Method for producing high temperature resistant coatings and structures

Abstract

The invention relates to methods for producing high temperature resistant coatings and structures. In particular, the invention discloses a method for forming a ceramic-based material, the method comprising: depositing a ceramic precursor composition on a surface of a substrate to form a deposited layer of the ceramic precursor composition, the ceramic precursor composition comprising nanoparticles and a carrier fluid, the nanoparticles having at least one dimension less than 100 nm and an aspect ratio of 1.5 or greater; and sintering the deposited layer of the ceramic precursor composition at a sintering temperature to form the ceramic-based material.

Description

Technical Field

[0001] This invention relates to the field of high-temperature coating manufacturing, and particularly to a method for manufacturing ceramic-based materials using a ceramic precursor composition containing nanoparticles, and the ceramic-based materials prepared therefrom. Background Technology

[0002] Ceramic materials are widely used in transportation industries, including aerospace, due to their high-temperature resistance and mechanical strength, corrosion resistance in oxidizing and reducing environments, lightweight nature, and low coefficient of thermal expansion. Components for aircraft and space vehicles requiring these properties include engine parts, brakes, insulating tiles, leading edges and cones, and even components for the interior of cabins. Ceramic-matrix composites, which combine ceramics with other materials such as carbon fibers, are also important because they combine resistance to temperatures up to 2910°F (1600°C) with fracture toughness, a combination that is quite difficult to achieve with single-component ceramics. Metal carbides are particularly important due to their lightweight and multifunctional properties.

[0003] However, processing ceramic composites into coatings or other aerospace components is challenging. The initial stages typically involve chemical vapor deposition (CVD), precursor pyrolysis, reactive melt infiltration, slurry infiltration, and hot pressing. Annealing requires high-temperature treatment of the precursor at temperatures up to 5430°F (3000°C) to sinter the constituent particles and fibers. Both the bulk component and the coating are susceptible to deformation during this process, and the assembly may also undergo undesirable phase transformations. Summary of the Invention

[0004] This invention provides a method for forming ceramic-based materials, including coatings, three-dimensional (3D) objects, and ceramic composites thereof, which possess desired properties such as high-temperature resistance and increased toughness. However, the method of this invention utilizes significantly lower temperatures compared to existing methods. This avoids problems such as warping and delamination and allows for the use of a wider variety of substrates (substrates, bases, substrates) in the manufacture of ceramic-based materials.

[0005] In Embodiment 1, a method for forming a ceramic matrix material includes: depositing a ceramic precursor composition comprising nanoparticles and a carrier fluid on the surface of a substrate to form a deposited layer (as-deposited layer) of the ceramic precursor composition, wherein the nanoparticles have at least one size less than 100 nm and an aspect ratio of 1.5 or greater; and sintering the deposited layer of the ceramic precursor composition at a sintering temperature to form a ceramic matrix material.

[0006] Embodiment 2 is the method according to Embodiment 1, wherein the nanoparticles have a size in the range of at least 1 nm to 100 nm.

[0007] Implementation method 3 is based on the method of implementation method 2, wherein the size of each nanoparticle is less than 100 nm.

[0008] Embodiment 4 is a method according to any one of Embodiments 1-3, wherein the nanoparticles are nanosheets.

[0009] Embodiment 5 is a method according to any one of Embodiments 1-4, wherein the nanoparticles comprise a ceramic compound.

[0010] Embodiment 6 is a method according to any one of Embodiments 1-5, wherein the nanoparticles comprise WO3, cerium dioxide, hafnium dioxide, titanium dioxide, or a combination thereof.

[0011] Embodiment 7 is a method according to any one of Embodiments 1-6, wherein the nanoparticles contain a compound that forms a ceramic compound during sintering.

[0012] Embodiment 8 is a method according to any one of Embodiments 1-7, wherein the nanoparticles are single crystals.

[0013] Embodiment 9 is a method according to any one of Embodiments 1-8, wherein the carrier fluid is water, an organic solvent, or an ionic liquid.

[0014] Embodiment 10 is a method according to any one of Embodiments 1-8, wherein the carrier fluid is an inorganic ionic liquid.

[0015] Embodiment 11 is a method according to any one of Embodiments 1-8, wherein the carrier fluid is a polymer or a precursor thereof.

[0016] Embodiment 12 is the method according to Embodiment 11, wherein the polymer is an inorganic polymer or a precursor thereof.

[0017] Embodiment 13 is a method according to any one of Embodiments 1-12, wherein the deposition is carried out at a temperature of less than 100°C.

[0018] Embodiment 14 is the method according to Embodiment 13, wherein the deposition is performed at room temperature or lower.

[0019] Embodiment 15 is a method according to any one of Embodiments 1-14, wherein deposition is performed using layer-by-layer deposition to provide a deposited multilayer structure comprising a deposited layer of ceramic precursor composition.

[0020] Embodiment 16 is a method according to any one of Embodiments 1-15, wherein the sintering temperature is lower than the sintering temperature used under the following conditions: the particles used have the same composition as nanoparticles, but have a diameter of about 5 μm to about 100 μm.

[0021] Embodiment 17 is a method according to any one of Embodiments 1-16, wherein the sintering temperature is 1000°C or lower.

[0022] Embodiment 18 is a method according to any one of Embodiments 1-17, wherein the substrate is a porous carbonized substrate.

[0023] In embodiment 19, a method for forming a ceramic-based material includes: depositing a ceramic precursor composition comprising ceramic nanoparticles and a carrier fluid onto the surface of a substrate via layer-by-layer deposition to form a deposition layer of the ceramic precursor composition, wherein the ceramic nanoparticles have at least one size less than 100 nm and an aspect ratio of 1.5 or greater; and sintering the deposited multilayer structure at a sintering temperature to form the ceramic-based material.

[0024] Embodiment 20 is the method according to Embodiment 19, further comprising depositing a composition comprising a non-ceramic material via layer-by-layer deposition, thereby forming a non-ceramic material layer in a deposited multilayer structure.

[0025] Other key features and advantages of this disclosure will become clear to those skilled in the art upon reading the accompanying drawings, detailed descriptions, and appended claims. Attached Figure Description

[0026] The following description will use the accompanying drawings to illustrate illustrative embodiments of this disclosure.

[0027] Figure 1 This is a schematic diagram of the layer-by-layer deposition of ceramic precursor composition 1 and ceramic precursor composition 2 according to an exemplary embodiment of the method of the present invention, wherein ceramic precursor composition 1 and ceramic precursor composition 2 each comprise ceramic nanosheets dispersed in a carrier fluid. The resulting multilayer structure is also shown.

[0028] Figure 2 This is a schematic diagram of the layer-by-layer deposition of cationic and anionic ceramic precursor compositions according to an exemplary embodiment of the method of the present invention, using roll-to-roll coating as the coating technique.

[0029] Figure 3 This is a scanning electron microscope (SEM) image of an aromatic polyamide nanofiber scaffold, which can be used as a porous substrate in embodiments of the method of the present invention. This porous substrate can be pyrolyzed to form N-doped carbon foam prior to the deposition of the ceramic precursor composition.

[0030] Figure 4 Is it so? Figure 3 A schematic diagram illustrating the transformation of N-doped carbon foam formed from an aromatic polyamide nanofiber scaffold into a ceramic matrix material according to an exemplary embodiment of the method of the present invention. Detailed Implementation

[0031] A method is provided for forming a ceramic-based material including coatings and three-dimensional (3D) objects.

[0032] The method of the present invention includes depositing a ceramic precursor composition comprising nanoparticles and a carrier fluid onto a surface of a substrate to form a deposited layer of the ceramic precursor composition on the surface. Deposition may be performed once to form a monolayer, but is typically performed multiple times to form a multilayer structure. In some embodiments, each layer has an opposite charge to the underlying previously deposited layer (after any excess material that may remain is washed away from the underlying previously deposited layer), and these layers are bonded by covalent and non-covalent forces. Before depositing the initial layer of the ceramic precursor composition, the substrate can be prepared by treating the area to be coated with an opposite charge to the initial layer. If the same ceramic precursor composition is used during multiple depositions, the chemical composition of each layer in the multilayer structure is the same. If different ceramic precursor compositions with different chemical compositions are used, the chemical composition of each layer will be different. Other types of compositions (e.g., those containing other materials, including non-ceramic materials) can be deposited to incorporate other materials within the multilayer structure. This is useful for providing ceramic composite materials. As further described below, although various deposition techniques can be used, the temperatures used during deposition are relatively low, e.g., room temperature. Next, the deposited (multiple) layers are sintered to form a ceramic matrix material. As further described below, the temperature used during the sintering process is lower than the temperature typically used for sintering ceramics. For example, this includes using sintering temperatures below 1000°C.

[0033] Nanoparticles used in the methods of this invention can be characterized by their morphology and size. However, nanoparticles are typically non-spherical with an aspect ratio (length-to-width ratio) of 1.5 or higher. This includes aspect ratios of 1.7, 2, 5, 10, 50, 100, etc. At least one size of the nanoparticle is nanoscale, i.e., 100 nm or smaller. This includes one-dimensional, two-dimensional, or all three-dimensional nanoparticles. Nanoscale sizes can be 90 nm or smaller, 70 nm or smaller, 50 nm or smaller, 25 nm or smaller. This includes embodiments where the nanoscale size is in the ranges of 1 nm to 20 nm, 1 nm to 15 nm, 1 nm to 10 nm, 1 nm to 5 nm, and 2 nm to 5 nm. Any non-nanoscale size (if any) is greater than 100 nm. For example, the shapes of non-spherical nanoparticles include nanorods, nanotubes, nanofibers, nanowhisks, nanodisks, nanoplates, nanosheets, nanoplates, etc. Figure 1 The shape of the illustrative nanosheet is shown. However, the nanosheets do not need to have a perfectly circular cross-section, nor do they need to be exactly the same as depicted in the schematic diagram. Each of the three dimensions of such a nanosheet can be nanoscale, but as mentioned above, the aspect ratio of the nanosheet is greater than 1, 1, 1.5 (in the x, y, and z directions, respectively), for example, 1.5 or greater, and the surface area to volume ratio is relatively large. In some embodiments, the nanoparticles are nanosheets with at least one size (in the z direction) in the range of 1 to 100 nm. This includes at least one size (in the z direction) in the range of 1 to 50 nm, 1 to 25 nm, 1 to 5 nm, or 2 to 5 nm. In some embodiments, the nanoparticles are nanosheets having at least two or all three sizes in any of these ranges. The use of nanoparticles with nanoscale sizes (such as nanosheets) is contrasted with the typical size (e.g., 5 μm to 100 μm) of ceramic particles used to form high-temperature ceramics using existing methods. The aspect ratio and size of the nanoparticles can refer to average values, i.e., averages taken over a representative number of nanoparticles.

[0034] The composition of nanoparticles is typically a ceramic compound. A ceramic compound refers to an inorganic (but elements in a ceramic compound may include carbon), a nonmetal (but elements in a ceramic compound may include metals), and a crystalline (i.e., the opposite of amorphous) solid. Exemplary ceramic compounds include oxides such as alumina, beryllium oxide, cerium dioxide, zirconium oxide, and hafnium dioxide. Ceramic compounds also include nonoxides such as borides, carbides, carbonates, nitrides, phosphates, silicides, and phosphates. Oxides and nonoxides include those that are metals and metalloids, such as calcium, titanium, hafnium, and silicon, without limitation. Specific illustrative ceramic compounds include boron oxide, boron nitride, aluminum oxynitride, silicon carbide, silicon nitride, tantalum carbide, hafnium carbide, titanium carbide, tungsten oxide, and tungsten carbide. In some embodiments, the nanoparticles are composed of WO3, cerium dioxide, hafnium dioxide, or titanium dioxide.

[0035] In some embodiments, the nanoparticles consist of a material capable of forming a ceramic compound during process steps (e.g., during sintering), rather than being composed of a ceramic compound. This includes nanoparticles that form a ceramic compound with the substrate during process steps. Formable ceramic compounds include any of the ceramic compounds described above.

[0036] A single type of nanoparticle (e.g., having a single type of chemical composition) or a combination of different types (e.g., having more than one type of chemical composition) can be used. In some embodiments, a single type of nanoparticle is used.

[0037] These nanoparticles can also be characterized by their crystal structure. In some embodiments, the nanoparticles are single-crystal, meaning they consist of a single-crystal phase (i.e., the opposite of polycrystalline).

[0038] Nanoparticles can be unfunctionalized, functionalized (e.g., to facilitate their dispersion in a carrier fluid), or have a spontaneously forming layer (i.e., self-assembly via surface adsorption onto a substrate) to provide desired components for ceramic composites formed using the methods of the present invention, or both. For example, during sintering, the organic ligands of organically functionalized nanoparticles can be carbonized to provide carbon as a component of the ceramic composite. Functionalization can also be used to obtain nanoparticles with a desired total charge, which can be used for layer-by-layer deposition as described below.

[0039] Carrier fluids provide a support for dispersing and carrying nanoparticles. Ideally, carrier fluids allow for the formation of stable dispersions of nanoparticles, i.e., colloids. Carrier fluids can also be used to impart a desired total charge to the deposited layer to facilitate layer-by-layer deposition as described below. Therefore, the appropriate choice of carrier fluid can depend on the desired nanoparticles and the deposition technique used. A single type (e.g., a single chemical composition) of carrier fluid or a combination of different types (e.g., different chemical compositions) of carrier fluid can be used.

[0040] Exemplary carrier fluids include water, organic solvents, ionic liquids, and polymers or their precursors. Short-chain alcohols such as ethanol, methanol, and isopropanol can be used. Regarding ionic liquids, this includes materials comprising one or more cations and one or more anions, and these materials have a melting point at or below room temperature. Exemplary anions of ionic liquids include trifluoromethanesulfonate (CF3SO3). - ), bis(trifluoromethylsulfonyl)imide (N(CF3SO2)2 - ), bis(perfluoroethylsulfonyl)imide ((C2F5SO2)2N - ), tri(trifluoromethylsulfonyl)methyl compound ((CF3SO2)3C -)), tetrafluoroborate (BF4) - ), hexafluorophosphate (PF6) - ), hexafluoroantimonate (SbF6) - ) and hexafluoroarsenate (AsF6) - Mixtures and combinations of different anions can be used.

[0041] Other suitable commercially available ionic liquids include those from BASF (Florham Park, NJ). Ionic liquid products, including: 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium methanesulfonate, 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium methanesulfonate, methyl-tri-n-butylammonium methyl sulfate, 1,2,4-trimethylpyrazole methyl sulfate, 1-ethyl-2,3-dimethylimidazolium ethyl sulfate, 1,2,3-trimethylimidazolium methyl sulfate, methylimidazolium chloride, methylimidazolium hydrogen sulfate, 1-ethyl-3-methylimidazolium hydrogen sulfate, 1 1-Ethyl-3-methylimidazolium tetrachloroaluminate, 1-Butyl-3-methylimidazolium hydrogen sulfate, 1-Butyl-3-methylimidazolium tetrachloroaluminate, 1-Ethyl-3-methylimidazolium acetate, 1-Butyl-3-methylimidazolium acetate, 1-Ethyl-3-methylimidazolium ethyl sulfate, 1-Butyl-3-methylimidazolium methyl sulfate, 1-Ethyl-3-methylimidazolium thiocyanate, 1-Butyl-3-methylimidazolium thiocyanate, acetylcholine, salicylate choline, tris-(2-hydroxyethyl)-methylammonium methyl sulfate. Mixtures and combinations of different ionic liquids can be used.

[0042] Illustrative cations for ionic liquids include tetraalkylammonium cations. Quaternary ammonium cations can be substituted with H, F, phenyl, alkyl groups having 1 to 15 carbon atoms, and other chemical substituents. The cations may further have bridging ring structures. Mixtures and combinations of different cations can be used.

[0043] Other illustrative cations used in ionic liquids include: imidazolium, pyridinium, pyridazinium, pyrazinium, pyrazolium, oxazolium, 1,2,3-triazolium, 1,2,4-triazolium, thiazolylium, piperidinium, pyrrolidineonium, quinolineonium, and isoquinolineonium.

[0044] While organic cations / anions can be used, in some embodiments, the ionic liquid contains only inorganic ions to provide an inorganic ionic liquid. Inorganic ionic liquids include those composed of metal halides such as mixed metal halides and thiocyanates. Inorganic ionic liquids can be used to enhance the heat resistance and oxidation resistance of ceramic-based materials formed using the methods of the present invention.

[0045] In some embodiments, the polymer or its precursor is used as a carrier fluid. A “precursor” refers to a compound capable of forming a polymer during process steps (e.g., during sintering). While organic polymers / precursors can be used, in some embodiments, the polymer / precursor is an inorganic polymer (i.e., one whose polymer backbone does not contain carbon atoms). Furthermore, inorganic polymers can be used to enhance heat resistance and oxidation resistance. Polysiloxanes, polysilazanes, polyphosphazenes, polyborazylenes, and polyaminoboranes are exemplary inorganic polymers. For the purposes of this disclosure, those inorganic polymers as described above (but also those with organic substituents) can be used and may be referred to as inorganic polymers.

[0046] Additives can be included in the ceramic precursor composition as needed to modulate the properties of the ceramic precursor composition and the desired performance of the ceramic matrix material. Additives that stabilize the dispersion of nanoparticles in the ceramic precursor composition can be used. Additives that promote chemical transformations during the sintering process (described below) may also be included. For example, illustrative additives include organic substances, metal salts, boric acids, and ammonium salts.

[0047] The carrier fluid may include various loadings of nanoparticles and additives (if present) to form a ceramic precursor composition. The loading can be readily determined based on the type of nanoparticles and carrier fluid used.

[0048] Various thin film deposition techniques can be used to form deposited (multi) layers. However, deposition techniques are those that can be performed at relatively low temperatures, including room temperature (20°C to 25°C). Furthermore, depending on the thermal properties of the carrier fluid, a deposition temperature range such as 10°C to 100°C can be used. Therefore, the temperature at which deposition is performed can be less than 100°C. One example includes layer-by-layer deposition. Layer-by-layer deposition typically involves sequentially applying a composition to the surface of a substrate to construct a multilayer structure. Application can include spraying (see...). Figure 1 Dip coating, spin coating, roll-to-roll coating (see...) Figure 2 ), impregnation, etc. For example Figure 1As shown, coating causes nanoparticles to self-assemble into a relatively close-packed monolayer of nanoparticles, facilitated by their relatively high aspect ratio. Individual layers can be attached together within the multilayer structure via electrostatic interactions (e.g., compositions of two ceramic precursors with opposite charges due to charged nanoparticles, charged carrier fluids, or a combination thereof). However, other non-covalent and covalent interactions can be used to attach adjacent layers. Rinsing is used between the coating layers. Drying / heating can be used between layer coatings as needed. The substrate surface can be chemically and / or mechanically treated to create a charged surface before depositing the initial layer. Excess carrier fluid can be removed and recovered by heating or other means before depositing subsequent layers, after depositing a single layer and before depositing another layer (further layers). Any desired number of coatings and sequence can be used to obtain various multilayer structures with diverse compositions, properties, and total thicknesses (e.g., nanometer to micrometer, micrometer to millimeter). Although layer-by-layer deposition is often used in combination with at least two compositions of different chemical compositions, this is not necessary. For example, two ceramic precursor compositions can be used that have the same type of nanoparticles (e.g., the same chemical composition) but different charges on them. As mentioned above, other types of compositions (e.g., those containing other materials, including non-ceramic materials) can be deposited using layer-by-layer deposition to include other materials within a multilayer structure. This is useful for providing ceramic composite materials.

[0049] It should be noted that layer-by-layer deposition allows for very high nanoparticle loadings, far exceeding those achievable with existing techniques. Furthermore, this loading can be adjusted for each individual layer, so each layer can have the same or different nanoparticle loadings. Additionally, each layer or combination of layers can include a loading adjusted for the desired performance level of any of the properties described herein.

[0050] Another cryogenic deposition technique that can be used is cryo-casting. In this embodiment, after the ceramic precursor composition is applied to the surface of the substrate (such application can be performed using the layer-by-layer deposition described above), a directional temperature gradient is applied to induce freezing of the carrier fluid (e.g., water) and alignment of the nanoparticles. The frozen carrier fluid can be removed (e.g., sublimated) to form a porous (multi)layer of aligned nanoparticles.

[0051] Ceramic precursor compositions can be deposited on a variety of substrates as needed. Substrates with planar (i.e., flat) and non-planar (e.g., curved, 3D morphology) surfaces can be used. Porous substrates, such as those formed from filamentous or woven / nonwoven carbon or ceramic fibers (e.g., aramid nanofibers), can be used. Such porous substrates can be pyrolyzed prior to deposition of the ceramic precursor composition to form undoped or doped carbon foams. The selection of substrate materials can be guided by the need for the substrate to form a ceramic compound with nanoparticles: the requirement to provide components of the ceramic composite (e.g., carbon); and / or the requirement to achieve the desired chemical and / or physical transformations during sintering (described further below). Other illustrative substrate materials include silica, carbon, metals, and ceramics (e.g., silicon carbide).

[0052] As described above, the method of the present invention further includes sintering the deposited (multiple) layers to provide a ceramic matrix material. Sintering involves heating the deposited (multiple) layers to a sintering temperature for a period of time. The sintering temperature is high enough to densify and / or melt the individual nanoparticles together to form a solid matrix. This may include the merging of the lattices of the individual nanoparticles. However, due to the use of the nanoparticles of the present invention, the sintering temperature is lower than that used in existing methods for forming ceramics. The specific sintering temperature depends at least in part on the composition of the nanoparticles. However, by way of example only, the sintering temperature required for a deposited layer comprising a ceramic precursor composition of ceramic nanoparticles having one or more sizes of 2-5 nm can be at least 300°C lower than the sintering temperature required when using larger ceramic particles, for example, micron-sized particles having a diameter of 5 to 100 μm (and additionally sintering under the same conditions, for example, the same sintering time). This includes at least 400°C lower, at least 500°C lower, at least 600°C lower, or at least 700°C lower. In some embodiments, the sintering temperature is 1000°C or lower. This includes 950°C or lower, 900°C or lower, 850°C or lower, 800°C or lower, or in the range of 100°C to 1000°C. These temperatures can refer to sintering without additional external forces (e.g., pressure). This does not preclude the application of pressure during sintering, in which case the sintering temperature can be further reduced. Sintering can be light-induced, for example, by a laser or another focused light source, in which case the sintering temperature refers to the light-induced heating. The above temperatures can refer to a specific time range for sintering to take place, such as from seconds to hours. Sintering can be performed "in situ" after deposition.

[0053] Figure 3 This is a SEM image of an aramid nanofiber scaffold, which can be used as an exemplary porous substrate. As mentioned above, this porous substrate can be pyrolyzed to form N-doped carbon foam. Figure 4This is a schematic diagram illustrating the conversion of N-doped carbon foam 400 into a ceramic matrix material 408 according to an exemplary embodiment of the method of the present invention. As shown in step 402, any disclosed ceramic precursor composition (e.g., containing nanosheets 404) can be deposited onto the surface of the N-doped carbon foam 400, followed by in-situ sintering in step 406 to form the ceramic matrix material 408. For example, densification as shown in step 410 can be performed by hot-pressing.

[0054] Other chemical and physical transformations (besides nanoparticle densification and / or melting) can occur during sintering. Transformations involving individual nanoparticles, substrates, and / or nanoparticles and substrates include decomposition and / or carbonization of ligands on functionalized nanoparticles; hydrogen bonding; non-classical crystallization; seed growth of mesophases; seed crystallization of the substrate; ion exchange; recrystallization of nanoparticles; self-assembly of nanoparticles into other forms, such as chains / plates / capsules; ionic, covalent, or coordination bonding with the substrate; and densification of nanoparticles with the substrate. Chemical and physical transformations that can occur with the carrier fluid include evaporation, polymerization, decomposition / carbonization, covalent bonding with nanoparticles, and crystallization from the ceramic phase formed therefrom.

[0055] The composition, morphology, and dimensions of the ceramic-based material formed using the method of this invention depend on the details described above. However, the ceramic-based material is typically in the form of a coating attached to a substrate or 3D object. If the coating or 3D object consists only of ceramic compounds or is primarily composed of ceramic compounds, it can be referred to as a ceramic coating / 3D object. If the coating or 3D object contains a non-ceramic material (e.g., non-carbide carbon), it can be referred to as a ceramic composite coating / 3D object. The distinction between coatings and 3D objects is not intended to be particularly limiting. However, coatings can typically be thick (e.g., mm), with the other two dimensions significantly larger than that thickness. In contrast, 3D objects can be smaller, but are typically on the order of micrometers or larger, and have three dimensions that are more similar in size to each other.

[0056] The ceramic matrix material formed using the method of this invention can be characterized by a variety of properties. These include tensile strength (σ). Tensile testing of the coating can be performed using an indentation test with a standard Hysitron nanoindenter. Load-strain curves can be obtained using a Berkovich tip. The stress-strain curve of the ceramic composite material can be obtained on a rectangular strip approximately 1 mm wide and 4–6 mm long. Properties also include Young's modulus (E), which can be quantified using compression testing and evaluation of E in the deformation-stable region. Other properties include electrical conductivity, adhesion, and density, which can be measured according to ASTM standards used in the aerospace industry. Specific values ​​for each of these properties depend on the type of ceramic matrix material used. Advantageously, these values ​​can be tuned for the selected substrate, thereby promoting adhesion over a wide temperature range and meeting the intended use requirements.

[0057] The method of this invention can be used to provide ceramic-based materials for use in a variety of environments, including the aerospace industry, automotive industry, submarine industry, electronics industry, and construction industry. Therefore, the phrases "aerospace industry," "automotive industry," and "submarine industry" can refer to any device, aircraft, machine, or component thereof used in industries such as aircraft, airplanes, rotorcraft, ships, submarines, spacecraft, trajectory devices, drones, satellites, automobiles, buses, locomotives, train carriages, etc.

[0058] Furthermore, this disclosure includes embodiments according to the following entries:

[0059] Item 1, A method for forming a ceramic matrix material, the method comprising:

[0060] (a) A ceramic precursor composition is deposited 402 on the surface of a substrate 400 to form a deposited layer of the ceramic precursor composition, the ceramic precursor composition comprising nanoparticles and a carrier fluid, the nanoparticles having at least one size less than 100 nm and an aspect ratio of 1.5 or greater; and

[0061] (b) Sintering the deposited layer of the 406 ceramic precursor composition at a sintering temperature to form a ceramic matrix material 408.

[0062] The methods of Item 2 and Item 1, wherein the nanoparticles have at least one size in the range of 1 nm to 100 nm, preferably wherein the nanoparticles are nanosheets 404.

[0063] Item 3, the method according to Item 1 or 2, wherein the nanoparticles comprise a ceramic compound, preferably wherein the nanoparticles comprise WO3, cerium dioxide, hafnium dioxide, titanium dioxide, or a combination thereof.

[0064] Item 4, the method of any one of items 1 to 3, wherein the nanoparticles comprise a compound that forms a ceramic compound during sintering 406.

[0065] Item 5, the method of any one of items 1 to 4, wherein the nanoparticles are single crystals.

[0066] Item 6, the method according to any one of items 1 to 5, wherein the carrier fluid is water, an organic solvent or an ionic liquid.

[0067] Item 7. The method according to any one of items 1 to 6, wherein the carrier fluid is an inorganic ionic liquid.

[0068] Item 8. The method according to any one of items 1 to 7, wherein the carrier fluid is a polymer or a precursor thereof, preferably wherein the polymer is an inorganic polymer or a precursor thereof.

[0069] Item 9. The method according to any one of items 1 to 8, wherein deposition 402 is carried out at a temperature below 100°C, preferably wherein deposition 402 is carried out at room temperature or lower.

[0070] Item 10, the method of any one of items 1 to 9, wherein layer-by-layer deposition 402 is performed to provide a deposited multilayer structure comprising a deposited layer of ceramic precursor composition.

[0071] Item 11. The method according to any one of Items 1 to 10, wherein the sintering temperature is lower than the sintering temperature used under the following conditions: the particles used have the same composition as nanoparticles, but have a diameter of about 5 μm to about 100 μm.

[0072] Item 12, the method according to any one of items 1 to 11, wherein the sintering temperature is 1000°C or lower.

[0073] Item 13, the method according to any one of items 1 to 12, wherein the substrate 400 is a porous carbonized substrate.

[0074] Item 14. The method of any one of items 1 to 13, wherein the nanoparticles comprise a ceramic compound, and wherein layer-by-layer deposition 402 is performed to provide a deposited multilayer structure comprising a deposited layer of a ceramic precursor composition.

[0075] Item 15, the method according to Item 14, further includes depositing a composition comprising a non-ceramic material via layer-by-layer deposition to form a layer of non-ceramic material in a deposited multilayer structure.

[0076] The term “illustrative” is used herein to mean used as an example, instance, or illustration. Any aspect or design described herein as “illustrative” is not necessarily to be construed as superior to or better than other aspects or designs. Furthermore, for the purposes of this disclosure and unless otherwise specified, “a” or “an” means “one or more”.

[0077] Unless otherwise specified, all numerical values ​​of the parameters in this disclosure are indicated by the term "about," which means approximation. This covers those variations inherent in the measurement of the relevant parameters as understood by those skilled in the art. This also covers the exact values ​​of the disclosed numerical values ​​as well as values ​​rounded to the disclosed values.

[0078] For illustrative and descriptive purposes, the above description of illustrative embodiments of the present disclosure has been shown. It is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed, and modifications and variations are possible, or may be obtained, from practice of the present disclosure, in accordance with the above teachings. These embodiments were chosen and described to explain the principles of the present disclosure and as a practical application of the disclosure, so that those skilled in the art can use the disclosure in different embodiments and with different modifications suitable for the particular intended use. It is intended that the scope of the present disclosure be defined by the appended claims and their equivalents.

Claims

1. A method for forming a ceramic matrix material, the method comprising: a. A ceramic precursor composition is deposited on the surface of a substrate (400) by layer-by-layer deposition to form a deposited multilayer structure comprising a deposited layer of the ceramic precursor composition, the ceramic precursor composition comprising nanoparticles and a carrier fluid, the nanoparticles having at least one size in the range of 2 nm to 5 nm and an aspect ratio of 1.5 or greater, and wherein the nanoparticles comprise WO3, cerium dioxide, hafnium dioxide, titanium dioxide or a combination thereof, wherein the carrier fluid is an inorganic ionic liquid containing only inorganic ions and having a melting point at or below room temperature, the inorganic ionic liquid being composed of a metal halide and a thiocyanate; as well as b. Sinter the deposited multilayer structure at a sintering temperature of 800°C or lower to form a ceramic matrix material (408).

2. The method according to claim 1, wherein the nanoparticles are nanosheets (404).

3. The method of claim 1, wherein the nanoparticles comprise a compound that forms a ceramic compound during sintering.

4. The method according to any one of claims 1 to 3, wherein the nanoparticles are single crystals.

5. The method according to any one of claims 1 to 3, wherein the deposition is performed at a temperature below 100°C.

6. The method according to any one of claims 1 to 3, wherein the sintering temperature is lower than the sintering temperature used when the particles used have the same composition as the nanoparticles but have a diameter of 5 µm to 100 µm.

7. The method according to any one of claims 1 to 3, wherein the substrate (400) is a porous carbonized substrate.

8. The method of claim 1, further comprising depositing a composition comprising a non-ceramic material via layer-by-layer deposition to form a layer of the non-ceramic material in the deposited multilayer structure.

9. The method according to any one of claims 1 to 3, wherein the deposition is performed at room temperature or lower.

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