72 results about "Gel casting" patented technology

The invention provides a high-porosity ceramic bond diamond micro-powder grinding tool and a preparation method and application thereof. The preparation method comprises the following steps: preparing ceramic bond diamond micro-powder composite powder by adopting a sol-gel method; the preparation method comprises the following steps: preparing porous agglomerated diamond microspheres by taking ceramic bond diamond micro-powder composite powder and an organic pore-forming agent as raw materials and adopting an atomization granulation method; the preparation method comprises the following steps: taking sodium alginate and calcium salt as raw materials, and preparing a calcium alginate water ball solution by adopting a multiple emulsion method and an atomization granulation method; the porous agglomerated diamond microspheres and the calcium alginate water balls are used as main raw materials, and a gel casting method is adopted for preparing the ceramic bond diamond micro-powder grinding tool. According to the diamond micro-powder grinding tool, the organic pore forming agent and the sodium alginate water balls are used as the pore forming agents, so that the particle size and proportion of pores in the prepared diamond micro-powder grinding tool can be accurately controlled, and the diamond micro-powder grinding tool has the characteristics of high porosity, good self-sharpening performance, low grinding resistance and the like and can be used for efficient and high-quality machining of semiconductor materials.

The invention discloses a preparation method of thermal shock resistant magnesium aluminate spinel transparent ceramic, and belongs to the technical field of ceramic materials. The preparation method comprises the following steps: (1) synthesizing crystalline MgAl2O4 nano powder by adopting an additive-free hydrothermal method; (2) depolymerizing the powder, performing water-based gel casting to prepare a green body, and performing staged debonding treatment on the green body; (3) carrying out two-step vacuum presintering on the green body; (4) carrying out hot isostatic pressing densification treatment in a subgrain growth temperature region of 1380-1420 DEG C; and (5) carrying out annealing treatment on the densified ceramic. High-purity crystalline powder is synthesized through an additive-free hydrothermal method, grain boundary impurities are eliminated, and the intermediate infrared transmittance is remarkably improved; by combining the synergistic effect of optimized two-step pre-sintering and hot isostatic pressing in a sub-grain region, precise refinement of the grain size is realized; and finally, the bending strength, the fracture toughness and the critical thermal shock temperature difference of the material are greatly improved under the strengthening mechanism of ultrafine grains and defect-free grain boundaries.

The invention relates to the technical field of silicon carbide ceramics, and discloses a high-precision silicon carbide vacuum chuck manufacturing method which comprises the following steps: uniformly mixing composite silicon carbide micro powder, a sintering aid, a dispersing agent, a cross-linking agent, acrylamide, hydroxyethyl methylacrylate and deionized water, and carrying out ball milling to obtain gel slurry; mixing the gel slurry with an initiator and a catalyst, injecting the mixture into a deep-hole mold, carrying out gel reaction, carrying out compression molding, finishing, taking out, putting into a sintering furnace, sintering, and cooling to room temperature, so as to obtain a suction cup prefabricated body; milling, polishing and cleaning the suction cup prefabricated body to obtain the silicon carbide vacuum suction cup; the compact and uniform silicon carbide ceramic suction cup is formed through the processes of gel casting, sintering, milling, polishing and cleaning, and the silicon carbide ceramic suction cup has high mechanical strength, heat-conducting property and specific stiffness.

The invention discloses a SiCf / SiC composite material containing a high-strength and high-modulus matrix as well as a preparation method and application of the SiCf / SiC composite material, and relates to the technical field of silicon carbide-based composite materials. The method comprises the following steps: preparing a CVI-BN interface phase in a SiC fiber preform by adopting a chemical vapor infiltration process, and introducing SiC whiskers into the SiC fiber preform by adopting a gel casting process to obtain a porous composite material; the porous composite material is placed in first polycarbosilane slurry for multiple times of dipping and cracking, and a semi-compact SiCf / SiC composite material is obtained; the semi-compact SiCf / SiC composite material is placed in second polycarbosilane slurry for multiple times of dipping and cracking, and a compact SiCf / SiC composite material is obtained; according to the invention, the inert filler SiCw and the active filler silicon powder are combined to jointly modify the PIP-SiC matrix, so that a continuous rigid transfer skeleton is formed in the matrix, the defect content of the matrix is reduced, the crystallization degree is improved, and the components are purified. The mechanical property of the modified composite material is improved by more than 30%.

The invention is suitable for the technical field of composite materials, and provides an Al / SiC composite material with metal continuously distributed, the metal Al phase is continuously distributed, and SiC-rich ceramic columns are separately distributed; the SiC-rich ceramic stand column is composed of A1 and SiC particles together, and a network structure with soft phases surrounding hard phases and interpenetrating soft phases is formed. The plane figure of the SiC-rich ceramic upright post is one of a circle, a rectangle, a triangle, a star, a honeycomb, a concave honeycomb, a broken line shape and a wave shape; the volume fraction of ceramic in the SiC-rich ceramic stand column is 25-60 vol.%. The invention further provides a preparation method of the Al / SiC composite material with the metal continuously distributed. According to the preparation method, digital light treatment and gel casting are combined, a ceramic blank reverse mold is constructed by using calcium carbonate, the design is flexible and changeable, and the metal ceramic composite material with continuously distributed metal is obtained through an infiltration technology, so that a continuous soft phase can effectively disperse external loads, stress concentration is avoided, and the toughness of the composite material is improved.

This application relates to a preparation mold and method for gel casting of reaction-bonded silicon carbide barrels, belonging to the field of silicon carbide product technology. It includes an inner cylinder, an outer tube, and an outer cylinder. The outer tube is sleeved outside the inner cylinder. One end of the inner cylinder extends out of the outer tube and is connected to a first base plate. The outer tube abuts against the surface of the first base plate. A first molding cavity is formed between the inner wall of the outer tube and the outer wall of the inner cylinder. The first molding cavity is used for pouring paraffin wax and forming the inner barrel mold. The inner diameter of the outer cylinder is larger than the diameter of the inner barrel mold. A second base plate is provided on the inner wall of one end of the outer cylinder. After the inner barrel mold is inserted into the outer cylinder, it abuts against the second base plate. A second molding cavity is formed between the inner wall of the outer cylinder and the outer wall of the inner barrel mold. The second molding cavity is used for pouring gel-based sauce and forming the silicon carbide barrel blank. This application has the effect of improving the removal efficiency of the inner mold and the forming quality of the inner wall of the silicon carbide barrel blank in the gel casting process.

The invention relates to the technical field of thermal insulation materials, in particular to bionic hollow tubular mullite hierarchical porous ceramic and a preparation method thereof. Comprising the following steps: step 1, weighing wastes containing aluminum and silicon and WO3, and carrying out pretreatment to obtain raw material powder; and 2, preparing the bionic hollow tubular mullite hierarchical porous ceramic from the raw material powder in the step 1 by adopting a foaming-gel pouring method. According to the invention, 5wt% of WO3 is added, when heat treatment is carried out at 1300 DEG C, the total porosity of the prepared bionic hollow tubular mullite hierarchical porous ceramic is 72.14%, the closed porosity is 14.26%, the heat conductivity coefficient at room temperature is as low as 0.081 W / (m.K), the heat conductivity coefficient at 1000 DEG C is 0.203 W / (m.K), and the fracture resistance and compressive strength can respectively reach 21.78 MPa and 35.08 MPa. Compared with granular mullite porous ceramics with the same porosity, the fracture resistance of a mullite sample with the bionic hollow tubular morphology is improved by 29%, and the heat conductivity coefficient is reduced by 35%.

The invention relates to a method for preparing an aluminum oxide ceramic substrate through gel casting by using a three-stage drying method, which effectively reduces capillary force in a water evaporation process through replacement drying of polyethylene glycol, relieves the problem of rapid shrinkage of the surface of a green body, and avoids the phenomenon of internal high stress concentration through uniform diffusion of a replacement solution; in the microwave drying stage, synchronous migration of moisture inside and outside the green body is achieved through temperature control adjustment, the dry shell effect is avoided, finally hot air drying is carried out, and the compactness and dimensional precision of the finally sintered ceramic substrate are further improved. And the replacement drying and the microwave drying are combined, so that the moisture removal rate is obviously increased. Compared with a traditional natural drying mode or a single hot air drying mode, the whole drying time of the process is shortened by 30% or above. Through a scientifically designed three-stage drying process, the problems of cracks, deformation, low drying efficiency and the like in the preparation of the gel-casting aluminum oxide ceramic substrate are comprehensively solved, and the yield and the performance of the substrate are remarkably improved.

The invention relates to the technical field of grinding in material engineering, and discloses a high-porosity honeycomb pore ceramic bond grinding tool and a preparation method and application thereof.The preparation method of the mold comprises the following steps that S1, a solvent, a gelatinizing agent, a ceramic bond, a pore forming agent and a grinding material are pretreated to prepare sol slurry; s2, after gel treatment, the sol slurry forms a gel body, pore-forming agents in the gel body are mutually adsorbed through self-tightening treatment, gaps between the pore-forming agents are filled with a ceramic bonding agent and an abrasive material, and a grinding tool blank is obtained; and S3, the grinding tool blank is subjected to firing process treatment, and the target grinding tool is obtained. According to the preparation method disclosed by the invention, the pore-forming agent is used as a template, and the ceramic bond grinding tool prepared by a process method of stacking and self-assembling an in-situ gel casting mold through the pore-forming agent has the advantages of high porosity, high macro porosity, uniform pore size and uniform distribution, and has good mechanical properties and grinding properties such as cooling and chip containing.

The embodiments disclosed herein are directed to a masking device (20) for enhancing the fidelity of sample wells of a photopolymerized electrophoretic gel contained in a gel casting assembly (10) that comprises a comb (30) having a one or more teeth. The masking device (20) includes a light blocking agent fixedly located on the gel casting assembly (10) where the light blocking agent overlaps with the teeth of the comb to prevent photopolymerization of a portion of an electrophoretic gel contained between the comb and the inner surfaces of the gel casting assembly. Upon removal of the comb after electrophoretic gel photopolymerization the sample wells remain uniform.

The invention provides an aerogel production assembly that includes a mold with a mold base defined by a casting substrate, where the casting substrate includes a film. The invention also provides an aerogel production method that involves filling such a mold with a wet gel precursor solution. In other embodiments, the invention provides an aerogel production assembly that includes a film and a film handling system. In still other embodiments, the invention provides an aerogel production assembly that includes an advantageous aging clamp mechanism. Further, some embodiments of the invention provide an aerogel production method that involves a wet gel sheet casted to a casting substrate, where the casting substrate includes a film, and the method includes both peeling the film off the wet gel sheet and conveying the wet gel sheet onto a drying substrate.

This invention relates to the field of membrane materials technology, specifically to a biaxially stretched polyolefin film, its preparation process, and its applications. This invention solves the problem of uneven microstructure caused by non-uniform preheating and stretching of thick gel castings in existing technologies through a specific heat-setting process. It provides a gel film precursor with uniform three-dimensional properties (i.e., along the film production line's forward direction, width direction, and thickness direction) for subsequent stretching, thereby obtaining a microporous membrane with narrower pore size distribution and a more regular structure. It also solves the problem of the limiting stretching ratio restricted by the accumulation of stress within the connecting chains in existing stretching processes. By relaxing stress and widening the process safety window, it enables higher-ratio uniform biaxial stretching, thereby improving the final mechanical strength (such as tensile strength) and air permeability of the microporous membrane.

The invention provides a demolding method of a large-size complex-shape MAX phase gel casting green body, and belongs to the field of ceramic part preparation. The method comprises the steps that S1, the inner surface of a mold for injection molding is washed clean with clear water, then the inner surface of the mold is wiped with an organic solvent, the cleaned mold is naturally aired or dried, and a dry mold is obtained; s2, uniformly spraying a polytetrafluoroethylene emulsion on the inner surface of a dry mold, or dipping the dry mold in the polytetrafluoroethylene emulsion, removing the redundant polytetrafluoroethylene emulsion to form a uniform polytetrafluoroethylene emulsion adhesion layer on the inner surface of the mold, and airing or drying to obtain a mold adhered with a polytetrafluoroethylene coating; s3, the mold adhered with the polytetrafluoroethylene coating is placed in a sintering furnace to be baked, the mold is taken out after cooling, and an injection mold is obtained; and S4, injecting the MAX-phase gel injection molding slurry into an injection molding mold, opening the injection molding mold after the injection molding slurry is polymerized and cured, and taking out an injection molding green body.

The invention discloses a preparation method of rare earth silicate ceramic, and belongs to the technical field of preparation of inorganic ceramic materials. Compared with a traditional sintering process, the process integrating in-situ synthesis of nano powder, gel casting and microwave-assisted hot pressing sintering has the advantages that the sintering time is greatly shortened, the energy consumption is reduced, the density and uniformity of the ceramic are remarkably improved, the defects such as air holes are effectively reduced, and the production efficiency is improved. The prepared rare earth silicate ceramic has excellent mechanical properties, thermal properties and chemical stability, and meets the strict requirements of aerospace, energy and other high-end fields on high performance of materials.

A high-throughput multiplexing electrophoretic gel system is disclosed. The system includes a gel casting device which includes an interior, gel casting chamber by which a polymerized gel layer is formed. The polymerized gel layer includes a plurality of integrally formed sample loading wells. The wells are aligned to be simultaneously loaded with samples via an automated microliter mult i -pipette sample loader. The sample-loaded gel layer is adapted to undergo immersed horizontal electrophoresis protein separation.

The utility model discloses an automatic agarose gel making instrument which comprises an instrument body, a heating base arranged at the bottom of one side of the instrument body, and a container tank placed on the heating base, and is characterized in that a tank cover is arranged at the top of the container tank, a motor is arranged at the upper end of the tank cover, a fixedly connected stirring rod is arranged at the lower end of the motor, and the stirring rod extends into the container tank; a plurality of stirring blades A and a plurality of stirring blades B are upwards arranged on the stirring rod from the bottom end, the stirring blades A and the stirring blades B are alternately arranged at intervals, and the structures of the stirring blades A and the stirring blades B form a vertical mirror image. The motor is arranged in a motor box at the top end of the tank cover. According to the automatic agarose gel making instrument, the stirring rod is provided with a plurality of groups of vertical mirror image stirring blades, so that the pushing directions of liquid flow are rich, a low-efficiency stirring area does not exist, and even if a container is large and the amount of a solution is large, the uniformity and sufficiency of stirring can be ensured.

The invention provides a method for preparing porous ceramic through gel casting of emulsion, and belongs to the technical field of porous ceramic materials, and the method comprises the following steps: adding a catalyst and an initiator into the emulsion, carrying out mechanical stirring and injection molding, and then putting the emulsion into a drying oven for heating and curing to obtain a porous ceramic biscuit; degreasing and sintering the obtained biscuit to obtain porous ceramic; the emulsion comprises ceramic powder and / or sol nanoparticles, an organic monomer, a cross-linking agent, a binder, a defoaming agent, deionized water, an oil phase and a surfactant. According to the invention, rapid curing molding of the emulsion is realized through a cross-linking polymerization reaction of the organic monomer and the cross-linking agent, the advantages of simple and convenient operation and adjustable pore structure of an emulsion template method are retained, and a novel efficient technical route is provided for rapid and controllable preparation of porous ceramics with a complex structure and high porosity.

The invention discloses a method for preparing a honeycomb porous wafer thinned grinding wheel based on an in-situ gel casting method, which comprises the following steps of: placing superfine diamond micro-powder in an acidic strong oxidizing solution, heating, centrifugally cleaning until the superfine diamond micro-powder is neutral, and drying to obtain pre-oxidized diamond micro-powder; adding the modified diamond micro-powder into a silane coupling agent solution for grafting reaction to obtain modified diamond micro-powder; the method comprises the following steps: dissolving an organic monomer and a cross-linking agent in deionized water according to a predetermined mass ratio, and stirring to obtain an organic monomer premixed solution; adding microcrystalline glass binder powder, a polymeric dispersant and modified diamond micro-powder into the organic monomer premixed liquid, and carrying out dispersion treatment to obtain high-solid-content ceramic slurry; adding a macroporous pore-forming agent into the ceramic slurry, stirring, fully discharging bubbles, adding an initiator and a catalyst, pouring into a forming mold, carrying out in-situ polymerization reaction on organic monomers to form a gel network, and further forming a wet blank; and the wet blank is dried, degummed and sintered to obtain the grinding wheel block with the honeycomb structure. And cutting the honeycomb-structure grinding wheel blocks, and pasting the honeycomb-structure grinding wheel blocks in the grooves of the grinding wheel base body in an array manner to form the honeycomb porous wafer thinning grinding wheel. The problem of agglomeration of the ultrafine diamond powder is solved, and the bending strength of the prepared grinding wheel can be improved while the high porosity is guaranteed.

The invention belongs to the technical field of inorganic non-metallic materials, and relates to a silicon carbide whisker toughened boron carbide composite material based on gel casting. The invention discloses a silicon carbide whisker toughened boron carbide composite material based on gel casting molding, the silicon carbide whisker toughened boron carbide composite material has a dumbbell-shaped B4C-SiCw-B4C structure, and the structure is characterized in that two ends of silicon carbide whiskers with the length-diameter ratio of more than 50: 1 are connected with boron carbide particles; the silicon carbide whisker toughened boron carbide composite material based on gel casting is prepared by the following steps: performing ball milling, gelatinization, carbonization treatment and siliconizing treatment on composite powder obtained by premixing silicon carbide whiskers and boron carbide of which the length-diameter ratio is greater than 50: 1 and a gel mixture. A small amount of silicon carbide whiskers with a high length-diameter ratio are introduced into boron carbide, so that the silicon carbide whiskers with the high length-diameter ratio in the obtained silicon carbide whisker toughened boron carbide composite material are promoted to be connected with B4C particles, a dumbbell-shaped B4C-SiCw-B4C structure is formed, crack propagation is effectively hindered, cracks are deflected or bridged, and effective toughening is achieved.

A high-throughput multiplexing electrophoretic gel system is disclosed. The system includes a gel casting device which includes an interior, gel casting chamber by which a polymerized gel layer is formed. The polymerized gel layer includes a plurality of integrally formed sample loading wells. The wells are aligned to be simultaneously loaded with samples via an automated microliter multi-pipette sample loader. The sample-loaded gel layer is adapted to undergo immersed horizontal electrophoresis separation.

The invention provides a zirconia porcelain block based on gel casting, a preparation method and application. Comprising the following steps: injecting mixed slurry into a mold, adding an initiator and a catalyst in the injection process until the mixture is completely cured, demolding, and then carrying out drying and glue discharging treatment to obtain a glue-discharged green body; and carrying out mechanical processing on the degummed green body, and then carrying out rapid sintering to obtain the zirconium oxide porcelain block. Wherein the mixed slurry comprises a precursor solution and inorganic powder; the precursor solution comprises one or more of polyvinyl alcohol, chitosan and polyacrylic acid; the inorganic powder comprises the following components in parts by mass: 85-94 parts of zirconium oxide, 2-10 parts of yttrium oxide, 2-5 parts of hafnium oxide, 2-5 parts of aluminum oxide and 1-5 parts of other inorganic oxides. The preparation method disclosed by the invention is simple, convenient to operate, low in cost and easy for large-scale production and application.

The invention relates to a method of preparing a microneedle array, comprising the steps of dissolving a water-soluble copolymer, comprising maleic anhydride and isobutylene monomers, in an aqueous solvent to obtain an aqueous solution, adding a ceramic material to said aqueous solution to obtain an aqueous ceramic slurry for gel casting, adding at least a portion of said aqueous ceramic slurry to a mould to obtain a layer of aqueous ceramic slurry in said mould, degassing said layer of aqueous ceramic slurry to obtain a degassed layer of aqueous ceramic slurry in said mould, gelling said degassed layer of aqueous ceramic slurry to remove said aqueous solvent from said aqueous ceramic slurry and removing said mould to obtain a gelled tape, drying said gelled tape to obtain a green tape, sintering said green tape to obtain said microneedle array. Further, the invention provides for a green tape, comprising a base plate and a set of microneedles integrated with said base plate, a microneedle array, comprising a base plate and a set of microneedles integrated with said base plate, a system for enabling transport of a substance through a material barrier, and a use of a microneedle array for intradermal drug or vaccine delivery, diagnostics, cosmeceuticals,, sensing of biomarkers found in the skin and monitoring of physiological conditions of the body.

The invention provides an aerogel production assembly that includes a mold with a mold base defined by a casting substrate, where the casting substrate includes a film. The invention also provides an aerogel production method that involves filling such a mold with a wet gel precursor solution. In other embodiments, the invention provides an aerogel production assembly that includes a film and a film handling system. In still other embodiments, the invention provides an aerogel production assembly that includes an advantageous aging clamp mechanism. Further, some embodiments of the invention provide an aerogel production method that involves a wet gel sheet casted to a casting substrate, where the casting substrate includes a film, and the method includes both peeling the film off the wet gel sheet and conveying the wet gel sheet onto a drying substrate.

The application discloses a ceramic slurry preparation equipment for gel casting, and relates to the technical field of preparation equipment.The ceramic slurry preparation equipment for gel casting comprises a vacuum stirring assembly, a temperature control assembly and a vacuum feeding assembly.The vacuum stirring assembly comprises a stirring barrel, a stirrer and a vacuum pump in communication with the stirring barrel.The stirrer is inserted into the stirring barrel to stir the slurry in the stirring barrel.The temperature control assembly comprises a cooling circulator in communication with the stirring barrel and a temperature sensor.The cooling circulator is used for cooling the slurry in the stirring barrel, and the temperature sensor is used for measuring the slurry temperature of the stirring barrel.The vacuum feeding assembly comprises a peristaltic pump and a sealed container in communication with the stirring barrel.The sealed container and the stirring barrel are respectively in communication with the peristaltic pump, and are used for precisely adding catalysts and initiators into the stirring barrel under the vacuum and isobaric environment.The application realizes the full automation of the preparation of the ceramic slurry for gel casting in the same equipment, and also reduces the generation of air bubbles in the preparation process of the ceramic slurry.

The invention belongs to the technical field of ceramics, and relates to a high-thermal-conductivity reaction-sintered silicon carbide ceramic material and a preparation method thereof. According to the invention, SiC is mainly used as a raw material, resorcinol and formaldehyde are used as carbon sources, and the SiC / C porous preform which is uniform and compact in microstructure and has excellent heat-conducting property can be manufactured by combining gel casting with a reaction siliconizing process. In the process, a porous carbon network is formed after a product generated by reaction of resorcinol and formaldehyde is carbonized, SiC particles are uniformly wrapped by the network, and when siliconizing treatment is carried out, due to the existence of the porous carbon network, the finally obtained reaction sintered silicon carbide ceramic material has more uniform phase distribution, so that the performance of the silicon carbide ceramic material is improved, and the service life of the silicon carbide ceramic material is prolonged. Meanwhile, the content of residual silicon is remarkably reduced, so that the thermal conductivity of the material is effectively improved.

This invention provides a high-porosity ceramic-bonded diamond micropowder abrasive, its preparation method, and its application. The preparation method includes: preparing a ceramic-bonded diamond micropowder composite powder using a sol-gel method; preparing porous agglomerated diamond microspheres using an atomization granulation method with the ceramic-bonded diamond micropowder composite powder and an organic pore-forming agent as raw materials; preparing a calcium alginate aqueous solution using a multiple emulsion method and an atomization granulation method with sodium alginate and calcium salt as raw materials; and preparing a ceramic-bonded diamond micropowder abrasive using a gel casting method with the porous agglomerated diamond microspheres and calcium alginate aqueous spheres as the main raw materials. The above-mentioned diamond micropowder abrasive utilizes the organic pore-forming agent and sodium alginate aqueous spheres as pore-forming agents, allowing for precise control of the particle size and ratio of pores in the prepared diamond micropowder abrasive. It exhibits high porosity, good self-sharpening properties, and low grinding resistance, making it suitable for efficient and high-quality processing of semiconductor materials.

The invention relates to the field of sheet ceramic production, in particular to an energy-saving type water-based gel casting continuous forming device for sheet ceramics, one side of a roller frame is provided with an extruder, the other side of the roller frame is provided with a plurality of groups of rotatable winding drums through a support frame, one side far away from the winding drums is provided with a guide roller, and an execution roller is slidably mounted below the guide roller; and the strip-shaped film is sequentially wound on the guide roller, the execution roller and the winding drum. According to the film cutting device, the winding drum structure can excite the oil cylinder structure to stretch out the film inserting knife in the rotary material changing process, so that a film body is cut while being inserted into an empty roll, and the film body is compacted through the execution roller reset clockwise to guarantee the subsequent winding stability; and process defects and energy waste caused by traditional shutdown roll replacement can be avoided while non-shutdown roll replacement is realized.

The invention relates to a low-cost preparation method of a silicon nitride complex structural member, which belongs to the field of preparation of ceramic material lightweight members, and is characterized in that a low-temperature molten metal material is adopted as a mold, a silicon nitride complex structural member ceramic green body is prepared in a gel casting mode, and then the silicon nitride complex structural member ceramic green body is put into a sintering furnace to be sintered; the high temperature in the silicon nitride preparation process is utilized, the metal mold is molten into liquid, the metal liquid is collected again to prepare a new mold, the effect of recycling the mold is achieved, and the preparation cost is effectively reduced in the field of complex silicon nitride structural part preparation.

The invention relates to a carbon fiber reinforced ceramic material with near-zero expansion characteristic and a preparation method thereof, and belongs to the field of ceramic matrix composite materials. Comprising the following steps: obtaining a pyrolytic carbon interface layer on the surface of a fiber bundle through a chemical vapor deposition method; the preparation method comprises the following steps: ball-milling and uniformly mixing low-expansion ceramic powder, a monomer, a cross-linking agent and a dispersing agent, adding an initiator and a catalyst, stirring, and carrying out vacuum defoaming; soaking the carbon fiber woven body in the ceramic slurry, curing the slurry into a wet blank, drying, repeatedly soaking and circulating until the weight is not increased any more, and drying to constant weight; densification is achieved through precursor impregnation and pyrolysis, and the carbon fiber reinforced ceramic material is obtained. According to the preparation method, a composite process of pressure-assisted gel casting and ultrasonic vibration-assisted pressurized impregnation-cracking is utilized, so that the introduction amount and uniformity of a low-expansion or negative-expansion ceramic phase in a fiber woven body are improved, and the problems of low impregnation efficiency, multiple cycle periods and the like of a ceramic precursor in a traditional PIP process are solved; the thermal expansion coefficient of the ceramic-based composite material can be greatly reduced, the overall strength is high, and the fracture toughness resistance is good.

This invention belongs to the field of ceramic refractory materials technology, specifically relating to a method for preparing an aluminosilicate fiber crucible with an anti-erosion coating, the crucible itself, and its applications. The method involves using aluminosilicate ceramic fibers, a solvent, organic monomers, and a crosslinking agent, followed by gel casting in a mold to form a three-dimensional skeleton structure of the aluminosilicate ceramic fibers. After drying and sintering, an aluminosilicate ceramic fiber crucible matrix is ​​obtained. A coating slurry is prepared using multi-stage Y₂O₃ powder and two grinding balls of different diameters. This slurry is then coated onto the inside of the aluminosilicate ceramic fiber crucible matrix. Finally, a multi-stage heating process is used for sintering to obtain an aluminosilicate fiber crucible with an anti-erosion coating. This invention improves the crucible's strength through gel casting and enhances its resistance to melt erosion by coating the inner wall of the crucible with a yttrium oxide coating, thus preventing interfacial reactions between the crucible and the melt.