Inorganic ultrahigh-temperature-resistant anti-corrosion anti-oxidation coating and preparation method thereof

Abstract

The invention discloses an inorganic ultrahigh-temperature-resistant anti-corrosion anti-oxidation coating and a preparation method thereof, and relates to the technical field of high-temperature-resistant protective paints.The inorganic ultrahigh-temperature-resistant anti-corrosion anti-oxidation coating is prepared through the steps that nanometer rare earth oxide, superfine refractory oxide with the melting point being 3000 DEG C or above, refractory carbide, refractory boride and the like are used as filler, and under the cooperation of multiple functional auxiliaries and deionized water, the inorganic ultrahigh-temperature-resistant anti-corrosion anti-oxidation coating is prepared; the inorganic ultrahigh-temperature-resistant anti-corrosion and anti-oxidation coating is prepared. The high temperature resistance of the coating is greater than or equal to 2500 DEG C, and the coating still has certain mechanical strength when the high temperature reaches 3000 DEG C. The coating of the paint is tested by 4-time sound velocity flame (namely 4-Mach velocity flame) for 5 minutes, the coating is intact and has no damage phenomena such as falling off, and a metal body is well protected.

Description

Technical Field

[0001] This invention relates to the field of high-temperature resistant protective coatings, and in particular to an inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating and its preparation method. Background Technology

[0002] The heat resistance of metallic materials has increased from 700°C to 750°C in the 1950s to nearly 2000°C today. Coating materials have evolved from simple aluminide coatings to today's ceramic thermal barrier coating technology. Application methods have also progressed from simple aluminizing and heated aluminizing techniques to today's low-pressure plasma spraying, physical or chemical vapor deposition, and other methods. Although the coatings prepared using these materials and processes exhibit excellent high-temperature resistance, oxidation resistance, and corrosion resistance, the high cost of raw materials and application equipment, coupled with the difficulty of large-scale application, makes them impractical for large-scale industrial use.

[0003] Currently, commonly used inorganic binders mainly fall into several categories, including silicates, phosphates, and sols. Alkali metal silicates are a typical representative of silicate binders. They have advantages such as low-temperature or even room-temperature film formation, low cost, and environmental friendliness. However, their disadvantages include easy aging, high brittleness, easy water absorption, poor acid resistance, poor coating density, and large curing shrinkage. Temperature-resistant coatings prepared with appropriate amounts of pigments and fillers have a coating temperature resistance below 1000°C, limiting their application in high-temperature fields.

[0004] Aluminum dihydrogen phosphate (ADPH) is the most commonly used phosphate binder. ADPH binders possess high temperature resistance (1600°C), ablation resistance, high plasticity, low curing shrinkage, and strong thermal shock resistance. They also exhibit high-temperature vitrification and refractoriness similar to refractory materials. ADPH binders exist in the form of cristobalite-type aluminum phosphate when the temperature rises between 1300°C and 1600°C. This crystal form is the most stable form of aluminum phosphate and has the highest refractoriness (1600°C). o C) Coatings prepared with appropriate amounts of high-temperature resistant pigments and fillers have a coating temperature resistance of approximately 1800°C. This is not suitable for applications requiring temperature resistance above 2000°C.

[0005] Commonly used sol-based binders include silica sol, alumina sol, titanium sol, and zirconium sol. When used as film-forming substances, these binders produce coatings with superior properties such as acid and alkali resistance, high temperature resistance, and wear resistance. However, due to their inherent properties, sol-based binders are difficult to form films on their own and need to be used in combination with other film-forming substances. After drying and curing, silica sol, titanium sol, alumina sol, and zirconium sol form silicon dioxide, titanium dioxide, aluminum oxide, and zirconium dioxide, respectively. These substances all have high melting points, especially zirconium dioxide, which has a melting point of 2680°C and a refractoriness of 2200°C. After zirconium dioxide film formation, the coating exhibits extremely high heat resistance.

[0006] Currently, there are numerous reports on coatings suitable for medium and low temperature applications, widely used in steam pipes, engine casings, and exhaust pipes, all demonstrating excellent temperature resistance and corrosion protection. However, high-temperature corrosion protection in high-temperature applications, such as various high-temperature kilns, sintering furnaces, high-temperature smelting, aircraft engines, aircraft propulsion systems, missiles, and rockets, remains extremely challenging. Therefore, developing ultra-high temperature coatings capable of withstanding temperatures above 2000°C has significant practical importance and broad market prospects.

[0007] Commonly used ultra-high temperature resistant protective coatings include refractory metals and alloys, refractory ceramic materials, refractory carbides, refractory borides and C / C composite materials, etc. However, the disadvantage of these coating technologies is that the preparation process is complex and it is difficult to apply them to large and complex parts.

[0008] To address the problems of existing inorganic high-temperature resistant protective coatings, this invention employs a composite inorganic high-temperature resistant binder (hereinafter referred to as composite inorganic high-temperature resistant binder) prepared by combining modified inorganic sol and aluminum dihydrogen phosphate as the base material, and nano-rare earth oxides, ultrafine refractory oxides with melting points above 3000℃, refractory carbides, and refractory borides as fillers. With the addition of various functional additives and deionized water, an inorganic high-temperature resistant anti-corrosion and anti-oxidation coating is prepared. This coating has a high temperature resistance of ≥2500℃, and even at temperatures reaching 3000℃, the coating still retains a certain mechanical strength. After being tested with a 4 times the speed of sound flame (i.e., a Mach 4 flame) for 5 minutes, the coating remained intact without peeling or other damage, providing excellent protection for the metal substrate. Summary of the Invention

[0009] The purpose of this invention is to provide an inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating and its preparation method, so as to solve the problems mentioned in the background art.

[0010] To achieve the above objectives, the present invention provides the following technical solution: an inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating and its preparation method, wherein the coating comprises liquid and powder; The liquid composition, by mass percentage, includes the following components: 60-80% composite inorganic ultra-high temperature resistant binder, 20-30% deionized water, 0.5-1% dispersant, 0.3-0.5% defoamer, 0.5-1% silane coupling agent, 0.3-0.5% leveling agent, 0.5-1% flash rust inhibitor, 0.5-1% bentonite, and 0.3-0.6% fumed SiO2. The powder composition, by mass percentage, includes the following components: 10-20 parts ultrafine boron carbide, 5-15 parts yttrium-stabilized zirconium oxide, 10-20 parts tantalum carbide, 10-20 parts hafnium carbide, 5-15 parts zirconium boride, 10-20 parts spherical tungsten powder, 10-20 parts spherical titanium carbide powder, and 10-15 parts cordierite powder.

[0011] Preferably, the composite inorganic ultra-high temperature resistant binder comprises the following components: silane-modified zirconium sol / aluminum sol, aluminum dihydrogen phosphate, inorganic pigment, borosilicate glass powder, composite rare earth oxide, deionized water, and additives.

[0012] Preferably, a method for preparing an inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating includes step one: preparing a composite inorganic ultra-high temperature resistant binder; Step 2: Prepare the liquid material; Step 3: Prepare the powder; Step 4: Prepare ultra-high temperature resistant anti-corrosion and anti-oxidation coating.

[0013] Preferably, the preparation method of the composite inorganic ultra-high temperature resistant binder is as follows: Silane-modified zirconium sol, silane-modified aluminum sol, and deionized water are added sequentially to the dispersion vessel under medium-low speed stirring. The mixture is stirred at medium speed until homogeneous, heated to 40-50℃, aluminum dihydrogen phosphate is added, and the mixture is kept at this temperature and stirred for 0.5 hours. The mixture is then cooled to room temperature. Dispersant, defoamer, nano-composite rare earth oxide, inorganic pigment, and borosilicate glass powder are added, and the mixture is dispersed at high speed for 30 minutes. The mixture is then ground to a fineness of less than 10 μm using a grinder to obtain the composite inorganic ultra-high temperature resistant binder.

[0014] Preferably, the method for preparing the liquid material is as follows: Weigh the liquid according to the formula, add the composite inorganic ultra-high temperature resistant binder to the mixing tank, and add deionized water, dispersant, defoamer, silane coupling agent, leveling agent, flash rust inhibitor, bentonite and fumed SiO2 in sequence under medium and low speed stirring. Stir for 30 minutes and finally package.

[0015] Preferred method for preparing powder: Weigh out the yttrium-stabilized zirconium oxide powder, tantalum carbide, hafnium carbide, and zirconium boride according to the powder formula, add them to the powder mixer, stir and mix for 20 minutes, then add ultrafine boron carbide powder, spherical tungsten powder, spherical titanium carbide powder, and cordierite powder, stir and mix for another 20 minutes, and finally discharge and package the powder.

[0016] Preferred formulation of ultra-high temperature resistant, corrosion-resistant, and oxidation-resistant coating: At the construction site, mix the liquid material and powder material at a ratio of 1:1 by mechanical stirring for 20 minutes until homogeneous. Filter through a 200-mesh sieve to obtain an ultra-high temperature resistant, corrosion-resistant, and oxidation-resistant coating.

[0017] Application method: Apply by spraying or brushing. The coating thickness is 0.5mm. Curing is done at room temperature. Drying time is 48-72 hours in sunny weather and one week in cloudy weather. After the coating is surface dry, bake at 200℃ for 1.5-2 hours.

[0018] The technical effects and advantages of this invention are as follows: This invention utilizes a high-temperature resistant binder (hereinafter referred to as composite inorganic high-temperature resistant binder) prepared by combining modified inorganic sol and aluminum dihydrogen phosphate as the base material, and nano-rare earth oxides, ultrafine refractory oxides with melting points above 3000℃, refractory carbides, and refractory borides as fillers, in combination with various functional additives and deionized water to prepare an inorganic high-temperature resistant anti-corrosion and anti-oxidation coating. This coating has a high temperature resistance of ≥2500℃, and even at temperatures reaching 3000℃, the coating still retains a certain mechanical strength. After being tested with a 4 times the speed of sound flame (i.e., a Mach 4 flame) for 5 minutes, the coating remained intact, without peeling or other damage, and the metal substrate was well protected.

[0019] Features of inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coatings: (1) Excellent coating performance: After the coating is fully cured, the coating has the characteristics of high melting point, high hardness and high chemical stability, corrosion resistance, high temperature oxidation resistance and impact resistance; at high temperature, various materials form solid solution, produce addition effect and synergistic effect, resulting in good mechanical properties, and the coating can maintain certain mechanical properties at 3000℃.

[0020] (2) It has a certain self-repairing property at high temperature: The ultra-high temperature resistant anti-corrosion and anti-oxidation coating uses a certain amount of rare earth oxides that have been treated at high temperature. Under high temperature conditions, the coating has the ability to self-heal and resynthesize under the synergistic effect of the materials.

[0021] (3) Good heat transfer performance of coating: The coating is made of high temperature resistant chemical materials with high thermal conductivity, good heat transfer, good ductility and high thermal shock resistance.

[0022] (4) The coating has two-way properties: the density of the coating can prevent oxygen from penetrating into the metal substrate at high temperature, prevent the metal from oxidizing at high temperature, and prevent oxygen from diffusing into the substrate; the coating can also prevent the metal elements in the substrate from diffusing outward at high temperature.

[0023] (5) Non-volatile coating: The coating is a water-based inorganic coating. No volatile gas is generated at high or low temperatures, which also avoids self-oxidation and degradation at high temperatures and prevents ablation and oxidation in high-speed and high-temperature airflow. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] This invention provides an inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating and its preparation method, including construction and application: Used for the protection of carbon steel, high-strength alloys, stainless steel components, high-temperature alloys, and other metal components in ultra-high temperature environments of 2000-3000℃. Applied to solid-fuel rocket engines, missile casings, supersonic aircraft, fuel nozzles, tips, nose caps, blades, and ultra-high temperature equipment, providing high-temperature resistance and corrosion protection for metals.

[0026] Construction method: Sandblasting treatment of the substrate surface; Spray or brush this coating, applying one coat to a thickness of 80-200µm. After surface drying for 15 minutes, cure at 200℃ for 1.5 hours. A second (cured) and a third (cured) coat can be applied until the required coating thickness is achieved (generally 0.25-0.5mm).

[0027] Main performance: Composition: Two-component (liquid and powder) Appearance: Blackish-green; Density: 2.2 g / cm³; Surface drying time / min15 Drying / 200℃ for 1-2 hours The coating remained intact and without cracks during the bending test. Complete lubricating oil resistant coating Heat resistance (2500℃) / h100 Salt spray resistance / h1000 Methanol resistance test: coating intact High temperature resistance limit: 3000℃ Linear expansion coefficient: 16×10⁻⁶ / ℃ Pressure resistance: ≤80MPa Thermal vibration resistance: No change after 100 cycles.

[0028] The composition of a two-component inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating: it consists of liquid and powder components.

[0029] The composition of the liquid material, preferably by mass percentage, includes the following components: 65-78% composite inorganic ultra-high temperature resistant binder, 15-25% deionized water, 0.5-1% dispersant, 0.3-0.5% defoamer, 0.5-1% silane coupling agent, 0.3-0.5% leveling agent, 0.5-1% flash rust inhibitor, 0.5-1% bentonite, and 0.3-0.6% fumed SiO2.

[0030] The powder composition, by mass percentage, includes the following components: 10-15% ultrafine boron carbide, 6-12% yttrium-stabilized zirconium oxide, 10-20% tantalum carbide, 10-15% hafnium carbide, 6-14% zirconium boride, 10-20% spherical tungsten powder, 10-15% spherical titanium carbide powder, and 10-15% cordierite powder.

[0031] To address the aforementioned technical problems, this invention also provides a method for preparing an inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating, comprising the following four steps: Step 1: Composition and preparation method of composite inorganic ultra-high temperature resistant adhesive: In step one, the composite inorganic ultra-high temperature resistant binder comprises the following components: silane-modified zirconium sol / aluminum sol, aluminum dihydrogen phosphate, inorganic pigments, borosilicate glass powder, composite rare earth oxides, and additives. The preparation method of the composite inorganic ultra-high temperature resistant binder in step one is as follows: In a dispersion vessel under medium-low speed stirring, silane-modified zirconium sol, silane-modified aluminum sol, and deionized water are added sequentially and stirred at medium speed until uniformly mixed. The temperature is raised to 40-50℃, aluminum dihydrogen phosphate is added, and the mixture is kept at this temperature and stirred for 0.5 hours. The mixture is then cooled to room temperature. Dispersant, defoamer, nano-composite rare earth oxides, inorganic pigments, and borosilicate glass powder are added, and the mixture is dispersed at high speed for 30 minutes. Finally, the mixture is ground to a fineness of less than 10 μm to obtain the composite inorganic ultra-high temperature resistant binder.

[0032] The composite inorganic ultra-high temperature resistant binder has a solid content of 43% and a refractoriness of 2000℃.

[0033] Step 2, Preparation method of liquid material: Weigh the liquid according to the formula, add the composite inorganic ultra-high temperature resistant binder to the mixing tank, and add deionized water, dispersant, defoamer, silane coupling agent, leveling agent, flash rust inhibitor, bentonite and fumed SiO2 in sequence under medium and low speed stirring. Stir for 30 minutes and then package.

[0034] Step 3, Preparation method of powder: Weigh the yttrium-stabilized zirconium oxide powder, tantalum carbide, hafnium carbide, and zirconium boride according to the powder formula, add them to the powder mixer, stir and mix for 20 minutes, then add ultrafine boron carbide powder, spherical tungsten powder, spherical titanium carbide powder, and cordierite powder, stir and mix for 20 minutes, then discharge and package.

[0035] Step 4, Preparation of Inorganic Ultra-High Temperature Resistant Anti-corrosion and Anti-oxidation Coating: At the construction site, the liquid and powder are mixed mechanically for 20 minutes until homogeneous, and then filtered through a 200-mesh sieve to obtain an inorganic, ultra-high temperature resistant, anti-corrosion, and anti-oxidation coating.

[0036] Application Method: Apply by spraying or brushing, with a coating thickness of 0.5mm. It can cure at room temperature, drying in 48-72 hours on sunny days and one week on cloudy days; oven curing is preferred: after the coating is surface dry, bake at 200℃ for 1.5-2 hours. In this embodiment, the composite inorganic ultra-high temperature resistant adhesive is a high-temperature resistant adhesive composed of silane-modified zirconium sol, silane-modified aluminum sol, aluminum dihydrogen phosphate, inorganic pigments, borosilicate glass powder, composite rare earth oxides, deionized water, and additives. This adhesive can form a film by air drying at room temperature or by baking at 200℃, and its temperature resistance exceeds 2000℃. The adhesive contains a large number of OH active groups, which react rapidly with the active components in the filler and the active surface of the steel to generate a three-dimensional inorganic polymer, bonding the coating to the steel substrate to form a heat-resistant and corrosion-resistant coating with electrochemical protection and physical shielding, particularly suitable for long-term protection of steel structures operating in high-temperature and corrosive environments. It has the advantages of being green and environmentally friendly, resistant to ultra-high temperature, good corrosion resistance, strong resistance to high temperature oxidation, aging resistance, radiation resistance, salt spray resistance, organic solvent resistance, strong adhesion between the coating and the substrate, high coating hardness, scratch resistance, and impact resistance.

[0037] In the embodiments, the silane coupling agent-modified nano-zirconium sol in the composite inorganic ultra-high temperature resistant binder component undergoes grafting between the functional groups of the silane coupling agent KH-560 and the -OH groups on the surface of the nano-zirconium sol particles, generating an organic-inorganic hybrid network structure. This improves the film-forming properties, toughness, hydrophobicity, heat resistance, and corrosion resistance of the zirconium sol. The modified nano-zirconium sol exhibits high dispersibility, homogenization, and stabilization; it also possesses higher activity and ease of addition. Nano-zirconium oxide possesses unique optical properties, with a reflectivity of over 85% for ultraviolet long-wave, mid-wave, and infrared rays. After the coating dries, the nanoparticles tightly fill the gaps between the coating layers, forming a complete air insulation layer. Furthermore, its low thermal conductivity forces a longer heat transfer time within the coating, resulting in a low thermal conductivity and thus improving the coating's thermal insulation performance. Meanwhile, the severely under-coordinated and oxygen-deficient surface of nano-zirconia exhibits extremely high reactivity, readily forming bonds with oxygen on the surfaces of other materials in the coating, thereby improving the density and physicochemical properties of the coating. Nano-zirconia possesses a spatial network structure with numerous unsaturated residual bonds and hydroxyl groups in various states on its surface, enabling it to exhibit good affinity with the coating system, thus improving the suspension stability of the coating.

[0038] In this embodiment, the composite inorganic ultra-high temperature resistant binder component contains a silane coupling agent-modified aluminum sol. Aluminum sol is a colloidal solution of positively charged, feather-like alumina particles dispersed in water, possessing adhesiveness, thixotropy, water solubility and reversibility, suspension, adsorption, and stability, as well as film-forming properties and wear resistance. By grafting the functional groups of the silane coupling agent KH-560 onto the -OH groups on the surface of the nano-aluminum sol particles, an organic-inorganic hybrid network structure is generated, improving the film-forming properties, toughness, hydrophobicity, heat resistance, corrosion resistance, hardness, and wear resistance of the aluminum sol.

[0039] In the embodiments, the aluminum dihydrogen phosphate component of the composite inorganic ultra-high temperature resistant binder has high temperature resistance (1600°C), ablation resistance, high plasticity, low curing shrinkage, high thermal shock resistance, and high-temperature vitrification and refractoriness similar to refractory materials. The aluminum dihydrogen phosphate binder exists in the form of cristobalite-type aluminum phosphate when the temperature rises to between 1300°C and 1600°C. This crystal form is the most stable form of aluminum phosphate salt and has the highest refractoriness (1600°C). When aluminum dihydrogen phosphate is combined with zirconium sol and aluminum sol in an appropriate proportion, the binder can achieve a refractoriness of over 2000°C. This effect is achieved because aluminum dihydrogen phosphate itself can withstand a high temperature of 1600°C, zirconium oxide has a melting point of 2680°C and a refractoriness of 2200°C, and in this system, zirconium dioxide is introduced in the form of zirconium sol. When aluminum dihydrogen phosphate and zirconium sol are compounded in a certain proportion, the Zr-OH groups on the surface of the zirconium sol particles can combine with aluminum phosphate salts to form Zr-OP bonds at high temperatures, thereby improving the temperature resistance of the binder. Aluminum oxide is introduced in the form of aluminum sol. Aluminum oxide has a melting point of 2054℃ and a boiling point of 2980℃. When aluminum dihydrogen phosphate and aluminum sol are compounded in a certain proportion, the Al-OH groups on the surface of the aluminum sol particles can combine with aluminum phosphate salts to form Za-OP bonds at high temperatures, thereby improving the temperature resistance of the binder.

[0040] In the embodiments, the inorganic pigment in the composite inorganic ultra-high temperature resistant binder component is one of chromium trioxide, iron oxide red, iron chromium black, and cobalt blue.

[0041] In this embodiment, the borosilicate glass powder in the composite inorganic ultra-high temperature resistant binder component possesses excellent high-temperature stability, preventing the refractory material from bending and cracking at high temperatures. Adding an appropriate amount of borosilicate glass powder can enhance the thermal shock resistance of the refractory material and improve its crack resistance under thermal stress. Borosilicate glass powder also exhibits good corrosion resistance; its addition to the refractory material can effectively improve its corrosion resistance and extend its service life.

[0042] In this embodiment, the composite rare earth oxide in the composite inorganic ultra-high temperature resistant binder component is a rare earth oxide composed of nano-cerium oxide, nano-lanthanum oxide, nano-ruthenium oxide, and nano-dysprosium oxide in a certain proportion. It features well-formed crystals, high specific gravity, and small grain size, making it a multifunctional rare earth element that acts as a highly efficient catalyst, ultraviolet absorber, heat stabilizer, anti-aging agent, and lubricant. Adding an appropriate amount of nano-rare earth oxides to high-temperature resistant coatings can significantly improve the strength and toughness of ceramic coatings and reduce sintering temperature. Rare earth oxides can form solid solutions with other fillers, generating crystal defects, activating the crystal lattice, and promoting the ceramic sintering of the coating; they can improve the microstructure of the ceramic coating, increase its density, and improve its mechanical properties; they can also prevent the formation of pores in the coating, inhibit crystal growth, and improve the density and thermal stability of the coating.

[0043] In this embodiment, the yttrium-stabilized zirconium oxide powder in the powder component contains pure zirconium oxide, which exists as a monoclinic crystal at room temperature. It transforms into a tetragonal crystal at approximately 1173°C, a cubic crystal at 2370°C, and a liquid phase at 2690°C. Zirconia does not exist in a cubic crystal phase (fluorite crystal structure) at room temperature, but by adding other oxides, the temperature range in which zirconium dioxide exists stably in a cubic crystal phase can be significantly increased. Zirconia doped with phase stabilizers is called stabilized zirconium oxide. This invention uses ultrafine yttrium-stabilized zirconium oxide doped with rare earth yttrium trioxide, which exists in a cubic crystal phase with a melting point of 2690°C and a refractoriness of 2200°C. Adding an appropriate amount of ultrafine yttrium-stabilized zirconium oxide as a filler to ultra-high temperature resistant coatings can significantly improve the high-temperature resistance of the coatings. Sub-nanometer yttrium-stabilized zirconia particles are permeable and can penetrate into the substrate. After high-temperature sintering, the coating forms a glazed ceramic polymer that is hard, wear-resistant, and has strong adhesion. It is firmly bonded to the substrate and is not affected by the thermal expansion and contraction of the substrate. It can greatly reduce surface energy, making the coating self-cleaning and resistant to contamination. It also makes the coating dense, reducing the intrusion of corrosive media and improving service life.

[0044] In the embodiments, tantalum carbide, a transition metal carbide, is a black or dark brown powder with a cubic crystal system, a relative density of 13.9, a melting point of 3880℃, and a boiling point of 4780℃. It has a Mohs hardness of 9-10, a thermal conductivity of 22 W / (m·K), and a coefficient of thermal expansion of 6.29 × 10⁻⁶. -6 K-1 is a hard and chemically stable compound with excellent physical and chemical properties, including high hardness, high melting point, good electrical conductivity, thermal shock resistance, chemical corrosion resistance, high oxidation resistance, and certain catalytic properties. In the field of ultra-high temperature coatings, such as for jet engine turbine blades and rocket nozzle coatings, it can significantly improve their ablation resistance and extend their service life.

[0045] In this embodiment, hafnium carbide, one of the powder components, has a melting point of 3890℃ and high surface activity, making it widely used in powder metallurgy. Hafnium carbide possesses a high elastic modulus, good electrical and thermal conductivity, a very low coefficient of thermal expansion, and good impact resistance. Ultrafine hafnium carbide can form solid solutions with many compounds, such as zirconium carbide and tantalum carbide. It can be used in the throat material field of rocket nozzles and is also an important metal-ceramic material.

[0046] In the embodiments, the zirconium boride in the powder component is a typical ultra-high temperature ceramic with a high melting point (3250℃), high hardness (22GPa), and high thermal conductivity. High and the coefficient of thermal expansion (5.9×10) -6 Zirconium diboride (K-1) is characterized by its low density. Industrial production primarily utilizes zirconium diboride, which is a hexagonal crystal, gray crystal or powder with a relative density of 5.8 and a melting point of 30-40℃. It exhibits high temperature resistance, with high strength at both room and high temperatures. It also demonstrates good thermal shock resistance, low electrical resistance, and oxidation resistance at high temperatures. Furthermore, zirconium diboride possesses excellent neutron control capabilities.

[0047] In the embodiments, the ultrafine boron carbide in the powder component has a small particle size, uniform distribution, large specific surface area, high surface activity, and low bulk density. It is a synthetically produced superhard material with a hardness second only to diamond, a Mohs hardness of 9.46, a melting point of 2250℃, and stable physical and chemical properties. It has a high neutron absorption efficiency and is therefore widely used in the nuclear and defense industries. The high-temperature resistant coating prepared by adding nano-boron carbide powder significantly improves the mechanical properties and refractoriness of the coating film.

[0048] In this embodiment, the spherical tungsten powder in the powder component is a fine, grayish-black powder with a melting point of approximately 3400°C, a boiling point of approximately 5555°C, a density comparable to gold (19.3 g / cm³), a hardness similar to diamond, strong reducing properties, a purity of up to 99.9%, a loose density of 11.6 g / cm³, and a tapped density of 12.5 g / cm³. Under normal circumstances, the higher the degree of spheroidization, the smaller the particle size, and the narrower the particle size distribution, the better the powder's flowability and the greater its loose density. Adding an appropriate amount of spherical tungsten powder as a filler to ultra-high temperature resistant coatings can significantly improve the coating's high-temperature resistance.

[0049] In the embodiments, the spherical titanium carbide powder and near-spherical black fluffy powder in the powder composition have a melting point of 3200℃, are resistant to high temperatures and oxidation, and are excellent refractory and wear-resistant materials with high hardness, corrosion resistance, and good thermal stability. They are widely used in cemented carbide and wear-resistant superhard materials. Adding an appropriate amount of spherical titanium carbide powder as a filler to ultra-high temperature resistant coatings can significantly improve the coating's high temperature resistance, wear resistance, and corrosion resistance.

[0050] In this embodiment, the cordierite powder in the powder component is a silicate mineral powder with characteristics such as low thermal expansion coefficient, good refractoriness, good thermal stability, high elastic modulus, and low dielectric constant. Adding an appropriate amount of cordierite powder as a filler to ultra-high temperature resistant coatings can significantly improve the thermal shock resistance of the coatings.

[0051] In the embodiments, the dispersant is BYK-190 from BYK Corporation. In the embodiments, the defoamer is BYK-019 from BYK Corporation. In the embodiments, the silane coupling agent is domestically produced KH-560. In the embodiments, the leveling agent is BYK-341 from BYK Corporation. In the embodiments, the flash rust inhibitor is FA179 from Hemings Deqian. In the embodiments, the bentonite is BENTONE.EW from Hemings. In the embodiments, the fumed SiO2 is A200 from Degussa. Specific Implementation

[0052] Example 1

[0053] Embodiment 1 of the present invention provides the composition and preparation method of a two-component inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating.

[0054] Embodiment 1 of the present invention provides a two-component inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating: it consists of liquid and powder components.

[0055] The composition of the liquid material, by mass percentage, includes the following components: composite inorganic ultra-high temperature resistant binder 66, deionized water 30, dispersant 0.5, defoamer 0.3, silane coupling agent 0.8, leveling agent 0.4, anti-flash rust agent 1, bentonite 0.5, and fumed SiO2 0.5.

[0056] The powder composition, by mass percentage, includes the following components: 8% ultrafine boron carbide, 12% yttrium-stabilized zirconium oxide, 20% tantalum carbide, 15% hafnium carbide, 10% zirconium boride, 15% spherical tungsten powder, 10% spherical titanium carbide powder, and 10% cordierite powder.

[0057] To address the aforementioned technical problems, this invention also provides a method for preparing an inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating, comprising the following four steps: Step 1: Composition and preparation method of composite inorganic ultra-high temperature resistant adhesive: In step one, the composite inorganic ultra-high temperature resistant binder comprises the following components: silane-modified zirconium sol / aluminum sol, aluminum dihydrogen phosphate, inorganic pigments, borosilicate glass powder, composite rare earth oxides, deionized water, and additives. The preparation method of the composite inorganic ultra-high temperature resistant binder in step one is as follows: In a dispersion vessel under medium-low speed stirring, silane-modified zirconium sol, silane-modified aluminum sol, and deionized water are added sequentially and stirred at medium speed until uniformly mixed. The temperature is raised to 40-50℃, aluminum dihydrogen phosphate is added, and the mixture is kept at this temperature and stirred for 0.5 hours. The mixture is then cooled to room temperature. Dispersant, defoamer, nano-composite rare earth oxides, inorganic pigments, and borosilicate glass powder are added, and the mixture is dispersed at high speed for 30 minutes. Finally, the mixture is ground to a fineness of less than 10 μm using a grinder to obtain the composite inorganic ultra-high temperature resistant binder.

[0058] The composite inorganic ultra-high temperature resistant binder has a solid content of 43% and a refractoriness of 2000℃.

[0059] Step 2, Preparation method of liquid material: Weigh the liquid according to the formula, add the composite inorganic ultra-high temperature resistant binder to the mixing tank, and add deionized water, dispersant, defoamer, silane coupling agent, leveling agent, flash rust inhibitor, bentonite and fumed SiO2 in sequence under medium and low speed stirring. Stir for 30 minutes and then package.

[0060] Step 3, Preparation method of powder: Weigh the yttrium-stabilized zirconium oxide powder, tantalum carbide, hafnium carbide, and zirconium boride according to the powder formula, add them to the powder mixer, stir and mix for 20 minutes, then add ultrafine boron carbide powder, spherical tungsten powder, spherical titanium carbide powder, and cordierite powder, stir and mix for 20 minutes, then discharge and package.

[0061] Step 4, Preparation of ultra-high temperature resistant anti-corrosion and anti-oxidation coating: At the construction site, mix the liquid and powder materials at a ratio of 1:1 (by mass) mechanically for 20 minutes until homogeneous, then filter through a 200-mesh sieve to obtain an ultra-high temperature resistant, corrosion-resistant, and oxidation-resistant coating.

[0062] Application methods: Apply by spraying or brushing, with a coating thickness of 0.5mm. It can cure at room temperature, drying in 48-72 hours on sunny days and one week on cloudy days; oven curing is preferred: after the coating is surface dry, bake at 200℃ for 1.5-2 hours.

[0063] The coating has a high temperature resistance of ≥2500℃ and a short-term high temperature resistance of up to 2900℃. After being tested with a flame at 4 times the speed of sound (Mach 4) for 5 minutes, the coating remained intact without any peeling or damage, providing excellent protection for the metal body.

[0064] Example 2

[0065] Example 2 of the present invention provides the composition and preparation method of a two-component inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating.

[0066] Embodiment 2 of the present invention provides a two-component inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating: it consists of liquid and powder components.

[0067] The composition of the liquid material, by mass percentage, includes the following components: 68% composite inorganic ultra-high temperature resistant binder, 28% deionized water, 0.6% dispersant, 0.4% defoamer, 0.6% silane coupling agent, 0.5% leveling agent, 0.8% anti-flash rust agent, 0.6% bentonite, and 0.6% fumed SiO2.

[0068] The powder composition, by mass percentage, includes the following components: 10% ultrafine boron carbide, 10% yttrium-stabilized zirconium oxide, 15% tantalum carbide, 12% hafnium carbide, 14% zirconium boride, 20% spherical tungsten powder, 11% spherical titanium carbide powder, and 8% cordierite powder.

[0069] To solve the above-mentioned technical problems, the present invention also provides a method for preparing an inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating, which includes the following four steps: the same as in Example 1, and will not be repeated here.

[0070] The coating has a high temperature resistance of ≥2500℃ and a short-term high temperature resistance of up to 3000℃. After being tested with a flame at 4 times the speed of sound (Mach 4) for 5 minutes, the coating remained intact without any peeling or damage, providing excellent protection for the metal body.

[0071] Example 3

[0072] Example 3 of the present invention provides the composition and preparation method of a two-component inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating.

[0073] Embodiment 3 of the present invention provides a two-component inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating: it consists of liquid and powder components.

[0074] The composition of the liquid material, by mass percentage, includes the following components: 70% composite inorganic ultra-high temperature resistant binder, 26% deionized water, 0.7% dispersant, 0.5% defoamer, 0.7% silane coupling agent, 0.4% leveling agent, 0.7% flash rust inhibitor, 0.7% bentonite, and 0.3% fumed SiO2.

[0075] The powder composition, by mass percentage, includes the following components: 12% ultrafine boron carbide, 8% yttrium stabilized zirconium oxide, 18% tantalum carbide, 10% hafnium carbide, 12% zirconium boride, 19% spherical tungsten powder, 15% spherical titanium carbide powder, and 10% cordierite powder.

[0076] To solve the above-mentioned technical problems, the present invention also provides a method for preparing an inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating, which includes the following four steps: the same as in Example 1, and will not be repeated here.

[0077] The coating has a high temperature resistance of ≥2500℃ and a short-term high temperature resistance of up to 3000℃. After being tested with a flame at 4 times the speed of sound (Mach 4) for 5 minutes, the coating remained intact without any peeling or damage, providing excellent protection for the metal body.

[0078] Example 4

[0079] Example 4 of this invention provides the composition and preparation method of a two-component inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating.

[0080] Embodiment 4 of the present invention provides a two-component inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating: it consists of liquid and powder components.

[0081] The composition of the liquid material, by mass percentage, includes the following components: 72% composite inorganic ultra-high temperature resistant binder, 24% deionized water, 0.8% dispersant, 0.6% defoamer, 0.4% silane coupling agent, 0.5% leveling agent, 0.6% anti-flash rust agent, 0.8% bentonite, and 0.5% fumed SiO2.

[0082] The powder composition, by mass percentage, includes the following components: 13% ultrafine boron carbide, 7% yttrium stabilized zirconium oxide, 16% tantalum carbide, 14% hafnium carbide, 13% zirconium boride, 10% spherical tungsten powder, 14% spherical titanium carbide powder, and 13% cordierite powder.

[0083] To solve the above-mentioned technical problems, the present invention also provides a method for preparing an inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating, which includes the following four steps: the same as in Example 1, and will not be repeated here.

[0084] The coating has a high temperature resistance of ≥2500℃ and a short-term high temperature resistance of up to 3000℃. After being tested with a flame at 4 times the speed of sound (Mach 4) for 5 minutes, the coating remained intact without any peeling or damage, providing excellent protection for the metal body.

[0085] Example 5

[0086] Example 5 of the present invention provides the composition and preparation method of a two-component inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating.

[0087] Embodiment 5 of the present invention provides a two-component inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating: it consists of liquid and powder components.

[0088] The composition of the liquid material, by mass percentage, includes the following components: 75% composite inorganic ultra-high temperature resistant binder, 21% deionized water, 1% dispersant, 0.5% defoamer, 0.5% silane coupling agent, 0.3% leveling agent, 0.5% anti-flash rust agent, 1% bentonite, and 0.4% fumed SiO2.

[0089] The powder composition, by mass percentage, includes the following components: 15% ultrafine boron carbide, 6% yttrium-stabilized zirconium oxide, 17% tantalum carbide, 13% hafnium carbide, 15% zirconium boride, 10% spherical tungsten powder, 12% spherical titanium carbide powder, and 12% cordierite powder.

[0090] To solve the above-mentioned technical problems, the present invention also provides a method for preparing an inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating, which includes the following four steps: the same as in Example 1, and will not be repeated here.

[0091] The coating has a high temperature resistance of ≥2500℃ and a short-term high temperature resistance of up to 3000℃. After being tested with a flame at 4 times the speed of sound (Mach 4) for 5 minutes, the coating remained intact without any peeling or damage, providing excellent protection for the metal body.

[0092] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An inorganic, ultra-high temperature resistant, corrosion-resistant, and oxidation-resistant coating, characterized in that: The coating includes liquid and powder components; The liquid composition, by mass percentage, includes the following components: 60-80% composite inorganic ultra-high temperature resistant binder, 20-30% deionized water, 0.5-1% dispersant, 0.3-0.5% defoamer, 0.5-1% silane coupling agent, 0.3-0.5% leveling agent, 0.5-1% flash rust inhibitor, 0.5-1% bentonite, and 0.3-0.6% fumed SiO2. The powder composition, by mass percentage, includes the following components: 10-20 parts ultrafine boron carbide, 5-15 parts yttrium-stabilized zirconium oxide, 10-20 parts tantalum carbide, 10-20 parts hafnium carbide, 5-15 parts zirconium boride, 10-20 parts spherical tungsten powder, 10-20 parts spherical titanium carbide powder, and 10-15 parts cordierite powder.

2. The inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating according to claim 1, characterized in that: The composite inorganic ultra-high temperature resistant binder comprises the following components: silane-modified zirconium sol / aluminum sol, aluminum dihydrogen phosphate, inorganic pigments, borosilicate glass powder, composite rare earth oxides, deionized water, and additives.

3. The preparation method of the inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating according to claim 2, characterized in that: Step 1: Preparation of composite inorganic ultra-high temperature resistant adhesive; Step 2: Prepare the liquid material; Step 3: Prepare the powder; Step 4: Prepare ultra-high temperature resistant anti-corrosion and anti-oxidation coating.

4. The preparation method of the inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating according to claim 3, characterized in that: The preparation method of the composite inorganic ultra-high temperature resistant adhesive is as follows: under medium-low speed stirring, silane-modified zirconium sol, silane-modified aluminum sol and deionized water are added to the dispersion vessel in sequence, stirred at medium speed and mixed evenly, heated to 40-50℃, aluminum dihydrogen phosphate is added, and the reaction is carried out by stirring for 0.5h and then cooled to room temperature.

5. The preparation method of the inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating according to claim 4, characterized in that: After cooling to room temperature, dispersant, defoamer, nano-composite rare earth oxide, inorganic pigment, and borosilicate glass powder are added, and the mixture is dispersed at high speed for 30 minutes. Then, it is ground to a fineness of less than 10 μm to obtain a composite inorganic ultra-high temperature resistant binder.

6. The preparation method of the inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating according to claim 3, characterized in that: The preparation method of the liquid material: Weigh the liquid according to the formula, add the composite inorganic ultra-high temperature resistant binder into the mixing tank, and add deionized water, dispersant, defoamer, silane coupling agent, leveling agent, flash rust inhibitor, bentonite and fumed SiO2 in sequence under medium and low speed stirring. Stir for 30 minutes and finally package.

7. The preparation method of the inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating according to claim 3, characterized in that: Preparation method of powder: Weigh out the yttrium-stabilized zirconium oxide powder, tantalum carbide, hafnium carbide, and zirconium boride according to the powder formula, add them to the powder mixer, stir and mix for 20 minutes, then add ultrafine boron carbide powder, spherical tungsten powder, spherical titanium carbide powder, and cordierite powder, stir and mix for another 20 minutes, and finally discharge and package the powder.

8. The preparation method of the inorganic ultra-high temperature resistant anti-corrosion and anti-oxidation coating according to claim 3, characterized in that: Formulation of ultra-high temperature resistant, corrosion-resistant, and oxidation-resistant coatings: At the construction site, mix the liquid material and powder material at a ratio of 1:1 by mechanical stirring for 20 minutes until homogeneous. Filter through a 200-mesh sieve to obtain an ultra-high temperature resistant, corrosion-resistant, and oxidation-resistant coating. Application method: Apply by spraying or brushing. The coating thickness is 0.5mm. Curing is done at room temperature. Drying time is 48-72 hours in sunny weather and one week in cloudy weather. After the coating is surface dry, bake at 200℃ for 1.5-2 hours.