Multifunctional nanocomposite ceramic coating and method of making same

Abstract

This invention belongs to the field of ceramic coating technology. It provides a multifunctional nanocomposite ceramic coating, which is formed by curing and sintering oxide nanoparticles, binders, and water. This multifunctional nanocomposite ceramic coating, by incorporating organic and inorganic binders and oxide nanoparticles that penetrate the metal substrate to form an atomically solid solution, increases the thermal compatibility between the coating and the substrate, enhances the adhesion between them, and exhibits excellent resistance to salt spray corrosion, hydrogen barrier properties, wear resistance, and high-temperature resistance, meeting the coating requirements for the inner and outer surfaces of metal components. Furthermore, the preparation process of this invention is simple and low-cost, meeting the needs of large-scale production.

Description

Technical Field

[0001] This invention relates to the field of ceramic coating technology, and in particular to a multifunctional nanocomposite ceramic coating and its preparation method. Background Technology

[0002] Located in the subtropical monsoon climate zone, southeastern coastal my country experiences consistently high temperatures, humidity, and salt spray, with an average annual relative humidity exceeding 80% and salt spray deposition reaching 0.3-1.5 mg / (dm²·d). This causes severe corrosion of steel components and other equipment used in coastal operations, reducing their lifespan to 30%-50% of that in normal environments. Equipment in the deep sea is not only subject to seawater corrosion and abrasion, but the water pressure also causes hydrogen embrittlement due to hydrogen permeation into the metallic materials.

[0003] Hydrogen energy, due to its pollution-free nature, is hailed as the most promising secondary energy source today. Hydrogen storage and transportation are crucial links in the industrialization of hydrogen energy. High-pressure hydrogen storage, with its simple equipment structure and rapid filling speed, has become the dominant hydrogen storage method in current industrial applications. However, the high-pressure hydrogen environment reduces the plasticity of materials, accelerates fatigue crack propagation rates, and causes hydrogen embrittlement, posing a significant challenge to the safety of high-pressure hydrogen systems. On the other hand, in the development of advanced nuclear energy in my country, new reactor vessels also face the problem of hydrogen embrittlement caused by hydrogen permeation. Hydrogen permeation leads to the deterioration of many material properties, not only causing raw material loss but also triggering hydrogen embrittlement in the base material, and in more severe cases, radioactive contamination. Current hydrogen barrier coatings are primarily made of alumina and its composites, which lack sufficient wear and corrosion resistance. Furthermore, they are mainly prepared using methods such as embedding aluminizing, magnetron sputtering, and spin coating, making large-scale production difficult and unable to meet engineering application requirements. Therefore, there is an urgent need to develop hydrogen barrier coatings that can be used in engineering applications while also possessing wear resistance.

[0004] Current mainstream anti-corrosion methods (such as hot-dip galvanizing, epoxy coating, and cathodic protection) have significant drawbacks: 1. Insufficient corrosion resistance: Traditional organic coatings are prone to peeling and powdering in salt spray environments, and their protection period is generally less than 5 years; 2. Lack of wear resistance: Under the combined effects of mechanical wear and marine biological erosion, the coating is easily damaged and localized corrosion spreads, leading to increased life-cycle costs due to frequent maintenance; 3. There is no coating that combines corrosion resistance, wear resistance, and hydrogen barrier properties. Ceramic composite coatings, with their high hardness, chemical inertness, and dense structure, possess both corrosion resistance, wear resistance, and environmental friendliness, making them a viable material for achieving multi-layered corrosion resistance, wear resistance, and hydrogen barrier properties. Therefore, researching and developing a multifunctional nanocomposite ceramic coating and its preparation method has promising application prospects. Summary of the Invention

[0005] The purpose of this invention is to provide a multifunctional nanocomposite ceramic coating and its preparation method, addressing the shortcomings of existing technologies. This coating can be used as a wear-resistant, corrosion-resistant, and hydrogen-permeability-blocking layer on the surface of complex structural components with a metal substrate, exhibiting excellent high-temperature resistance and strong adhesion to the substrate. This coating is suitable for metal components in mechanical wear environments, salt spray and acid / alkali corrosion environments, and single or multi-factor coupled environments involving hydrogen energy and nuclear energy.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a multifunctional nanocomposite ceramic coating, which is formed by curing and sintering oxide nanoparticles, binder and water.

[0008] Preferably, the oxide nanoparticles contain the following components: α-alumina, silicon dioxide, manganese oxide, zinc oxide, calcium oxide, and potassium oxide; the particle size of the components contained in the oxide nanoparticles is 50~100nm.

[0009] Preferably, the adhesive includes organic adhesives and inorganic adhesives;

[0010] The organic binder is a silane coupling agent, and the inorganic binder is sodium silicate.

[0011] Preferably, the mass percentages of all components of the multifunctional nanocomposite ceramic coating are as follows: α-alumina 5~8%, silicon dioxide 10~15%, manganese oxide 1~3%, zinc oxide 3~6%, calcium oxide 10~13%, potassium oxide 5~7%, silane coupling agent 10~15%, water 10~13%, and the remainder is sodium silicate.

[0012] Preferably, the curing and sintering temperature is 500~800℃, the curing and sintering time is 20~40min, the curing and sintering is carried out in an oxygen-rich atmosphere, and the heating rate to the curing and sintering temperature is 4~6℃ / min.

[0013] The present invention also provides a method for preparing the aforementioned multifunctional nanocomposite ceramic coating, comprising the following steps:

[0014] 1) Pre-treat the matrix;

[0015] 2) Mix oxide nanoparticles, binder, and water in a certain proportion to obtain a coating;

[0016] 3) The coating is sprayed onto the substrate surface and then cured and sintered to obtain a multifunctional nanocomposite ceramic coating.

[0017] Preferably, the substrate in step 1) is stainless steel, carbon steel or nickel alloy; the shape of the substrate is a round tube or a round sheet.

[0018] Preferably, the pretreatment in step 1) is sanding or sandblasting.

[0019] Preferably, the parameters to be controlled during the spraying process in step 3) are: spraying temperature of 20~30℃, spraying time of 10~30s, atomizing air pressure of 0.3~0.5MPa, powder supply pressure of 0.04~0.10MPa, and distance between the spray gun nozzle and the substrate surface of 150~300mm.

[0020] Preferably, after the spraying in step 3) is completed, the resulting coating is dried;

[0021] The drying temperature is 130~150℃ o C, the drying time is 20~40 minutes.

[0022] The beneficial effects of this invention include the following:

[0023] 1) The multifunctional nanocomposite ceramic coating prepared by this invention can be used as a protective coating for corrosion resistance, wear resistance and hydrogen permeation prevention on the surface of metal parts with different configurations.

[0024] 2) The multifunctional nanocomposite ceramic coating prepared by this invention has a thermal expansion coefficient that is well compatible with the steel substrate (stainless steel, carbon steel), exhibiting good adhesion (>60MPa) and synchronous deformation capability, with a coating-substrate adhesion strength >50MPa; the surface is dense and uniform, free from defects such as microcracks and pinholes; it possesses excellent high-temperature fatigue resistance, and the coating's service environment temperature is room temperature to 800°C. o C; The coating has high hardness, more than twice that of the stainless steel substrate; the room temperature friction coefficient is 0.6, close to that of 316L stainless steel; it has a high hydrogen barrier factor, at 1MPa pressure, 550 o C, hydrogen barrier factor > 10 4 It has strong resistance to salt spray corrosion, and can withstand NaCl concentrations of 5% and temperatures of 35°C. o C-40 o Neutral salt spray corrosion of C for 1000 hours (no corrosion spots observed by SEM).

[0025] 3) After heat treatment, the multifunctional nanocomposite ceramic coating components of the present invention undergo a chemical reaction to form a more stable eutectic oxide system. At the same time, some elements agglomerate at the interface and penetrate into the matrix and metal matrix to form atomic-level solid solution, which strengthens the bonding force between the coating and the surface of the metal matrix. The dense silicon oxide and aluminum oxide and other oxide components work together to hinder the diffusion of hydrogen atoms.

[0026] 4) The preparation process of the present invention is simple and low in cost, which can meet the needs of large-scale production. Attached Figure Description

[0027] Figure 1 This is a photograph of the multifunctional nanocomposite ceramic coating on the outer wall of the 316L stainless steel pipe in Example 1.

[0028] Figure 2 The images show the tritium permeation test results and the surface morphology and elemental distribution after salt spray corrosion of the multifunctional nanocomposite ceramic coating prepared in Example 1. (a) shows the tritium permeation test results of the multifunctional nanocomposite ceramic coating, and (b) shows the surface morphology and elemental distribution of the multifunctional nanocomposite ceramic coating after salt spray corrosion.

[0029] Figure 3 The image shows the wear resistance of 316L stainless steel and multifunctional nanocomposite ceramic coating in Example 1. In the image, (a) is the friction coefficient of 316L stainless steel, (b) is the friction wear of 316L stainless steel, (c) is the friction coefficient of the coating under the same experimental conditions, and (d) is the friction wear result of the coating under the same experimental conditions.

[0030] Figure 4 Hardness diagram of 316L stainless steel and multifunctional nanocomposite ceramic coating;

[0031] Figure 5 This is a photograph of the multifunctional nanocomposite ceramic coating on the outer wall of the DH40 steel pipe in Example 2.

[0032] Figure 6 The images show the wear resistance of the DH40 steel pipe and the multifunctional nanocomposite ceramic coating in Example 2, and the deuterium permeation results of the multifunctional nanocomposite ceramic coating. (a) shows the deuterium permeation test results of the multifunctional nanocomposite ceramic coating, (b) shows the wear resistance of the DH40 steel pipe, and (c) shows the wear resistance of the multifunctional nanocomposite ceramic coating.

[0033] Figure 7 The image shows the surface morphology and elemental distribution of the multifunctional nanocomposite ceramic coating obtained in Example 2 after it has been subjected to salt spray corrosion.

[0034] Figure 8 These are photographs of the multifunctional nanocomposite ceramic coating prepared in Example 3 after being kept at different temperatures for 48 hours. Detailed Implementation

[0035] This invention provides a multifunctional nanocomposite ceramic coating, which is formed by curing and sintering oxide nanoparticles, binder and water.

[0036] In this invention, the oxide nanoparticles preferably contain the following components: α-alumina and silicon dioxide. Manganese oxide, zinc oxide, calcium oxide, and potassium oxide;

[0037] The particle size of the components contained in the oxide nanoparticles is preferably 50-100 nm, more preferably 60-90 nm, and even more preferably 70-80 nm.

[0038] In this invention, the adhesive preferably includes organic adhesives and inorganic adhesives;

[0039] The organic binder is preferably a silane coupling agent, and the inorganic binder is preferably sodium silicate.

[0040] In this invention, the preferred mass percentage of all components of the multifunctional nanocomposite ceramic coating is: 5-8% α-alumina, 10-15% silicon dioxide, 1-3% manganese oxide, 3-6% zinc oxide, 10-13% calcium oxide, 5-7% potassium oxide, 10-15% silane coupling agent, 10-13% water, and the remainder being sodium silicate. More preferably, the composition is: 6-7% α-alumina, 12-14% silicon dioxide, 1.5-2.5% manganese oxide, 4-5% zinc oxide, 11-12% calcium oxide, 5.5-6.5% potassium oxide, 12-14% silane coupling agent, 11.5-12.5% ​​water, and the remainder being sodium silicate. Even more preferably, the composition is: 6.5% α-alumina, 13% silicon dioxide, 2% manganese oxide, 4.5% zinc oxide, 11.5% calcium oxide, 6% potassium oxide, 13% silane coupling agent, 12% water, and the remainder being sodium silicate.

[0041] In this invention, the curing and sintering temperature is preferably 500~800℃, more preferably 600~700℃, and even more preferably 650℃; the curing and sintering time is preferably 20~40min, more preferably 25~35min, and even more preferably 30min; the curing and sintering is preferably carried out in an oxygen-rich atmosphere, and even more preferably in an air atmosphere; the heating rate to the curing and sintering temperature is preferably 4~6℃ / min, and even more preferably 5℃ / min.

[0042] The present invention also provides a method for preparing the aforementioned multifunctional nanocomposite ceramic coating, comprising the following steps:

[0043] 1) Pre-treat the matrix;

[0044] 2) Mix oxide nanoparticles, binder, and water in a certain proportion to obtain a coating;

[0045] 3) The coating is sprayed onto the substrate surface and then cured and sintered to obtain a multifunctional nanocomposite ceramic coating.

[0046] In this invention, the substrate in step 1) is preferably stainless steel, carbon steel or nickel alloy; the shape of the substrate is preferably a round tube or a round sheet.

[0047] In this invention, the pretreatment in step 1) is preferably sanding or sandblasting.

[0048] In this invention, the sanding is preferably done using 80# sandpaper.

[0049] In this invention, the sandblasting medium is preferably steel grit, the mesh size of the steel grit is preferably 80-120 mesh, more preferably 100 mesh, the sandblasting pressure is preferably 4-6 MPa, more preferably 5 MPa, the sandblasting temperature is preferably 20-30℃, more preferably 25℃, and the sandblasting time is preferably 1-3 hours, more preferably 2 hours.

[0050] In this invention, the pretreatment can increase the roughness of the substrate surface.

[0051] In this invention, after the pretreatment described in step 1) is completed, it is preferable to clean the substrate surface with anhydrous ethanol.

[0052] In this invention, cleaning the substrate surface with alcohol can remove impurities and deposits from the substrate surface.

[0053] In this invention, the parameters that need to be controlled during the spraying process in step 3) are as follows: the spraying temperature is preferably 20~30℃, more preferably 25℃; the spraying time is preferably 10~30s, more preferably 15~25s, and more preferably 20s; the atomizing air pressure is preferably 0.3~0.5MPa, more preferably 0.35~0.45MPa, and more preferably 0.4MPa; the powder supply pressure is preferably 0.04~0.1MPa, more preferably 0.05~0.08MPa, and more preferably 0.06~0.07MPa; and the distance between the spray gun nozzle and the substrate surface is preferably 150~300mm, more preferably 180~220mm, and more preferably 200mm.

[0054] In this invention, after the spraying in step 3) is completed, it is preferable to dry the coating; the drying temperature is preferably 130~150℃. o C, further preferably 135~145 o C, more preferably 140 o C; The drying time is preferably 20-40 min, more preferably 25-35 min, and even more preferably 30 min.

[0055] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0056] In Examples 1 and 2, the particle size of the components contained in the oxide nanoparticles was 100 nm.

[0057] In Example 3, the particle size of all components contained in the oxide nanoparticles was 80 nm. Example 1

[0058] A 316L stainless steel pipe with a diameter of 20mm and a length of 100mm was sandblasted using 100-mesh steel grit at a pressure of 5MPa, a temperature of 25℃, and a duration of 2 hours. It was then cleaned with anhydrous ethanol for 10 minutes and dried before use. A 200g slurry was prepared by mixing α-alumina, silica, manganese oxide, zinc oxide, calcium oxide, potassium oxide, silane coupling agent, water, and sodium silicate in a mass percentage ratio of 8:15:3:3:10:5:10:10:36. The slurry was then stirred evenly to obtain a coating.

[0059] The coating was sprayed onto the surface of the stainless steel pipe at a temperature of 25℃ for 20 seconds, with an atomizing air pressure of 0.3MPa and a powder supply pressure of 0.06MPa. The distance between the spray gun nozzle and the surface of the stainless steel pipe was 200mm. After spraying, the resulting coating was heated to 130°C. o Dry at C for 40 min, then heat to 600°C in air at a heating rate of 5°C / min, and solidify and sinter at this temperature for 30 min. Cool with the furnace to obtain a multifunctional nanocomposite ceramic coating.

[0060] The physical image of the multifunctional nanocomposite ceramic coating prepared in this embodiment is shown below. Figure 1 As shown, by Figure 1 It can be seen that the multifunctional nanocomposite ceramic coating has a smooth and dense surface with a glaze-like luster, and the cross-sectional view shows a thickness of approximately 45 micrometers.

[0061] The tritium permeation test results and the surface morphology and elemental distribution after salt spray corrosion of the multifunctional nanocomposite ceramic coating are shown in the figure. Figure 2 As shown, (a) is the tritium permeation test result of the multifunctional nanocomposite ceramic coating, and (b) is the surface morphology and elemental distribution of the multifunctional nanocomposite ceramic coating after salt spray corrosion resistance. Figure 2 It can be seen that the multifunctional nanocomposite ceramic coating significantly reduces deuterium flux in the temperature range of 350-650℃, indicating that it has excellent deuterium blocking performance in high-temperature deuterium shielding applications, especially in the high-temperature range (550-650℃). o (C) The coating almost completely inhibits deuterium penetration, providing strong support for thermal control and deuterium load protection; the multifunctional nanocomposite ceramic coating has strong resistance to salt spray corrosion, even at a NaCl concentration of 5% and a temperature of 35°C. o Under conditions C, no corrosion spots were observed on the surface after 1000 hours of salt spray corrosion.

[0062] The wear resistance performance of 316L stainless steel and multifunctional nanocomposite ceramic coating is shown in the figure. Figure 3As shown, (a) is the coefficient of friction of 316L stainless steel, (b) is the friction and wear of 316L stainless steel, (c) is the coefficient of friction of the coating under the same experimental conditions, and (d) is the friction and wear result of the coating under the same experimental conditions. Figure 3 It can be seen that the coating has excellent wear resistance, approaching that of stainless steel.

[0063] Hardness chart of 316L stainless steel and multifunctional nanocomposite ceramic coating as shown in the figure. Figure 4 As shown, by Figure 4 It can be seen that the coating has high hardness, more than twice that of the stainless steel substrate. Example 2

[0064] A DH40 steel pipe with a diameter of 200 mm and a length of 500 mm was sandblasted using 100-mesh steel abrasive at a pressure of 5 MPa, a temperature of 25°C, and a duration of 2 hours. It was then cleaned with anhydrous ethanol for 10 minutes and dried before use. α-alumina and silica were then added. Manganese oxide, zinc oxide, calcium oxide, potassium oxide, silane coupling agent, water, and sodium silicate are mixed in a mass percentage ratio of 8:15:3:3:10:5:10:10:36 to prepare 200g of slurry. The slurry is then stirred evenly to obtain the coating.

[0065] The coating was sprayed onto the surface of a DH40 steel pipe at a temperature of 25℃ for 20 seconds. The atomizing air pressure was 0.4 MPa, the powder supply pressure was 0.1 MPa, and the distance between the spray gun nozzle and the surface of the DH40 steel pipe was 150 mm. After spraying, the resulting coating was then sprayed on a 150 mm thick surface. o Dry at C for 30 min, then heat to 600°C in air at a heating rate of 5°C / min, and solidify and sinter at this temperature for 30 min. Cool with the furnace to obtain a multifunctional nanocomposite ceramic coating.

[0066] The physical image of the multifunctional nanocomposite ceramic coating prepared in this embodiment is shown below. Figure 5 As shown, by Figure 5 It can be seen that a smooth and flat composite ceramic coating with a glaze-like luster is formed on the surface of DH40 steel pipe;

[0067] The wear resistance of the DH40 steel pipe and the multifunctional nanocomposite ceramic coating in this embodiment, and the deuterium permeation results of the multifunctional nanocomposite ceramic coating are shown in the figure below. Figure 6 As shown, (a) is the deuterium permeation test result of the multifunctional nanocomposite ceramic coating, (b) is the wear resistance performance of DH40 steel pipe, and (c) is the wear resistance performance of the multifunctional nanocomposite ceramic coating. Figure 6 (a) It can be seen that: 650 oC, hydrogen barrier factor PRF = 5120, 550 o C, PRF=14000, 500 o C, PRF=13000. From (b) and (c), we know that the coefficient of friction of the coating is 0.6, while the coefficient of friction of stainless steel is 0.5; the friction wear rate is approximately 1.2 times that of stainless steel, indicating that the hydrogen barrier performance of this coating is within the range of 300-650. o C, PRF>10 3 The coating has excellent hydrogen barrier properties and wear resistance.

[0068] The surface morphology and elemental distribution of the multifunctional nanocomposite ceramic coating after salt spray corrosion resistance are shown in the figure below. Figure 7 As shown, by Figure 7 It can be seen that: when the NaCl concentration is 5% and the temperature is 35°C... o Under C conditions, after 1000 hours of salt spray corrosion, the coating surface remained smooth with a very uniform element distribution and virtually no damage. Example 3

[0069] An Inconel 625 nickel alloy tube with a diameter of 150 mm and a length of 400 mm was polished with 80# sandpaper for 10 minutes, then cleaned with anhydrous ethanol for 12 minutes, and dried before use; α-alumina and silicon dioxide were then... Manganese oxide, zinc oxide, calcium oxide, potassium oxide, silane coupling agent, water, and sodium silicate are mixed in a mass percentage ratio of 5:10:1:6:13:7:15:13:30 to prepare 200g of slurry. The slurry is then stirred evenly to obtain the coating.

[0070] The coating was sprayed onto the surface of an Inconel 625 alloy tube at a temperature of 30°C for 10 seconds. The atomizing pressure was 0.5 MPa, the powder supply pressure was 0.04 MPa, and the distance between the spray gun nozzle and the surface of the nickel alloy tube was 300 mm. After spraying, the resulting coating was heated to 140°C. o Dry at C for 20 min, then heat to 800°C in air at a heating rate of 6°C / min, and solidify and sinter at this temperature for 20 min. Cool with the furnace to obtain a multifunctional nanocomposite ceramic coating.

[0071] The multifunctional nanocomposite ceramic coating prepared in this embodiment was photographed after being kept at 500℃, 700℃, and 800℃ for 48 hours, respectively. Figure 8 As shown, by Figure 8 It can be seen that after the coating is kept at different temperatures, the surface remains intact and glossy without damage, indicating that it has good high-temperature resistance.

[0072] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A multifunctional nanocomposite ceramic coating, characterized in that, The multifunctional nanocomposite ceramic coating is formed by curing and sintering oxide nanoparticles, binder and water. The oxide nanoparticles comprise the following components: α-alumina, silicon dioxide, manganese oxide, zinc oxide, calcium oxide, and potassium oxide; The particle size of the components contained in the oxide nanoparticles is 50~100nm; The adhesives include organic adhesives and inorganic adhesives; The organic binder is a silane coupling agent, and the inorganic binder is sodium silicate; The mass percentages of all components of the multifunctional nanocomposite ceramic coating are as follows: α-alumina 5~8%, silicon dioxide 10~15%, manganese oxide 1~3%, zinc oxide 3~6%, calcium oxide 10~13%, potassium oxide 5~7%, silane coupling agent 10~15%, water 10~13%, and the remainder is sodium silicate. The curing and sintering temperature is 500~800℃, the curing and sintering time is 20~40min, the curing and sintering is carried out in an oxygen-rich atmosphere, and the heating rate to the curing and sintering temperature is 4~6℃ / min.

2. The method for preparing the multifunctional nanocomposite ceramic coating according to claim 1, characterized in that, It includes the following steps: 1) Pre-treat the matrix; 2) Mix oxide nanoparticles, binder, and water in a certain proportion to obtain a coating; 3) The coating is sprayed onto the substrate surface and then cured and sintered to obtain a multifunctional nanocomposite ceramic coating.

3. The preparation method according to claim 2, characterized in that, Step 1) The substrate is stainless steel, carbon steel or nickel alloy; the shape of the substrate is a round tube or a round plate.

4. The preparation method according to claim 2 or 3, characterized in that, Step 1) The pretreatment is sanding or sandblasting.

5. The preparation method according to claim 4, characterized in that, Step 3) The parameters that need to be controlled during the spraying process are: spraying temperature of 20~30℃, spraying time of 10~30s, atomizing air pressure of 0.3~0.5MPa, powder supply pressure of 0.04~0.1MPa, and distance between the spray gun nozzle and the substrate surface of 150~300mm.

6. The preparation method according to claim 5, characterized in that, After the spraying is completed in step 3), the coating is dried. The drying temperature is 130~150℃ o C, the drying time is 20~40 minutes.

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