484 results about "Sic fiber" patented technology

The invention belongs to the technical field of polymer plastic materials, and particularly relates to a high-temperature-resistant anti-corrosion polytetrafluoroethylene material and a preparation method thereof. The polytetrafluoroethylene is prepared from the following raw materials in parts by weight: 50 to 60 parts of polytetrafluoroethylene, 5 to 10 parts of fluorinated modified graphene oxide, 3 to 5 parts of aluminum powder, 5 to 8 parts of modified silicon carbide fiber, 3 to 5 parts of silane modified nano silicon dioxide, 2 to 3 parts of polyphenylene sulfide, 2 to 3 parts of polyimide, 0.5 to 0.8 part of dispersing agent and 0.5 to 1 part of antioxidant. The heat conduction performance and the interface bonding force are improved through the fluorinated modified graphene oxide, the impact resistance and the wear resistance are enhanced through the silicon carbide fibers, and the corrosion resistance and the wear resistance are improved through the aluminum powder; silane modified silicon dioxide enhances the mechanical property of the composite material by improving the dispersity of the filler, and PPS and PI interact with the surface of the filler through polar groups in molecular chains, so that the interface strength is improved, and the toughness and the thermal stability are improved.

The invention belongs to the technical field of ceramics, and discloses a preparation method of fracture-resistant and wear-resistant ceramics. The preparation method comprises the following steps: weighing the raw materials in parts by weight; the preparation method comprises the following steps: mixing 40 parts of potassium feldspar, 10 to 25 parts of albite, 1 to 10 parts of kaolin, 1 to 10 parts of serpentine, 5 to 25 parts of dolomite, 2 to 9 parts of nano zirconium oxide, 0.1 to 1 part of nano cerium oxide, 0.1 to 1 part of nano molybdenum disulfide, 0.1 to 0.8 part of silicon carbide fiber, 0.5 to 2.5 parts of polyethylene glycol, 0.1 to 0.6 part of fullerene trifluoromethyl derivative, 0.1 to 3 parts of sodium dodecyl sulfate, 0.1 to 2 parts of sodium tripolyphosphate and 10 to 60 parts of solvent to obtain slurry; and carrying out spray granulation to obtain a blank, carrying out compression molding to obtain a green body, and sintering to obtain the fracture-resistant and wear-resistant ceramic. The breaking strength of the breaking-resistant and wear-resistant ceramic can exceed 70 MPa, and the length of a grinding pit does not exceed 8.5 mm.

The invention belongs to the technical field of nano porous materials, discloses a high-strength and low-thermal-conductivity SiC-TiO2 nanofiber aerogel and a preparation method thereof, and aims to solve the problems of insufficient structural stability, shear strength and high-temperature thermal conductivity of traditional ceramic aerogel. TiO2 nanorods are introduced onto a SiC nanofiber membrane by adopting an in-situ growth technology, and the high-strength and low-thermal-conductivity SiC-TiO2 nanofiber aerogel is prepared. And constructing the SiC nano composite fiber membrane into the layered porous ceramic nanofiber aerogel with a multilevel structure by combining a layer-by-layer stacking method with a directional freezing casting technology. TiO2 nanorods growing on the surface of the SiC fiber in situ serve as a secondary structure, so that the overall mechanical performance of the material is enhanced; the TiO2 nanorods have specific high infrared light reflection and scattering capabilities, so that the transmittance of the aerogel material to radiation is reduced, and the thermal radiation conduction in a high-temperature environment is effectively reduced. In addition, a silica sol binder is introduced between layers of the aerogel multilevel structure, stable bonding points are formed between fibers after calcination, and the mechanical stability is improved.

The invention discloses a high-entropy alloy silicon carbide nanofiber composite material and a preparation method and application thereof, a high-entropy alloy is loaded on silicon carbide nanofibers, compared with a carbon fiber material carrier, SiC fibers can form a compact SiO2 protective layer in a high-temperature aerobic environment, further oxidation failure of the internal structure can be prevented, and the high-entropy alloy silicon carbide nanofiber composite material is prepared. And meanwhile, SiC also has relatively high high-temperature stability and weather resistance, so that the high-entropy alloy silicon carbide nanofiber composite material can stably work in an extreme high-temperature oxidation environment (such as a spacecraft thermal protection system and an engine tail gas pipeline) of over 1000 DEG C, and perfectly adapts to a high-temperature wave-absorbing scene.

The invention belongs to the technical field of radar stealth materials and high-temperature electromagnetic protection, and particularly relates to design and a preparation method of a high-temperature-resistant wave-absorbing material based on alumina fibers. According to the material, a high-temperature-resistant ceramic precursor serves as a base body, a reinforcing phase is formed by alternately stacking alumina fiber cloth and an alumina fiber web tire containing chopped silicon carbide fibers, and a three-dimensional reinforcing structure is formed through a needling technology; the chopped silicon carbide fibers are directionally distributed in the net tire in a non-uniform mode, an enhanced area array with the local geometric regular pattern is constructed, the size and the arrangement period change in a gradient mode in the thickness direction, a vertical dielectric gradient structure is formed in the material, and multi-path propagation, reflection and polarization loss of electromagnetic waves are improved; the surface of alumina fiber cloth is coated with a ceramic interface layer, so that the interface bonding strength and thermal stability are improved; the ceramic matrix is densified for multiple rounds, so that the structure is compact; the material has excellent electromagnetic absorption performance, heat resistance and mechanical strength, and is suitable for high-temperature electromagnetic environments such as aerospace, missile bay sections and the like.

A method for manufacturing a part of SiC / SiC composite material includes the production of a fibrous preform from silicon carbide fibers; the deposition of an interphase on the fibers of the fibrous preform; a first densification including the formation of a first matrix phase by chemical vapor infiltration with a first matrix precursor including methyltrichlorosilane (MTS); a second densification including the formation of a second matrix phase by chemical vapor infiltration with a second SiC precursor different from the first precursor, the second precursor forming an SiC deposit comprising residual hydrogen and free silicon; and a third densification including the impregnation of the fibrous preform with an impregnation composition containing at least silicon so as to obtain a part made of SiC / SiC composite material.

The invention relates to a preparation method of an irradiation-resistant and accident-resistant SiC / SiC nuclear fuel cladding. The preparation method comprises the following steps: (1) alternately carrying out the following step (A) and step (B) from step (A) to step (A) to obtain a tubular SiC fiber preform with at least two PyC interface layers and at least one SiC nanowire interface layer: (A) depositing the PyC interface layers on the surface of the tubular SiC fiber preform through a chemical vapor deposition process; (B) loading a catalyst on the PyC interface layer through vacuum impregnation, and generating a SiC nanowire interface layer on the surface of the PyC interface layer in situ through a chemical vapor deposition process; (2) carrying out densification treatment on the tubular SiC fiber preform by adopting a chemical vapor infiltration process; and (3) depositing a SiC coating on the surface of the tubular SiC fiber preform by adopting a chemical vapor deposition process to obtain the SiC / SiC nuclear fuel cladding tube.

The invention provides a high-strength low-stress continuous SiC fiber reinforced Ti3Al composite material as well as a preparation method and application thereof, and belongs to the technical field of aeronautical materials. The Mo interface layer with the thermal expansion coefficient matched with that of SiC and Ti3Al is introduced to the interface of the SiC / Ti3Al composite material, so that the stable transition of the thermal expansion coefficient is realized, the interface stress is dispersed, the interface bonding strength is further improved, and the stability of the material performance is guaranteed; meanwhile, an Nb element is introduced into a Ti3Al matrix to refine Ti3Al grains and optimize a microstructure, so that the strength and toughness of the material are enhanced, and a Ti3Al / Nb composite structure is constructed to relieve stress concentration and improve the tensile strength, so that the material failure is effectively prevented.

The invention relates to the field of composite material ultrathin laminated plates, in particular to a preparation method of a SiC fiber reinforced Ti-based composite material ultrathin laminated plate. The method comprises the following steps: plating Ti alloy on the surface of SiC fiber by using a physical vapor deposition method; the titanium alloy foil is subjected to acid pickling to remove a surface oxide layer and impurities; the plated fibers are tightly arranged to form a SiCf / Ti alloy plate, the upper surface and the lower surface of the SiCf / Ti alloy plate are bonded to a titanium alloy foil through an adhesive, and a foil-plate-foil prefabricated body is manufactured; sealing the periphery of the prefabricated body, covering gaskets on the upper surface and the lower surface of the prefabricated body, removing the adhesive from the prefabricated body, and placing the prefabricated body in a vacuum hot-pressing mold; and a hot-pressing process is adopted to realize densification composite molding of the laminated plate. According to the method, uniform distribution of SiC fibers is achieved, the mechanical property of the material is effectively improved, the surface flatness is good after the laminated plate is prepared, and the method is suitable for weight reduction application of aerospace structural parts such as skins and reinforcing ribs.

The invention belongs to the field of continuous SiC fiber reinforced metal matrix composite materials, and particularly relates to a SiCf / TiMoNb-Ti2AlNb / Ti2AlNb laminated composite material and a preparation method of the SiCf / TiMoNb-Ti2AlNb laminated composite material. The composite material is of a hot isostatic pressing composite structure of a precursor wire and a Ti2AlNb sheath outside the precursor wire, the precursor wire is formed by uniformly distributing SiC fibers in a TiMoNb-Ti2AlNb laminated alloy matrix, the volume fraction of the SiC fibers accounts for 40-55% of the total volume fraction of the SiCf / TiMoNb-Ti2AlNb / Ti2AlNb laminated composite material, and the composite material is good in combination, compact and free of holes. Through the introduction of the TiMoNb-Ti2AlNb lamination layer, the composite material can be compact under a relatively low hot isostatic pressure parameter, and the effect of improving the performance can be achieved after process parameters are optimized.

The invention discloses a preparation method of a toughening environmental barrier coating, and relates to a preparation method of a coating. The invention aims to solve the problem of poor fracture toughness of the existing environmental barrier coating. The method comprises the following steps: 1, pretreating a base material; 2, preparing a bonding layer; and 3, preparing the environmental barrier layer. The high-melting-point metal silicide prepared on the surface of the base material or the bonding layer compounded by the high-melting-point metal silicide and the rare earth silicate has excellent temperature resistance and good interface bonding strength, and due to the addition of the rare earth silicate, the expansion coefficient of the bonding layer is highly matched with that of the base material; according to the prepared yttrium oxide stabilized zirconia fiber, mullite fiber or silicon carbide fiber reinforced rare earth silicate environmental barrier layer, the fracture toughness of pure Yb2SiO5 is improved to 6.5 MPa.m < 1 / 2 >-8.0 MPa.m < 1 / 2 > from about 1.85 MPa.m < 1 / 2 >. The strengthening and toughening environmental barrier coating prepared by the invention has very important significance on development of thermal protection coatings of hot end parts of aircrafts with high thrust-weight ratios in China.

The invention belongs to the technical field of material preparation, and aims to solve the problem that the comprehensive performance of a material is affected by non-uniform microstructure of the material due to the fact that the distribution and grain size of each phase in a metal ceramic matrix are difficult to accurately control in the conventional preparation process of the metal ceramic material. Therefore, the invention provides the preparation method of the fiber-reinforced metal ceramic material, and the preparation method comprises the following steps: pretreating silicon carbide fibers; mixing and grinding the titanium metal powder and the silicon carbide ceramic powder according to a preset proportion; adding silicon carbide fiber particles and putting the mixture into an ultrasonic mixer; adding a dispersing agent and a binding agent and mixing again; sequentially carrying out cold isostatic pressing molding and hot pressing molding on the mixture; and sequentially carrying out pre-sintering, high-temperature sintering, cutting and surface treatment on the obtained green body. The strength, toughness, hardness, high temperature resistance, wear resistance and corrosion resistance of the prepared metal ceramic material are remarkably improved, the high-performance requirement of the aviation field can be better met, and powerful support is provided for the aviation industry.

The invention belongs to the technical field of composite material preparation, and particularly relates to a preparation method of a SiCf / TiMoNb heterogeneous core material reinforced GH4169 composite material. The preparation method comprises the following steps: depositing a TiMoNb alloy matrix on the surface of SiC fiber by using a magnetron sputtering method to form a precursor wire, carrying out composite molding on the obtained precursor wire and a GH4169 sheath in a hot isostatic pressing manner, and carrying out diffusion bonding to form the composite material. The obtained composite material SiCf / TiMoNb / GH4169 has excellent unidirectional performance at high temperature, the tensile strength at 850 DEG C can reach 1057 MPa, and the high-temperature strength of GH4169 alloy is effectively improved. The prepared composite material is high in high-temperature strength and has good application prospects, and the adopted preparation process is mature in technology and little in pollution.

The invention provides a bionic hollow petal-shaped SiC fiber porous thermal insulation material as well as a preparation method and application thereof, and belongs to the technical field of thermal insulation materials. The preparation method comprises the following steps: taking a viscose-based carbon fiber felt as an initial structure template, dipping the carbon fiber felt in siloxane sol, taking out the carbon fiber felt, and carrying out suction filtration to remove redundant sol on the surfaces of carbon fibers; curing the impregnated carbon fiber felt, and carrying out heat treatment to obtain the carbon fiber felt of which the carbon fiber surface is covered with a uniform SiC coating; and carrying out thermal oxidation treatment on the carbon fiber felt with the SiC coating to obtain the bionic hollow petal-shaped SiC fiber porous thermal insulation material. Compared with a traditional sol-gel method, the method has the advantages of being short in preparation period, low in cost, small in volume shrinkage rate and the like, and the obtained bionic hollow petal-shaped SiC fiber porous heat insulation material has good rebound resilience and excellent high-temperature heat insulation performance and has wide application prospects in a high-temperature oxidation environment.

The invention provides a silicon carbide fiber reinforced ceramic-based composite material as well as a preparation method and application thereof, and belongs to the technical field of ceramic-based composite materials. The composite material comprises a silicon carbide fiber reinforced phase, a boron nitride interface layer and a silicon-based multiphase ceramic matrix from inside to outside, the silicon-based multiphase ceramic matrix comprises an infiltration reaction generation phase, an introduced ceramic particle phase and a silicon-containing binary alloy phase, and the infiltration reaction generation phase comprises a water-oxygen corrosion resistant phase, a silicon phase, a silicon carbide phase and a boride phase. The water oxygen corrosion resistant phase comprises a compound of boron and any element of yttrium, ytterbium, hafnium, molybdenum and aluminum, the boride phase comprises B12 (C, Si, B) 3, the bending strength of the composite material is larger than or equal to 600 MPa, and the fracture toughness of the composite material is larger than or equal to 19 MPa.m < 1 / 2 >. According to the preparation method, the matching property among the components of the composite material is optimized, the mechanical property of the composite material is improved, and a new thought and a process method are provided for preparing the high-strength and water-oxygen-corrosion-resistant ceramic matrix composite material.

The invention relates to a rare earth element doped multiphase continuous silicon carbide ceramic fiber and a preparation method thereof.The preparation method comprises the steps of ceramic precursor preparation, melt spinning, air crosslinking, pyrolysis inorganic treatment and high-temperature ceramization. In the preparation method, heterogeneous metal elements, rare earth elements and boron elements are introduced through precursor synthesis; by combining air crosslinking, the sintering performance in the fiber is improved, the content of free carbon in the fiber is reduced, and the grain boundary composition and structure of the silicon carbide ceramic fiber are optimized. The prepared rare earth doped metal boride-containing multiphase silicon carbide ceramic fiber has excellent mechanical properties, high temperature resistance and oxidation resistance.

The invention discloses a preparation method of a high-temperature-resistant wave-absorbing honeycomb sandwich structure in the technical field of wave-absorbing materials, which comprises the following steps: synthesizing a transition metal modified polycarbosilane precursor under the protection of inert gas, and performing high-temperature cracking to obtain a magnetic silicon carbide wave-absorbing agent; blending and grinding the wave-absorbing agent and high-temperature-resistant resin to prepare a wave-absorbing glue solution; after a honeycomb core material is formed by adopting inorganic fiber cloth, a wave-absorbing glue solution is loaded through a repeated dipping-drying process, and the high-temperature-resistant wave-absorbing honeycomb is obtained through gradient heat treatment. And finally, compounding and curing with the wave-transparent skin and the carbon fiber composite material through a high-temperature-resistant adhesive film. The sandwich structure is prepared on the basis of the composite material, and the magnetic silicon carbide wave-absorbing agent has the characteristics of high temperature resistance, low density, oxidation resistance and adjustable dielectric property; the phthalocyanine resin matrix is adopted, so that excellent formability and high-temperature stability are guaranteed; honeycomb nodes are sewn and reinforced by silicon carbide fibers, so that the problem of node cracking in a high-temperature environment is solved.

The invention relates to a Ti3SiC2-containing SiC fiber and a preparation method thereof, and belongs to the technical field of ceramic fibers. The invention discloses a SiC fiber containing Ti3SiC2. The SiC fiber containing Ti3SiC2 is prepared by performing spinning, non-melting and high-temperature firing on a spinning precursor comprising a polycarbosilane precursor, a titanium source and an auxiliary agent. The Ti3SiC2 structure is introduced into the SiC fiber, so that the conductivity and the wave-absorbing property of the SiC fiber are improved.

The invention relates to a modified silicon carbide fiber and a preparation method and application thereof, the modified silicon carbide fiber endows magnetic loss, and combines high strength and corrosion resistance of a geopolymer matrix to realize double improvement of mechanical properties and wave absorbing efficiency of concrete. Carbon fibers in conventional wave-absorbing concrete are replaced by modified silicon carbide fibers, so that on one hand, the wave-absorbing concrete has good oxidation resistance at high temperature, carbon emission is greatly reduced, and the wave-absorbing concrete has the advantages of energy conservation and environmental protection; and on the other hand, the defect that the performance is reduced at high temperature is overcome, and the modified silicon carbide fiber enables the magnetic loss of metal and the dielectric loss of a matrix to form a synergistic effect, so that the wave absorbing performance is greatly improved. The invention is suitable for green communication infrastructures, and has the characteristics of environmental protection, high durability and broadband wave absorption.

The invention discloses a preparation method of near-stoichiometric ZrB2 doped SiC fibers, which comprises the following steps: preparing a zirconium-containing multiphase ceramic precursor (PZMS) and polymethylsilane (PMS) into a PZMS / PMS mixed precursor, and blending the PZMS / PMS mixed precursor with spinning-grade polycarbosilane (PCS) to obtain a mixed precursor; the ZrB2-doped silicon carbide fiber with the C / Si atomic ratio close to an ideal value is obtained through the processes of melt spinning, electron beam / BCl3 crosslinking-heat treatment, hydrogen high-temperature pyrolysis, high-temperature sintering and the like in sequence, and regulation and control of fiber components are achieved.

The invention belongs to the technical field of conductive ceramics, and discloses a silicon nitride conductive ceramic material and a preparation method thereof.The method comprises the steps that a yttrium oxide, aluminum oxide and magnesium oxide ternary composite system is arranged, rare earth elements are doped, and a sintering aid is formed; a resistance adjusting agent is composed of a titanium nitride-titanium dioxide core-shell structure and silicon carbide fibers, and the silicon carbide fibers are directionally distributed and arranged in a magnetic field, so that efficient composition of the silicon nitride conductive ceramic material is achieved, and the effects of high bending resistance, high conductivity and low sintering temperature are achieved; forming the slurry; performing spark plasma sintering; conducting network directional regulation and control; the preparation method comprises the steps of raw material mixing and ball milling, post-treatment and performance optimization, a convenient preparation process can be formed, too many tedious steps are not needed, a ball mill used in raw material mixing and ball milling is further provided with a pre-grinding device for pre-grinding the materials, the subsequent ball milling quality is enhanced, and the situation that the materials are not completely ground is avoided.

The present invention relates to a device and a method for using a carbon coating that is rapidly deposited on the surface of a continuous silicon carbide fiber. The device is designed for the first time on the basis of existing equipment to have a wire hanging device with wire hanging teeth, and before assembling it to an impregnation device, the wire hanging device processes the surface of the raw material continuous silicon carbide fiber, which can not only remove the surface hairs but also mechanically activate the surface, which provides the necessary conditions for obtaining a high-quality carbon layer later. The present invention relies on the designed continuous carbon coating production line, and does not require pre-corrosion treatment of the fiber surface. The continuous SiC fiber is first activated by the wire hanging device and then impregnated in an aqueous organic solution, and then dried and cracked and CVD are performed, so as to quickly form a firm carbon coating on the surface of the continuous SiC fiber. The device structure of the present invention is reasonably designed, the preparation process is simple and controllable, the obtained product has excellent performance, and is convenient for large-scale industrial application.

The invention provides a silicon carbide fiber-copper composite bonding wire and a preparation method thereof, and relates to the technical field of electronic materials. The preparation method of the silicon carbide fiber-copper composite bonding wire comprises the following steps: pre-plating copper on the surface of silicon carbide fiber to obtain copper-coated silicon carbide fiber; laying copper-coated silicon carbide fibers to obtain a copper-coated silicon carbide fiber layer, then constructing a copper alloy layer on the copper-coated silicon carbide fiber layer by using composite copper powder, then arranging the copper-coated silicon carbide fiber layer on the surface of the copper alloy layer again, and repeating the operation to obtain a composite wire blank in which the copper-coated silicon carbide fiber layers and the copper alloy layers are alternately arranged; and sequentially carrying out hot isostatic pressing treatment, drawing and aging treatment on the composite wire blank to obtain the silicon carbide fiber-copper composite bonding wire. The copper powder further comprises Ag, Hf and Sc, the metal elements can form fine and dispersed second-phase particles in the preparation process, and the strength of the copper bonding wire is remarkably improved through a precipitation strengthening mechanism.

The invention belongs to the field of wave-absorbing materials, and particularly relates to a fiber-reinforced barium titanate-polymer conversion ceramic-based composite wave-absorbing material and a preparation method thereof. The composite wave-absorbing material provided by the invention comprises a ceramic matrix and a fiber reinforcement embedded in the ceramic matrix, the ceramic matrix comprises a barium titanate ceramic phase and a polymer conversion ceramic phase; the fiber reinforcement body is formed by stacking a plurality of layers of fiber cloth, and an interface layer is deposited on the surface of each layer of fiber cloth; fibers in the multi-layer fiber cloth comprise multiple of carbon fibers, silicon dioxide fibers, silicon carbide fibers, glass fibers, aluminum oxide fibers and zirconium oxide fibers, and the interface layer is one or more of a PyC interface, a BN interface and a SiC interface. The composite wave-absorbing material provided by the invention takes various fibers as reinforcements and barium titanate-polymer converted ceramic as a matrix, and has excellent mechanical properties and wave-absorbing properties.

The utility model discloses a high-performance high-temperature-resistant oil-stain-resistant anti-interference medium-voltage power cable, and the power cable comprises a cable core which is formed by twisting a plurality of insulated shielding wire cores. A gap of the cable core is filled with thermoplastic polyurethane elastomer rubber; the cable core is wrapped by a superconducting silicon carbide fiber tape shielding wrapping layer, and the superconducting silicon carbide fiber tape shielding wrapping layer is wrapped by an LCP high-molecular liquid crystal polymer high-temperature-resistant fireproof layer in an extruded mode. A graphene aerogel layer is extruded outside the LCP macromolecular liquid crystal polymer high-temperature-resistant fireproof layer, a polysulfonamide fiber braid layer is lapped outside the graphene aerogel layer, a polyphenylene sulfide fiber tape is coated outside the polysulfonamide fiber braid layer through a semi-conductive adhesive, an armor layer is arranged outside the polyphenylene sulfide fiber tape, and the armor layer is wrapped outside the LCP macromolecular liquid crystal polymer high-temperature-resistant fireproof layer. And a hydrogenated butadiene-acrylonitrile rubber outer sheath is extruded outside the armor layer. According to the utility model, normal operation of a line can be ensured in a complex and severe environment for a long time, and the service life of the cable is greatly prolonged.

The invention belongs to the technical field of high-temperature-resistant elastic materials, and relates to a preparation method of a high-temperature-resistant ceramic fiber felt. The preparation method comprises the following steps: preparing a SiC nanowire dispersion liquid and a SiC micron fiber dispersion liquid, mixing the SiC nanowire dispersion liquid and the SiC micron fiber dispersion liquid, and carrying out filter pressing to obtain a SiC multi-scale nano / micron ceramic fiber felt matrix; enabling a silica sol protective agent to pass through the SiC multi-scale nano / micron ceramic fiber felt matrix in a suction filtration manner, cleaning and drying to obtain a high-temperature-resistant ceramic fiber felt precursor; and carrying out heat treatment on the high-temperature-resistant ceramic fiber felt precursor, and cooling to obtain the high-temperature-resistant ceramic fiber felt. When the prepared high-temperature-resistant ceramic fiber felt is in a high-temperature working environment, a molten glass phase formed by amorphous SiO2 at a high temperature cannot flow in the radial direction of the SiC micron fibers, a compact and uniform glass coating is formed on the surfaces of the micron fibers, the oxidation cracking phenomenon caused when the SiC fibers make contact with oxygen at the high temperature is effectively prevented, and the service life of the high-temperature-resistant ceramic fiber felt is prolonged. And the high temperature resistance of the material is improved.

The invention provides a high-strength winding thin-wall SiC composite cladding tube and a preparation method thereof. A preparation method of a high-strength winding thin-wall SiC composite cladding tube comprises the steps that silicon carbide fibers are wound and laid around a core mold, the winding pre-tightening force is smaller than or equal to 10 N. The winding mode comprises the first mode that one layer of annular winding is conducted firstly, then one layer of spiral winding is conducted, and the number of fiber intersection points in the whole annular direction at a certain position of the outer surface of the core mold is 1. One-layer annular winding is carried out firstly, then two-layer spiral winding is carried out, the number of fiber intersection points in the whole annular direction at a certain position of the outer surface of the core mold is 3, and a prefabricated body is obtained; carrying out a densification deposition process on the preform, wherein the densification deposition process comprises PyC pyrolytic carbon interface deposition, CVI chemical vapor infiltration and CVD chemical vapor deposition; and precise inner circle and outer circle machining is conducted, and the SiC composite cladding pipe is obtained. According to the preparation method disclosed by the invention, through a specific dry winding mode and a densification deposition process, the SiC composite material tube blank is higher in density and better in mechanical property.

The invention relates to the technical field of thermal insulation materials, in particular to a high-temperature-resistant aerogel composite material and a preparation method thereof. The high-temperature-resistant aerogel composite material is prepared from the following components in parts by weight: 15 to 35 parts of reinforced fiber matrix, 43 to 65 parts of silicon-aluminum-zirconium ternary aerogel network, 3 to 12 parts of functional nano filler, 2 to 8 parts of zinc borate flame-retardant component and 0.5 to 2 parts of surface hydrophobic modified layer. Wherein the reinforced fiber matrix is composed of aluminum silicate fibers, silicon carbide fibers and aluminum oxide nanofibers; the molar ratio of silicon to aluminum to zirconium in the silicon-aluminum-zirconium ternary aerogel network is 5: 2: 1; the functional nanofiller comprises aluminum oxide nanoparticles, titanium oxide nanoparticles, carbon nanotubes and boron nitride nanosheets; the zinc borate flame-retardant component is zinc borate; the surface hydrophobic modification layer comprises an inner methyltrimethoxysilane modification layer and an outer hexamethyldisilazane modification layer. The high temperature resistance and thermal shock resistance of the material are remarkably improved, a low-energy-consumption preparation process is adopted, and the material has excellent comprehensive performance.

The invention discloses an anti-hydrogen-permeation composite coating for a hydrogen conveying pipeline and a preparation method of the anti-hydrogen-permeation composite coating, and belongs to the field of physically modified metal corrosion prevention. The method comprises the following steps: step 1, firstly weighing quantitative silicon carbide powder, silicon carbide fiber and modified silicon carbide powder, adding a dispersing agent for dispersing, and uniformly stirring under the action of magnetic stirring; step 2, adding quantitative organic resin and a curing agent thereof in the step 1, further stirring uniformly, defoaming under a vacuum condition, and removing bubbles and a dispersing agent therein; and thirdly, the steel plate is pretreated, then the steel plate is evenly coated with the coating, and the stable coating can be obtained through normal-temperature curing and heating curing. The preparation method of the coating is easy to operate, low in cost and high in hydrogen permeability resistance, the service life of the hydrogen conveying pipeline can be effectively prolonged, and the hydrogen conveying efficiency and the pipeline safety are improved.

The invention discloses a preparation method of a near-stoichiometric aluminum-doped silicon carbide fiber, which comprises the following steps: doping PMS with an aluminum element, blending with PCS, and sequentially carrying out melt spinning, non-melting treatment, high-temperature pyrolysis, high-temperature sintering and the like to obtain the aluminum-doped silicon carbide fiber with a C / Si atomic ratio close to an ideal value. And the near-stoichiometric ratio regulation and control of the silicon carbide fiber components are realized.