Method for manufacturing a ceramic article

Abstract

This invention relates to a method for manufacturing ceramic articles, the method comprising the following steps: (step 1) providing at least one ceramic structure obtained by a binder jet 3D ceramic printer using at least one ceramic compound and at least one binder, wherein the ceramic structure has an open porosity of at least 35.00%; and (step 2) providing at least one slurry S1 comprising solid particles [hereinafter, solid particles A] and at least one liquid phase, wherein the d 50 The particle size is equal to or greater than 1.00 µm and less than 30.00 µm, and (step 3) at least a portion of the ceramic structure is impregnated at least once in the slurry S1, thereby impregnating the openings of the ceramic structure at least partially with solid particles A [hereinafter, the impregnated ceramic structure].

Description

[0001] This invention relates to a method for manufacturing ceramic articles. The invention further relates to a ceramic article for use in ceramic casting filters for filtering molten metal, and to the use of the ceramic article in wear-resistant parts for high-wear applications. Background of the Invention Ceramic products obtained by binder jet 3D ceramic printers are typically used in a wide range of applications, where their properties in terms of thermal strength, high resistance and durability are utilized.

[0002] Typically, in metallurgical processes, casting filters are used for filtering molten metal, such as ceramic filters used to filter molten metal before casting. Filters used for filtering molten metal must be able to physically withstand high temperatures. For example, in steelmaking processes, filters must be able to physically withstand temperatures greater than 1400°C.

[0003] Known ceramic filters used in foundries for filtering steel are made from monolithic porous ceramic foam structures, where the ceramic material is composed of zirconium oxide (ZrO2). These conventional zirconium oxide-based ceramic foam structures are typically produced by coating a reticulated polyurethane foam (RPF) with a slurry containing zirconium oxide. However, these conventional zirconium oxide-based ceramic foam filters are prone to deformation or even cracking due to shrinkage that occurs during the firing process.

[0004] For example, GB 2599112 A discloses a cast filter for filtering molten metal. In this document, the filter comprises a porous ceramic filter structure, such as a ceramic filter structure obtained by a 3D ceramic printer. This ceramic structure includes multiple through-holes and is impregnated with ceramic material. By carefully configuring the size and number of through-holes, this filter offers the advantage of allowing molten metal to pass through the filter at a relatively constant flow rate while preventing the filter from being blocked by inclusions / slag present in the molten metal. However, this document does not mention the impregnation of the molten metal within the pores of the filter structure.

[0005] Another example of ceramic structural applications is in wear-resistant parts used in high-wear applications.

[0006] For example, WO 2023 / 200625 A1 discloses a reinforced wear-resistant member comprising a steel body and a ceramic core embedded in the steel body. The ceramic core in the steel body enhances the wear-resistant member, making it suitable for grounding applications. The ceramic core does not have to be porous. Alternatively, the ceramic core can be formed as an open-cell, porous ceramic matrix that allows molten steel to flow into, around, and through the porous matrix, flowing around the fibrils defining the pores of the matrix. When molten steel flows into the pores of the ceramic matrix, the ceramic core is suitably embedded in the steel body and the mechanical resistance of the wear-resistant member is improved. Unfortunately, when molten metal impregnates into the pores of the ceramic structure, damage occurs due to cracking of the ceramic structure.

[0007] Using high-performance ceramic products as filter media for molten metal offers significant and measurable sustainability benefits. The ceramic foam filter process eliminates the need for a polyurethane (PUR) foam burn-off stage, thus avoiding the release of harmful gases associated with burning off polymer models, making it a more environmentally friendly option. By effectively removing inclusions and impurities from the molten metal, high-performance ceramic products significantly reduce casting defects, which in turn minimizes waste generation and the energy-intensive rework typically associated with defective parts. A cleaner metal flow also improves downstream processing efficiency, reducing machining time, consumable usage (as its high capacity and stable flow rate mean fewer or smaller filters can be used), and overall waste. Therefore, users of high-performance ceramic-based filter media achieve higher yields, more consistent production, and higher-quality cast parts. In summary, these effects contribute to reduced energy consumption, lower emissions, and more efficient use of untreated molten metal, highlighting high-performance ceramic-based filters as a key enabler for sustainable and economically resilient casting operations.

[0008] In view of the above, there is a continued need for improved methods for manufacturing ceramic articles, wherein such methods are easy to implement and provide ceramic articles with several different shapes while maintaining their high structural strength / integrity. Therefore, the method provides a ceramic article that not only exhibits improved performance characteristics in terms of thermal strength, mechanical resistance, and overall durability, but also offers a sustainable solution. Summary of the Invention

[0009] The inventors have unexpectedly discovered that the method for manufacturing ceramic articles according to the present invention satisfies the above-mentioned needs and overcomes the above-mentioned disadvantages.

[0010] In one aspect of the present invention, a method for manufacturing ceramic articles is provided, wherein the method includes the following steps: Step 1: Provide at least one ceramic structure obtained by using at least one ceramic compound and at least one binder through a binder jet 3D ceramic printer, wherein the ceramic structure has an open porosity of at least 35.00%; Step 2: Provide at least one slurry S1 comprising solid particles [hereinafter, solid particles A] and at least one liquid phase, wherein the solid particles A have a d 50 Particle size equal to or greater than 1.00 µm and less than 30.00 µm; Step 3: Impregnate at least a portion of the ceramic structure at least once in the slurry S1, thereby impregnating at least a portion of the openings of the ceramic structure with solid particles A [hereinafter, the impregnated ceramic structure].

[0011] The ceramic articles obtained according to the method of the present invention are another aspect of the present invention.

[0012] The use of the ceramic articles of the present invention in ceramic casting filters for filtering molten metal is another aspect of the present invention.

[0013] The use of the ceramic articles of the present invention in wear-resistant parts is another aspect of the present invention. Detailed Implementation

[0014] The term "comprising" as used in the claims should not be construed as limited to the means listed thereafter; the term does not exclude other elements or steps. The term is to be interpreted as specifically describing the presence of the stated features, integers, steps, or components mentioned, but does not exclude the presence or inclusion of one or more other features, integers, steps, or components or a set thereof. Therefore, the expression "the method comprises steps A and B" should not be limited to the method consisting solely of steps A and B. This means that, with respect to the invention, only steps A and B are relevant in the method. Therefore, the terms "comprising" and "including" encompass the more restrictive terms "consistently consisting of" and "consisting of".

[0015] As used herein, the terms “optional” or “optionally” mean that an event or situation described below may or may not occur, and the description includes both scenarios in which the event or situation occurs and scenarios in which the event or situation does not occur.

[0016] Unless otherwise mentioned or specified, it should be understood that, in the context of this invention, temperature means room temperature. In the context of this invention, the expression "room temperature" is intended to refer to a temperature ranging from -5°C to 50°C, preferably from 10°C to 30°C.

[0017] In the context of this invention, unless otherwise stated, the term "particle size" is intended to refer to the average diameter of the particles. Particle size is measured by mechanical sieving or by laser diffraction analysis according to EN ISO 1927-3 (2013) standard.

[0018] In the context of this invention, the expression "d" is used. x "y µm" is intended to indicate that a percentage (x%) of particles by weight has a particle size equal to or less than y µm. In other words, the expression "d" indicates that... x "µm" refers to particle size distribution (PSD). Typically, particle size distribution can be measured using methods known in the art. Preferably, the particle size distribution is measured by mechanical sieving or by laser diffraction analysis according to EN ISO 1927-3 (2013). More preferably, the particle size distribution is measured by laser diffraction analysis.

[0019] In the context of this invention, the term "open porosity" is intended to refer to the volume percentage of open pores. Therefore, open porosity does not include closed pores, which are a part of closed porosity.

[0020] It goes without saying that, according to the present invention, pores are not comparable to holes that may exist in the general shape of a ceramic structure or ceramic article. For example, when a ceramic structure / ceramic article has a shape suitable for use as a ceramic filter or as a wear-resistant part, it typically includes a plurality of pores with an average diameter greater than 1 mm. For example, a ceramic filter may have pores with an average diameter ranging from 3 mm to 10 mm.

[0021] Typically, open-pore porosity can be measured using methods known in the art, such as optical methods, computed tomography, liquid absorption, water saturation, water evaporation, water displacement, mercury porosimetry, gas expansion, or thermoporosimetry and cryoporosimetry. Unless otherwise stated, in the context of this invention, the method used to measure open-pore porosity is to use Archimedes, according to standard ASTM C20 (2022) "..." Standard Test Methods for Apparent Porosity, Water Absorption, Apparent Specific Gravity, and Bulk Density of Burned Refractory Brick and Shapes by Boiling Water [Measured by Boiling Water] Standard test methods for apparent porosity, water absorption, apparent specific gravity and bulk density of fired refractory bricks and products. The drainage method.

[0022] In the context of this invention, the term "apparent density," also known as bulk density, is intended to refer to the mass of a material's particles divided by its bulk volume. Bulk volume is defined as the total volume occupied by the particles, including the volume of the particles themselves, the volume of the voids between the particles, and the volume of the internal pores within the particles.

[0023] Apparent density can typically be measured using methods known in the art. Unless otherwise stated, in the context of this invention, the method used to measure apparent density is according to standard ASTM C20 (2022) "...". Standard Test Methods for Apparent Porosity, Water Absorption, Apparent Specific Gravity, and Bulk Density of Burned Refractory Brick and Shapes by Boiling Water [Measured by Boiling Water] Standard test methods for apparent porosity, water absorption, apparent specific gravity and bulk density of fired refractory bricks and products. .

[0024] In the context of this invention, viscosity is measured using an Anton Paar Modular Compact Rheometer (MCR302) at 20°C over 10 s⁻¹. -1 The shear rate was measured.

[0025] As mentioned, according to the present invention, a method for manufacturing ceramic articles includes step 1: providing at least one ceramic structure obtained by using at least one ceramic compound and at least one binder through a binder jet 3D ceramic printer, wherein the ceramic structure has an open porosity of at least 35.00%.

[0026] It goes without saying that ceramic products can take any shape. Ceramic products are typically used when high refractoriness (e.g., the ability to withstand temperatures exceeding 1650°C) and high structural strength / integrity are required. Notable non-limiting examples of ceramic products include ceramic filters (such as ceramic casting filters for filtering molten metal) and wear-resistant parts. Wear-resistant parts are used, for example, in high-abrasion applications, in other words, in applications involving the handling of abrasives such as rock, sand, and ore. Notable non-limiting examples of applications using wear-resistant parts include digging, loading, bulldozing, grading, milling, and grinding.

[0027] Ceramic structure In the context of this invention, the phrase "at least one ceramic structure" is intended to refer to one or more ceramic structures.

[0028] Ceramic structures are obtained using a binder jetting 3D ceramic printer with at least one ceramic compound and at least one binder. Generally, binder jetting 3D ceramic printing techniques known in the art can be used to obtain ceramic structures. Typically, binder jetting is a form of additive manufacturing, also known as powder bed 3D printing. The binder jetting process is based on inkjet technology. Similar to an inkjet printer, a ceramic structure is printed by dripping a binder onto a ceramic compound. The binder bonds the ceramic compound to create the ceramic structure. The ceramic compound is continuously replenished and brought into contact with the binder, and the ceramic structure is printed layer by layer. Therefore, the ceramic structure is typically built from bottom to top. Needless to say, the shape of the ceramic structure is preferably chosen according to the application of the final ceramic product as detailed above.

[0029] In the context of this invention, the expression "at least one ceramic compound" is intended to mean one or more ceramic compounds.

[0030] Generally, ceramic compounds refer to inorganic non-metallic solid materials typically composed of metallic and non-metallic elements bonded together by strong ionic or covalent bonds. These compounds can have crystalline or partially crystalline structures. Ceramic compounds are typically characterized by their hardness, high melting point, chemical resistance, and electrical insulation properties.

[0031] Typically, ceramic compounds are known to those skilled in the art, and the properties of such ceramic compounds can be selected according to their intended application.

[0032] It should be further understood that the ceramic compounds detailed above may be commercially available or chemically synthesized from commercially available starting materials by any method known to those skilled in the art.

[0033] Typically, ceramic compounds can be synthesized using a variety of methods known in the art or can be of natural origin.

[0034] Non-limiting examples of ceramic compounds include oxides, nitrides, carbides, silicates, or mixtures thereof. Notably, non-limiting examples of oxides include aluminum oxide, zirconium oxide, silicon oxide, cerium oxide, titanium oxide, magnesium oxide, and mixtures thereof.

[0035] Non-limiting examples of carbides include silicon carbide, tungsten carbide, and mixtures thereof. Non-limiting examples of silicates include zirconium silicate, aluminum silicate, and mixtures thereof.

[0036] Preferably, the ceramic compound is selected from alumina, zirconium oxide, zirconium silicate, aluminum silicate, silicon oxide, silicon carbide, cerium oxide, titanium oxide, titanium carbide, magnesium oxide, tungsten carbide, and mixtures of two or more thereof.

[0037] More preferably, the ceramic compound is selected from alumina, zirconium oxide, cerium oxide, and mixtures thereof.

[0038] Even more preferably, the ceramic compound is a mixture of zirconium oxide and cerium oxide.

[0039] Notable examples of ceramic compounds that are mixtures of zirconium oxide and cerium oxide include CeraBeads. ® .

[0040] Advantageously, the ceramic compound may contain impurities of less than 3.00 wt.%, preferably less than 2.00 wt.%, and more preferably less than 1.00 wt.% relative to the total weight of the ceramic compound.

[0041] Preferably, the ceramic compound is a powder. In the context of this invention, the term "powder" is intended to refer to any solid in the form of powder, granules, fragments, or equivalent.

[0042] Advantageously, the ceramic compound consists of solid particles [hereinafter, solid particles B] having a particle size value equal to or greater than 10.00 µm.

[0043] Advantageously, the particle size of solid particle B is equal to or greater than 20.00 µm, more preferably equal to or greater than 30.00 µm, more preferably equal to or greater than 40.00 µm, and even more preferably equal to or greater than 53.00 µm. It should be further understood that the upper limit of the particle size of solid particle B is advantageously equal to or less than 500.00 µm, preferably equal to or less than 450.00 µm, more preferably equal to or less than 400.00 µm, more preferably equal to or less than 350.00 µm, and more preferably equal to or less than 300.00 µm.

[0044] In embodiments of the method of the present invention, the particle size of the solid particles B, as detailed above, ranges from 10.00 µm to 500.00 µm, preferably from 20.00 µm to 450.00 µm, more preferably from 30.00 µm to 400.00 µm, even more preferably from 40.00 µm to 350.00 µm, and even more preferably from 53.00 µm to 300.00 µm.

[0045] Advantageously, the d of solid particle B 10The particle size is equal to or greater than 53.00 µm, preferably equal to or greater than 57.00 µm, more preferably equal to or greater than 60.00 µm, more preferably equal to or greater than 63.00 µm, more preferably equal to or greater than 67.00 µm, and even more preferably equal to or greater than 70.00 µm. It should be further understood that the d of solid particle B... 10 The upper limit of the particle size value is advantageously equal to or less than 106.00 µm, preferably equal to or less than 100.00 µm, more preferably equal to or less than 95.00 µm, more preferably equal to or less than 90.00 µm, more preferably equal to or less than 85.00 µm, and even more preferably equal to or less than 80.00 µm.

[0046] In embodiments of the method of the present invention, the d of the solid particle B as detailed above 10 The particle size ranges from 53.00 µm to 106.00 µm, preferably from 57.00 µm to 100.00 µm, more preferably from 60.00 µm to 95.00 µm, more preferably from 63.00 µm to 90.00 µm, more preferably from 67.00 µm to 85.00 µm, and even more preferably from 70.00 µm to 80.00 µm.

[0047] According to the present invention, the d of solid particle B 50 The particle size is equal to or greater than 75.00 µm, preferably equal to or greater than 80.00 µm, more preferably equal to or greater than 85.00 µm, more preferably equal to or greater than 90.00 µm, more preferably equal to or greater than 95.00 µm, and even more preferably equal to or greater than 100.00 µm. It should be further understood that the d of solid particle B... 50 The upper limit of the particle size value is advantageously equal to or less than 150.00 µm, preferably equal to or less than 140.00 µm, more preferably equal to or less than 130.00 µm, more preferably equal to or less than 120.00 µm, more preferably equal to or less than 115.00 µm, and even more preferably equal to or less than 110.00 µm.

[0048] In embodiments of the method of the present invention, the d of the solid particle B as detailed above 50 The particle size ranges from 75.00 µm to 150.00 µm, preferably from 80.00 µm to 140.00 µm, more preferably from 85.00 µm to 130.00 µm, more preferably from 90.00 µm to 120.00 µm, more preferably from 95.00 µm to 115.00 µm, and even more preferably from 100.00 µm to 110.00 µm.

[0049] According to the present invention, the d of solid particle B 70The particle size is equal to or greater than 106.00 µm, preferably equal to or greater than 110.00 µm, more preferably equal to or greater than 115.00 µm, more preferably equal to or greater than 120.00 µm, more preferably equal to or greater than 125.00 µm, more preferably equal to or greater than 130.00 µm, more preferably equal to or greater than 135.00 µm, more preferably equal to or greater than 140.00 µm, and even more preferably equal to or greater than 145.00 µm. It should be further understood that the d of solid particle B... 70 The upper limit of the particle size value is advantageously equal to or less than 212.00 µm, preferably equal to or less than 200.00 µm, more preferably equal to or less than 190.00 µm, more preferably equal to or less than 180.00 µm, more preferably equal to or less than 175.00 µm, more preferably equal to or less than 170.00 µm, more preferably equal to or less than 165.00 µm, more preferably equal to or less than 160.00 µm, and even more preferably equal to or less than 155.00 µm.

[0050] In embodiments of the method of the present invention, the d of the solid particle B as detailed above 70 The particle size ranges from 106.00 µm to 212.00 µm, preferably from 110.00 µm to 200.00 µm, more preferably from 115.00 µm to 190.00 µm, more preferably from 120.00 µm to 180.00 µm, more preferably from 125.00 µm to 175.00 µm, more preferably from 130.00 µm to 170.00 µm, more preferably from 135.00 µm to 165.00 µm, more preferably from 140.00 µm to 160.00 µm, and even more preferably from 145.00 µm to 155.00 µm.

[0051] According to the present invention, the d of solid particle B 90 The particle size is equal to or greater than 150.00 µm, preferably equal to or greater than 160.00 µm, more preferably equal to or greater than 170.00 µm, more preferably equal to or greater than 175.00 µm, more preferably equal to or greater than 180.00 µm, more preferably equal to or greater than 185.00 µm, more preferably equal to or greater than 190.00 µm, more preferably equal to or greater than 195.00 µm, more preferably equal to or greater than 200.00 µm, and even more preferably equal to or greater than 205.00 µm. It should be further understood that the d of solid particle B... 90The upper limit of the particle size value is advantageously equal to or less than 300.00 µm, preferably equal to or less than 290.00 µm, more preferably equal to or less than 280.00 µm, more preferably equal to or less than 270.00 µm, more preferably equal to or less than 260.00 µm, more preferably equal to or less than 250.00 µm, more preferably equal to or less than 240.00 µm, more preferably equal to or less than 230.00 µm, more preferably equal to or less than 220.00 µm, and even more preferably equal to or less than 215.00 µm.

[0052] In embodiments of the method of the present invention, the d of the solid particle B as detailed above 90 The particle size ranges from 150.00 µm to 300.00 µm, preferably from 160.00 µm to 290.00 µm, more preferably from 170.00 µm to 280.00 µm, more preferably from 175.00 µm to 270.00 µm, more preferably from 180.00 µm to 260.00 µm, more preferably from 185.00 µm to 250.00 µm, more preferably from 190.00 µm to 240.00 µm, more preferably from 195.00 µm to 230.00 µm, more preferably from 200.00 µm to 220.00 µm, and even more preferably from 205.00 µm to 215.00 µm.

[0053] It goes without saying that solid particles B can have various shapes. For example, the solid particles B of the present invention can be spherical, flake-shaped, plate-shaped, or a mixture thereof.

[0054] When alumina is used in solid particles B, the alumina is preferably selected from the group consisting of spherical alumina, lamellar alumina, plate-shaped alumina, and mixtures thereof. Preferably, the alumina is plate-shaped alumina.

[0055] Advantageously, the ceramic compound is a pre-sintered ceramic compound. In the context of this invention, "pre-sintered" is intended to mean that the ceramic compound undergoes a pre-sintering step before use. Typically, pre-sintering is a heat treatment in which the ceramic compound is fired at a temperature below the melting point of the ceramic compound. During the pre-sintering step, the particles of the ceramic compound can form bonds, and the contact points between the particles increase, thereby improving the interparticle cohesion (intergranular cohesion), which improves the mechanical properties of the pre-sintered ceramic compound. Advantageously, those skilled in the art can determine the pre-sintering temperature based on the properties of the ceramic compound, because the pre-sintering temperature does not necessarily have to reach the melting point of the ceramic compound.

[0056] Typically, the pre-sintering of ceramic compounds is carried out at a temperature equal to or greater than 1400°C, preferably equal to or greater than 1450°C, more preferably equal to or greater than 1500°C, and even more preferably equal to or greater than 1550°C. It should be further understood that the upper limit of the temperature for pre-sintering ceramic compounds is advantageously equal to or less than 1800°C, preferably equal to or less than 1750°C, more preferably equal to or less than 1700°C, and even more preferably equal to or less than 1650°C.

[0057] In embodiments of the method of the present invention, the temperature range for pre-sintering ceramic compounds, as detailed above, is 1400°C to 1800°C, preferably 1450°C to 1750°C, more preferably 1500°C to 1700°C, and even more preferably 1550°C to 1650°C.

[0058] In the context of this invention, the expression "at least one adhesive" is intended to mean one or more adhesives.

[0059] Typically, adhesives are known to those skilled in the art, and their properties can be selected based on their application.

[0060] It should be further understood that the binder detailed above may be commercially available or chemically synthesized from commercially available starting materials by any method known to those skilled in the art.

[0061] Typically, binders can be synthesized using a variety of methods known in the art or can be of natural origin. Suitable binders can be organic or inorganic. For example, inorganic binders notably include ceramic binders. Generally, inorganic binders are known to those skilled in the art and can be selected based on the intended application.

[0062] Non-limiting examples of inorganic binders notably include silicates, phosphates, aluminates, phosphoric acid, alumina gels, and mixtures thereof. For example, inorganic binders may include aluminum phosphate.

[0063] In one embodiment of the invention, the adhesive is an organic adhesive. Organic adhesives are known to those skilled in the art and can be selected according to the intended application.

[0064] Advantageously, when the adhesive is an organic adhesive, the organic adhesive comprises resins selected from the group consisting of furan resins, phenolic resins, and mixtures thereof. Preferably, the organic adhesive comprises furan resins.

[0065] As previously mentioned, the ceramic structure has an open porosity of at least 35.00%.

[0066] Advantageously, the ceramic structure has an open porosity of 36.00%, more preferably 37.00%, more preferably 38.00%, more preferably 39.00%, more preferably 40.00%, more preferably 41.00%, and even more preferably 42.00%. It should be further understood that the upper limit of the open porosity of the ceramic structure is advantageously equal to or less than 90.00%, preferably equal to or less than 85.00%, more preferably equal to or less than 80.00%, more preferably equal to or less than 75.00%, more preferably equal to or less than 70.00%, more preferably equal to or less than 65.00%, more preferably equal to or less than 60.00%, and even more preferably equal to or less than 53.00%.

[0067] In embodiments of the method of the present invention, the porosity of the ceramic structure as detailed above ranges from 35.00% to 90.00%, preferably 36.00% to 85.00%, more preferably 37.00% to 80.00%, more preferably 38.00% to 75.00%, more preferably 39.00% to 70.00%, more preferably 40.00% to 65.00%, more preferably 41.00% to 60.00%, and even more preferably 42.00% to 53.00%.

[0068] As detailed above, the term "open-pore porosity" refers to the volume percentage of open pores in a ceramic structure. Typically, the size of the open pores in a ceramic structure is less than 1.0 mm.

[0069] Advantageously, the ceramic structure has an apparent density equal to or less than 1.85 g / cm³, preferably equal to or less than 1.80 g / cm³, more preferably equal to or less than 1.75 g / cm³, more preferably equal to or less than 1.70 g / cm³, more preferably equal to or less than 1.65 g / cm³, more preferably equal to or less than 1.60 g / cm³, more preferably equal to or less than 1.55 g / cm³, and even more preferably equal to or less than 1.52 g / cm³. It should be further understood that the lower limit of the apparent density of the ceramic structure is advantageously equal to or greater than 1.10 g / cm³, preferably equal to or greater than 1.15 g / cm³, more preferably equal to or greater than 1.20 g / cm³, more preferably equal to or greater than 1.25 g / cm³, more preferably equal to or greater than 1.30 g / cm³, more preferably equal to or greater than 1.35 g / cm³, more preferably equal to or greater than 1.40 g / cm³, and even more preferably equal to or greater than 1.42 g / cm³.

[0070] In embodiments of the method of the present invention, the apparent density of the ceramic structure as detailed above ranges from 1.10 g / cm³ to 1.85 g / cm³, preferably from 1.15 g / cm³ to 1.80 g / cm³, more preferably from 1.20 g / cm³ to 1.75 g / cm³, more preferably from 1.25 g / cm³ to 1.70 g / cm³, more preferably from 1.30 g / cm³ to 1.65 g / cm³, more preferably from 1.35 g / cm³ to 1.60 g / cm³, more preferably from 1.40 g / cm³ to 1.55 g / cm³, and even more preferably from 1.42 g / cm³ to 1.52 g / cm³.

[0071] The method according to the invention includes step 2: providing at least one slurry S1 comprising solid particles [hereinafter, solid particles A] and at least one liquid phase, wherein the solid particles A have a d 50 The particle size is equal to or greater than 1.00 µm and less than 30.00 µm.

[0072] slurry In the context of this invention, the expression "at least one slurry S1" is intended to mean one or more slurries S1.

[0073] Slurry S1 contains solid particles [hereinafter, solid particles A]. It goes without saying that solid particles A of any shape can be used according to the present invention. The shape of solid particles A of the present invention can be spherical, flake-like, plate-like, or a mixture thereof.

[0074] Typically, the properties of solid particle A can be selected by those skilled in the art based on the intended application. According to the present invention, solid particle A can be selected to improve the performance characteristics of ceramic articles in terms of thermal strength, high resistance, and durability. Generally, those skilled in the art will be able to suitably select appropriate solid particle A to improve the performance characteristics of ceramic articles in terms of thermal strength, high resistance, and durability.

[0075] Specifically, solid particles A can be made of inorganic materials, preferably refractory materials.

[0076] Advantageously, solid particle A is selected from the group consisting of: alumina, zirconium oxide, zirconium silicate, aluminum silicate, silicon carbide, cerium oxide, titanium oxide, magnesium oxide, and mixtures of two or more thereof. Preferably, solid particle A is selected from the group consisting of: alumina, zirconium oxide, aluminum silicate, titanium oxide, magnesium oxide, and mixtures of two or more thereof.

[0077] Advantageously, solid particles A may contain impurities of less than 3.00 wt.%, preferably less than 2.00 wt.%, and more preferably less than 1.00 wt.% relative to the total weight of solid particles A.

[0078] Advantageously, the d of solid particle A 50 The particle size is equal to or less than 25.00 µm, more preferably equal to or less than 20.00 µm, more preferably equal to or less than 17.00 µm, more preferably equal to or less than 14.00 µm, and even more preferably equal to or less than 11.00 µm. It should be further understood that the d of solid particle A... 50 The lower limit for particle size is equal to or greater than 1.00 µm.

[0079] In embodiments of the method of the present invention, the d of the solid particle A as detailed above... 50 The particle size ranges from 1.00 µm to 30.00 µm, preferably from 1.00 µm to 25.00 µm, more preferably from 1.00 µm to 20.00 µm, more preferably from 1.00 µm to 17.00 µm, more preferably from 1.00 µm to 14.00 µm, and even more preferably from 1.00 µm to 11.00 µm.

[0080] Advantageously, when solid particle A is alumina, preferably activated alumina, d 50 The particle size ranges from 1.0 µm to 6 µm, more preferably from 1.2 µm to 5.0 µm, and even more preferably from 1.5 µm to 4 µm.

[0081] Advantageously, when solid particle A is plate-shaped alumina, d 50 The particle size ranges from 1 µm to 20 µm, preferably from 1.5 µm to 18 µm, more preferably from 2.0 µm to 15.0 µm, even more preferably from 3.0 µm to 15.0 µm, and even more preferably from 5.0 µm to 12.0 µm, with the most preferred value being from 7.0 µm to 12.0 µm.

[0082] Advantageously, slurry S1 has a content of solid particles A equal to or greater than 35.00 wt.%, preferably equal to or greater than 40.00 wt.%, more preferably equal to or greater than 45.00 wt.%, and even more preferably equal to or greater than 50.00 wt.% [hereinafter, solid content] relative to the total weight of slurry S1. It should be further understood that the upper limit of the content of solid particles A in slurry S1 relative to the total weight of slurry S1 is advantageously equal to or less than 95.00 wt.%, preferably equal to or less than 90.00 wt.%, more preferably equal to or less than 85.00 wt.%, even more preferably equal to or less than 80.00 wt.%, more preferably equal to or less than 70.00 wt.%, and most preferably equal to or less than 60.00 wt.%.

[0083] In embodiments of the method of the present invention, the content of solid particles A in slurry S1, as detailed above, ranges from 35.00 wt.% to 95.00 wt.%, preferably 40.00 wt.% to 90.00 wt.%, more preferably 45.00 wt.% to 85.00 wt.%, more preferably 50.00 wt.% to 80.00 wt.%, more preferably 50.00 wt.% to 70.00 wt.%, and most preferably 50.00 wt.% to 60.00 wt.%, relative to the total weight of slurry S1.

[0084] As mentioned, slurry S1 contains at least one liquid phase.

[0085] In the context of this invention, the expression "at least one liquid phase" is intended to mean one or more liquid phases.

[0086] Typically, the properties of the liquid phase can be selected by those skilled in the art according to their intended purpose.

[0087] Advantageously, the liquid phase of slurry S1 is a solvent selected from the group consisting of: water, ethanol, isopropanol, acetone, monopropylene glycol, and mixtures thereof.

[0088] The slurry S1 may further contain at least one additive for improving the viscosity of the slurry S1. Typically, the nature of this at least one additive in the slurry S1 can be selected by those skilled in the art according to their purpose. Preferably, the at least one additive in the slurry S1 is a thickener, defoamer, dispersant, wetting agent, or a mixture thereof. Preferably, the additive in the slurry S1 is an organic additive. For example, the thickener in the slurry S1 may be xanthan gum. For example, the dispersant in the slurry S1 may be a composition containing carboxylic acids, such as Dolapix CE 64®. For example, the defoamer in the slurry S1 may be an aqueous emulsion of vegetable oil, polyether, and nonionic emulsifier, such as Agtan DF 6686 W®.

[0089] Advantageously, relative to the total weight of pulp S1, the content of additives in pulp S1, as detailed above, is equal to or greater than 1.00 wt.%, preferably equal to or greater than 2.00 wt.%, and more preferably equal to or greater than 3.00 wt.%. It should be further understood that, relative to the total weight of pulp S1, the upper limit of additives in pulp S1 is advantageously equal to or less than 15.00 wt.%, preferably equal to or less than 10.00 wt.%, more preferably equal to or less than 8.00 wt.%, and even more preferably equal to or less than 6.00 wt.%.

[0090] In embodiments of the method of the present invention, the content of additives in slurry S1 ranges from 1.00 wt.% to 15.00 wt.%, preferably 2.00 wt.% to 10.00 wt.%, preferably 3.00 wt.% to 8.00 wt.%, preferably 3.00 wt.% to 6.00 wt.%, relative to the total weight of slurry S1.

[0091] Advantageously, slurry S1 has a viscosity equal to or greater than 70.00 mPa·s, preferably equal to or greater than 80.00 mPa·s, preferably equal to or greater than 90.00 mPa·s, more preferably equal to or greater than 100.00 mPa·s, even more preferably equal to or greater than 110.00 mPa·s, and most preferably equal to or greater than 120.00 mPa·s. It should be further understood that the upper limit of the viscosity of slurry S1 is equal to or less than 200.00 mPa·s.

[0092] Slurry S1 can be prepared by a method including mixing the various components contained in slurry S1 as detailed above. Furthermore, it should be understood that any mixing order of the various components contained in slurry S1 as detailed above is acceptable.

[0093] The mixing described above can be performed using a variety of mixing methods known in the art. Non-limiting examples of such mixing methods include bubbling or mechanical mixing, such as conventional mixers and blenders, high-intensity mixers, and electric stirrers.

[0094] It should be understood that those skilled in the art will perform the mixing in accordance with general practice, such as noteworthy use of optimal time, weight, volume, and batch quantities. The mixing can be carried out at room temperature.

[0095] Dipping The method of the present invention includes step 3: impregnating at least a portion of the ceramic structure at least once in the slurry S1, thereby impregnating at least partially the open pores of the ceramic structure with solid particles A [hereinafter, the impregnated ceramic structure].

[0096] In other words, the ceramic structure or at least a portion thereof, as detailed above, is impregnated in the slurry S1 as detailed above, thereby impregnating the openings of the ceramic structure at least partially with the solid particles A as detailed above.

[0097] In the context of this invention, the expression "at least one impregnation" is intended to mean one or more impregnations.

[0098] Generally, it should be understood that any impregnation step known to those skilled in the art can be used to impregnate ceramic structures with the aim of at least partially impregnating the open porosity of the ceramic structure with solid particles A. It should be understood that those skilled in the art will perform the impregnation according to general practice, such as using optimal time, weight, volume, and batch size.

[0099] The inventors have unexpectedly discovered that by impregnating the ceramic structure described above in the slurry S1, the resulting impregnated ceramic structure exhibits improved thermal strength and is less prone to crack propagation. Unbound by this theory, the inventors believe that when solid particles A impregnate the open pores of the ceramic structure, the impregnated ceramic structure possesses higher density and lower porosity.

[0100] Depending on the properties and form of the ceramic structure, the impregnation step (step 3) can be performed in different ways. For example, the ceramic structure can be at least partially or completely immersed in the slurry S1, preferably, the ceramic structure is completely immersed in the slurry S1.

[0101] The immersion time can be selected to achieve the desired immersion target. Preferably, the immersion time is equal to or less than 120 s, more preferably equal to or less than 90 s, more preferably equal to or less than 60 s, even more preferably equal to or less than 40 s, and most preferably equal to or less than 30 s.

[0102] Preferably, before and / or during the impregnation step (step 3), the slurry S1 is stirred to improve the dispersion of solid particles A in the slurry S1. Typically, stirring can be performed using bubbling or mechanical mixing such as conventional mixers and blenders, high-intensity mixers, and electric agitators, wherein the mixers, blenders, and agitators may be equipped with at least one dispersion disc.

[0103] The impregnation step (step 3) can be carried out at room temperature.

[0104] The method according to the invention may include one or more impregnation steps (i.e., step 3 may be repeated once or multiple times). Therefore, the method according to the invention may include at least two impregnation steps, or at least three impregnation steps, or at least four impregnation steps, or at least five impregnation steps, or at least six impregnation steps. Generally, those skilled in the art will be able to select an appropriate number of impregnation steps to improve the performance characteristics of the ceramic structure in terms of thermal strength, high resistance, and durability. It should be further understood that the upper limit of the impregnation steps (step 3) is not critical. However, five, six, seven, eight, nine, or ten impregnation steps are particularly preferred.

[0105] According to embodiments of the present invention, the expression "one or more impregnation steps" means two impregnation steps, three impregnation steps, four impregnation steps, or five impregnation steps.

[0106] It should be further understood that all the definitions and preferences described above also apply to the additional impregnation steps. It should also be understood that all the definitions and preferences described above can vary from one impregnation step to another. For example, the solid particles A, the liquid phase, and the impregnation conditions detailed above can vary from one impregnation step to another. For instance, at least a portion of the ceramic structure can undergo a first impregnation step in a slurry S1 containing alumina as solid particles A and water as the liquid phase, thereby at least partially impregnating the open pores of the ceramic structure with alumina as solid particles A, and then further undergo a second impregnation step in a slurry S1 containing alumina and zirconium oxide as solid particles A and water as the liquid phase, thereby further at least partially impregnating the open pores of the ceramic structure with alumina and zirconium oxide as solid particles A.

[0107] Advantageously, the impregnated ceramic structure has an open porosity of 5.00% or greater, preferably 7.00% or greater, more preferably 9.00% or greater, more preferably 11.00% or greater, more preferably 13.00% or greater, more preferably 15.00% or greater, more preferably 17.00% or greater, and even more preferably 19.00% or greater. It should be further understood that the upper limit of the open porosity of the impregnated ceramic structure is advantageously equal to or less than 41.00%, preferably equal to or less than 39.00%, more preferably equal to or less than 37.00%, more preferably equal to or less than 35.00%, more preferably equal to or less than 33.00%, more preferably equal to or less than 31.00%, more preferably equal to or less than 29.00%, and even more preferably equal to or less than 27.00%.

[0108] In embodiments of the method of the present invention, the porosity of the impregnated ceramic structure, as detailed above, ranges from 5.00% to 41.00%, preferably 7.00% to 39.00%, more preferably 9.00% to 37.00%, more preferably 11.00% to 35.00%, more preferably 13.00% to 33.00%, more preferably 15.00% to 31.00%, more preferably 17.00% to 29.00%, and even more preferably 19.00% to 27.00%.

[0109] Advantageously, the impregnated ceramic structure has an apparent density equal to or greater than 1.90 g / cm³, preferably equal to or greater than 1.95 g / cm³, more preferably equal to or greater than 2.00 g / cm³, more preferably equal to or greater than 2.05 g / cm³, more preferably equal to or greater than 2.10 g / cm³, more preferably equal to or greater than 2.15 g / cm³, more preferably equal to or greater than 2.20 g / cm³, and even more preferably equal to or greater than 2.23 g / cm³. It should be further understood that the upper limit of the apparent density of the impregnated ceramic structure is advantageously equal to or less than 2.70 g / cm³, preferably equal to or less than 2.65 g / cm³, more preferably equal to or less than 2.60 g / cm³, more preferably equal to or less than 2.55 g / cm³, more preferably equal to or less than 2.50 g / cm³, more preferably equal to or less than 2.45 g / cm³, more preferably equal to or less than 2.40 g / cm³, and even more preferably equal to or less than 2.37 g / cm³.

[0110] In embodiments of the present invention, the apparent density of the impregnated ceramic structure, as detailed above, ranges from 1.90 g / cm³ to 2.70 g / cm³, preferably from 1.95 g / cm³ to 2.65 g / cm³, more preferably from 2.00 g / cm³ to 2.60 g / cm³, more preferably from 2.05 g / cm³ to 2.55 g / cm³, more preferably from 2.10 g / cm³ to 2.50 g / cm³, more preferably from 2.15 g / cm³ to 2.45 g / cm³, more preferably from 2.20 g / cm³ to 2.40 g / cm³, and even more preferably from 2.23 g / cm³ to 2.37 g / cm³.

[0111] Advantageously, the impregnated ceramic structure has a weight gain of 20.00% or higher, preferably 30.00% or higher, more preferably 40.00% or higher, and even more preferably 50.00% or higher. It should be further understood that the upper limit of the weight gain of the impregnated ceramic structure is equal to or less than 95.00%, preferably equal to or less than 90.00%, and more preferably equal to or less than 80.00%.

[0112] In embodiments of the present invention, the weight gain of the impregnated ceramic structure ranges from 20.00% to 95.00%, preferably 30.00% to 90.00%, preferably 40.00% to 80.00%, or 50.00% to 80.00%.

[0113] In the context of this invention, the term "weight gain" is intended to refer to the difference between the weight of the ceramic structure before the impregnation step and the weight of the impregnated ceramic structure after the impregnation step. Generally, the term "weight gain" refers to an increase in weight.

[0114] Typically, weight gain can be measured using methods known in the art. Unless otherwise stated, in the context of this invention, the method used to measure weight gain is a weighing method. Preferably, the weight gain of an object is the difference between the initial weight of the object measured before the impregnation step and the final weight of the object measured after the impregnation step, expressed as a percentage (%).

[0115] The method according to the invention may further include, after step 3, drying the impregnated ceramic structure at a temperature of at least 90°C.

[0116] Drying can be carried out using a variety of drying apparatuses known in the art. Non-limiting examples of such drying apparatuses include conventional drying apparatuses used in the refractory materials industry, such as hot air dryers. Generally, it should be understood that any drying step known to those skilled in the art can be used to dry impregnated ceramic structures for the purpose of removing the liquid phase from the impregnated ceramic structure.

[0117] Advantageously, the drying of the impregnated ceramic structure is carried out at a temperature equal to or greater than 100°C, more preferably equal to or greater than 110°C, and even more preferably equal to or greater than 115°C. It should be further understood that the upper limit of the temperature for drying the impregnated ceramic structure is advantageously equal to or less than 150°C, preferably equal to or less than 140°C, more preferably equal to or less than 130°C, and even more preferably equal to or less than 125°C.

[0118] In embodiments of the present invention, the temperature range for drying the impregnated ceramic structure as detailed above is preferably 90°C to 150°C, more preferably 100°C to 140°C, more preferably 110°C to 130°C, and even more preferably 115°C to 125°C.

[0119] Advantageously, when the method of the present invention includes more than one impregnation step, a drying step as detailed above is performed between each impregnation step.

[0120] Coating The method according to the invention may further include the step of coating at least a portion of the surface of the impregnated ceramic structure with the slurry S1 as detailed above. It should be understood that all the definitions and preferences described above for the slurry S1 also apply to the coating step.

[0121] It should also be understood that all the definitions and preferences described above for slurry S1 can vary from the impregnation step to the coating step. Preferably, the coating step is the step of completely coating the surface of the impregnated ceramic structure with the slurry S1 as detailed above.

[0122] Therefore, according to one embodiment of the present invention, the method according to the present invention includes, after step 3, coating at least a portion of the surface of the impregnated ceramic structure with a slurry S1 containing solid particles A as detailed above.

[0123] Alternatively, the method according to the invention may further include using at least one slurry [hereinafter, S] 涂覆 The step of coating at least a portion of the surface of the impregnated ceramic structure with a slurry, wherein the slurry is different from at least one slurry used in the impregnation step 3 as detailed above, wherein slurry S 涂覆 It comprises solid particles [hereinafter, solid particles C] and at least one liquid phase, wherein the solid particles C have a d 50 The particle size ranges from 0.05 µm to 30.0 µm.

[0124] Slurry S 涂覆 The solid particles C can have any shape known to those skilled in the art, such as spherical, flake, plate, and mixed shapes.

[0125] Typically, slurry S 涂覆 The properties of the solid particles C can be selected by those skilled in the art based on the intended application. According to this embodiment, the slurry S can be selected. 涂覆 Solid particles C are used to improve the performance characteristics of impregnated ceramic structures in terms of thermal strength, high resistance, and durability. Additionally, slurry S can be selected. 涂覆 The properties of solid particles C are used to provide improved resistance of the impregnated ceramic structure to molten metal erosion.

[0126] Specifically, slurry S 涂覆 The solid particles C can be made of inorganic materials, preferably refractory materials.

[0127] Advantageously, slurry S 涂覆 The solid particles C are selected from the group consisting of: alumina, zirconium oxide, zirconium silicate, aluminum silicate, silicon carbide, cerium oxide, titanium oxide, magnesium oxide, and mixtures of two or more of these. Preferably, the slurry S... 涂覆 The solid particles C are selected from the group consisting of: alumina, zirconium oxide, aluminum silicate, titanium oxide, magnesium oxide, and mixtures of two or more of these. More preferably, the slurry S 涂覆 The solid particles C are selected from the following group: alumina, zirconium oxide and mixtures thereof.

[0128] Advantageously, slurry S 涂覆 The solid particles C may contain impurities of less than 3.00 wt.%, preferably less than 2.00 wt.%, and more preferably less than 1.00 wt.% relative to the total weight of the solid particles C.

[0129] Advantageously, slurry S 涂覆 solid particles C of d 50 The particle size is equal to or less than 25.00 µm, more preferably equal to or less than 20.00 µm, more preferably equal to or less than 17.00 µm, more preferably equal to or less than 14.00 µm, and even more preferably equal to or less than 11.00 µm. It should be further understood that the slurry S 涂覆 solid particles C of d 50 The lower limit of the particle size value is advantageously equal to or greater than 0.05 µm, preferably equal to or greater than 0.10 µm, more preferably equal to or greater than 0.25 µm, more preferably equal to or greater than 0.50 µm, more preferably equal to or greater than 0.75 µm, and even more preferably equal to or greater than 1.00 µm.

[0130] In embodiments of the method of the present invention, the slurry S as detailed above... 涂覆 solid particles C of d 50 The particle size ranges from 0.05 µm to 30.00 µm, preferably from 0.10 µm to 25.00 µm, more preferably from 0.25 µm to 20.00 µm, more preferably from 0.50 µm to 17.00 µm, more preferably from 0.75 µm to 14.00 µm, and even more preferably from 1.00 µm to 11.00 µm.

[0131] Advantageously, when slurry S 涂覆 When the solid particle C is zirconium oxide, d 50 The particle size ranges from 0.1 µm to 10.0 µm, preferably from 0.2 µm to 7 µm, more preferably from 0.3 µm to 6 µm, even more preferably from 0.4 µm to 5.0 µm, and even more preferably from 0.5 µm to 4.0 µm, with the most preferred range being from 0.6 µm to 2.0 µm.

[0132] Advantageously, when slurry S 涂覆 When the solid particle C is alumina, preferably activated alumina, d 50 The particle size ranges from 0.5 µm to 10 µm, more preferably from 0.7 µm to 7 µm, more preferably from 1.0 µm to 6 µm, more preferably from 1.2 µm to 5.0 µm, and even more preferably from 1.5 µm to 4 µm.

[0133] Advantageously, when slurry S 涂覆 When the solid particle C is plate-shaped alumina, d 50The particle size ranges from 1 µm to 20 µm, preferably from 1.5 µm to 18 µm, more preferably from 2.0 µm to 15.0 µm, even more preferably from 3.0 µm to 15.0 µm, and even more preferably from 5.0 µm to 12.0 µm, with the most preferred value being from 7.0 µm to 12.0 µm.

[0134] Advantageously, slurry S 涂覆 Having relative to slurry S 涂覆 The total weight of solid particles C is equal to or greater than 35.00 wt.%, preferably equal to or greater than 40.00 wt.%, more preferably equal to or greater than 45.00 wt.%, and even more preferably equal to or greater than 50.00 wt.% [hereinafter, solid content]. It should be further understood that, relative to the slurry S 涂覆 Total weight of slurry S 涂覆 The upper limit of the content of solid particles C is advantageously equal to or less than 95.00 wt.%, preferably equal to or less than 90.00 wt.%, more preferably equal to or less than 85.00 wt.%, even more preferably equal to or less than 80.00 wt.%, more preferably equal to or less than 70.00 wt.%, and most preferably equal to or less than 60.00 wt.%.

[0135] In an embodiment of the method of the present invention, relative to slurry S 涂覆 The total weight, as detailed above for slurry S 涂覆 The content of C in the medium solid particles ranges from 35.00 wt.% to 95.00 wt.%, preferably 40.00 wt.% to 90.00 wt.%, more preferably 45.00 wt.% to 85.00 wt.%, more preferably 50.00 wt.% to 80.00 wt.%, more preferably 50.00 wt.% to 70.00 wt.%, and most preferably 50.00 wt.% to 60.00 wt.%.

[0136] As mentioned, slurry S 涂覆 It contains at least one liquid phase.

[0137] In the context of this invention, the expression "at least one liquid phase" is intended to mean one or more liquid phases.

[0138] Typically, slurry S 涂覆 The properties of the liquid phase can be selected by those skilled in the art according to their intended purpose.

[0139] Advantageously, slurry S 涂覆 The liquid phase is a solvent selected from the group consisting of: water, ethanol, isopropanol, acetone, monopropylene glycol, and mixtures thereof.

[0140] Slurry S 涂覆It may further include ingredients for improving slurry S 涂覆 At least one additive that increases the viscosity of the slurry. Typically, the slurry S... 涂覆 The properties of the at least one additive in the slurry can be selected by those skilled in the art according to their purpose. Preferably, the at least one additive is a thickener, defoamer, dispersant, wetting agent, or a mixture thereof. Preferably, the slurry S 涂覆 The additives in it are organic additives. For example, slurry S 涂覆 The thickener in the paste can be xanthan gum. For example, slurry S 涂覆 The dispersant in the mixture can be a composition containing carboxylic acids, such as Dolapix CE 64®. For example, slurry S 涂覆 The defoamer in the solution can be an aqueous emulsion of vegetable oil, polyether, or nonionic emulsifier, such as Agtan DF 6686 W®.

[0141] Advantageously, relative to slurry S 涂覆 The total weight, as detailed above for slurry S 涂覆 The content of additives is equal to or greater than 1.00 wt.%, preferably equal to or greater than 2.00 wt.%, and preferably equal to or greater than 3.00 wt.%. It should be further understood that, relative to slurry S... 涂覆 Total weight of slurry S 涂覆 The upper limit of the additive is advantageously equal to or less than 15.00 wt.%, preferably equal to or less than 10.00 wt.%, more preferably equal to or less than 8.00 wt.%, and even more preferably equal to or less than 6.00 wt.%.

[0142] In an embodiment of the method of the present invention, relative to slurry S 涂覆 Total weight of slurry S 涂覆 The content of the additive ranges from 1.00 wt.% to 15.00 wt.%, preferably from 2.00 wt.% to 10.00 wt.%, preferably from 3.00 wt.% to 8.00 wt.%, preferably from 3.00 wt.% to 6.00 wt.%.

[0143] Advantageously, slurry S 涂覆 It has a viscosity equal to or greater than 70.00 mPa·s, preferably equal to or greater than 80.00 mPa·s, preferably equal to or greater than 90.00 mPa·s, more preferably equal to or greater than 100.00 mPa·s, even more preferably equal to or greater than 110.00 mPa·s, and most preferably equal to or greater than 120.00 mPa·s. It should be further understood that the slurry S 涂覆 The upper limit of viscosity is equal to or less than 200.00 mPa·s.

[0144] Slurry S 涂覆It can be prepared by methods including mixing the various components contained in the slurry as detailed above. Furthermore, it should be understood that the slurry S detailed above... 涂覆 Any mixing order of the various components contained herein is acceptable.

[0145] The mixing described above can be performed using a variety of mixing methods known in the art. Non-limiting examples of such mixing methods include bubbling or mechanical mixing, such as conventional mixers and blenders, high-intensity mixers, and electric stirrers.

[0146] It should be understood that those skilled in the art will perform the mixing according to general practice, such as noteworthy use of optimal time, weight, volume, and batch size. Mixing can be carried out at room temperature.

[0147] Generally, it should be understood that any coating step known to a person skilled in the art can be used to coat an impregnated ceramic structure with the aim of forming a coated ceramic structure. This can be achieved using slurry S1 or slurry S as detailed above. 涂覆 Suitable methods for at least partially coating the surface of the impregnated ceramic structure as detailed above include spraying, flow coating, impregnating, dipping, spreading, pouring, etc. Preferably, the coating step is performed by applying the slurry S1 or slurry S as detailed above. 涂覆 The coating is performed by at least partially impregnating the ceramic structure as detailed above. Preferably, the coating step is carried out by applying the slurry S1 or slurry S2 as detailed above. 涂覆 The process involves complete impregnation of the ceramic structure as detailed above.

[0148] The inventors have discovered that when an impregnated ceramic structure is coated with slurry S1 to form a coated ceramic structure, the coated ceramic structure exhibits improved resistance, particularly to impregnation with molten metal. Unbound by this theory, the inventors believe that the coating on the impregnated ceramic structure prevents molten metal from entering the pores of the coated ceramic structure.

[0149] The inventors also discovered that when the impregnated ceramic structure is coated with a slurry S containing solid particles C, 涂覆 At that time, a specific d 50 The particle size allows for the acquisition of coated ceramic structures with improved resistance, particularly to impregnation with molten metal, by providing a uniform coating across the entire surface of the impregnated ceramic structure, while limiting or inhibiting cracking of this coating, especially when in contact with molten metal. Preferably, the coating step is performed using a slurry S1 or coating S as detailed above. 涂覆 The entire surface of the coated and impregnated ceramic structure.

[0150] When the method according to the invention includes a coating step, the slurry S1 or slurry S2 used in the coating step 涂覆 It can have a higher content than the slurry S1 or S used in the impregnation step. 涂覆 The content of solid particles A or C is higher. Advantageously, the slurry S1 or slurry S2 used in the coating step has a higher solid content. 涂覆 The slurry has a solid particle content of A or C of 35.00 wt.%, preferably 40.00 wt.%, more preferably 45.00 wt.%, and even more preferably 50.00 wt.%, relative to the total weight of the slurry [hereinafter, solid content]. It should be further understood that, relative to slurry S1 or slurry S... 涂覆 The total weight of slurry S1 or slurry S2 used in the coating step. 涂覆 The upper limit of the content of solid particles A or solid particles C is advantageously equal to or less than 95.00 wt.%, preferably equal to or less than 90.00 wt.%, more preferably equal to or less than 85.00 wt.%, even more preferably equal to or less than 80.00 wt.%, more preferably equal to or less than 70.00 wt.%.

[0151] In an embodiment of the method of the present invention, the content of solid particles A in the slurry S1 used for the coating step ranges from 35.00 wt.% to 95.00 wt.%, preferably 40.00 wt.% to 90.00 wt.%, more preferably 45.00 wt.% to 85.00 wt.%, more preferably 50.00 wt.% to 80.00 wt.%, and more preferably 50.00 wt.% to 70.00 wt.%, relative to the total weight of the slurry S1.

[0152] In another embodiment of the method of the present invention, relative to slurry S 涂覆 The total weight of the slurry S used in the coating step 涂覆 The content of C in the medium solid particles ranges from 35.00 wt.% to 95.00 wt.%, preferably from 40.00 wt.% to 90.00 wt.%, more preferably from 45.00 wt.% to 85.00 wt.%, more preferably from 50.00 wt.% to 80.00 wt.%, and even more preferably from 50.00 wt.% to 70.00 wt.%.

[0153] Advantageously, when used in the coating step, slurry S1 or slurry S 涂覆 It further comprises at least one additive as detailed above. Preferably, when the method includes a coating step, slurry S1 or slurry S... 涂覆 The additives included are thickeners. Typically, the purpose of thickeners is to increase the viscosity of slurry S1 or slurry S... 涂覆The viscosity. Unbound by this theory, thickeners are designed to prevent slurry S1 or slurry S... 涂覆 Further impregnation of the ceramic structure's pores improves the coating process.

[0154] Advantageously, the impregnated and coated ceramic structure has an open porosity of 7.00%, 9.00%, 11.00%, 13.00%, 15.00%, 17.00%, 19.00%, or 21.00%. It should be further understood that, after coating, the upper limit of the open porosity of the impregnated ceramic structure is advantageously equal to or less than 41.00%, preferably equal to or less than 39.00%, more preferably equal to or less than 37.00%, more preferably equal to or less than 35.00%, more preferably equal to or less than 33.00%, more preferably equal to or less than 31.00%, more preferably equal to or less than 29.00%, and even more preferably equal to or less than 27.00%.

[0155] In embodiments of the method of the present invention, the open porosity of the impregnated and coated ceramic structure as detailed above ranges from 7.00% to 41.00%, or 9.00% to 39.00%, or 11.00% to 37.00%, or 13.00% to 35.00%, or 15.00% to 33.00%, or 17.00% to 31.00%, or 19.00% to 29.00%, or 21.00% to 27.00%.

[0156] Advantageously, the impregnated and coated ceramic structure has an apparent density equal to or greater than 1.90 g / cm³, preferably equal to or greater than 1.95 g / cm³, more preferably equal to or greater than 2.00 g / cm³, more preferably equal to or greater than 2.05 g / cm³, more preferably equal to or greater than 2.10 g / cm³, more preferably equal to or greater than 2.15 g / cm³, and more preferably equal to or greater than 2.20 g / cm³. It should be further understood that, after coating, the upper limit of the apparent density of the impregnated ceramic structure is advantageously equal to or less than 2.70 g / cm³, preferably equal to or less than 2.65 g / cm³, more preferably equal to or less than 2.60 g / cm³, more preferably equal to or less than 2.55 g / cm³, more preferably equal to or less than 2.50 g / cm³, more preferably equal to or less than 2.45 g / cm³, more preferably equal to or less than 2.40 g / cm³, and even more preferably equal to or less than 2.35 g / cm³.

[0157] In embodiments of the present invention, the apparent density of the impregnated and coated ceramic structure, as detailed above, ranges from 1.90 g / cm³ to 2.70 g / cm³, preferably from 1.95 g / cm³ to 2.65 g / cm³, more preferably from 2.00 g / cm³ to 2.60 g / cm³, more preferably from 2.05 g / cm³ to 2.55 g / cm³, more preferably from 2.10 g / cm³ to 2.50 g / cm³, more preferably from 2.15 g / cm³ to 2.45 g / cm³, more preferably from 2.20 g / cm³ to 2.40 g / cm³, and even more preferably from 2.20 g / cm³ to 2.35 g / cm³.

[0158] Advantageously, the impregnated and coated ceramic structure has a weight gain of 5.00% or greater, preferably 7.00% or greater, more preferably 10.00% or greater, and even more preferably 15.00% or greater. It should be further understood that, after coating, the upper limit of the weight gain of the impregnated ceramic structure is equal to or less than 50.00%, preferably equal to or less than 40.00%, and more preferably equal to or less than 35.00%.

[0159] In embodiments of the present invention, the weight gain of the impregnated and coated ceramic structure ranges from 5.00% to 50.00%, preferably 7.00% to 40.00%, preferably 10.00% to 30.00%, and even more preferably 15.00% to 35.00%.

[0160] The term "weight gain" has the same meaning as described above for impregnated ceramic structures. The weight gain of an impregnated and coated ceramic structure is the difference between the initial weight of the impregnated ceramic structure measured before the coating step and the final weight of the impregnated and coated ceramic structure measured after the coating step, expressed as a percentage (%).

[0161] The method according to the invention may further include at least one firing step of the impregnated ceramic structure before and / or after coating the impregnated ceramic structure, thereby forming a fired ceramic article.

[0162] Preferably, the firing temperature is selected to achieve sintering of the impregnated ceramic structure. The definition of pre-sintering as detailed above also applies to sintering. It should be understood that those skilled in the art will be able to select the firing temperature of the impregnated ceramic structure for the purpose of sintering the impregnated ceramic structure.

[0163] Advantageously, the firing step is carried out at a temperature equal to or greater than 1400°C, preferably equal to or greater than 1450°C, more preferably equal to or greater than 1500°C, and even more preferably equal to or greater than 1550°C. It should be further understood that the upper limit of the firing temperature is advantageously equal to or less than 1800°C, preferably equal to or less than 1750°C, more preferably equal to or less than 1700°C, and even more preferably equal to or less than 1650°C.

[0164] In embodiments of the present invention, the temperature range of the firing step as detailed above is 1400°C to 1800°C, preferably 1450°C to 1750°C, more preferably 1500°C to 1700°C, and even more preferably 1550°C to 1650°C.

[0165] Advantageously, the shrinkage rate of the fired ceramic article is equal to or greater than 0.50%, preferably equal to or greater than 0.70%, preferably equal to or greater than 1.00%, more preferably equal to or greater than 1.20%, and even more preferably equal to or greater than 1.50%. It should be further understood that the upper limit of the shrinkage rate of the fired ceramic article is equal to or less than 5.00%, preferably equal to or less than 4.00%, preferably equal to or less than 3.00%, and even more preferably equal to or less than 2.00%.

[0166] In embodiments of the present invention, the shrinkage rate of the fired ceramic product ranges from 0.50% to 5.00%, preferably from 0.70% to 4.00%, preferably from 1.00% to 3.00%, more preferably from 1.20% to 2.00%, or from 1.50% to 2.00%.

[0167] In the context of this invention, the term "shrinkage rate" is intended to refer to the dimensional difference between the ceramic structure impregnated before the firing step and the ceramic article fired after the firing step. Generally, the term "shrinkage rate" refers to a reduction in size.

[0168] Typically, shrinkage levels can be measured using methods known in the art. Unless otherwise stated, in the context of this invention, the method used to measure shrinkage rate is a geometric method. Preferably, the shrinkage rate of an object is the difference between the initial length of the object measured before the firing step and the final length of the object measured after the firing step, expressed as a percentage (%).

[0169] The inventors have discovered that when the method includes a firing step, the material already impregnated in the ceramic structure specifically possesses d 50 Solid particles A with a particle size of less than 30.00 µm are used to improve sintering and thus improve the mechanical properties of ceramic products.

[0170] In a preferred embodiment, the method for manufacturing ceramic articles as detailed above includes the following steps: Step 1: Provide at least one ceramic structure obtained by a binder jet 3D ceramic printer using at least one ceramic compound and at least one binder, wherein the ceramic structure has an open porosity of at least 35.00%, wherein the ceramic compound is selected from the group consisting of alumina, zirconium oxide and mixtures thereof, and the binder is an organic binder; Step 2: Provide at least one slurry S1 comprising solid particles [hereinafter, solid particles A] and at least one liquid phase, wherein the solid particles A have a d 50 The particle size is equal to or greater than 1.00 µm and less than 30.00 µm, wherein the solid particles A are selected from the group consisting of: alumina, zirconium oxide, zirconium silicate, aluminum silicate, silicon carbide, cerium oxide, titanium oxide, magnesium oxide and mixtures of two or more of these, and wherein the content of solid particles A in slurry S1 [hereinafter, solid content] is at least 50.00% by weight relative to the total weight of slurry S1 [hereinafter, wt.%]; Step 3: Impregnate at least a portion of the ceramic structure at least once in the slurry S1, thereby impregnating at least partially the openings of the ceramic structure with solid particles A [hereinafter, the impregnated ceramic structure].

[0171] In an alternative embodiment, the method for manufacturing ceramic articles as detailed above includes the following steps: Step 1: Provide at least one ceramic structure obtained by a binder jet 3D ceramic printer using at least one ceramic compound and at least one binder, wherein the ceramic structure has an open porosity of at least 35.00%, wherein the ceramic compound is selected from the group consisting of alumina, zirconium oxide and mixtures thereof, and the binder is an organic binder; Step 2: Provide at least one slurry S1 comprising solid particles [hereinafter, solid particles A] and at least one liquid phase, wherein the solid particles A have a d 50 The particle size is equal to or greater than 1.00 µm and less than 30.00 µm, wherein the solid particles A are selected from the group consisting of: alumina, zirconium oxide, zirconium silicate, aluminum silicate, silicon carbide, cerium oxide, titanium oxide, magnesium oxide and mixtures of two or more of these, and wherein the content of solid particles A in slurry S1 [hereinafter, solid content] is at least 50.00% by weight relative to the total weight of slurry S1 [hereinafter, wt.%]; Step 3: Impregnate at least a portion of the ceramic structure at least once in the slurry S1, thereby impregnating at least partially the openings of the ceramic structure with solid particles A [hereinafter, the impregnated ceramic structure].

[0172] Step 4: In slurry S 涂覆The impregnated ceramic structure is impregnated at least once, thereby coating the impregnated ceramic structure at least partially with solid particles C.

[0173] Ceramic articles are another aspect of the present invention, said ceramic articles comprising: - At least one ceramic structure obtained by a binder jet 3D ceramic printer using at least one ceramic compound and at least one binder, wherein the ceramic structure has an open porosity including openings; -d 50 Solid particles with a particle size of 1.00 µm or greater and less than 30.00 µm [hereinafter, solid particles A], wherein the solid particles A are impregnated in the openings of the ceramic structure; The ceramic products have an open porosity between 7.00% and 41.00%.

[0174] According to one embodiment of the present invention, the ceramic article comprises: - At least one ceramic structure obtained by a binder jet 3D ceramic printer using at least one ceramic compound and at least one binder, wherein the ceramic structure has an open porosity including openings; -d 50 Solid particles with a particle size of 1.00 µm or greater and less than 30.00 µm [hereinafter, solid particles A], wherein the solid particles A are impregnated in the openings of the ceramic structure; -d 50 Solid particles with a particle size between 0.05 µm and 30.0 µm [hereinafter, solid particles C], wherein the solid particles C are coated and impregnated with a ceramic structure; The ceramic products have an open porosity between 7.00% and 41.00%.

[0175] It should be further understood that all the definitions and preferences described above also apply to ceramic products.

[0176] Advantageously, the ceramic articles are obtained according to the method of the present invention as detailed above.

[0177] Advantageously, the ceramic article has an open porosity of 34.00%, preferably 33.00%, more preferably 32.00%, more preferably 31.00%, more preferably 30.00%, more preferably 29.00%, more preferably 28.00%, and even more preferably 26.00%.

[0178] In embodiments of the present invention, the porosity of the ceramic article as detailed above ranges from 7.00% to 34.00%, preferably from 7.00% to 33.00%, more preferably from 7.00% to 32.00%, more preferably from 7.00% to 31.00%, more preferably from 7.00% to 30.00%, more preferably from 7.00% to 29.00%, more preferably from 7.00% to 28.00%, and even more preferably from 7.00% to 26.00%.

[0179] In a preferred embodiment, the ceramic article as detailed above comprises: - At least one ceramic structure obtained by a binder jet 3D ceramic printer using at least one ceramic compound and at least one binder, wherein the ceramic structure has an open porosity including openings, wherein the ceramic structure has an open porosity of at least 35.00%, wherein the ceramic compound is selected from the group consisting of alumina, zirconium oxide and mixtures thereof, and the binder is an organic binder. -d 50 Solid particles with a particle size of 1.00 µm or greater and less than 30.00 µm [hereinafter, solid particles A], wherein the solid particles A are impregnated in the openings of the ceramic structure, and wherein the solid particles A are selected from the group consisting of: alumina, zirconium oxide, zirconium silicate, aluminum silicate, silicon carbide, cerium oxide, titanium oxide, magnesium oxide, and mixtures of two or more of these. The ceramic products have an open porosity between 7.00% and 41.00%.

[0180] In one embodiment, the ceramic article as detailed above comprises: - At least one ceramic structure obtained by a binder jet 3D ceramic printer using at least one ceramic compound and at least one binder, wherein the ceramic structure has an open porosity including openings, wherein the ceramic structure has an open porosity of at least 35.00%, wherein the ceramic compound is selected from the group consisting of alumina, zirconium oxide and mixtures thereof, and the binder is an organic binder. -d 50 Solid particles with a particle size of 1.00 µm or greater and less than 30.00 µm [hereinafter, solid particles A], wherein the solid particles A are impregnated in the openings of the ceramic structure, and wherein the solid particles A are selected from the group consisting of: alumina, zirconium oxide, zirconium silicate, aluminum silicate, silicon carbide, cerium oxide, titanium oxide, magnesium oxide, and mixtures of two or more of these. -d 50Solid particles with a particle size between 0.05 µm and 30.00 µm [hereinafter, solid particles C], wherein the solid particles C are coated and impregnated with a ceramic structure, and wherein the solid particles C are selected from the group consisting of alumina, zirconium oxide and mixtures thereof; The ceramic products have an open porosity between 7.00% and 41.00%.

[0181] The use of the ceramic articles of the present invention, as detailed above, in ceramic casting filters for filtering molten metal is another aspect of the present invention.

[0182] It should be further understood that all the definitions and preferences described above also apply to the use of ceramic articles in ceramic casting filters for filtering molten metal.

[0183] In one embodiment, the ceramic article used in a ceramic casting filter for filtering molten metal comprises a plurality of pores having an average diameter greater than 1 mm, more preferably 3 mm to 10 mm.

[0184] In the context of this invention, it should be understood that the multiple pores in the ceramic article used in a ceramic casting filter for filtering molten metal are intended to represent spaces in the ceramic article not occupied by the structure of the ceramic article. In other words, the multiple pores are intended to represent spaces through which molten metal can pass.

[0185] The use of the ceramic articles of the present invention in wear-resistant parts, as detailed above, is another aspect of the present invention.

[0186] It should be further understood that all the definitions and preferences described above also apply to the use of ceramic articles in wear-resistant parts.

[0187] According to one embodiment, wear-resistant parts are used in high-wear applications.

[0188] In the context of this invention, high-wear applications are intended to refer to any application in which abrasives are processed.

[0189] Non-limiting examples of abrasives may include rocks, sand, and ores.

[0190] Non-limiting examples of wear-resistant parts for high-wear applications can include any part of equipment used in high-wear applications, such as parts of excavators, digging buckets, material crushers, conveyors, loaders, or cable shovels.

[0191] Example The invention will now be described in further detail with reference to the following examples, which are merely illustrative and not intended to limit the scope of the invention.

[0192] Test methods Measurement of open porosity and apparent density The measurements of open porosity and apparent density are performed according to the standard ASTM C20 (2022) detailed above. Standard Test Methods for Apparent Porosity, Water Absorption, Apparent Specific Gravity, and Bulk Density of Burned Refractory Brick and Shapes by Boiling Water [ The apparent porosity, water absorption, apparent specific gravity, and bulk density of fired refractory bricks and products were determined by boiling water. Quasi-testing method ]"conduct.

[0193] slurry The slurry is prepared by mixing solid particles A or C, water (as a solvent), and additives, as detailed in Tables 1 and 2.

[0194] Table 1: The slurry used in the impregnation and coating steps in the example Table 2: The slurry used in the impregnation and coating steps in the example Processes used for manufacturing ceramic products The following sections detail how to prepare ceramic articles according to the present invention.

[0195] The exact composition of the instance (regarding the types and quantities of the components contained therein) is described in Tables 1 and 2 above.

[0196] In the first step (i.e., step 1 of the method for manufacturing ceramic articles), a 3D ceramic printer with a binder jet is provided. 70 A ceramic structure was obtained using 150 µm pre-sintered zirconium oxide and cerium oxide particles (cerabeads®) as the ceramic compound and organic binder. The ceramic structure has an open porosity of 50%. The ceramic structure is shaped like a filter for molten metal filtration, with dimensions of 100 mm × 100 mm.

[0197] In the subsequent step (i.e., step 2 of the method for manufacturing ceramic articles), the slurry prepared as detailed above is provided at room temperature and atmospheric pressure.

[0198] Impregnation steps The ceramic structure was then impregnated in the slurry (i.e., step 3 of the method for manufacturing ceramic articles) for 10 s. Example 4 was carried out using two consecutive impregnation steps, first in a slurry with a solid content (particle A) of 72.0 wt.%, and then in a slurry with a solid content (particle A) of 66.0 wt.%, as detailed in Table 2. The impregnated ceramic structure was dried at 120°C after each impregnation step.

[0199] Coating steps The impregnated ceramic structures are then subjected to a coating step by impregnation (Examples 1 and 4) or casting (Examples 2 and 3) in the slurry detailed in Tables 1 and 2. Coating is performed within 5 seconds. Following the coating step, the impregnated and coated ceramic structures are dried at 120°C. The impregnated and coated ceramic structures are then fired at 1620°C, thereby forming a ceramic article.

[0200] Shrinkage and metal testing To evaluate the performance of the ceramic articles prepared according to the present invention in terms of thermal strength, high resistance and durability, the shrinkage rate was measured after the firing step.

[0201] The experimental results are shown in Table 3 below.

[0202] Table 3: Experimental results The experimental results shown in Table 3 first clearly demonstrate that the impregnation step using the slurry according to the invention (i.e., E1 to E4) provides a weight gain. This indicates that the particles A contained in slurry S1 impregnate the openings of the ceramic structure. Furthermore, the experimental results for E1 to E4 show a second weight gain after the coating step, confirming the coating of the impregnated ceramic structure with particles contained in the slurry used for coating. The shrinkage measured after the firing step also highlights the reduction in the open porosity of the ceramic article compared to the ceramic structure used in step 1. Examples 1-4 show open porosities between 15% and 30% after firing at 1620°C for 150 min. In particular, the shrinkage rates of Examples 1 and 4 are better than those of Examples 2 and 3. This is likely due to the fact that the weight gain after the impregnation step is lower for Examples 2 and 3.

[0203] Furthermore, the experimental results shown in Table 3 confirm that the ceramic articles obtained by the method according to the invention can be effectively used as filters for molten metal filtration. Consistent with previous results, the results of Examples 2 and 3 are slightly worse than those of Examples 1 and 4.

Claims

1. A method for manufacturing ceramic articles, the method comprising the following steps: Step 1: Provide at least one ceramic structure obtained by using at least one ceramic compound and at least one binder via a binder jet 3D ceramic printer, wherein the ceramic structure has an open porosity of at least 35.00%; Step 2: Provide at least one slurry S1 comprising solid particles [hereinafter, solid particles A] and at least one liquid phase, wherein the solid particles A have a d 50 Particle size equal to or greater than 1.00 µm and less than 30.00 µm; Step 3: Impregnate at least a portion of the ceramic structure at least once in the slurry S1, thereby impregnating at least partially the openings of the ceramic structure with the solid particles A [hereinafter, the impregnated ceramic structure].

2. The method according to claim 1, further comprising, after step 3, coating at least a portion of the surface of the impregnated ceramic structure with the slurry S1.

3. The method according to claim 1 or claim 2, wherein, The content of solid particles A in the slurry S1 [hereinafter, solid content] is at least 35.00% by weight [hereinafter, wt.%] relative to the total weight of the slurry S1.

4. The method according to any one of claims 1 to 3, wherein, The solid particle A is selected from the group consisting of: alumina, zirconium oxide, zirconium silicate, aluminum silicate, silicon carbide, cerium oxide, titanium oxide, magnesium oxide, and mixtures of two or more of these.

5. The method according to any one of claims 1 to 4, wherein, The ceramic compound is selected from the group consisting of: alumina, zirconium oxide, zirconium silicate, aluminum silicate, silicon oxide, silicon carbide, cerium oxide, titanium oxide, titanium carbide, magnesium oxide, tungsten carbide, and mixtures of two or more of these.

6. The method according to any one of claims 1 to 5, wherein, The ceramic compound is selected from the group consisting of: alumina, zirconium oxide, cerium oxide and mixtures thereof, preferably, the ceramic compound is a mixture of zirconium oxide and cerium oxide.

7. The method according to any one of claims 1 to 6, wherein, The ceramic compound is a pre-sintered ceramic compound.

8. The method according to any one of claims 1 to 7, wherein, The ceramic compound is composed of solid particles [hereinafter, solid particles B], wherein the solid particles B have a d 50 Particle size equal to or greater than 75.00 µm.

9. The method according to any one of claims 1 to 8, wherein, The adhesive is an organic adhesive, preferably selected from the group consisting of furan resins, phenolic resins, and mixtures thereof.

10. The method according to any one of claims 1 to 9, wherein, The liquid phase of the slurry S1 is a solvent selected from the group consisting of: water, ethanol, isopropanol, acetone and mixtures thereof.

11. The method according to any one of claims 1 to 10, the method further comprising, after step 3, drying the impregnated ceramic structure at a temperature of at least 90°C.

12. The method according to any one of claims 2 to 11, the method further comprising the step of firing the impregnated ceramic structure at a temperature of at least 1400°C before and / or after the coating step.

13. A ceramic article, said ceramic article comprising: - At least one ceramic structure obtained by a binder jet 3D ceramic printer using at least one ceramic compound and at least one binder, wherein the ceramic structure has an open porosity including openings; -d 50 Solid particles with a particle size equal to or greater than 1.00 µm and less than 30.00 µm [hereinafter, solid particles A], wherein the solid particles A are impregnated in the openings of the ceramic structure; The ceramic article described therein has an open porosity between 7.00% and 41.00%.

14. A ceramic article obtained by the method according to any one of claims 1 to 12, wherein, The ceramic product has an open porosity between 7.00% and 41.00%.

15. Use of the ceramic article according to claim 13 in a ceramic casting filter for filtering molten metal.

16. Use of the ceramic article according to claim 13 in wear-resistant parts for high-wear applications, wherein the abrasive is preferably selected from rocks, sand and ores.

Images