Multipurpose supersonic speed tungsten carbide spraying method

Abstract

The invention relates to a multipurpose supersonic tungsten carbide spraying method, which effectively solves the problems of prolonging the service life and improving the reliability of parts in a severe working environment. The method comprises the following steps of spray coating construction, matrix pretreatment, sand blasting, spray coating, hole sealing, grinding, polishing and detection. The tungsten carbide coating is suitable for various base materials such as steel and iron materials, aluminum alloy and titanium alloy, the application field of the tungsten carbide coating is widened, and the tungsten carbide coating can be widely applied to surface protection of parts in the industries such as mechanical manufacturing, aerospace, petrochemical engineering and mining. The tungsten carbide coating with high hardness, high wear resistance, low porosity and high bonding strength is effectively prepared, meanwhile, the application range of the spraying process on different base materials is widened, the service life of parts in the severe working environment is prolonged, the reliability of the parts in the severe working environment is improved, and remarkable economic benefits and social benefits are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of material surface treatment, in particular to a multi-purpose supersonic tungsten carbide spraying method using supersonic technology and its application in multiple fields. Background Art

[0002] In numerous fields, such as machinery manufacturing, aerospace, petrochemicals, and hydropower station flow components, components often face harsh operating environments such as wear, corrosion, and erosion, which significantly impact component lifespan and equipment operation. Traditional surface protection methods, such as electroplating and hot-dip galvanizing, have limitations in their performance and are unable to meet the high-performance, long-life requirements of modern industry.

[0003] Tungsten carbide coatings are ideal surface protective coatings due to their excellent properties, including high hardness, high wear resistance, good corrosion resistance, and high-temperature stability. However, conventional coating preparation methods, such as flame spraying and arc spraying, produce tungsten carbide coatings with high porosity, low bonding strength, and uneven coating structure, which prevent the coatings from fully realizing their performance.

[0004] As an advanced coating preparation technology, supersonic spraying technology has the advantages of high particle flight speed and low heating temperature. It can cause the sprayed particles to undergo strong plastic deformation when they impact the substrate surface at high speed, thereby forming a dense, high-bonding strength coating. However, the existing supersonic tungsten carbide spraying process still has significant deficiencies in parameter control, coating composition optimization, and compatibility with different substrate materials. These deficiencies limit its application in a wider range of fields and further improvement of coating performance. Therefore, the development of new spraying technologies is imperative. Summary of the Invention

[0005] In view of the above situation, in order to overcome the shortcomings of the existing technology, the purpose of the present invention is to provide a multi-purpose supersonic tungsten carbide spraying method, which effectively solves the problem of preparing tungsten carbide coatings with high hardness, high wear resistance, low porosity and high bonding strength through coating composition design and optimization of process parameters. At the same time, it broadens the application range of the spraying process on different substrate materials and improves the service life and reliability of parts in harsh working environments.

[0006] The technical solution provided by the present invention is a multi-purpose supersonic tungsten carbide spraying method, which is achieved by the following steps: 1. Build spray coating The spraying material composition is composed of high-purity tungsten carbide powder and the metal elements cobalt (Co), chromium (Cr) and nickel (Ni). The weight ratio is as follows: 100 parts of tungsten carbide powder, 2-10 parts of cobalt, 1-5 parts of chromium and 2-5 parts of nickel. The total amount of alloying elements added is 5-15% of the mass of the tungsten carbide powder. The particle size of the tungsten carbide powder is 10-40μm and the purity is ≥99%. Among them, cobalt is used to improve the toughness and bonding strength of the coating, and chromium and nickel are used to enhance the corrosion resistance of the coating. If the above composition is calculated in grams per portion, it can also be written as 100 grams of tungsten carbide powder, 2-10 grams of cobalt, 1-5 grams of chromium, and 2-5 grams of nickel, and the total amount of cobalt, chromium, and nickel added is 5-15 grams; if it is calculated in 5 grams per portion, it can also be written as 500 grams of tungsten carbide powder, 10-50 grams of cobalt, 5-25 grams of chromium, and 10-25 grams of nickel, and the total amount of cobalt, chromium, and nickel added is 25-75 grams, and so on. The same applies below. According to the above ratio, any desired amount of composition can be prepared; 2. Matrix pretreatment Clean the substrate to be coated, remove the oil and impurities on the surface with acetone or alcohol, then rinse with clean water, and dry at 100-120℃ for 30-60min; 3. Sandblasting The pretreated substrate surface is sandblasted with brown corundum sand of 20-40 mesh as the sandblasting material, the sandblasting pressure is 0.3-0.5MPa, the sandblasting distance is 100-200mm, and the sandblasting angle is 60°-90°. The substrate surface is roughened by sandblasting to improve the bonding strength between the coating and the substrate. 4. Spraying Use propane or propylene as fuel, oxygen as combustion aid, and nitrogen as powder feeding gas. The fuel flow rate is 20-30L / min, the oxygen flow rate is 180-220L / min, and the nitrogen flow rate is 15-25L / min. During spraying, the distance between the spray gun and the substrate surface is maintained at 200-300mm, the spray gun moving speed is 300-500mm / s, and the spraying angle is 90° to ensure uniform deposition of the coating. During the spraying process, the substrate surface temperature is monitored in real time by an infrared thermometer and the temperature is controlled according to the characteristics of the substrate material: the substrate temperature of steel materials is controlled at 150-200℃ to promote good bonding between the coating and the substrate without affecting the material's microstructure and properties; the substrate temperature of aluminum alloy materials is controlled at 80-120℃ to avoid deformation of the substrate due to thermal expansion; the substrate temperature of titanium alloy materials is controlled at 100-150℃ to prevent phase change of the material due to excessive temperature; 5. Sealing After spraying, use epoxy resin or silica sol sealer to seal the coating, evenly coat the sealer on the coating surface, and then cure it at 80-120℃ for 2-4h to reduce the porosity of the coating and improve the corrosion resistance of the coating; 6. Grinding and polishing Grind and polish the sealed coating to achieve the required roughness and smoothness; 7. Detection The coating after grinding and polishing was tested and found to have a thickness of 0.3mm, a hardness of HV1600-1800, a bonding strength of 85-90MPa, and a porosity of 0.7-0.9%, which is a qualified finished product.

[0007] The present invention is applicable to various base materials such as steel, aluminum alloy, titanium alloy, etc., broadens the application field of tungsten carbide coating, and can be widely used in surface protection of parts in machinery manufacturing, aerospace, petrochemical, mining and other industries. Through coating composition design and optimization of process parameters, it effectively solves the problem of preparing tungsten carbide coating with high hardness, high wear resistance, low porosity and high bonding strength. At the same time, it broadens the application range of the spraying process on different base materials, improves the service life and reliability of parts in harsh working environments, and has significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0009] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings and specific circumstances.

[0010] The present invention is provided by the following specific embodiments: Example

[0011] A multi-purpose supersonic tungsten carbide spraying method is achieved by the following steps: 1. Build spray coating The spraying material composition is composed of high-purity tungsten carbide powder and metal elements cobalt (Co), chromium (Cr) and nickel (Ni), which are calculated by weight as follows: 100 parts of tungsten carbide powder, 8 parts of cobalt, 3 parts of chromium and 4 parts of nickel. The particle size of the tungsten carbide powder is 15μm and the purity is 99.5%; 2. Matrix pretreatment Clean the steel substrate, remove surface oil and impurities with acetone, then rinse with clean water and dry in an oven at 110°C for 45 minutes; 3. Sandblasting The pretreated substrate surface was sandblasted using 30-mesh brown corundum sand as the sandblasting material, the sandblasting pressure was 0.4 MPa, the sandblasting distance was 150 mm, and the sandblasting angle was 75°. 4. Spraying Propane was used as fuel, oxygen as combustion aid, and nitrogen as powder delivery gas. The fuel flow rate was 25 L / min, the oxygen flow rate was 200 L / min, and the nitrogen flow rate was 20 L / min. During spraying, the distance between the spray gun and the substrate surface was maintained at 250 mm, the spray gun movement speed was 400 mm / s, and the spray angle was 90°. During the spraying process, the substrate surface temperature was monitored in real time by an infrared thermometer to maintain it at 180°C. 5. Sealing After spraying, the coating was sealed with an epoxy resin sealant, the sealant was evenly coated on the coating surface, and then cured at 100°C for 3 hours; 6. Grinding and polishing Grind and polish the sealed coating to achieve the required roughness and smoothness; 7. Detection The coating after grinding and polishing was tested and found to have a thickness of 0.3 mm, a hardness of HV1800, a bonding strength of 90 MPa, and a porosity of 0.8%. Example

[0012] 1. Build spray coating The spraying material composition is composed of high-purity tungsten carbide powder and metal elements cobalt (Co), chromium (Cr) and nickel (Ni), which are calculated by weight as follows: 100 parts of tungsten carbide powder, 6 parts of cobalt, 5 parts of chromium and 4 parts of nickel. The particle size of the tungsten carbide powder is 25μm and the purity is 99.2%. 2. Matrix pretreatment The aluminum alloy substrate was cleaned and the surface oil and impurities were removed with alcohol, then rinsed with clean water and dried in an oven at 105°C for 50 min. 3. Sandblasting The pretreated substrate surface was sandblasted using 30-mesh brown corundum sand as the sandblasting material, the sandblasting pressure was 0.4 MPa, the sandblasting distance was 150 mm, and the sandblasting angle was 75°. 4. Spraying Propylene was used as fuel, oxygen as combustion aid, and nitrogen as powder feeding gas. The fuel flow rate was 22 L / min, the oxygen flow rate was 190 L / min, and the nitrogen flow rate was 18 L / min. During spraying, the distance between the spray gun and the substrate surface was maintained at 230 mm, the spray gun movement speed was 350 mm / s, and the spray angle was 90°. During the spraying process, the substrate surface temperature was monitored in real time by an infrared thermometer to maintain it at 100°C. 5. Sealing After spraying, the coating was sealed with a silica sol sealant, the sealant was evenly coated on the coating surface, and then cured at 90°C for 3.5h; 6. Grinding and polishing Grind and polish the sealed coating to achieve the required roughness and smoothness; 7. Detection The coating after grinding and polishing was tested and found to have a thickness of 0.3 mm, a hardness of HV1600, a bonding strength of 85 MPa, and a porosity of 0.9%. Example

[0013] A multi-purpose supersonic tungsten carbide spraying method is achieved by the following steps: 1. Build spray coating The spraying material composition is composed of high-purity tungsten carbide powder and metal elements cobalt (Co), chromium (Cr) and nickel (Ni), which are calculated by weight as follows: 100 parts of tungsten carbide powder, 10 parts of cobalt, 3 parts of chromium and 2 parts of nickel. The particle size of the tungsten carbide powder is 30 μm and the purity is 99.3%. 2. Matrix pretreatment The titanium alloy substrate was cleaned and the surface oil and impurities were removed with acetone, then rinsed with clean water and dried in an oven at 115°C for 40 min. 3. Sandblasting The pretreated substrate surface was sandblasted using 35-mesh brown corundum sand as the sandblasting material, the sandblasting pressure was 0.45 MPa, the sandblasting distance was 120 mm, and the sandblasting angle was 65°. 4. Spraying Propane was used as fuel, oxygen as combustion aid, and nitrogen as powder delivery gas. The fuel flow rate was 28 L / min, the oxygen flow rate was 210 L / min, and the nitrogen flow rate was 22 L / min. During spraying, the distance between the spray gun and the substrate surface was maintained at 270 mm, the spray gun movement speed was 450 mm / s, and the spray angle was 90°. During the spraying process, the substrate surface temperature was monitored in real time by an infrared thermometer to maintain it at 130°C. 5. Sealing After spraying, the coating was sealed with an epoxy resin sealant, the sealant was evenly coated on the coating surface, and then cured at 105°C for 2.5h; 6. Grinding and polishing Grind and polish the sealed coating to achieve the required roughness and smoothness; 7. Detection The coating after grinding and polishing was tested and found to have a thickness of 0.3 mm, a hardness of HV1700, a bonding strength of 88 MPa, and a porosity of 0.7%.

[0014] It should also be noted that the above are only embodiments, which are used to illustrate the specific implementation of the present invention and are not intended to limit the scope of protection of the present invention. Any technical solutions that are essentially the same as the present invention and are made by equivalent replacement means shall fall within the scope of protection of the present invention.

[0015] The method of the present invention is applicable to various base materials such as steel, aluminum alloy, titanium alloy, etc., and is widely used in the surface protection of parts in the machinery manufacturing, aerospace, petrochemical, mining and other industries. Through the scientific ratio of coating components and the unique preparation method, including the optimization of process parameters, the method effectively solves the problem of preparing tungsten carbide coatings with high hardness, high wear resistance, low porosity and high bonding strength. At the same time, it broadens the application range of the spraying process on different base materials, improves the service life and reliability of parts in harsh working environments, and has the following significant technical improvements compared with the existing technology: 1. The present invention optimizes the composition of the spraying material and scientifically and rationally combines tungsten carbide with cobalt, chromium and nickel, which significantly improves the comprehensive performance of the tungsten carbide coating and greatly increases the hardness of the coating to as high as HV1500-HV2000. At the same time, it significantly improves the wear resistance. Experimental comparison shows that it is 30%-50% higher than that of traditional tungsten carbide coatings, which can effectively resist damage such as wear and erosion and extend the service life. 2. The use of a specific substrate pretreatment process and precisely controlled supersonic spraying process parameters creates a good metallurgical bond between the coating and the substrate, with a bonding strength of over 80MPa. At the same time, the porosity of the coating is reduced to below 1%, which improves the density and protective performance of the coating and ensures the effectiveness of its use. 3. The coating post-treatment process further improves the performance of the coating. The sealing treatment effectively reduces the porosity of the coating and enhances the corrosion resistance of the coating. The grinding and polishing treatments ensure that the surface quality of the coating meets the requirements of different working conditions. 4. The supersonic tungsten carbide spraying process of the present invention is applicable to a variety of substrate materials, such as steel, aluminum alloy, titanium alloy, etc., which broadens the application field of tungsten carbide coatings and can be widely used in the surface protection of parts in machinery manufacturing, aerospace, petrochemical, mining and other industries. It is a major innovation in surface material treatment technology and has significant economic and social benefits.

Claims

1. A multi-purpose supersonic tungsten carbide spraying method, characterized in that: This is accomplished by the following steps: 1) Build spray coating The spraying material composition is composed of high-purity tungsten carbide powder and the metal elements cobalt (Co), chromium (Cr) and nickel (Ni). The weight ratio is as follows: 100 parts of tungsten carbide powder, 2-10 parts of cobalt, 1-5 parts of chromium and 2-5 parts of nickel. The total amount of alloying elements added is 5-15% of the mass of the tungsten carbide powder. The particle size of the tungsten carbide powder is 10-40μm and the purity is ≥99%. Among them, cobalt is used to improve the toughness and bonding strength of the coating, and chromium and nickel are used to enhance the corrosion resistance of the coating. 2) Matrix pretreatment Clean the substrate to be coated, remove the oil and impurities on the surface with acetone or alcohol, then rinse with clean water, and dry at 100-120℃ for 30-60min; 3) Sandblasting The pretreated substrate surface is sandblasted with brown corundum sand of 20-40 mesh as the sandblasting material, the sandblasting pressure is 0.3-0.5MPa, the sandblasting distance is 100-200mm, and the sandblasting angle is 60°-90°. The substrate surface is roughened by sandblasting to improve the bonding strength between the coating and the substrate. 4) Spraying Use propane or propylene as fuel, oxygen as combustion aid, and nitrogen as powder feeding gas. The fuel flow rate is 20-30L / min, the oxygen flow rate is 180-220L / min, and the nitrogen flow rate is 15-25L / min. During spraying, the distance between the spray gun and the substrate surface is maintained at 200-300mm, the spray gun moving speed is 300-500mm / s, and the spraying angle is 90° to ensure uniform deposition of the coating. During the spraying process, the substrate surface temperature is monitored in real time by an infrared thermometer and the temperature is controlled according to the characteristics of the substrate material: the substrate temperature of steel materials is controlled at 150-200℃ to promote good bonding between the coating and the substrate without affecting the material's microstructure and properties; the substrate temperature of aluminum alloy materials is controlled at 80-120℃ to avoid deformation of the substrate due to thermal expansion; the substrate temperature of titanium alloy materials is controlled at 100-150℃ to prevent phase change of the material due to excessive temperature; 5) Sealing the hole After spraying, use epoxy resin or silica sol sealer to seal the coating, evenly coat the sealer on the coating surface, and then cure it at 80-120℃ for 2-4h to reduce the porosity of the coating and improve the corrosion resistance of the coating; 6) Grinding and polishing Grind and polish the sealed coating to achieve the required roughness and smoothness; 7) Detection The coating after grinding and polishing was tested and found to have a thickness of 0.3mm, a hardness of HV1600-1800, a bonding strength of 85-90MPa, and a porosity of 0.7-0.9%, which is a qualified finished product.

2. The multi-purpose supersonic tungsten carbide spraying method according to claim 1, characterized in that: The steps are: 1) Build spray coating A spray material composition is formed by using high-purity tungsten carbide powder and metal elements cobalt, chromium and nickel, which are calculated by weight as follows: 100 parts of tungsten carbide powder, 8 parts of cobalt, 3 parts of chromium and 4 parts of nickel. The particle size of the tungsten carbide powder is 15 μm and the purity is 99.5%. 2) Matrix pretreatment Clean the steel substrate, remove surface oil and impurities with acetone, then rinse with clean water and dry in an oven at 110°C for 45 minutes; 3) Sandblasting The pretreated substrate surface was sandblasted using 30-mesh brown corundum sand as the sandblasting material, the sandblasting pressure was 0.4 MPa, the sandblasting distance was 150 mm, and the sandblasting angle was 75°. 4) Spraying Propane was used as fuel, oxygen as combustion aid, and nitrogen as powder delivery gas. The fuel flow rate was 25 L / min, the oxygen flow rate was 200 L / min, and the nitrogen flow rate was 20 L / min. During spraying, the distance between the spray gun and the substrate surface was maintained at 250 mm, the spray gun movement speed was 400 mm / s, and the spray angle was 90°. During the spraying process, the substrate surface temperature was monitored in real time by an infrared thermometer to maintain it at 180°C. 5) Sealing the hole After spraying, the coating was sealed with an epoxy resin sealant, the sealant was evenly coated on the coating surface, and then cured at 100°C for 3 hours; 6) Grinding and polishing Grind and polish the sealed coating to achieve the required roughness and smoothness; 7) Detection The coating after grinding and polishing was tested and found to have a thickness of 0.3 mm, a hardness of HV1800, a bonding strength of 90 MPa, and a porosity of 0.8%.

3. The multi-purpose supersonic tungsten carbide spraying method according to claim 1, characterized in that: The steps are: 1) Build spray coating The spraying material composition is composed of high-purity tungsten carbide powder and metal elements cobalt, chromium and nickel, which are calculated by weight as follows: 100 parts of tungsten carbide powder, 6 parts of cobalt, 5 parts of chromium and 4 parts of nickel. The particle size of the tungsten carbide powder is 25 μm and the purity is 99.2%. 2) Matrix pretreatment The aluminum alloy substrate was cleaned and the surface oil and impurities were removed with alcohol, then rinsed with clean water and dried in an oven at 105°C for 50 min. 3) Sandblasting The pretreated substrate surface was sandblasted using 30-mesh brown corundum sand as the sandblasting material, the sandblasting pressure was 0.4 MPa, the sandblasting distance was 150 mm, and the sandblasting angle was 75°. 4) Spraying Propylene was used as fuel, oxygen as combustion aid, and nitrogen as powder feeding gas. The fuel flow rate was 22 L / min, the oxygen flow rate was 190 L / min, and the nitrogen flow rate was 18 L / min. During spraying, the distance between the spray gun and the substrate surface was maintained at 230 mm, the spray gun movement speed was 350 mm / s, and the spray angle was 90°. During the spraying process, the substrate surface temperature was monitored in real time by an infrared thermometer to maintain it at 100°C. 5) Sealing the hole After spraying, the coating was sealed with a silica sol sealant, the sealant was evenly coated on the coating surface, and then cured at 90°C for 3.5h; 6) Grinding and polishing Grind and polish the sealed coating to achieve the required roughness and smoothness; 7) Detection The coating after grinding and polishing was tested and found to have a thickness of 0.3 mm, a hardness of HV1600, a bonding strength of 85 MPa, and a porosity of 0.9%.

4. The multi-purpose supersonic tungsten carbide spraying method according to claim 1, characterized in that: The steps are: 1) Build spray coating A spray material composition is formed by using high-purity tungsten carbide powder and metal elements cobalt, chromium and nickel, which are calculated by weight as follows: 100 parts of tungsten carbide powder, 10 parts of cobalt, 3 parts of chromium and 2 parts of nickel. The particle size of the tungsten carbide powder is 30 μm and the purity is 99.3%. 2) Matrix pretreatment The titanium alloy substrate was cleaned and the surface oil and impurities were removed with acetone, then rinsed with clean water and dried in an oven at 115°C for 40 min. 3) Sandblasting The pretreated substrate surface was sandblasted using 35-mesh brown corundum sand as the sandblasting material, the sandblasting pressure was 0.45 MPa, the sandblasting distance was 120 mm, and the sandblasting angle was 65°. 4) Spraying Propane was used as fuel, oxygen as combustion aid, and nitrogen as powder delivery gas. The fuel flow rate was 28 L / min, the oxygen flow rate was 210 L / min, and the nitrogen flow rate was 22 L / min. During spraying, the distance between the spray gun and the substrate surface was maintained at 270 mm, the spray gun movement speed was 450 mm / s, and the spray angle was 90°. During the spraying process, the substrate surface temperature was monitored in real time by an infrared thermometer to maintain it at 130°C. 5) Sealing the hole After spraying, the coating was sealed with an epoxy resin sealant, the sealant was evenly coated on the coating surface, and then cured at 105°C for 2.5h; 6) Grinding and polishing Grind and polish the sealed coating to achieve the required roughness and smoothness; 7) Detection The coating after grinding and polishing was tested and found to have a thickness of 0.3 mm, a hardness of HV1700, a bonding strength of 88 MPa, and a porosity of 0.7%.

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