] Step 3: Dry the mixed powder obtained in step 2 in a vacuum drying oven at 60° C. and take it out after keeping it warm for 8 hours.

[0084] Step 4: polish the surface of the simplified iron metal cultural relic to be repaired with 80 mesh, 200 mesh, 1000 mesh, 1500 mesh, and 2000 mesh water sandpaper in sequence, then perform ultrasonic cleaning, and then perform sandblasting;

[0085] Step 5: Use a supersonic laser deposition method to spray the mixed powder dried in step 3 onto the surface of the iron metal cultural relic (with a notch angle of 90°) that has been sandblasted to form a cold spray deposition layer with a thickness of 2000 μm; wherein, during the cold spraying, the carrier gas used is nitrogen, the carrier gas pressure is 2.5 MPa, the spraying distance is 5 mm, the spray gun speed is 20 mm / s, the spraying temperature is 500°C, and the powder feeding rate is 1.5 r / min. The sand used for sandblasting the surface of the iron metal cultural relic to be repaired is brown corundum with a particle size of 400 μm, and the sandblasting pressure is 0.7 MPa.

[0086] Step 6: The cold spray deposited layer is mechanically processed, such as using wire cutting technology, and the surface of the supersonic laser deposited layer is polished using water sandpaper of different particle sizes. The surface after supersonic laser deposition is then polished using a diamond polishing agent with a particle size of 0.5 microns to restore the iron metal artifact to its original size after repair. The surface roughness after treatment is Ra0.2. Then, using ethanol as a solution, the structural iron metal artifact with the cold spray deposited layer is placed in an ultrasonic cleaning chamber for ultrasonic cleaning. After cleaning, it is placed in a drying oven for drying at a drying temperature of 80°C and a drying time of 1 hour.

[0087] In step 7, porosity and electrochemical corrosion tests were performed on the repaired ferrous metal artifact layer. The coating showed a porosity of 0.62% and good coating density. Electrochemical corrosion tests revealed enhanced pitting corrosion resistance in the repaired coating, demonstrating that the cold-sprayed iron-based amorphous coating not only restored the damaged ferrous metal artifact's dimensions but also enhanced its corrosion resistance, thus protecting it.

[0088] Example 4

[0089] The surface restoration and protection method of ferrous metal cultural relics in this embodiment includes the following steps:

[0090] Step 1: Weigh 500g of Al2O3 powder and 1000g of iron-based amorphous alloy powder respectively, wherein the particle size of the iron-based amorphous alloy powder is 5μm to 30μm, and the average particle size is 20μm; the particle size of the Al2O3 powder is 30μm to 100μm, and the average particle size is 50μm.

[0091] Step 2: Mix the Al2O3 powder and the iron-based amorphous alloy powder weighed in step 1, and then place them in a mixer for mixing. Take them out after mixing for 2 hours;

[0092] Step 3: Dry the mixed powder obtained in step 2 in a vacuum drying oven at 100° C. and take it out after keeping it warm for 5 hours.

[0093] Step 4: polish the surface of the simplified iron metal cultural relic to be repaired with 80 mesh, 200 mesh, 1000 mesh, 1500 mesh, and 2000 mesh water sandpaper in sequence, then perform ultrasonic cleaning, and then perform sandblasting;

[0094] Step 5: Use a supersonic laser deposition method to spray the mixed powder dried in step 3 onto the surface of the iron metal cultural relic (notch angle is 100°) that has been sandblasted to form a cold spray deposition layer with a thickness of 2000 μm; wherein, during the cold spraying, the carrier gas used is nitrogen, the carrier gas pressure is 4.5 MPa, the spraying distance is 30 mm, the spray gun speed is 40 mm / s, the spraying temperature is 100°C, and the powder feeding rate is 0.8 r / min. The sand used for sandblasting the surface of the iron metal cultural relic to be repaired is brown corundum with a particle size of 700 μm, and the sandblasting pressure is 0.5 MPa.

[0095] In step 6, the cold-sprayed deposited layer is mechanically processed, such as using wire-cut machining. The surface of the supersonic laser-deposited layer is polished using water-repellent sandpaper of varying grit sizes. The supersonic laser-deposited surface is then polished using a 0.5-micron diamond polishing compound to restore the restored iron artifact to its original dimensions. The surface roughness after treatment is Ra 0.2. The iron artifact with the cold-sprayed deposited layer is then ultrasonically cleaned in an ethanol solution in an ultrasonic cleaning chamber. After cleaning, the artifact is dried in a drying oven at 80°C for 1 hour. In step 7, porosity and electrochemical corrosion testing of the restored layer reveal a coating porosity of 0.32% and good coating density. Electrochemical corrosion testing reveals enhanced pitting resistance in the repaired coating, demonstrating that the cold-sprayed iron-based amorphous coating not only restores the damaged artifact's dimensions but also enhances its corrosion resistance, thus protecting the artifact.

Claims

1. A method for repairing and protecting the surface of ferrous metal cultural relics, characterized in that: The process includes the following: The material used to repair the iron metal cultural relic is deposited on the part to be repaired of the iron metal cultural relic by cold spraying, forming a cold spray deposition layer on the surface of the part to be repaired, and the cold spray deposition layer is processed to the original dimensional accuracy and surface roughness of the iron metal cultural relic to be repaired, and the repair is completed; Calculated by mass percentage, the material for repairing iron and metal cultural relics includes: 50% to 95% of micron iron-based metal powder and 5% to 50% of submicron ceramic powder; The particle size of the micron iron-based metal powder is 5 μm to 30 μm, and the particle size of the submicron ceramic powder is 30 μm to 100 μm; The micron iron-based metal powder is made of iron-based amorphous particles, and the submicron ceramic particles are made of Al2O3 powder, which is a powder formed by agglomeration of fine lamellar aluminum oxide with a particle size of 1 to 10 μm. The chemical composition of the micron iron-based metal powder is shown in Table 1: Table 1 When the material for repairing iron metal cultural relics is deposited on the part to be repaired of the iron metal cultural relics by cold spraying: When the carrier gas pressure is 2.5-3MPa, the spraying temperature is 400-500℃, the spraying distance is 5-10mm, the spray gun moving speed is 10-20mm / s, and the powder feeding speed is 1.0-2.0r / min; When the carrier gas pressure is 3-3.5 MPa, the spraying temperature is 300-400°C, the spraying distance is 10-20 mm, the spray gun moving speed is 20-30 mm / s, and the powder feeding speed is 0.8-1.5 r / min; When the carrier gas pressure is 3.5-4 MPa, the spraying temperature is 200-300°C, the spraying distance is 15-25 mm, the spray gun moving speed is 30-40 mm / s, and the powder feeding speed is 0.5-1.0 r / min; When the carrier gas pressure is 4-4.5MPa, the spraying temperature is 100-250℃, the spraying distance is 10-30mm, the spray gun moving speed is 40-50mm / s, and the powder feeding speed is 0.5-0.8r / min; Before depositing the material for repairing the iron metal cultural relic on the part to be repaired of the iron metal cultural relic by cold spraying, the notch or crack of the part to be repaired of the iron metal cultural relic is firstly subjected to water sandpaper polishing, laser cleaning and sandblasting treatment in sequence, and then the cold spray deposition is carried out; Among them, sandblasting makes the surface roughness of the structural parts reach Ra60μm~80μm. During the sandblasting process, the sand is brown corundum with a particle size of 400~700μm, and the compressed air pressure during sandblasting is 0.5~0.7MPa; After the cold spray deposited layer is processed to the original dimensional accuracy and surface roughness of the iron metal cultural relic to be repaired, the iron metal cultural relic to be repaired with the cold spray deposited layer is ultrasonically cleaned and dried using ethanol as a solution; The angle of the notch is 90° to 120°.

2. The method for repairing and protecting the surface of ferrous metal cultural relics according to claim 1, characterized in that: The thickness of the cold spray deposition layer is 1000μm~5000μm.

3. The method for repairing and protecting the surface of ferrous metal cultural relics according to claim 1, characterized in that: The material of the iron metal cultural relic to be repaired is an iron-based metal material, and the micron iron-based metal powder is an iron-based amorphous alloy powder.

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