Metal matrix corrosion-resistant coating composite material and its preparation method

Abstract

The present invention provides a metal-based corrosion-resistant coating composite material and a preparation method thereof. The metal-based corrosion-resistant coating composite material is composed of a metal matrix and a corrosion-resistant coating coated thereon. The material of the corrosion-resistant coating is titanium, titanium alloy or titanium-based composite powder. The thickness of the corrosion-resistant coating is 0.05-8 mm, the porosity is ≤2%, the purity of the corrosion-resistant coating is higher, the corrosion-resistant coating is dense, the porosity can be as low as below 0.4%, the corrosion resistance is better, and the cost is reduced by more than 70% compared with traditional spherical powder.

Description

Technical Field

[0001] The present invention relates to the technical field of preparing metal matrix surface coatings, and particularly relates to a metal matrix corrosion-resistant coating composite material and a preparation method thereof. Background Art

[0002] Titanium is a material with very good corrosion resistance, and its corrosion resistance in seawater is second only to the noble metal platinum. A stable oxide film with a strong passivation tendency is extremely easy to form on the surface of titanium, reducing or inhibiting the dissolution of titanium in marine corrosion media. The oxide film also has very good self-healing properties. When the film is damaged, it can be quickly repaired to form a new protective film. Therefore, the corrosion resistance of titanium is far superior to that of commonly used marine metal materials such as stainless steel and can adapt to various marine environments. However, the cost of titanium and titanium alloy materials is expensive, and it is difficult to process and form, so it is impossible to completely replace commonly used marine metal materials such as steel and aluminum alloy.

[0003] Adopting coating preparation technology to achieve the combination of titanium and conventional marine metal materials can not only greatly reduce costs but also obtain excellent corrosion resistance, which is a commonly used and effective method for marine corrosion protection. However, at present, the domestic titanium coating preparation technology has one or more problems in aspects such as oxidation, phase transformation, residual thermal stress, grain size, porosity, etc. In particular, the coating is not dense enough, which easily causes coating failure and reduces the corrosion protection life. Even though the laser cladding coating technology can achieve good corrosion protection, its cost is high and the deposition efficiency is not high.

[0004] Therefore, providing a method for forming a pure and low-porosity corrosion-resistant coating based on a metal matrix and obtaining a low-cost metal matrix corrosion-resistant coating composite material that perfectly exerts the corrosion-resistant advantages of titanium is an urgent research direction. Summary of the Invention

[0005] The main object of the present invention is to provide a metal matrix corrosion-resistant coating composite material and a preparation method thereof. The metal matrix corrosion-resistant coating composite material is composed of a metal matrix and a corrosion-resistant coating coated thereon. The material of the corrosion-resistant coating is titanium, titanium alloy or titanium-based composite material powder. The thickness of the corrosion-resistant coating is 0.05 - 8 mm, and the porosity is ≤ 2%. The corrosion-resistant coating has a higher purity, a lower porosity, and better corrosion resistance, so as to solve the problems of unsatisfactory corrosion protection effect and short service life of the existing metal matrix surface coating.

[0006] To achieve the above object, according to the first aspect of the present invention, a metal matrix titanium powder corrosion-resistant coating composite material is provided.

[0007] The metal matrix corrosion-resistant coating composite material is composed of a metal matrix and a corrosion-resistant coating coated on the metal matrix; the material of the corrosion-resistant coating is titanium, titanium alloy or titanium-based composite material powder, and the thickness of the corrosion-resistant coating is 0.05 - 8 mm, and the porosity is ≤ 2%.

[0008] Further, the titanium alloy powder includes, but is not limited to, Ti-6Al-4V alloy powder, TiMo alloy powder, TiCu alloy powder, and TiNi alloy powder; the titanium matrix composite powder includes, but is not limited to, TiB / Ti composite powder.

[0009] Preferably, the thickness of the corrosion-resistant coating is 0.05 - 0.2 mm, and the porosity is ≤ 0.5%.

[0010] Further, the particle size of the titanium, titanium alloy or titanium matrix composite powder is ≤ 100 μm, the oxygen content is ≤ 5000 ppm, and the nitrogen content is ≤ 5000 ppm.

[0011] Preferably, the particle size is ≤ 40 μm, the oxygen content is 800 - 2500 ppm, and the nitrogen content is 500 - 2000 ppm.

[0012] Further, the titanium, titanium alloy or titanium matrix composite powder is spherical powder or irregular powder.

[0013] Preferably, the spherical powder includes atomized powder; the irregular powder includes shaped powder and hydrogenated dehydrogenated powder.

[0014] Further, the metal matrix includes, but is not limited to, stainless steel, aluminum alloy, titanium alloy, structural steel, and magnesium alloy.

[0015] Preferably, the shape of the surface to be coated of the metal matrix is a plane, any curved surface, a groove with an angle ≥ 20°, the inner wall of a pipe with an inner diameter ≥ 200 mm, or the inner surface of a sphere with an inner diameter ≥ 200 mm.

[0016] To achieve the above object, according to the second aspect of the present invention, a method for preparing a metal matrix titanium powder corrosion-resistant coating composite material is provided.

[0017] The method for preparing the metal matrix corrosion-resistant coating composite material includes the following steps:

[0018] Provide a metal matrix;

[0019] Deposit and cover the surface of the metal matrix with titanium, titanium alloy or titanium matrix composite powder by using a cold spraying process to form a corrosion-resistant coating; wherein, the process parameters of the cold spraying process are: the working temperature is ≤ 1100 °C, the powder feeding rate is 20 - 250 g / min, the spraying gas pressure is ≤ 6 MPa, the powder feeding air flow pressure is higher than the air flow pressure at the nozzle contraction section, the moving rate of the spray gun is 0 - 150 mm / s, the distance between the spray gun and the surface of the metal matrix is 20 - 100 mm, and the powder feeding gas and the working gas both include, but are not limited to, argon, nitrogen, and helium.

[0020] Further, the working temperature is 700 - 900 °C, the powder feeding rate is 50 - 120 g / min, the spraying gas pressure is 4 - 6 MPa, the moving rate of the spray gun is 30 - 80 mm / s, and the distance between the spray gun and the surface of the metal substrate is 30 - 75 mm.

[0021] Further, the preparation method further includes pre-treating the titanium, titanium alloy or titanium matrix composite powder before deposition;

[0022] The pre-treatment includes sequentially performing screening treatment and vacuum drying treatment on the titanium, titanium alloy or titanium matrix composite powder.

[0023] Further, the temperature of the drying treatment is 50 - 100 °C, and the drying time is 2 - 36 h;

[0024] Preferably, the drying temperature is 80 - 100 °C, and the drying time is 12 - 36 h.

[0025] Further, the preparation method further includes pre-treating the metal substrate before forming the corrosion-resistant coating;

[0026] The pre-treatment includes sequentially performing grinding, ultrasonic treatment and sandblasting on the metal substrate;

[0027] Preferably, the ultrasonic treatment is carried out in absolute ethanol, and the treatment time is 20 - 100 min; the sandblasting material used for the sandblasting treatment is alumina sand or zirconia sand.

[0028] Advantages of the present invention:

[0029] 1. The preparation method provided by the present invention can keep the powder particles in a low-temperature and high-speed state, without phase change and oxidation occurring, and the obtained corrosion-resistant coating has high purity; due to the severe plastic deformation and impact of the powder particles, dynamic recrystallization often occurs inside the material, resulting in grain refinement; when the powder particles are deposited, the continuous impact of the subsequent particles on the already deposited particles produces a shot peening effect, making the corrosion-resistant coating have a large residual compressive stress, improving the fatigue resistance; the corrosion-resistant coating is dense, and the porosity can be as low as below 0.4%.

[0030] 2. The corrosion-resistant coating provided by the present invention effectively reduces the probability of corrosion medium penetrating into the interior of the coating, extends the service life of the coating, and provides better corrosion resistance for the metal substrate.

[0031] 3. The corrosion-resistant coating provided by the present invention can use irregular titanium alloy or its composite powder. Compared with traditional spherical powder, the cost is reduced by more than 70%. Moreover, the content of interstitial impurity elements such as oxygen and nitrogen in the titanium alloy powder allowed by this method is relatively high, and good performance can be obtained at the same time, which greatly broadens the selection range of raw material powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0033] Figure 1 Graph showing the results of salt spray corrosion tests for the metal substrate without coating (right) and the metal substrate covered with cold-sprayed TA2 coating (left) in Example 1 provided by the present invention;

[0034] Figure 2 Graph showing the comparison of salt spray corrosion mass loss between the cold-sprayed TA2 coating and the metal substrate in Example 1 provided by the present invention;

[0035] Figure 3 Microstructure diagram of the cold-sprayed TA2 coating in Example 1 provided by the present invention;

[0036] Figure 4 Graph showing the results of salt spray corrosion tests for the metal substrate without coating (right) and the metal substrate covered with cold-sprayed TA2 coating (left) in Example 2 provided by the present invention;

[0037] Figure 5 Graph showing the results of salt spray corrosion tests for the metal substrate without coating (right) and the metal substrate covered with cold-sprayed Ti-6Al-4V coating (left) in Example 3 provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0039] According to the specific embodiments of the present invention, a metal matrix corrosion-resistant coating composite material is provided. The metal matrix corrosion-resistant coating composite material is prepared by cold spraying a corrosion-resistant coating on the surface of marine metal materials such as stainless steel, that is, the corrosion-resistant coating is cold-sprayed and covered on the metal substrate.

[0040] The metal matrix corrosion-resistant coating composite material in the present invention is composed of a metal substrate and a corrosion-resistant coating coated on the metal substrate; the material of the corrosion-resistant coating can be titanium powder, titanium alloy powder or titanium-based composite powder, the thickness of the corrosion-resistant coating is 0.05 - 8 mm, and the porosity ≤ 2%.

[0041] In an embodiment of the present invention, the thickness of the corrosion-resistant coating can be 0.05 - 0.2 mm, and the porosity ≤ 0.5%.

[0042] As a specific embodiment of the present invention, the thickness of the corrosion-resistant coating of pure titanium powder can be 0.2 mm, and the porosity ≤ 0.4%.

[0043] In an embodiment of the present invention, the titanium alloy powder includes but is not limited to Ti-6Al-4V alloy powder, TiMo alloy powder, TiCu alloy powder, TiNi alloy powder;

[0044] The titanium matrix composite powder includes but is not limited to TiB / Ti composite powder.

[0045] In an embodiment of the present invention, the particle size of the titanium powder, titanium alloy powder or titanium matrix composite powder ≤ 100 μm, the oxygen content ≤ 5000 ppm, and the nitrogen content ≤ 5000 ppm.

[0046] As a specific embodiment of the present invention, the particle size of the titanium powder, titanium alloy powder or titanium matrix composite powder ≤ 40 μm, the oxygen content is 800 - 2500 ppm, and the nitrogen content is 500 - 2000 ppm.

[0047] In an embodiment of the present invention, the titanium powder, titanium alloy powder or titanium matrix composite powder can be spherical powder or irregularly shaped powder.

[0048] As a specific embodiment of the present invention, the titanium powder, titanium alloy powder or titanium matrix composite powder can be atomized powder, and can also be shaped powder or hydrogenated dehydrogenated powder.

[0049] In an embodiment of the present invention, the metal matrix includes but is not limited to stainless steel, aluminum alloy, titanium alloy, structural steel, and magnesium alloy.

[0050] As a specific embodiment of the present invention, the shape of the surface to be coated of the metal matrix is a plane, any curved surface, a groove with an angle ≥ 20°, the inner wall of a tube with an inner diameter ≥ 200 mm, or the inner surface of a sphere with an inner diameter ≥ 200 mm.

[0051] According to a specific embodiment of the present invention, a method for preparing a metal matrix corrosion-resistant coating composite is also provided.

[0052] The method for preparing a metal matrix corrosion-resistant coating composite in the present invention includes the following steps:

[0053] Provide a metal matrix; the metal matrix includes but is not limited to stainless steel, aluminum alloy, titanium alloy, structural steel, and magnesium alloy; the shape of the surface to be coated of the metal matrix is a plane, any curved surface, a groove with an angle ≥ 20°, the inner wall of a tube with an inner diameter ≥ 200 mm, or the inner surface of a sphere with an inner diameter ≥ 200 mm.

[0054] Pretreat the metal substrate; wherein, the pretreatment includes successively performing grinding, ultrasonic treatment, and sandblasting on the metal substrate; the ultrasonic treatment is carried out in absolute ethanol, and the treatment time is 20 to 100 min; alumina sand or zirconia sand is used as the sandblasting material for the sandblasting treatment.

[0055] Pretreat the titanium powder, titanium alloy powder, or titanium-based composite powder; wherein, the pretreatment includes successively performing screening treatment and vacuum drying treatment on the titanium powder, titanium alloy powder, or titanium-based composite powder; the drying temperature is 50 to 100 °C, and the drying time is 2 to 36 h.

[0056] As a specific embodiment of the present invention, the drying temperature can be 80 to 100 °C, and the drying time can be 12 to 36 h.

[0057] Deposit and cover the titanium powder, titanium alloy powder, or titanium-based composite powder on the surface of the metal substrate by using the cold spraying process to form a corrosion-resistant coating; wherein, the process parameters of the cold spraying process are: the working temperature ≤ 1100 °C, the powder feeding rate is 20 to 250 g / min, the spraying gas pressure ≤ 6 MPa, the powder feeding gas pressure is higher than the gas pressure at the nozzle contraction section, the moving rate of the spray gun is 0 to 150 mm / s, the distance between the spray gun and the surface of the metal substrate is 20 to 100 mm, the powder feeding gas includes but is not limited to argon, nitrogen, helium, and the working gas includes but is not limited to argon, nitrogen, helium. For example, the powder feeding gas and the working gas can also be an argon-nitrogen mixed gas.

[0058] As a specific embodiment of the present invention, the working temperature can be 700 to 900 °C, the powder feeding rate is 50 to 120 g / min, the spraying gas pressure is 4 to 6 MPa, the moving rate of the spray gun is 30 to 80 mm / s, and the distance between the spray gun and the surface of the metal substrate is 30 to 75 mm.

[0059] The following will further illustrate the metal-based titanium powder corrosion-resistant coating composite material and its preparation method in the present invention with specific examples.

[0060] Example 1

[0061] A preparation method of a composite material with a Q235 carbon steel as the metal substrate and pure titanium powder TA2 as the corrosion-resistant coating material is provided.

[0062] Step 1, the metal substrate is Q235 carbon steel. Grind the Q235 carbon steel successively with 220#, 360#, 600#, 800#, 1000#, and 2000# SiC sandpapers, then perform ultrasonic treatment in absolute ethanol for 20 min to remove surface oil stains and other contaminants, and then perform sandblasting treatment on the surface of the Q235 carbon steel. Alumina sand is used as the sandblasting material for the sandblasting treatment.

[0063] Step 2: The titanium powder is pure titanium powder TA2, the particle size range of the sieved powder is 10 - 40 μm, and the powder particles are irregular in shape. After sieving, it is dried at 80 °C for 12 h to reduce the influence of moisture on the quality of the corrosion-resistant coating. Then it is vacuum-sealed and stored for later use.

[0064] Step 3: Fix the surface-treated Q235 carbon steel on a lathe. The lathe rotates at a speed of 100 r / min. After the speed stabilizes, load the TA2 powder into the powder feeder, turn on the cold spraying equipment, and set the cold spraying equipment parameters for cold spraying. Among them, the temperature is 700 °C, the spraying nitrogen pressure is 5 MPa, the powder feeding rate is 80 g / min, the moving speed of the spray gun is 50 mm / s, and the distance between the spray gun and the substrate is 50 mm.

[0065] Design a salt spray corrosion test according to GB / T 20854-2007: The test surface of the specimen should face upward and form an angle of 20° with the vertical direction as required. According to the experimental conditions provided by the temperature and humidity system, it is set as the salt spray condition (time 2 h, temperature 35 °C, 50 g / L sodium chloride solution) + "dry" condition (time 4 h, temperature 60 °C, relative humidity < 30%RH) + "wet" condition (time 2 h, temperature 50 °C, relative humidity > 95%RH), and the time from salt spray to "dry" < 30 min, from "dry" to "wet" < 15 min, and from "wet" to salt spray < 30 min. During the test, ensure the continuity of the test. The test is set for 1000 hours, and then the specimen is taken out for observation.

[0066] After testing, the porosity of the 0.2 mm thick corrosion-resistant coating in Example 1 is 0.34%, the bonding strength is 42.3 ± 1.8 MPa, and the microhardness is 395 ± 9.5 HV;

[0067] After 1000 hours of salt spray test, there is no obvious corrosion phenomenon on the coating, as Figure 1 and Figure 2 shown.

[0068] Example 2

[0069] A preparation method of a composite material with a metal matrix of Q235 carbon steel and a corrosion-resistant coating material of pure titanium powder TA2 is provided.

[0070] Step 1: The metal matrix is Q235 carbon steel. The Q235 carbon steel is polished successively with 220#, 360#, 600#, 800#, 1000# and 2000# SiC sandpapers, and then ultrasonically treated in absolute ethanol for 20 min to remove surface contaminants such as oil stains. After that, the surface of the Q235 carbon steel is subjected to sandblasting treatment, and alumina sand is used as the sandblasting material.

[0071] Step 2: The titanium powder is pure titanium powder TA2, the particle size range of sieved powder is 10 - 40 μm, and the powder particles are irregular in shape. After sieving, it is dried at 100 °C for 12 h to reduce the influence of moisture on the quality of the corrosion-resistant coating. Then it is vacuum-sealed and stored for later use.

[0072] Step 3: Fix the surface-treated Q235 carbon steel on a lathe. The lathe rotates at a speed of 100 r / min. After the speed is stable, load the TA2 powder into the powder feeder, turn on the cold spraying equipment, and set the cold spraying equipment parameters for cold spraying. Among them, the temperature is 800 °C, the spraying nitrogen pressure is 6 MPa, the powder feeding rate is 80 g / min, the moving speed of the spray gun is 50 mm / s, and the distance between the spray gun and the substrate is 50 mm.

[0073] Design a salt spray corrosion test according to GB / T 20854-2007: The test surface of the specimen is facing up and forms an angle of 20° with the vertical direction as required. According to the experimental conditions provided by the temperature and humidity system, it is set as the salt spray condition (time 2 h, temperature 35 °C, 50 g / L sodium chloride solution) + "dry" condition (time 4 h, temperature 60 °C, relative humidity < 30% RH) + "wet" condition (time 2 h, temperature 50 °C, relative humidity > 95% RH), and the time from salt spray to "dry" < 30 min, from "dry" to "wet" < 15 min, from "wet" to salt spray < 30 min. During the test, ensure the continuity of the test. The test is set for 1000 hours, and then the specimen is taken out for observation.

[0074] After testing, the porosity of the 0.2-mm-thick corrosion-resistant coating in Example 2 is 0.22%, the bonding strength is 45.8 ± 0.9 MPa, and the microhardness is 398 ± 11.2 HV;

[0075] After 1000-hour salt spray test, there is no obvious corrosion phenomenon on the coating, as Figure 2 shown.

[0076] Example 3

[0077] A preparation method of a composite material with a Q235 carbon steel as the metal matrix and a Ti-6Al-4V alloy powder as the corrosion-resistant coating material is provided.

[0078] Step 1: The metal matrix is Q235 carbon steel. The metal matrix is polished successively with 220#, 360#, 600#, 800#, 1000# and 2000# SiC sandpapers, and then ultrasonically treated in absolute ethanol for 20 min to remove surface oil stains and other contaminants. After that, the surface of the Q235 carbon steel is subjected to sandblasting treatment, and alumina sand is used as the sandblasting material.

[0079] Step 2: The titanium alloy powder is Ti-6Al-4V alloy powder, the particle size range for sieving is 10 - 40 μm, and the powder particles are irregular in shape. After sieving, it is dried at 80 °C for 12 h to reduce the influence of moisture on the quality of the corrosion-resistant coating, and then vacuum-sealed and stored for later use.

[0080] Step 3: Fix the surface-treated Q235 carbon steel on a lathe, and the lathe rotates at a speed of 100 r / min. After the speed stabilizes, load the Ti-6Al-4V alloy powder into the powder feeder, turn on the cold spraying equipment, and set the cold spraying equipment parameters for cold spraying. Among them, the temperature is 900 °C, the spraying nitrogen pressure is 5 MPa, the powder feeding rate is 80 g / min, the moving speed of the spray gun is 50 mm / s, and the distance between the spray gun and the substrate is 50 mm.

[0081] Design a salt spray corrosion test according to GB / T 20854-2007: The test surface of the specimen is facing up and forms an angle of 20° with the vertical direction as required. According to the experimental conditions provided by the temperature and humidity system, it is set as the salt spray condition (time 2 h, temperature 35 °C, 50 g / L sodium chloride solution) + "dry" condition (time 4 h, temperature 60 °C, relative humidity < 30% RH) + "wet" condition (time 2 h, temperature 50 °C, relative humidity > 95% RH), and the time from salt spray to "dry" < 30 min, from "dry" to "wet" < 15 min, from "wet" to salt spray < 30 min. During the test, ensure the continuity of the test. The test is set for 1000 hours, and then the specimen is taken out for observation.

[0082] After testing, the porosity of the 0.2-mm-thick corrosion-resistant coating in Example 3 is 0.38%, the bonding strength is 43.9 ± 1.5 MPa, and the microhardness is 413 ± 14.9 HV.

[0083] After 1000 hours of salt spray test, there is no obvious corrosion phenomenon on the coating, as Figure 3 shown.

[0084] Example 4

[0085] A preparation method of a metal matrix corrosion-resistant coating composite material is provided, where the metal matrix is Q235 carbon steel and the corrosion-resistant coating material is Ti / TiB2 composite material powder.

[0086] Step 1: The metal matrix is Q235 carbon steel. The matrix is polished successively with 220#, 360#, 600#, 800#, 1000# and 2000# SiC sandpapers, and then ultrasonically treated in absolute ethanol for 20 min to remove surface contaminants such as oil stains. After that, the surface of Q235 carbon steel is subjected to sandblasting treatment, and alumina sand is used as the sandblasting material.

[0087] Step 2: The titanium matrix composite powder is a Ti / TiB2 composite powder with a mass fraction of TiB2 of 0.5% prepared by mixing hydrogenated dehydrogenated titanium powder with a particle size range of 15 - 52 μm and TiB2 with a particle size range of 4 - 10 μm. The sieving particle size range is 15 - 53 μm, and the powder particles are irregular in shape. After sieving, it is dried at 80 °C for 12 h to reduce the influence of moisture on the quality of the corrosion-resistant coating. Then it is vacuum-sealed and stored for later use.

[0088] Step 3: Fix the surface-treated Q235 carbon steel on a lathe. The lathe rotates at a speed of 100 r / min. After the speed is stable, load the Ti / TiB2 composite powder into the powder feeder, turn on the cold spraying equipment, and set the cold spraying equipment parameters for cold spraying. Among them, the temperature is 900 °C, the spraying nitrogen pressure is 5 MPa, the powder feeding rate is 80 g / min, the gun moving speed is 50 mm / s, and the distance between the gun and the substrate is 50 mm.

[0089] Design a salt spray corrosion test according to GB / T 20854 - 2007: The test surface of the specimen is facing up and forms an angle of 20° with the vertical direction as required. According to the experimental conditions provided by the temperature and humidity system, it is set as the salt spray condition (time 2 h, temperature 35 °C, 50 g / L sodium chloride solution) + "dry" condition (time 4 h, temperature 60 °C, relative humidity < 30% RH) + "wet" condition (time 2 h, temperature 50 °C, relative humidity > 95% RH), and the time from salt spray to "dry" < 30 min, from "dry" to "wet" < 15 min, from "wet" to salt spray < 30 min. During the test, ensure the continuity of the test. The test is set for 1000 hours, and then the specimen is taken out for observation.

[0090] After testing, the porosity of the 0.2 mm thick corrosion-resistant coating in Example 4 is 0.52%, the bonding strength is 41.5 ± 2.6 MPa, and the microhardness is 432 ± 7.5 HV;

[0091] After 1000 hours of salt spray test, there is no obvious corrosion phenomenon on the coating.

[0092] The present invention also conducts a comparative analysis on the metal matrix corrosion-resistant coating composite prepared in Example 1 and the metal matrix corrosion-resistant coating composite obtained by the laser cladding technology in the prior art to further illustrate the corrosion-resistant coating and its formation method in the present invention.

[0093] Comparative Example 1

[0094] The laser cladding technology refers to placing the selected coating material on the surface of the substrate to be coated in different filling ways, irradiating it with a laser to melt it simultaneously with a thin layer of the substrate surface, and rapidly solidifying to form a surface coating with a very low dilution rate and metallurgical bonding with the substrate material.

[0095] The metal matrix is Q235 carbon steel, and the coating powder is pure titanium powder. A pure titanium coating is formed on the surface of Q235 carbon steel by laser cladding technology. Among them, after testing, the bonding strength of the pure titanium coating with a thickness of 0.2 mm is 40 MPa, the microhardness is 380 HV, and the porosity is 0.5%; it can pass the 1000-hour salt spray test, and there is no obvious corrosion phenomenon on the pure titanium coating.

[0096] Compared with Comparative Example 1, the porosity of the corrosion-resistant coating with a thickness of 0.2 mm in Example 1 of the present invention is 0.34%, as Figure 3 shown, the bonding strength is 42.3 ± 1.8 MPa, the microhardness is 395 ± 9.5 HV, and it also has excellent corrosion resistance. It can pass the 1000-hour salt spray test, and the protection level is 10. Its mechanical properties and corrosion resistance are comparable to or even better than the current relatively excellent laser cladding coatings.

[0097] Moreover, compared with the high cost of 6000 yuan / m of the laser cladding technology 2 , the corrosion-resistant coating formation technology provided in the present invention has significant cost advantages, only 1500 yuan / m 2 , the cost is reduced by more than 70%, and at the same time, the deposition efficiency is doubled compared with the laser cladding technology.

[0098] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A metal-based corrosion-resistant coating composite material, characterized in that, The composite material consists of a metal matrix and a corrosion-resistant coating coated on the metal matrix; the metal matrix is Q235 carbon steel; the material of the corrosion-resistant coating is titanium-based composite powder, and the titanium-based composite powder is Ti / TiB2 composite powder containing 0.5% by mass of TiB2. The Ti / TiB2 composite powder is prepared by mixing hydrogenated dehydrogenated titanium powder with a particle size of 15 - 52 μm and TiB2 with a particle size of 4 - 10 μm. The particle size of the titanium-based composite powder is 15 - 53 μm and it is in an irregular shape; the thickness of the corrosion-resistant coating is 0.2 mm, the porosity is 0.52%, the bonding strength is 41.5 ± 2.6 MPa, and the microhardness is 432 ± 7.5 HV.

2. The metal-based corrosion-resistant coating composite material according to claim 1, wherein The oxygen content of the titanium-based composite powder is ≤5000 ppm, and the nitrogen content is ≤5000 ppm.

3. The metal matrix corrosion-resistant coating composite material according to claim 2, wherein The oxygen content of the titanium-based composite powder is 800 - 2500 ppm, and the nitrogen content is 500 - 2000 ppm.

4. The metal matrix corrosion-resistant coating composite material according to claim 1, wherein, The shape of the surface to be coated of the metal matrix is a plane or any curved surface.

5. The metal-based corrosion-resistant coating composite material according to claim 4, characterized in that, The any curved surface is a groove with an angle ≥20°, the inner wall of a pipe with an inner diameter ≥200 mm, or the inner surface of a sphere with an inner diameter ≥200 mm.

6. The preparation method of the metal-based corrosion-resistant coating composite material according to any one of claims 1-5, characterized in that The preparation method includes the following steps: Provide a metal matrix; the metal matrix is Q235 carbon steel; Deposit and cover the titanium-based composite powder on the surface of the metal matrix by cold spraying process to form a corrosion-resistant coating; wherein, the process parameters of the cold spraying process are: the working temperature is 900 °C, the powder feeding rate is 80 g / min, the spraying gas pressure is 5 MPa, the powder feeding gas flow pressure is higher than the gas flow pressure at the nozzle contraction section, the moving rate of the spray gun is 50 mm / s, the distance between the spray gun and the metal matrix surface is 50 mm, and both the powder feeding gas and the working gas are nitrogen.

7. The preparation method of the metal matrix corrosion-resistant coating composite material according to claim 6, characterized in that, The preparation method also includes pre-treating the titanium-based composite powder before deposition; The pre-treatment includes sequentially screening and vacuum drying the titanium-based composite powder.

8. The preparation method of the metal-based corrosion-resistant coating composite material according to claim 7, characterized in that, The temperature of the drying treatment is 80 °C, and the drying time is 12 h.

9. The preparation method of the metal matrix corrosion-resistant coating composite material according to claim 6, wherein, The preparation method also includes pre-treating the metal matrix before forming the corrosion-resistant coating; The pre-treatment includes sequentially grinding, ultrasonic treatment, and sandblasting of the metal matrix.

10. The preparation method of the metal-based corrosion-resistant coating composite material according to claim 9, characterized in that, The ultrasonic treatment is carried out in absolute ethanol, and the treatment time is 20 min; the sandblasting material used for the sandblasting treatment is alumina sand.

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