Paint, coating and preparation method thereof

Abstract

The invention provides a paint, a coating and a preparation method thereof. The coating comprises a non-metal filler, a metal filler, glaze and a dispersing agent, wherein the metal filler comprises at least one of nickel, chromium, manganese and titanium; the glaze comprises at least one of silicon oxide and aluminum oxide, at least one of boron oxide, sodium oxide and zirconium oxide, and beryllium oxide. The metal filler comprises at least one of nickel, chromium, manganese and titanium, the bonding performance between the metal filler and the metal matrix is high, and a coating prepared from the coating can be firmly bonded with the metal matrix (such as stainless steel). And due to the composition of the glaze, the coating has excellent moisture resistance and corrosion resistance, so that the coating can keep excellent performance in a severe environment, and the thermal shock resistance of the coating is enhanced.

Description

Technical Field

[0001] The present application relates to the field of coating technology, and in particular to coatings, coatings and preparation methods thereof. Background Art

[0002] Stainless steel sheets such as 304 and 316 will suffer from oxidation problems and high-temperature deformation and peeling when used under high temperature conditions for a long time. In order to avoid the above phenomenon, a coating is generally provided on the surface of the stainless steel. However, due to the limitations of relevant technologies, the existing coating is not sufficiently bonded to the substrate, and the effect of enhancing the thermal shock resistance of the stainless steel substrate is not ideal, which still needs further improvement. Summary of the invention

[0003] In view of this, the embodiments of the present application provide a coating, a coating and a method for preparing the same.

[0004] In a first aspect, the present application provides a coating, comprising: a non-metal filler, a metal filler, a glaze, and a dispersant;

[0005] The metal filler includes at least one of nickel, chromium, manganese and titanium; the glaze includes at least one of silicon oxide and aluminum oxide, at least one of boron oxide, sodium oxide and zirconium oxide, and beryllium oxide.

[0006] In one embodiment, the coating comprises: 10 to 20 parts by weight of non-metal filler; 5 to 15 parts by weight of metal filler; 20 to 30 parts by weight of glaze; and 80 to 100 parts by weight of dispersant;

[0007] Preferably, the coating comprises 15 to 20 parts by weight of a non-metal filler; 8 to 15 parts by weight of a metal filler; 20 to 28 parts by weight of a glaze; and 90 to 100 parts by weight of a dispersant.

[0008] In one embodiment, the non-metallic filler includes at least one of bimodal activated alumina, unimodal activated alumina, plate-like corundum, aluminum-rich spinel, and mullite.

[0009] In one embodiment, the metal filler includes metal filler particles, and the particle size of the metal filler particles is 0.4 to 50 microns;

[0010] Preferably, the metal filler particles include first metal filler particles, second metal filler particles and third metal filler particles, the particle size of the first metal filler particles is 38 to 50 microns; the particle size of the second metal filler particles is 4 to 6 microns; the particle size of the third metal filler particles is 0.4 to 0.6 microns;

[0011] Preferably, the mass ratio of the first metal filler particles, the second metal filler particles and the third metal filler particles is (7-5):(2-3):(1-2).

[0012] In one embodiment, the glaze comprises, by mass percentage: 5-15% beryllium oxide; 30-50% boron oxide; 40-60% silicon oxide; 2-10% aluminum oxide; 2-10% sodium oxide; 0-5% zirconium oxide;

[0013] Preferably, the glaze comprises, by mass percentage: 10-13% beryllium oxide; 30-40% boron oxide; 40-50% silicon oxide; 5-8% aluminum oxide; 5-8% sodium oxide; 0-3% zirconium oxide;

[0014] Preferably, the dispersant includes at least one of isooctyl alcohol, isopropyl alcohol, polyacrylic acid and ethanol.

[0015] The second aspect of the present application provides a coating, which is prepared by using the above-mentioned coating, and the coating comprises, by mass percentage:

[0016] Boron oxide 10-18%; silicon oxide 15-30%; aluminum oxide 20-30%; beryllium oxide 5-15%; sodium oxide 2-10%; zirconium oxide 0-1%; and metal 10-30%;

[0017] Wherein, the metal includes at least one of nickel, chromium, manganese and titanium.

[0018] In one embodiment, the coating comprises, by mass percentage: 15-18% boron oxide; 25-30% silicon oxide; 28-30% aluminum oxide; 10-12% beryllium oxide; 2-5% sodium oxide; 0.5-1% zirconium oxide; and 10-20% metal;

[0019] Preferably, the metal comprises nickel and chromium;

[0020] Preferably, in the metal, the mass ratio of nickel to chromium is (2-4):1.

[0021] The third aspect of the present application provides a method for preparing a coating, comprising:

[0022] Applying the aforementioned coating on the surface of the substrate;

[0023] The paint is heat treated to obtain a coating.

[0024] In one embodiment, before applying the coating on the surface of the substrate, the method further comprises:

[0025] The coating is ball-milled and sieved in sequence;

[0026] Preferably, the ball milling process is performed at a speed of 200 to 400 r / min and a time of 1 to 3 h;

[0027] Preferably, after ball milling, the coating is sieved through a 50-70 mesh sieve;

[0028] Preferably, the coating is applied to the substrate surface by a spray gun.

[0029] In one embodiment, after the step of coating the coating on the surface of the substrate and before the step of heat treating the coating, the method further comprises:

[0030] Pre-treat the coating, including:

[0031] Stage 1: Place the coating at 80-120°C for 1-3 hours;

[0032] The second stage: place the coating at 140-160℃ for 1-2h;

[0033] The third stage: place the coating at 170-190℃ for 0.4-0.6h;

[0034] Preferably, the heat treatment temperature is 900-1100°C and the time is 10-20 minutes;

[0035] Preferably, the heat treatment is carried out in an air atmosphere;

[0036] Preferably, the material of the base body comprises stainless steel.

[0037] According to the coating provided in the embodiment of the present application, the metal filler includes at least one of nickel, chromium, manganese and titanium, and the metal filler has a strong bonding performance with the metal substrate. The coating prepared using the coating can be firmly combined with the metal substrate (such as stainless steel). The silicon oxide and aluminum oxide in the glaze have a mesh structure, which becomes the skeleton of the body after sintering, improving the mechanical strength and chemical stability of the coating after construction; the metal filler has a better dispersion in the silicon oxide and aluminum oxide with a mesh structure, which is conducive to improving the bonding strength between the coating and the substrate; boron oxide, sodium oxide and zirconium oxide will form a glassy substance after sintering, filling between the substrate and the skeleton, reducing the expansion coefficient and improving thermal stability. Beryllium oxide in the glaze has extremely high thermal conductivity, which helps to quickly transfer heat and reduce the temperature gradient inside the substrate and coating, thereby reducing the level of thermal stress caused by the temperature gradient and improving the thermal shock stability of the substrate and coating. Moreover, beryllium oxide can be sintered at 1000°C at normal pressure, with moderate strength after sintering and high high-temperature compressive strength, which helps to maintain the integrity of the structure under thermal shock. The addition of beryllium oxide has almost no effect on the sintering performance of the glaze itself, and is evenly distributed in the mesh structure, dispersing stress in the structure and increasing thermal shock resistance. In addition, the composition of the glaze gives the coating excellent moisture resistance and corrosion resistance, allowing the coating to maintain excellent performance even in harsh environments and enhance its thermal shock stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is the morphology of the coating of Example 5 before thermal shock.

[0039] Figure 2 This is the morphology of the coating of Example 5 after thermal shock at 1000°C.

[0040] Figure 3 This is the morphology of the coating of Example 3 before thermal shock.

[0041] Figure 4 This is the morphology of the coating of Example 3 after thermal shock at 1000°C.

[0042] Figure 5 This is the morphology of the stainless steel substrate of Comparative Example 1 before thermal shock.

[0043] Figure 6 This is the morphology of the stainless steel substrate of Comparative Example 1 after thermal shock at 1000°C. DETAILED DESCRIPTION

[0044] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] In addition, in order to better illustrate the present application, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In some examples, methods and means well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present application.

[0046] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0047] The first aspect of the present application provides a coating, comprising: a non-metallic filler, a metal filler, a glaze, and a dispersant; wherein the metal filler comprises at least one of nickel, chromium, manganese and titanium; the glaze comprises at least one of silicon oxide and aluminum oxide, at least one of boron oxide, sodium oxide and zirconium oxide, and beryllium oxide.

[0048] According to the coating provided in the embodiment of the present application, the metal filler includes at least one of nickel, chromium, manganese and titanium, and the metal filler has a strong bonding performance with the metal substrate. The coating prepared using the coating can be firmly combined with the metal substrate (such as stainless steel). The silicon oxide and aluminum oxide in the glaze have a mesh structure, which becomes the skeleton of the body after sintering, improves the mechanical strength and chemical stability of the coating after construction, and silicon oxide can increase the viscosity of the coating, which is conducive to the adhesion of the coating to the surface of the substrate; the metal filler has a better dispersion in silicon oxide and aluminum oxide with a mesh structure, which is conducive to improving the bonding strength between the coating and the substrate; boron oxide, aluminum oxide, sodium oxide and zirconium oxide will form a glassy substance after sintering, which is filled between the substrate and the skeleton, reducing the expansion coefficient and improving thermal stability. Beryllium oxide in the glaze has extremely high thermal conductivity, which helps to quickly transfer heat and reduce the temperature gradient inside the substrate and coating, thereby reducing the level of thermal stress caused by the temperature gradient and improving the thermal shock stability of the substrate and coating. Moreover, beryllium oxide can be sintered at 1000°C at normal pressure, with moderate strength after sintering and high high-temperature compressive strength, which helps to maintain the integrity of the structure under thermal shock. The addition of beryllium oxide has almost no effect on the sintering performance of the glaze itself, and is evenly distributed in the mesh structure, dispersing stress in the structure and increasing thermal shock resistance. In addition, the composition of the glaze gives the coating excellent moisture resistance and corrosion resistance, allowing the coating to maintain excellent performance even in harsh environments and enhance its thermal shock stability.

[0049] It is understood that the coating can be prepared by using the coating of the embodiment of the present application, for example, the coating can be prepared by high-temperature sintering. For example, the coating can be applied to the surface of a substrate, such as a stainless steel substrate, and the coating and the substrate are sintered at high temperature to obtain a coating bonded to the surface of the substrate.

[0050] Exemplarily, among the metal fillers, nickel has good high thermal stability; and chromium has excellent corrosion resistance, oxidation resistance, and high temperature corrosion resistance.

[0051] In one embodiment, the coating includes: 10 to 20 parts by weight of non-metallic filler (for example, 10 parts by weight, 12 parts by weight, 14 parts by weight, 16 parts by weight, 18 parts by weight or 20 parts by weight, etc.); 5 to 15 parts by weight of metal filler (for example, 5 parts by weight, 6 parts by weight, 8 parts by weight, 10 parts by weight, 12 parts by weight, 14 parts by weight or 15 parts by weight, etc.); 20 to 30 parts by weight of glaze (for example, 20 parts by weight, 22 parts by weight, 24 parts by weight, 26 parts by weight, 28 parts by weight or 30 parts by weight, etc.); and 80 to 100 parts by weight of dispersant (for example, 80 parts by weight, 82 parts by weight, 84 parts by weight, 86 parts by weight, 88 parts by weight, 90 parts by weight, 92 parts by weight, 94 parts by weight, 96 parts by weight, 98 parts by weight or 100 parts by weight, etc.). Thus, the proportion of each component in the coating is appropriate, which is conducive to improving the thermal shock stability of the coating.

[0052] In one embodiment, the coating comprises 15 to 20 parts by weight of non-metallic filler, 8 to 15 parts by weight of metallic filler, 20 to 28 parts by weight of glaze, and 90 to 100 parts by weight of dispersant. Thus, the proportion of each component in the coating is more appropriate, which is more conducive to improving the thermal shock stability of the coating.

[0053] In one embodiment, the non-metal filler includes at least one of bimodal activated alumina, unimodal activated alumina, plate-like corundum, aluminum-rich spinel and mullite. Thus, the non-metal filler has a mesh structure, which can become the skeleton of the matrix after sintering, which is conducive to improving the mechanical strength and chemical stability of the coating; and the alumina particles have a high specific surface area and good filling properties, which can fill the tiny bumps on the surface of the coating and improve the flatness and hiding power of the coating; in addition, alumina can also increase the adhesion of the coating and improve the bonding strength between the coating and the substrate.

[0054] In one embodiment, the metal filler includes metal filler particles, and the particle size of the metal filler particles is 0.4 to 50 microns, for example, 0.4 microns, 1 micron, 5 microns, 10 microns, 15 microns, 20 microns, 25 microns, 30 microns, 35 microns, 40 microns, 45 microns, 50 microns, etc. Therefore, the particle size of the metal filler particles is suitable, which is conducive to uniform distribution in the mesh skeleton structure, dispersing stress in the structure, and improving thermal shock resistance; at the same time, the particle size of the metal filler particles within the above range is also conducive to increasing the contact area between the metal filler particles and the substrate, and further enhancing the bonding strength between the coating and the substrate.

[0055] In one embodiment, the metal filler particles include first metal filler particles, second metal filler particles and third metal filler particles, the particle size of the first metal filler particles is 38 to 50 microns (for example, 38 microns, 40 microns, 42 microns, 46 microns or 50 microns, etc.); the particle size of the second metal filler particles is 4 to 6 microns (for example, 4 microns, 4.5 microns, 5 microns, 5.5 microns or 6 microns, etc.); the particle size of the third metal filler particles is 0.4 to 0.6 microns (for example, 0.4 microns, 0.45 microns, 0.5 microns, 0.55 microns or 0.6 microns, etc.). Thus, the metal filler particles of different particle sizes are mixed, so that the metal filler particles can be more evenly distributed, and there are fewer voids, which is conducive to improving the density of the coating; moreover, fewer voids in the coating are conducive to improving the thermal conductivity of the coating, which helps to quickly transfer heat, reduce the temperature gradient inside the coating and the substrate, and reduce the thermal stress accumulation caused by the temperature gradient.

[0056] In one embodiment, the mass ratio of the first metal filler particles, the second metal filler particles, and the third metal filler particles is (7-5): (2-3): (1-2), for example, it can be (5, 6 or 7): (2, 2.5 or 3): (1, 1.5 or 2). Thus, the first metal filler particles, the second metal filler particles, and the third metal filler particles are easier to mix evenly.

[0057] In one embodiment, the glaze includes, by mass percentage: 5-15% beryllium oxide (for example, 5%, 10% or 15%); 30-50% boron oxide (for example, 20%, 40% or 50%); 40-60% silicon oxide (for example, 40%, 50% or 60%); 2-10% aluminum oxide (for example, 2%, 4%, 8% or 10%); 2-10% sodium oxide (for example, 2%, 4%, 8% or 10%); 0-5% zirconium oxide (for example, 1%, 2%, 4% or 5%). Beryllium oxide can be sintered at 1000℃ under normal pressure. Beryllium oxide has extremely high thermal conductivity, which is 7 to 8 times that of Al2O3. This high thermal conductivity helps to quickly transfer heat, reduce the temperature gradient inside the material, thereby reducing the level of thermal stress caused by the temperature gradient and improving the thermal shock stability of the material; beryllium oxide has moderate strength after sintering and high high-temperature compressive strength, which helps to maintain the integrity of the structure under thermal shock; the addition of beryllium oxide does not affect the sintering performance of the glaze itself. Beryllium oxide is evenly distributed in the mesh structure, dispersing stress in the structure and increasing thermal shock resistance. Silicon oxide and aluminum oxide react to form needle-net crystals during sintering, which become the skeleton of the body, improve the mechanical strength and chemical stability of the coating after application, and form a glassy substance with boron oxide, sodium oxide and zirconium oxide, filling between the body and the skeleton, reducing the expansion coefficient and improving thermal stability. Sodium oxide is a strong fluxing agent, which can reduce the melting point of the glaze, improve the fusibility of the glaze, and make the glaze easier to melt at high temperature and cover the surface of the substrate. Zirconia makes the coating have high thermal shock resistance and low intrinsic thermal conductivity after sintering; Zirconia has excellent thermal and mechanical properties and shows strong stability when used at high temperatures. The components in the above glazes cooperate with each other, so that the sintered coating has excellent moisture resistance and corrosion resistance, so that the coating can maintain excellent performance in harsh environments and enhance the thermal shock stability of the coating.

[0058] In a preferred embodiment, the glaze comprises, by mass percentage: 10-13% beryllium oxide; 30-40% boron oxide; 40-50% silicon oxide; 5-8% aluminum oxide; 5-8% sodium oxide; and 0-3% zirconium oxide.

[0059] In one embodiment, the dispersant includes at least one of isooctyl alcohol, isopropanol, polyacrylic acid and ethanol, thereby effectively dispersing non-metallic fillers, metal fillers and glazes.

[0060] The second aspect of the present application provides a coating, which is prepared by the aforementioned coating, and the coating comprises, by mass percentage: 10-18% boron oxide (for example, 10%, 12%, 14%, 16% or 18%); 15-30% silicon oxide (for example, 15%, 18%, 20%, 22%, 24%,

[0061] 26%, 28% or 30%, etc.); aluminum oxide 20-30% (for example, 20%, 22%, 24%,

[0062] 26%, 28% or 30%, etc.); beryllium oxide 5-15% (for example, 5%, 8%, 10%, 12%, 14% or 15%, etc.); sodium oxide 2-10% (for example, 2%, 4%, 6%, 8% or 10%, etc.); zirconium oxide 0-1% (for example, 0%, 0.2%, 0.4%, 0.6%, 0.8% or 1%

[0063] and 10-30% of metal (e.g., 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28% or 30%, etc.); wherein the metal includes at least one of nickel, chromium, manganese and titanium. As a result, the coating has excellent moisture resistance and corrosion resistance, can maintain excellent performance in harsh environments, and has strong thermal shock stability. Compared with the above content range, when the silicon oxide content is low, the viscosity of the coating is small and it is easy to sag, affecting the firing and adhesion of the coating; when the silicon oxide content is too high, the thixotropic property of the coating system is too strong, resulting in insufficient edge shear force during dispersion and a frozen state, affecting the dispersion efficiency, and also causing precipitation, agglomeration and the construction performance of the coating; boron oxide can reduce the melting temperature and viscosity of the glaze and improve the density of the glaze, but the viscosity of the coating is relatively strong when the content exceeds 15%, and it is not easy to form a uniform film layer, resulting in relatively poor coating effect; too high a proportion of sodium chloride will affect the adhesion of the coating to the substrate and the thermal shock resistance at high temperature; when the sodium oxide content is too low, the viscosity of the coating will be inappropriate, affecting the construction When the content of sodium oxide is too high, it will corrode the metal and cause the substrate to be easily oxidized; when the content of zirconium oxide is too high, it may affect the thermal shock resistance of the coating, shorten the service life of the coating, increase the permeability of the coating, and thus affect the protective performance of the coating; when the content of zirconium oxide is too low, the thermal shock resistance of the coating is reduced, the structural stability is poor, the protective ability is weakened, and the durability is reduced; when the metal content is too low, it affects the bonding between the coating and the metal substrate and the stress gradient fault under high temperature thermal shock; when the metal content is too high, the content of other components is reduced accordingly, and the optimal thermal shock performance of the coating and the ability to resist substrate deformation cannot be achieved.

[0064] In a preferred embodiment, the coating comprises, by mass percentage: 15-18% boron oxide; 25-30% silicon oxide; 28-30% aluminum oxide; 10-12% beryllium oxide; 2-5% sodium oxide; 0.5-1% zirconium oxide; and 10-20% metal.

[0065] Optionally, the metal includes nickel and chromium. The main components of stainless steel include nickel and chromium, and the inclusion of nickel and chromium in the metal is conducive to improving the adhesion between the coating and the stainless steel substrate; in addition, nickel has good high thermal stability; chromium has excellent corrosion resistance, oxidation resistance and high temperature corrosion resistance.

[0066] In one embodiment, in the metal, the mass ratio of nickel to chromium is (2-4):1, for example, 2:1, 3:1 or 4:1.

[0067] Illustratively, the coating of the present application has at least one of the following characteristics: 1. Maximum operating temperature of 950°C; 2. Long-term operating temperature of 900°C; 3. Excellent thermal shock resistance. Specifically, after repeated thermal shock at 900°C and 25°C water cooling for 10 times, the coating does not crack or fall off, and the adhesion does not change; 4. It can be used as a surface coating for substrates such as 304 stainless steel, 316 stainless steel, 310 stainless steel, etc.

[0068] A third aspect of the present application provides a method for preparing a coating, and the method for preparing the coating comprises the following steps.

[0069] S100: coating the aforementioned coating on the surface of the substrate.

[0070] In one embodiment, before applying the coating to the surface of the substrate, the process further includes: ball milling and sieving the coating in sequence. Thus, ball milling can make the particle size of solid particles in the coating smaller and more uniform, and can mix the components more evenly, which is conducive to obtaining a coating with more uniform composition; sieving can remove particles with larger sizes in the coating, which is more conducive to obtaining a flatter coating with more uniform composition.

[0071] Optionally, the ball milling speed is 200-400 r / min (for example, 200 r / min, 250 r / min, 300 r / min, 350 r / min or 400 r / min, etc.), and the time is 1-3 h (for example, 1 h, 1.5 h, 2 h, 2.5 h or 3 h, etc.).

[0072] Optionally, after ball milling, the coating is passed through a 50-70 mesh sieve (for example, 50 mesh, 55 mesh, 60 mesh, 65 mesh or 70 mesh, etc.), thereby facilitating the acquisition of a coating with a relatively flat surface.

[0073] Alternatively, the coating is applied to the substrate surface by a spray gun.

[0074] S200: heat-treating the paint to obtain a coating.

[0075] In one embodiment, after the step of coating the coating on the surface of the substrate and before the step of heat treating the coating, the coating is pretreated, and the pretreatment includes: the first stage: placing the coating at 80-120°C (for example, 80°C, 90°C, 100°C, 110°C or 120°C, etc.) for 1-3h (for example, 1h, 2h or 3h, etc.); the second stage: placing the coating at 140-160°C

[0076] (For example, it can be 140℃, 145℃, 150℃, 155℃ or 160℃, etc.) for 1-2h (for example, it can be 1h, 1.5h or 2h, etc.); the third stage: put the coating at 170-190℃ (for example, it can be 170℃, 175℃, 180℃, 185℃ or 190℃, etc.) for 0.4-0.6h (for example, it can be 0.4h, 0.5h or 0.6h, etc.). As a result, the temperature of the first stage, the second stage to the third stage gradually increases, which is conducive to gradually drying the liquid in the coating and preventing the coating from cracking due to the excessive outflow of the liquid phase.

[0077] In one embodiment, the heat treatment temperature is 900-1100°C (for example, 900°C, 950°C, 1000°C, 1050°C or 1100°C, etc.), and the time is 10-20 minutes (for example, 10 minutes, 15 minutes or 20 minutes, etc.). Thus, the coating can be melted at the above temperature and closely adhered to the surface of the substrate, which is conducive to obtaining a relatively flat coating with excellent moisture resistance and corrosion resistance and strong thermal shock stability.

[0078] It is understandable that during the heat treatment process, the components on the surface of the coating are partially oxidized to form a metal anti-oxidation protective layer, which makes the coating more corrosion-resistant.

[0079] In a specific embodiment, the method for preparing the coating comprises the following steps:

[0080] 1. Take non-metallic filler, metal filler, glaze, and dispersant, place them in a ball mill (zirconia ceramic), and mill them in a planetary vertical ball mill at a speed of 300 r / min for 2 hours to obtain a ball milled mixture.

[0081] 2. Pass the ball mill mixture through a 60-mesh sieve to obtain a suspended liquid coating.

[0082] 3. Use a spray gun to evenly spray the suspended liquid paint onto the metal surface. Before spraying, the metal surface needs to be sandblasted, cleaned, and activated.

[0083] 4. After the suspension liquid paint is sprayed, let it stand for 2-4 hours. After the surface is dry, place it in an oven for three-stage pretreatment. The first stage: heat treatment at 100°C for 2 hours; the second stage: heat treatment at 150°C for 1 hour; the third stage: heat treatment at 180°C for 0.5 hours.

[0084] 5. After drying, place it in air atmosphere for heat treatment at 1000℃ for 15 minutes, then quickly take it out of the furnace. After cooling in air, the coating on the metal surface is completed.

[0085] Optionally, the material of the substrate includes stainless steel, such as 316 stainless steel, 304 stainless steel, 310 stainless steel, etc. The substrate has a strong antioxidant capacity, and there is almost no problem of high-temperature deformation under high temperature conditions. Exemplarily, the coating of the present application is resistant to 900°C thermal shock. After the substrate with the coating on the surface is heat treated at 1000°C, the substrate and the coating are placed in air at 900°C for 24 hours, and the overall weight change is less than 0.3%, and the thermal shock resistance effect is excellent.

[0086] The present application is further described below in conjunction with specific embodiments. It should be noted that the following embodiments are only used to explain the present application and cannot be understood as limiting the present application.

[0087] Example 1

[0088] The method for preparing the coating comprises the following steps:

[0089] 1. Take non-metallic filler, metal filler, glaze, and dispersant, place them in a ball mill (zirconia ceramic), and mill them in a planetary vertical ball mill at a speed of 300 r / min for 2 hours to obtain a ball milled mixture.

[0090] 2. Pass the ball mill mixture through a 60-mesh sieve to obtain a suspended liquid coating.

[0091] 3. Use a spray gun to evenly spray the suspended liquid paint onto the surface of 304 stainless steel. Before spraying, sandblast, clean and activate the surface of 304 stainless steel.

[0092] 4. After the suspension liquid paint is sprayed, let it stand for 3 hours. After the surface is dry, place it in an oven for three-stage pretreatment. The first stage: heat treatment at 100°C for 2 hours; the second stage: heat treatment at 150°C for 1 hour; the third stage: heat treatment at 180°C for 0.5 hours.

[0093] 5. After drying, place it in air atmosphere for heat treatment at 1000℃ for 15 minutes, then quickly take it out of the furnace. After cooling in air, the coating on the metal surface is completed.

[0094] Examples 2 to 21 and Comparative Examples 2 to 3: The method for preparing the coating is basically the same as that of Example 1, except for the specific composition of the coating, as shown in Table 1 below.

[0095] Comparative Example 1 is a 304 stainless steel substrate without a coating.

[0096] Table 1

[0097]

[0098]

[0099] The adhesion between the coatings of Examples 1 to 21 and Comparative Examples 1 to 3 and the 304 stainless steel substrate before thermal shock was tested. The test results are shown in Table 2 below.

[0100] The coatings of Examples 1 to 21 and Comparative Examples 1 to 3 were subjected to a 1000°C thermal shock test, and the specific process was as follows: the sample was placed in a thermal shock furnace and heated to 1000°C, kept warm for 1 hour, and then immediately taken out and placed in a water tank, and the sample was taken out of the water after the temperature dropped to 50°C. The adhesion results between the coating and the 304 stainless steel substrate after thermal shock are shown in Table 2 below, and the surface oxidation or damage of the coating after thermal shock is shown in Table 2 below.

[0101] Table 2

[0102]

[0103] From the data of Examples 1 to 5, it can be seen that the effect of the coating containing nickel and chromium is better than that of the coating containing manganese and titanium, and the bonding force between nickel and chromium and the 304 stainless steel substrate is stronger. Figure 1 As shown in Figure 2, the morphology of the coating after thermal shock at 1000℃ is as follows: Figure 2 As shown in FIG. 1 , the coating morphology before and after the thermal shock has almost no change, and the coating has excellent thermal shock resistance. Figure 3 As shown in Figure 2, the morphology of the coating after thermal shock at 1000℃ is as follows: Figure 4 As shown in the figure, the coating is slightly peeled off after thermal shock, and the coating has better thermal shock resistance.

[0104] It can be seen from the data of Examples 6 and 7 that silicon dioxide can increase the viscosity of the coating. When the silicon dioxide content is low, the coating has a low viscosity and is prone to sagging, which affects the firing and adhesion of the coating. Boric oxide can reduce the melting temperature and viscosity of the glaze and improve the density of the glaze, but when the content exceeds 15%, the viscosity of the coating and its effect on the stainless steel substrate will also deteriorate.

[0105] It can be seen from the data of Examples 8 and 9 that the aluminum oxide particles have a high specific surface area and good filling properties, can fill the tiny bumps on the coating surface, and improve the flatness and hiding power of the coating. In addition, the aluminum oxide particles can also increase the adhesion of the coating and improve the bonding strength between the coating and the stainless steel substrate. Beryllium oxide is a good thermal conductive material that can effectively dissipate heat, so that the coating has a stress buffer reduction during the thermal shock process, which effectively protects the thermal shock resistance of the coating.

[0106] It can be seen from the data of Example 10 and Example 11 that a too high proportion of sodium chloride will affect the adhesion of the coating to the substrate and the high-temperature thermal shock resistance; zirconium oxide can improve the thermal shock resistance of the coating.

[0107] From the data of Comparative Example 1, it can be seen that 304 stainless steel without coating cannot withstand a high temperature of 1000°C. The morphology of the stainless steel substrate of Comparative Example 1 is as follows: Figure 5 As shown in Figure 2, the morphology of the stainless steel matrix after thermal shock at 1000℃ is as follows: Figure 6 As shown in the figure, the surface of the stainless steel matrix is ​​damaged after thermal shock, and the thermal shock resistance of the stainless steel matrix is ​​poor.

[0108] It can be seen from the data of Comparative Example 2 that the addition of beryllium oxide can improve the thermal shock resistance of the coating.

[0109] It can be seen from the data of Comparative Example 3 that the absence of nickel-chromium-manganese-titanium transition in the coating results in poor adhesion between the coating and the substrate.

[0110] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0111] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A coating, characterized in that: include: Non-metallic fillers, metallic fillers, glazes, and dispersants; The metal filler includes at least one of nickel, chromium, manganese and titanium; the glaze includes at least one of silicon oxide and aluminum oxide, at least one of boron oxide, sodium oxide and zirconium oxide, and beryllium oxide.

2. The coating according to claim 1, characterized in that The coating comprises: 10 to 20 parts by weight of non-metal filler; 5 to 15 parts by weight of metal filler; 20 to 30 parts by weight of glaze; and 80 to 100 parts by weight of dispersant; Preferably, the coating comprises 15 to 20 parts by weight of a non-metal filler; 8 to 15 parts by weight of a metal filler; 20 to 28 parts by weight of a glaze; and 90 to 100 parts by weight of a dispersant.

3. The coating according to claim 1, characterized in that The non-metal filler includes at least one of bimodal activated alumina, unimodal activated alumina, plate-like corundum and mullite.

4. The coating according to claim 1, characterized in that The metal filler includes metal filler particles, and the particle size of the metal filler particles is 0.4 to 50 microns; Preferably, the metal filler particles include first metal filler particles, second metal filler particles and third metal filler particles, the particle size of the first metal filler particles is 38 to 50 microns; the particle size of the second metal filler particles is 4 to 6 microns; the particle size of the third metal filler particles is 0.4 to 0.6 microns; Preferably, the mass ratio of the first metal filler particles, the second metal filler particles and the third metal filler particles is (7-5):(2-3):(1-2).

5. The coating according to claim 1, characterized in that In terms of mass percentage, the glaze comprises: 5-15% beryllium oxide; 30-50% boron oxide; 40-60% silicon oxide; 2-10% aluminum oxide; 2-10% sodium oxide; and 0-5% zirconium oxide. Preferably, the glaze comprises, by mass percentage: 10-13% beryllium oxide; 30-40% boron oxide; 40-50% silicon oxide; 5-8% aluminum oxide; 5-8% sodium oxide; 0-3% zirconium oxide; Preferably, the dispersant includes at least one of isooctyl alcohol, isopropanol, polyacrylic acid and ethanol.

6. A coating, characterized in that Prepared by using the coating according to any one of claims 1 to 5, the coating comprises, by mass percentage: Boron oxide 10-18%; silicon oxide 15-30%; aluminum oxide 20-30%; beryllium oxide 5-15%; sodium oxide 2-10%; zirconium oxide 0-1%; and metal 10-30%; Wherein, the metal includes at least one of nickel, chromium, manganese and titanium.

7. The coating according to claim 6, characterized in that In terms of mass percentage, the coating comprises: 15-18% boron oxide; 25-30% silicon oxide; 28-30% aluminum oxide; 10-12% beryllium oxide; 2-5% sodium oxide; 0.5-1% zirconium oxide; and 10-20% metal; Preferably, the metal comprises nickel and chromium; Preferably, in the metal, the mass ratio of nickel to chromium is (2-4):

1.

8. A method for preparing a coating, characterized in that: include: Applying the coating according to any one of claims 1 to 5 on the surface of a substrate; The paint is subjected to heat treatment to obtain the coating.

9. The preparation method according to claim 8, characterized in that: Before the step of applying the coating on the surface of the substrate, the method further comprises: The coating is subjected to ball milling treatment and sieving in sequence; Preferably, the ball milling process is performed at a speed of 200 to 400 r / min and for a time of 1 to 3 h; Preferably, after ball milling, the coating is sieved through a 50-70 mesh sieve; Preferably, the coating is applied to the surface of the substrate by a spray gun.

10. The preparation method according to claim 8, characterized in that: After the step of coating the coating on the surface of the substrate and before the step of heat treating the coating, the method further comprises: The coating is pretreated, and the pretreatment includes: The first stage: placing the coating at 80-120°C for 1-3 hours; The second stage: placing the coating at 140-160° C. for 1-2 hours; The third stage: placing the coating at 170-190° C. for 0.4-0.6 h; Preferably, the heat treatment temperature is 900-1100°C and the time is 10-20 minutes; Preferably, the heat treatment is carried out in an air atmosphere; Preferably, the material of the substrate includes stainless steel.

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