66results about How to "Improves ablation resistance" patented technology

The invention provides a high-temperature-resistant carbon fiber reinforced phenolic resin composite material and a preparation method thereof. The preparation method comprises the following steps: firstly, carrying out high-temperature oxidation treatment on carbon fibers; secondly, carrying out surface modification on the carbon fibers by using a chemical modifier; then mixing the modified carbon fiber, an antioxidant and a dispersing agent to prepare slurry; performing vacuum filtration on the prepared slurry, and drying to obtain a carbon fiber blank; preparing a phenolic resin infiltration solution, and impregnating the carbon fiber blank with the phenolic resin infiltration solution; and finally, carrying out mold pressing and curing to obtain the high-temperature-resistant carbon fiber reinforced phenolic resin composite The preparation method is simple in required equipment, convenient to operate, stable in process, high in production efficiency and suitable for large-scale industrial production. According to the high-temperature-resistant carbon fiber reinforced phenolic resin composite material prepared by the preparation method, the bonding property between the carbon fiber and the phenolic resin is improved, certain toughness and strength are provided, and meanwhile, the high-temperature-resistant carbon fiber reinforced phenolic resin composite material has the advantages of ablation resistance, good oxidation resistance in a high-temperature environment and the like.

The invention relates to a high-temperature ablation resistant ceramic matrix composite material and a preparation method thereof. The method comprises the following steps: preparing a rare earth acetylacetone complex from hexahydrate of rare earth chloride (rare earth nitrate) and acetylacetone; uniformly mixing the rare earth acetylacetone complex with poly (hafnium) oxane by using xylene to obtain a zirconium (hafnium)-rare earth ceramic precursor solution; densifying the porous carbon fiber preform by using a zirconium (hafnium)-rare earth ceramic precursor solution through a precursor impregnation and pyrolysis process to obtain a carbon fiber reinforced carbide ceramic-rare earth zirconium (hafnium) acid salt ceramic-based composite material; and densifying the carbon fiber reinforced carbide ceramic-rare earth zirconium (hafnium) acid salt ceramic-based composite material by using molybdenum chloride and silicon chloride through a chemical vapor infiltration method to prepare the high-temperature ablation resistant ceramic-based composite material. The prepared ceramic-based composite material has excellent high-temperature oxidation ablation resistance and excellent high-temperature mechanical properties at the temperature of 2000 DEG C or above.

The invention belongs to the technical field of high polymer materials. The invention particularly relates to a halogen-free flame-retardant ablation-resistant polypropylene composite material as well as a preparation method and application thereof. The polypropylene composite material comprises 40-60% of flame-retardant modified master batch and 40-60% of long glass fiber reinforced polypropylene master batch, the flame-retardant modified master batch is prepared from the following raw materials in parts by weight: 24-44 parts of polypropylene resin, 5-15 parts of PPE resin, 2-5 parts of a compatilizer, 20-40 parts of piperazine substances, 10-20 parts of ammonium phosphate substances, 4-8 parts of surface modified superfine aluminum hydroxide and 0.3-1.5 parts of a processing aid. The content of the long glass fibers in the long glass fiber reinforced polypropylene master batch is 40-60wt%. PPE resin is introduced into a polypropylene halogen-free flame-retardant system, modified superfine aluminum hydroxide is compounded, halogen-free flame-retardant master batches and long glass fiber reinforced polypropylene master batches are uniformly compounded in proportion, and the halogen-free flame-retardant ablation-resistant material is obtained. While the high flame retardance of the material is maintained, the ablation resistance can be greatly improved, and the material is not burnt through after being continuously burnt for 10 minutes by a flame spray gun at the temperature of 1300 DEG C.

The invention discloses an ablation-resistant long-fiber reinforced nylon material for a battery pack, and relates to the technical field of nylon materials, the ablation-resistant long-fiber reinforced nylon material comprises the following raw material components by weight: 60-80 parts of nylon resin powder, 30-50 parts of a long-fiber reinforced material, 10-18 parts of aluminum diethylhypophosphite master batch, 8-15 parts of bromine-antimony composite master batch, 3-7 parts of montmorillonite, 12-20 parts of aluminum hydroxide, and 2-6 parts of nano-silica. The composite material is prepared from the following components in parts by weight: 1-4 parts of carbon nanotubes, 0.5-1.2 parts of an antioxidant I, 0.3-0.8 part of a lubricant I, 2-5 parts of a compatilizer, 0.1-0.4 part of a nucleating agent and 0.2-0.6 part of an anti-ultraviolet agent. By adding the diethyl aluminum hypophosphite master batch, the flame retardant property of the nylon material is improved, the processability of the nylon material is improved, the ablation resistance of the nylon material is improved, and the problems of insufficient flame retardant property, poor processability and poor ablation resistance of the nylon material can be solved.

The invention belongs to the technical field of ablation-resistant polymer-based composite materials, and particularly relates to an ablation-resistant modified sugar-based carbon fiber composite material and a preparation method thereof.The preparation method comprises the following steps that S1, carbon black filler particles are subjected to surface modification treatment; s2, preparing a glycosyl dipping solution; s3, impregnating the carbon fiber preform in a glycosyl impregnation solution in a vacuum environment, and performing pressure maintaining treatment to obtain a pre-impregnated carbon fiber preform; s4, performing gelatinization treatment on sweet water of the pre-impregnated carbon fiber preform in a vacuum drying oven to obtain a gelatinized carbon fiber preform; s5, performing two-stage low-temperature stabilization treatment on the gelatinized carbon fiber preform in a vacuum drying oven to obtain a stabilized carbon fiber preform; and step S6, performing high-temperature normal-pressure carbonization treatment on the stabilized carbon fiber preform in a protective atmosphere to obtain the ablation-resistant modified glycosyl carbon fiber composite material.

The invention discloses an ablation-resistant EPDM (Ethylene-Propylene-Diene Monomer) thermal insulation material and a preparation method thereof, and belongs to the field of thermal insulation materials, the thermal insulation material is prepared from the following components in parts by mass: 70 to 80 parts of EPDM rubber, 20 to 30 parts of liquid EPDM, 15 to 20 parts of silicon dioxide, 10 to 40 parts of high-temperature-resistant filler, 10 to 15 parts of flame retardant, 10 to 15 parts of heat-resistant fiber and 3 to 5 parts of cross-linking agent. A third monomer of the ethylene propylene diene monomer is ethylidene norbornene, and the ethylene content is 50-60%. The raw materials are placed between double rollers to be mixed, and a mixed sheet is obtained; and performing vulcanization molding on the mixed sheet to obtain the ablation-resistant ethylene-propylene-diene monomer thermal insulation material. The content of the heat-resistant fibers is increased, the aramid fibers are subjected to in-situ carbonization to form a carbonized layer structure frame, and meanwhile, the content of SiO2 is regulated and controlled, so that the content of SiO2 is matched with the increase of the fibers, and the ablation resistance of the thermal insulation material is improved.

The invention relates to a phenyleneboronic hybrid silicon resin aerogel and a preparation method thereof, and belongs to the technical field of aerogel preparation, and the specific scheme comprises the following steps: step 1, adding alkoxy silane, organic phenylboronic acid, an organic solvent and deionized water into a reaction container, heating for hydrolysis-condensation, and after the reaction is finished, carrying out oil-water separation to obtain a phenyleneboronic hybrid silicon resin aerogel; carrying out reduced pressure distillation on the oily substance to remove small molecular organic matters and deionized water to obtain a phenylene boron-containing silicon resin prepolymer; step 2, dissolving the phenyleneborosilicate resin prepolymer in an organic solvent, adding a catalyst, pouring the mixture into a mold, and performing cross-linking curing to obtain phenyleneborosilicate resin gel; and step 3, heating and drying the phenyleneborosilicate resin gel at normal pressure, and after drying is finished, heating and aging to obtain the phenyleneborosilicate resin aerogel. The phenylene boron hybrid silicon resin aerogel disclosed by the invention can be used as a novel light, ablation-resistant, anti-oxidation and high-performance ablation heat-proof and heat-insulating composite material, and new application of the hybrid silicon resin in the fields of aerospace and the like is expanded.

The invention discloses transition metal carbonitride-SiCxNy composite ceramic and a preparation method thereof.The preparation method comprises the steps that MeSi2 powder and carbon powder are mixed and then subjected to uniform ball milling, drying is conducted, further grinding is conducted, and a fully and uniformly mixed powder mixture is obtained; pressing the powder mixture into a ceramic blank by adopting a cold pressing process; and performing high-temperature heat treatment on the ceramic blank in a nitrogen environment, and cooling to obtain the transition metal carbonitride-SiCxNy composite ceramic. In the preparation process of the transition metal carbonitride ceramic, a SiCxNy ceramic phase is generated at the same time, compared with single-phase ceramic, due to the existence of a second phase, the sintering performance of the composite ceramic is well improved, the strength and the toughness are improved, the silicon-based composite carbide ceramic also shows more excellent ablation resistance, and the service life of the silicon-based composite carbide ceramic is prolonged. And wide-temperature-range and high-temperature-range application of the transition metal carbonitride is realized.

The invention relates to the technical field of high polymer materials, and provides a high temperature ablation resistant coating material and a preparation method thereof, the high temperature ablation resistant coating material comprises the following materials: polysilazane resin, a composite ceramic material, carbon nanotubes and a filler; the composite ceramic material is prepared from silicon carbide and graphene through a coating construction method, and compared with an existing high-temperature-resistant ablation coating material, the graphene-modified silicon carbide composite ceramic material is good in dispersity and mechanical property, the performance of the graphene-modified composite material is effectively improved, and the service life of the graphene-modified composite material is prolonged. And the polysilazane is utilized to improve the bonding force of the composite material, so that the ablation resistance and mechanical properties of the final high-temperature ablation-resistant coating material are greatly enhanced.

The invention relates to a large-thickness ultra-low-density high-toughness silicone rubber heat-proof coating as well as a preparation method and application thereof, and belongs to the technical field of heat-proof coatings. The formula of the coating is optimally designed, and purified methyl diphenyl silicone rubber and large, medium and small hollow microspheres with different density sizes in a specific ratio are adopted, so that the high-toughness silicone rubber heat-proof coating is prepared. The silicon rubber heat-proof coating prepared from the silicon rubber, the reinforcing filler, the cork powder, the high-temperature-resistant antioxidant filler, the glass fiber, the tetraalkoxysilane, the polysilazane and the like is high in lightweight degree, good in toughness, capable of being sprayed in a large-thickness mode and good in ablation resistance, and the silicon rubber heat-proof coating passes ablation tests of a quartz lamp with the highest heat flux of 90 KW / m < 2 > in the CO2 atmosphere and a wind tunnel. Compared with the prior art, the high-strength and high-toughness coating has the advantages that the high-strength and high-toughness coating is low in density and better in toughness, the density is as low as 0.24-0.28 g / cm < 3 >, the elongation at break is as high as 15%-25%, and the high-strength and high-toughness coating can be sprayed in a large-thickness manner, is good in environmental adaptability and

The invention provides a flame-retardant PP material with high strength and high modulus and a preparation method thereof. The flame-retardant PP material comprises the following raw materials in percentage by weight: 30-60% of polypropylene resin; 20 to 30% of a flame retardant; 20 to 30% of short glass fiber; 5-10% of a filling material; 5-10% of a compatilizer; and 2-3 wt% of other auxiliary agents. By compounding the piperazine halogen-free flame retardant, the glass fiber and the inorganic mineral powder, the tensile strength of the obtained polypropylene composite material reaches 69-75 MPa, the bending modulus reaches 5000-5400 MPa, and the tensile strength and the bending modulus are higher than general requirements of new energy battery materials; the flame retardant grade can reach 1.5 V0 of UL94, and the flame retardant grade requirements of most new energy batteries are met.

The invention relates to a layered cathode structure based on functional layer-buffer layer alternate distribution and a rapid trial-manufacturing method thereof, and belongs to the technical field of machining, the layered cathode structure comprises a functional structure surface layer and a matrix, and the functional structure surface layer is further formed by stacking and alternately arranging a plurality of sub functional layers and buffer layers. In actual service, a refractory oxide layer is generated in situ on the basis of the functional layer made of the thermochemical material, self-protection is completed, and electrons are emitted to support arc discharge; and the buffer layer is made of a nanocrystalline material with high plastic deformation capacity, so that the thermal stress of the functional layer can be released through proper deformation of the buffer layer, and meanwhile, cathode spot migration can be accelerated when the buffer layer is in contact with a cathode arc so as to slow down cathode burning loss. Through the synergistic effect of the functional layer and the buffer layer, the problems of cracking, splitting and coating falling caused by plasma discharge shock heating and shock cooling of the layered cathode in application scenes such as electric spark machining hole making and electric arc welding are solved, meanwhile, the ablation uniformity is improved, and the ablation rate is reduced.

The invention relates to the technical field of high-entropy ultrahigh-temperature carbide ceramics, and discloses a boron-containing and nitrogen-containing carbide and a preparation method thereof. The molecular formula of the boron-containing and nitrogen-containing carbide is XCyBzNw, X is at least four of Zr, Hf, Ti, Ta, Nb, V and W, y is more than or equal to 0.6 and less than 1, z is more than 0 and less than or equal to 0.4, w is more than 0 and less than or equal to 0.4, y + z + w is less than or equal to 1, and the boron-containing and nitrogen-containing carbide is a single phase solid solution and has a face-centered cubic structure. The boron-containing and nitrogen-containing carbide provided by the invention has temperature resistance and oxidation resistance of an ultrahigh melting point, and has important potential application in an ultrahigh-temperature thermal protection system.

The invention discloses a polyphenyl ether composition as well as a preparation method and application thereof. The polyphenyl ether composition comprises the following components in parts by weight: 9-26 parts of PPE resin, 19-41 parts of PA resin, 5-10 parts of a phosphorus-containing flame retardant A, 2-6 parts of a phosphorus-containing flame retardant B, 5-15 parts of a compatilizer and 10-40 parts of glass fibers. The zero cutting viscosity of the polyphenyl ether composition is 10000 to 100000 Pa * s; the average retention length of the glass fibers is 0.2 to 0.35 mm; the phosphorus-containing flame retardant A is selected from one or more of hypophosphite flame retardants, red phosphorus and polyphosphate flame retardants; the phosphorus-containing flame retardant B is selected from one or more of phosphate flame retardants and phosphazene flame retardants. The polyphenyl ether composition disclosed by the invention has relatively good ablation resistance.

The invention belongs to the technical field of thermal insulation materials, and discloses a quartz fiber reinforced phenolic aerogel composite material with a densified surface layer and a preparation method of the quartz fiber reinforced phenolic aerogel composite material. The composite material comprises a densified surface layer and a light inner layer, the densified surface layer takes polycarbosilane modified bismaleimide resin as a matrix and quartz fiber woven cloth as a reinforcement; and the light inner layer takes phenolic aerogel as a matrix and quartz fiber needled felt as a reinforcement body. The preparation method comprises the following steps: connecting the surface layer woven fabric and the inner layer needled felt into a whole through needling, and then sequentially filling the surface layer matrix and the inner layer matrix. The aerogel composite material has the characteristics of ablation resistance, tough surface and heat insulation, the comprehensive density and the comprehensive mechanical property can be regulated and controlled, and the comprehensive requirements of heat insulation, low-speed impact resistance, light weight and certain mechanical strength of a large-area thermal protection structure of the windward side of a hypersonic speed device on the phenolic aerogel composite material can be met.

The invention discloses an epoxy POSS modified benzoxazine / ethylene propylene rubber ablation resistant composite material and a preparation method thereof. The composite material is composed of the following raw materials by weight: 100 parts of ethylene propylene rubber, 10-20 parts of benzoxazine resin, 1-2 parts of epoxy POSS, 4-6 parts of zinc oxide, 1-3 parts of stearic acid, 30-40 parts of flame retardant filler, 3-5 parts of coupling agent, 1-2 parts of vulcanizing accelerator, and 3-5 parts of vulcanizing agent. The present invention significantly improves the compatibility of benzoxazine resin and ethylene propylene rubber by epoxy POSS modification of benzoxazine resin, so that benzoxazine resin can produce appropriate cross-linking sites with EPDM, and the prepared composite material has excellent physical and mechanical properties and ablation resistance, and can be used in the field of aerospace thermal protection.

The invention relates to the field of silicon resin, in particular to benzocyclobutene modified phenyl silicon resin and a preparation method thereof, which are used for solving the problem that the application of the existing silicon resin in a high-temperature environment is limited due to poor high-temperature resistance, ablation resistance and charring performance of the existing silicon resin. The benzocyclobutene modified phenyl silicone resin contains a large number of benzene rings, so that the benzocyclobutene modified phenyl silicone resin is endowed with excellent high-temperature resistance, the thermal stability of the benzocyclobutene modified phenyl silicone resin is further improved after a benzocyclobutene structure is introduced, and the molecular structure of the benzocyclobutene modified phenyl silicone resin further contains a large number of phosphorus-containing structures and nitrogen-containing structures, so that the benzocyclobutene modified phenyl silicone resin can form more carbon protection layers during combustion, and the service life of the benzocyclobutene modified phenyl silicone resin is prolonged. The purposes of flame retardance and ablation resistance are achieved; the benzocyclobutene modified phenyl silicone resin has excellent high temperature resistance, ablation resistance, flame retardance and char forming performance and can be widely applied to the fields of aerospace, electrical industry, semiconductor packaging and the like, and the preparation method is simple, easy to operate and suitable for industrial production.

The application discloses a high-temperature curing ablation-resistant and heat-insulating two-component coating and a preparation process. The coating is composed of A component and B component. The A component comprises modified epoxy resin, liquid butyronitrile rubber, aluminum hydroxide powder, chromium trioxide, high-silica fiber powder, hollow glass microbead and toluene; the B component is a curing agent and a curing accelerator. In the preparation, the aluminum hydroxide powder, the chromium trioxide, the high-silica fiber powder and the hollow glass microbead are made into a filler dispersion liquid; then the epoxy resin and the liquid butyronitrile rubber are made into a resin-rubber mixture; then the filler dispersion liquid is slowly and uniformly added into the resin-rubber mixture under stirring, and the A component is obtained by soaking in a static magnetic field at room temperature and grinding; the curing agent and the curing accelerator are the B component. By optimizing the coating composition, the ablation resistance and the heat-insulating performance of the coating can be obviously improved by coating a single layer, the construction process is simplified, the coating thickness is reduced, and the high-temperature resistance of the coating is improved.

The invention discloses a titanium plate elastic grinding block material and a titanium plate elastic grinding block. The titanium plate elastic grinding block material is prepared from, by mass, 20%-25% of boron modified phenolic resin, 20%-25% of cardanol modified phenolic resin, 5%-8% of diamond, 10%-15% of silicon carbide, 5%-10% of white corundum, 5%-10% of potassium titanate whiskers, 5%-10% of basic magnesium sulfate whiskers and 8%-18% of filler. According to the titanium plate elastic grinding block material, the boron modified resin is selected, so that the temperature resistance of the grinding block can be improved, and the basic magnesium sulfate whiskers with flame retardance and cooling and heat dissipation performance are added, so that the high-temperature working performance of the grinding block is improved; moreover, cardanol modified phenolic resin is selected, so that the toughness and impact resistance of the grinding block can be improved, and potassium titanate whiskers are added, so that the strength and toughness of a matrix are improved, the holding force on diamond is improved, the wear resistance of a product is improved, and the cost performance is improved.

The invention discloses a method for preparing an ultra-long and ultra-thick plate-shaped carbon / carbon composite material on a large scale at low cost, which comprises the following steps: carrying out primary graphitization treatment on a carbon fiber preform to obtain a carbon fiber blank, loading the carbon fiber blank into a chemical vapor deposition furnace to carry out chemical vapor deposition treatment, and then carrying out secondary graphitization treatment to obtain the ultra-long and ultra-thick plate-shaped carbon / carbon composite material. A carbon / carbon green body is obtained, and the carbon / carbon green body is subjected to resin carbon densification treatment; according to the chemical vapor deposition, in the CVI deposition process, the flowing direction of gas in the deposition process is effectively controlled through the arrangement of an original chemical vapor deposition device, the freshness of carbon source gas in a deposition chamber is made to be consistent, an independent gas channel area is formed around each product, gas makes full contact with all parts of a blank, densification is uniform, the microstructure of the product is controllable, and the product quality is improved. After the product is subjected to high-temperature heat treatment at 2000-2500 DEG C, the graphitization degree range is 40-70%.

This invention provides a castable ablation-resistant coating material and its preparation method. The material is composed of unsaturated polyester resin, cobalt naphthenate, cyclohexanone peroxide, trichloroethyl phosphate, boron phenolic resin, silicon carbide, and hexa(4-aldehyde phenoxy)cyclotriphosphazene. Through optimized compounding design of the coating material, this invention achieves a castable ablation-resistant coating material with an ablation rate as low as 0.11 mm / s and a viscosity as low as 5900 mPa·s. This material possesses both excellent ablation resistance and casting process performance, and has broad application prospects in the casting and coating of solid rocket motor propellants.

The application provides a preparation method of an electrode part applied to a single crystal hot field device, which comprises the following steps: mixing cobalt powder, iron powder and carbon fiber particles to obtain a first mixed powder; mixing cobalt powder, copper powder, iron powder and carbon fiber particles to obtain a second mixed powder; filling the first mixed powder into a cavity of a mold, and making the volume of the first mixed powder account for 1 / 3-1 / 2 of the volume of the cavity; filling the second mixed powder into the cavity of the mold, and making the second mixed powder fill the cavity of the mold; performing die forming so that the first mixed powder and the second mixed powder jointly form an electrode green body; and sintering the electrode green body to obtain an electrode part. The electrode part has the excellent performance of both carbon / carbon composite material and cobalt-copper alloy material. The application further provides an electrode part prepared by the preparation method.

The invention discloses a modified aramid nanofiber / rubber composite material and a preparation method thereof.Aramid nanofibers with good water dispersibility are prepared through epoxy modification, the in-situ polycondensation effect of a silicate ester compound on the surfaces of the nanofibers is improved through a nucleophilic substitution reaction of epoxy groups and amino groups, ANFs (at) SiO2 is formed, and the modified aramid nanofiber / rubber composite material is prepared. The composite material with excellent physical and mechanical properties and ablation resistance can be obtained by using the ANFs (at) SiO2 reinforced rubber with lower parts by weight. In the ablation process, the nano silicon dioxide is firstly melted to form a protective film to coat the surface of the aramid nano fiber, so that the aramid nano fiber is prevented from being corroded and decomposed by heat flow, ceramic structures such as SiC and Si3N4 are generated in situ to promote densification of a carbon layer, and the ablation resistance of the rubber is remarkably enhanced.

This invention belongs to the field of ablation-resistant thermal insulation composite material preparation technology, specifically relating to a polyacrylonitrile-based hollow carbon fiber for thermal protection materials and its preparation method. The invention first pre-oxidizes porous polyacrylonitrile precursor fibers to obtain porous pre-oxidized fibers. Then, phenolic resin is coated onto the surface of the pre-oxidized fibers through solution polymerization. After impregnation in an organosilicon source solution, rapid Joule heating at high temperature deposits both phenolic carbon microspheres with excellent ablation resistance and a silica coating on the fiber surface, forming a unique hollow carbon fiber structure with excellent thermal insulation properties. This solves the problem that polyacrylonitrile-based carbon fibers cannot simultaneously achieve both thermal insulation and ablation resistance. The thermal conductivity of the polyacrylonitrile-based hollow carbon fiber prepared by this method is about 17% lower than that of porous polyacrylonitrile carbon fibers prepared by traditional carbonization methods, making it applicable to the field of integrated ablation-resistant thermal protection materials.

The application provides a high-conjugated aromatic core structure epoxy resin modified silicone rubber and a preparation method and application thereof, and belongs to the technical field of advanced materials. The high-conjugated aromatic core structure epoxy resin is used for modifying the silicone rubber, so that the mechanical property, thermal stability and heat oxidation resistance of the silicone rubber are improved, and the ordered arrangement of carbon and the growth of ceramic phase can be promoted under extreme heat flow conditions, a more continuous and compact carbon-silicon composite protective layer is formed, and the ablation resistance of the silicone rubber is significantly improved. The modified silicone rubber has excellent mechanical property, thermal stability, heat oxidation resistance and heat protection capacity, and has important scientific significance and application value for expanding the application scene of the silicone rubber in the field of extreme ablation resistance and protection and promoting the development of a new generation of high-speed aircraft heat protection technology.

The present invention belongs to the technical field of metal composite material preparation, and relates to a vacuum switch copper-chromium series contact material and its preparation process and device. The preparation process is specifically as follows: solid-phase sintering of Cr powder and W powder into a chromium-tungsten skeleton, and then liquid-phase sintering to obtain a copper-chromium-tungsten infiltrated material; gradually reducing the cooling temperature of the copper-chromium-tungsten infiltrated material to form a gradient temperature field distribution in which the temperature gradually decreases from the top to the bottom of the material, and the copper liquid above the copper-chromium-tungsten infiltrated material continues to flow from the top to the bottom, so that the copper liquid gradually solidifies from the bottom to the top; finally, after solid solution treatment and aging treatment, the vacuum switch copper-chromium series contact material is obtained. Also disclosed is a device for realizing the preparation process, wherein the furnace body is provided with a lifting mechanism, and during the solidification process, the lifting mechanism is adjusted to gradually descend, so that the material gradually solidifies from the bottom to the top, and it is ensured that there is always copper liquid replenished above during the solidification process, so that the prepared material has the least internal pores, the highest density, and improved pressure resistance, and can be applied to high-voltage vacuum switches.

This invention discloses a silicate colloid for high-solids-content, high-modulus composite fire-resistant glass and its preparation method, relating to the field of composite fire-resistant glass technology. Specifically, it describes a silicate colloid for high-solids-content, high-modulus composite fire-resistant glass and its preparation method. The colloid, by weight percentage, comprises a silicon source, water, glycerol / ethylene glycol / polyethylene glycol / polyglycerol, water-soluble organic acids and salts, water-soluble metal oxides or hydroxides, and alkali metal hydroxides, wherein the solids content is 60-75% and the modulus is 4.0-5.5. The preparation method includes: uniformly mixing the silicon source, water, additives, and functional additives, then adding alkali metal hydroxides, reacting at 50-90°C to obtain a prepolymer solution, followed by vacuum degassing. The viscosity is adjusted to the desired range by controlling the reaction conditions. This prepolymer solution is suitable for pouring or coating processes. After curing, the colloid forms a fire-resistant glass core layer. The resulting fire-resistant glass has advantages such as high light transmittance, ultra-thinness, dense foaming, low-temperature resistance, high weather resistance, and long lifespan.

The invention discloses a compression molding method for a quartz / phenolic aldehyde end of an embedded probe temperature sensor. The compression molding method comprises the following steps: molding and processing a probe temperature sensor protection bracket; packaging the probe temperature sensor; forming an end part; and machining the end part. According to the invention, the flexibility of the compression molding process, the designability of the material and the excellent ablation resistance of the quartz fiber and the phenolic resin are fully utilized, so that the problem that the operation cannot be carried out due to the characteristics of the molding process is avoided, and the preparation difficulty of a workpiece is reduced; the quartz / phenolic aldehyde composite material is adopted to replace a traditional conical metal piece to be internally arranged, so that the total mass of the end is greatly reduced; the formed product is high in size precision, good in internal quality and low in manufacturing cost, the overall pneumatic appearance structure of the end is not damaged under the condition that the requirement for normal use of the embedded probe type temperature sensor is met, and material selection and design of the end are obviously improved through force and heat test examination.

The invention discloses a flame retardant phenolic molding compound and a preparation method thereof, and belongs to the technical field of phenolic molding compounds. It includes the following parts by weight of raw materials: 40-60 parts of modified phenolic resin, 16-22 parts of reinforcing fibers, 20-40 parts of modified chitosan, 3-8 parts of curing agent, 1-3 parts of curing accelerator, and 2-6 parts of lubricant. The molding compound prepared by the present invention, the addition of reinforcing fibers and curing agents can enhance the mechanical strength of the molding compound; the phenolic resin is modified using boric acid to enhance the mechanical strength, heat resistance and ablation resistance of the molding compound; the filler is modified chitosan, which has better compatibility with the matrix than ordinary chitosan, can significantly enhance the flame retardancy and antibacterial properties of the molding compound, and the performance is long-term and stable. Therefore, the molding compound prepared by the present invention has stable and efficient flame retardancy and antibacterial properties, and does not need to be additionally added with flame retardants, has excellent mechanical properties, and has important application value in the technical field of phenolic molding compounds.

The invention discloses a method for repairing surface defects of a carbon-based composite material, and belongs to the technical field of composite materials. The method comprises the following steps: coating the defect part or the surface of a composite material base material with slurry, wherein the slurry comprises silica sol, repairing powder matched with the composite material base material, and chopped cellulose; according to the slurry, the chopped cellulose serves as a framework material, the supporting and strengthening effects can be achieved at the defect position, the repairing powder is matched with the material of the composite material base material, and meanwhile the silica sol has the bonding effect. According to the repairing slurry, coating repairing is carried out on defects of acceptable sizes on the surface of a base material, and compared with direct replacement of a new carbon-based composite material, the cost is reduced by 90% or above. On the basis of preparing the carbon-based composite material by adopting a reactive infiltration process, the composite material prepared by adopting a subsequent process disclosed by the invention is excellent in ablation resistance, the performance of the scouring-resistant and ablation-resistant carbon-based composite material can be quickly and specifically repaired, and the time cost is saved.