46results about How to "Improve anti-ablation performance" 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 discloses an ultra-high-temperature ceramic modified C / C composite material for aerospace power and a preparation method thereof. The oxidation ablation resistance of the C / C composite material is improved by introducing a ZrC and SiBCN multiphase ultra-high-temperature ceramic matrix into a C / C green body. The C / C-ZrC-SiBCN ultrahigh-temperature ceramic-based composite material is prepared by the following steps: carrying out high-temperature heat treatment on a carbon fiber preform, carrying out chemical vapor-phase oriented deposition on a carbon matrix process, carrying out densification by a high-pressure complex-phase precursor uniform mixing, dipping and co-cracking process, and carrying out post-high-temperature heat treatment until the material density reaches 2.3-2.5 g / cm < 3 >. The specific preparation method comprises the following steps: firstly, carrying out high-temperature heat treatment on a carbon fiber preform, then carrying out PyC interface deposition and matrix carbon preparation by adopting a chemical vapor deposition process, then preparing a ZrC ceramic matrix and a SiBCN matrix, and then carrying out post-high-temperature heat treatment on the formed composite material to obtain the ZrC / SiBCN composite material. Finally, SiC surface coating is conducted through chemical vapor deposition, and the C / C-ZrC-SiBCN ultrahigh-temperature ceramic-based composite material for aerospace power is obtained. The C / C-ZrC-SiBCN ultrahigh-temperature ceramic-based composite material has the advantages of being resistant to ultrahigh temperature, low in expansion coefficient, excellent in oxidation resistance and ablation performance and the like.

The invention belongs to the technical field of thermal protection coatings, and particularly relates to an ultra-high-temperature thermal protection powder coating, an ultra-high-temperature thermal protection coating and a preparation method and application of the ultra-high-temperature thermal protection powder coating. The invention provides an ultrahigh-temperature thermal protection powder coating. The ultrahigh-temperature thermal protection powder coating is prepared from transition metal boride, silicon carbide and metal carbide. The mass ratio of the transition metal boride to the silicon carbide is 9: (1-3); the metal carbide accounts for 5-35% of the total mass of the transition metal boride, the silicon carbide and the metal carbide. According to the ultrahigh-temperature thermal protection powder coating provided by the invention, the metal carbide is added into the transition metal boride-silicon carbide composite coating, the carbide has ablation resistance, and an oxidation product formed after oxidation of the metal boride and / or the metal carbide has a synergistic anti-oxidation effect, so that a high-melting-point compound can be obtained; therefore, the anti-ablation effect is improved.

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 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 discloses a method for rapidly preparing a Cf / SiC-HfC composite material, and belongs to the technical field of special ceramic materials. 1) preparing a pyrolytic carbon interface layer on the surface of the carbon fiber cloth after heat treatment; 2) uniformly mixing HfC powder, a sintering aid and polycarbosilane to prepare an adhesive film, and compounding the adhesive film with the carbon fiber cloth with the pyrolytic carbon interface to prepare a carbon ceramic prepreg; (3) paving the carbon ceramic prepreg in a mold, pressurizing and curing to prepare a carbon ceramic resin-based composite material; 4) performing hot-pressing cracking on the carbon ceramic resin-based composite material to prepare a carbon ceramic composite material; and 5) immersing the carbon fiber composite material into the precursor solution, carrying out vacuum pressure impregnation, curing and splitting decomposition (PIP) for 1-2 rounds to obtain the densified Cf / SiC-HfC composite material. The preparation method is high in efficiency, the prepared Cf / SiC-HfC composite material has the performance of high temperature resistance, oxidation resistance, ablation resistance and the like, the bending strength at the room temperature can reach 200-400 MPa, the bending strength at the temperature of 1800 DEG C is 100 MPa or above, and the Cf / SiC-HfC composite material is close to zero ablation after being examined by oxyacetylene flame at the temperature of 1800-2200 DEG C for 300 seconds.

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 application discloses a kind of multi-element ultra-high temperature nanocomposite ceramic matrix composites and preparation method thereof, the multi-element ultra-high temperature nanocomposite ceramic matrix composites are composed of multi-element ultra-high temperature nanocomposite ceramic and porous fiber body, wherein multi-element ultra-high temperature nanocomposite ceramic is composed of oxygen-free silicon-based ceramic and multi-element transition metal carbonitride uniformly distributed therein, and the preparation method is: at least two metal element complexes are reacted with silicon-based polymer to obtain single-source precursor polymer;Then porous fiber body is placed in single-source precursor polymer solution for multiple times of impregnation pyrolysis, and the composite material provided by the application has a nanocomposite structure, an ultra-high temperature ceramic multi-element single-phase solid solution, the type, content and ratio of metal elements can be adjusted, the ultra-high temperature ceramic in the matrix is uniformly distributed and has a nanoscale grain size, and the method can avoid damage to the fiber during preparation, thereby achieving simultaneous improvement of the mechanical properties and oxidation ablation resistance of the composite material.

The present invention discloses a composite coating for improving the surface performance of a carbon-based electrode, a graphite electrode and a preparation method. The composite coating of the present invention comprises a first transition layer, a second transition layer and a protective layer, the thickness of the composite coating is 15 to 35 μm, the first transition layer is a Ta layer with a thickness of 3 to 4 μm, and the second transition layer is a Ta layer with a thickness of 2 to 6 μm. x C layer, the protective layer is a TaC layer with a thickness of 10 to 20 μm, the Ta x The C layer is composed of Ta2C and TaC, wherein x is Ta in Ta x The molar ratio of elements in the C layer. The interface structure components of each layer of the composite coating prepared by the present invention change gradually. The outermost TaC layer has high purity, controllable thickness and good conductivity, and is the main protective layer; the Ta-Ta x The C two-layer transition structure has a high melting point and stable properties. It further enhances the membrane-substrate bonding strength while providing good protection for the internal graphite electrode, thereby greatly improving the bonding strength, anti-ablation and anti-oxidation properties of the entire coating.

A method for preparing a high-temperature ablation-resistant chopped carbon fiber reinforced SiBCN‑MAS composite material, which relates to a method for preparing a SiBCN ceramic-based composite material. The present invention aims to solve the problem that the existing carbon fiber or cracked carbon coated carbon fiber reinforced SiBCN ceramic-based composite materials have poor contact surface bonding and limited improvement in high-temperature ablation resistance. Method: 1. Prepare cracked carbon coated chopped carbon fibers; 2. Prepare SiBCN amorphous ceramic powder; 3. Mix raw materials; 4. Sinter. The present invention is used for the preparation of high-temperature ablation-resistant chopped carbon fiber reinforced SiBCN‑MAS composite materials.

The invention relates to a hafnium-based ultrahigh-temperature ceramic-based composite material and a preparation method thereof. The method comprises the following steps: mixing and weaving carbon nanotube fibers and PAN-based carbon fibers to obtain carbon nanotube fiber / carbon fiber bidirectional cloth; preparing the carbon nanotube fiber / carbon fiber bidirectional cloth into a sharp wedge profiling preform by adopting a lamination sewing process; preparing a pyrolytic carbon interface layer on the fiber surface of the sharp wedge profiling preform through a chemical vapor deposition method; the hafnium-zirconium composite ceramic precursor solution is used for dipping and filling internal pores of the sharp wedge profiling preform with the pyrolytic carbon interface layer, and the hafnium-based ultrahigh-temperature ceramic-based composite material is prepared through curing and cracking reaction. The carbon nanotube fiber / carbon fiber bidirectional cloth is woven to obtain a novel structure sharp wedge profiling preform, and a hafnium zirconium carbon solid solution is introduced as a ceramic matrix, so that the ablation resistance, the mechanical property and the heat conductivity of the ceramic matrix composite material are remarkably improved; the problem that a ceramic-based composite material prepared by a traditional technology is insufficient in ablation resistance and thermal conductivity is solved.

The invention provides a large-diameter engine heat insulation reinforcing method and structure meeting overload ablation, and mainly solves the problem that a heat insulation layer design method and structure of a traditional large-diameter solid rocket are difficult to meet local heat insulation design of an active section of an aircraft. According to the scheme, the reinforcing area is determined through numerical simulation of the two-phase flow of the flow field in the engine, the ablation rate and the ablation time are obtained in combination with the ablation test, the reinforcing thickness of the reinforcing area is obtained, and therefore fine design of the engine combustion chamber heat insulation profile is completed, and the working safety of the engine is improved. According to the reinforcing structure designed by the invention, the size thickness precision is high, the process is simple, the quality consistency is good, and the high-reliability design of the large-caliber solid rocket engine heat insulation structure capable of resisting long-time fixed overload ablation of the active section is realized.

The invention belongs to the technical field of cathode materials for plasma generators, and provides a silver-based material and a preparation method thereof, a cathode assembly and a plasma generator. The preparation method comprises: S1, adding silver nitrate, tin acetate, indium salt and zinc salt into water, stirring, adding sodium hydroxide solution until the pH value is 9-11, and obtaining a suspension; S2, adding polyacrylamide into the suspension, performing flocculation precipitation, and obtaining a composite precipitate; S3, heating the composite precipitate to 100-150°C in a reducing atmosphere, keeping the temperature, and then heating to 250-300°C, keeping the temperature, and obtaining a multi-component composite metal oxide silver composite powder; S4, hot isostatic pressing and sintering the multi-component composite metal oxide silver composite powder to obtain a silver-based material coarse material; S5, hot forging the silver-based material coarse material to obtain a silver-based material. The silver-based material obtained by the invention solves the problems of poor dispersion and easy ablation of metal oxides in existing silver-based materials.

The invention belongs to the technical field of preparation of carbon fiber reinforced carbon-based composite materials, and discloses a tungsten modified C / C composite material and a preparation method thereof.The C / C composite material is placed on a filter membrane, suction filtration is conducted on turbid liquid of tungsten powder, a first composite structure formed by compositing the tungsten powder and the C / C composite material is obtained, and the first composite structure is dried; and performing carbon deposition densification on the dried first composite structure to obtain the tungsten modified C / C composite material. The tungsten is distributed in a zigzag shape at the interface of the coating and the substrate, so that the binding force between the coating and the substrate is obviously enhanced. In the initial stage of ablation, the coating tungsten transfers heat on the surface of the composite material to the matrix, and then the matrix tungsten transfers the heat into the material, so that concentrated thermal stress on the surface of the material is reduced. Along with gradual increase of the temperature, the matrix tungsten firstly chemically reacts with C to strongly absorb heat, and WO3 formed by surface oxidation evaporates to absorb heat, so that the heating rate and the ablation temperature of the surface of the composite material are reduced, and the ablation resistance of the material can be powerfully improved.

The invention relates to an electric arc furnace gunning mix which comprises the following components in parts by weight: 35-55 parts of bauxite, 15-25 parts of silicon carbide (SiC), 10-25 parts of white corundum, 3-8 parts of silicon oxide (SiO2), 2-5 parts of silicon nitride (Si3N4), 0-3 parts of zirconium diboride (ZrB2), 3-8 parts of coke powder, 0-8 parts of a sintering aid and 5-10 parts of a binding agent, and the zirconium diboride is not zero. The method has the beneficial effects that a high-temperature ceramic body containing a ZrB2-SiC multiphase material is generated at a damaged furnace lining part through added zirconium diboride and silicon carbide and coke powder in the zirconium diboride under the action of a sintering aid, and the high-temperature ceramic body has good oxidation resistance, thermal shock resistance and ablation resistance, so that the service life of the electric arc furnace lining can be greatly prolonged.

The invention discloses a thrust adjusting device for a driving and cooling integrated variable thrust solid rocket engine. The thrust adjusting device comprises a throat bolt assembly, a high-pressure cold air source and a cold air channel. The throat bolt assembly is arranged on the convergent section of the spray pipe and comprises a base and a throat bolt, a throat bolt driving cavity is formed in the base, the first end of the throat bolt is slidably connected into the throat bolt driving cavity, the second end of the throat bolt is located on the throat portion of the spray pipe, and a tension piece is connected between the throat bolt and the base. One end of the cold air channel is communicated with the throat bolt driving cavity, and the other end of the cold air channel penetrates through the wall of the spray pipe and then is communicated with the high-pressure cold air source; one end of the air film hole is communicated with the throat bolt driving cavity, and the other end of the air film hole is communicated with the spray pipe. The device is applied to the field of rocket engines, can drive the throat bolt to move on the basis of avoiding adverse effects on engine charging and performance, and meanwhile effectively reduces high-temperature ablation of combustion gas of a combustion chamber to the throat bolt in the working process.

This invention discloses a method for preparing high-entropy ceramic matrix composites using a reactive infiltration process, belonging to the technical field of ceramic matrix composites. The steps are as follows: at least four single-component carbides are ball-milled and mixed with a carbon source, then dispersed in a dispersion liquid to obtain a slurry; continuous fibers are woven into a preform, and an interface layer and a matrix layer are deposited to obtain a semi-dense composite material; the slurry is introduced through vacuum or pressure impregnation; and a high-entropy carbide matrix is ​​generated in situ and densified by reactive infiltration after embedding with a transition metal and its alloy. This invention solves the problems of long process cycles, high porosity, high cost, and insufficient introduction of high-entropy ceramics in existing processes, achieving rapid densification and improving the material's high-temperature stability, oxidation resistance, and ablation resistance. It is suitable for the large-scale production of thermal protection materials for hypersonic vehicles.

The invention relates to a non-expansive refractory coating and a preparation method thereof, the non-expansive refractory coating comprises a component A and a component B. The component A comprises, by mass, 15-25% of high-alumina cement, 8-12% of refractory soil, 5-10% of glass powder, 5-15% of aluminum hydroxide, 5-10% of hollow glass beads, 2-5% of silica fume, 3-5% of an ethyl cellulose composite system, and the balance modified vitrified microbeads; the component B comprises 10-20% of lithium silicate, 5-10% of an acrylic emulsion, 5-15% of a pure acrylic emulsion, 0.1-0.3% of a water reducing agent, 1-2% of a wetting agent, 1-3% of a coalescing agent and the balance of water; the modified glass beads comprise titanium dioxide composite glass beads, tetrabutyl titanate and silver. The coating has the effect of improving the fire resistance of the coating.

The invention relates to preparation of a ceramic-based composite material, in particular to a rapid densification method of a ceramic-based composite material, which is used for overcoming the defects that in the prior art, after being impregnated, ultrahigh-temperature ceramic particles are coated by combining CVI-C or PIP-C, the cycle time is long, and the coating uniformity is difficult to guarantee. According to the rapid densification method for the ceramic-based composite material, a layer of amorphous carbon is coated on the surface of ultra-high-temperature nano-powder by adopting a one-step in-situ polymerization method, and the uniform carbon coating layer is beneficial to improving the wetting power of the ultra-high-temperature nano-powder during RMI, so that the RMI process effect of the ceramic-based composite material is improved.

The present invention provides a method for preparing a lightweight, low-ablation nozzle expansion section, comprising: mixing high-residue carbon phenolic resin, polyacrylonitrile-based short-cut carbon fiber and solvent in proportion to form a premix; after the premix is ​​desolventized, it is loaded into an expansion section preform curing tooling, and cured by heating and pressurizing a press to form a preform blank; the preform blank is machined to obtain a preform; the composite expansion section preform is woven on the outside of the preform and the large end of the expansion section by a carbon cloth / mesh tire + needle punching molding process, and after it is made, it is impregnated with phenolic resin, and then in the expansion section integral molding tooling, it is cured by heating and pressurizing a press to form a composite expansion section product; the expansion section blank is partially machined in the subsequent nozzle production and assembled with the nozzle shell. The present invention solves the problems of low material strength of the winding expansion section, large ablation amount under high temperature and high pressure working environment, and heavy nozzle weight, and meets the performance requirements of solid rocket engines for high impact-to-mass ratio nozzles.

The invention discloses a high-toughness anti-ablation hafnium-tantalum-carbon solid solution ceramic-based composite material and a preparation method thereof, and mainly solves the problems of low fracture toughness and poor ablation resistance of hafnium-tantalum-carbon solid solution ceramic in the prior art. According to the scheme, mixed powder of silicon carbide whiskers, hafnium carbide and tantalum carbide is sintered to obtain the silicon carbide whisker toughened hafnium tantalum carbon solid solution ceramic-based composite material, wherein the silicon carbide whiskers are uniformly distributed in the material; the preparation method comprises the following steps: mixing and ball-milling hafnium carbide and tantalum carbide powder to obtain hafnium carbide-tantalum carbide mixed powder; performing ultrasonic dispersion on silicon carbide whiskers, and adding the silicon carbide whiskers into the mixed powder to obtain whisker-containing powder which is uniformly mixed; finally, spark plasma hot pressed sintering is adopted, the whisker-containing powder obtained in the last step is placed in a graphite mold for high-temperature sintering, and the composite material is obtained. The fracture toughness of the hafnium-tantalum-carbon solid solution ceramic and the high-temperature thermal stability of an oxidation product of the hafnium-tantalum-carbon solid solution ceramic can be improved, and meanwhile the cracking resistance and ablation resistance of the hafnium-

The invention provides a ceramic matrix composite air rudder and a preparation method thereof. The air rudder comprises a rudder leading edge, a rudder skin and a rudder framework, and the rudder skin and the rudder leading edge are connected with the rudder framework through connecting screws; wherein the rudder leading edge is formed by molding a hafnium modified C / SiC ceramic matrix composite material, and the rudder skin, the rudder skeleton and the connecting screw are all formed by molding a C / SiC ceramic matrix composite material. According to the scheme, all the components are formed by adopting different ceramic matrix composite materials, the rudder leading edge is made of the hafnium modified C / SiC ceramic matrix composite materials, and the composite materials have excellent high temperature resistance and ablation resistance; the rudder framework and the rudder skin are made of C / SiC ceramic-based composite materials, the composite materials enable the rudder framework and the rudder skin to have excellent bearing capacity, meanwhile, the connecting screws are made of the C / SiC ceramic-based composite materials, and the thermal matching performance of the ceramic-based composite materials, the rudder leading edge, the rudder framework and the rudder skin is good. Therefore, the connection between the rudder leading edge and the rudder skeleton and the rudder skin is more reliable.

The application provides a gradient wave-transparent heat shield forming method, comprising the following steps: S1, preparing a preform of a heat shield; S2, configuring ceramic slurry; S3, fusing the ceramic slurry into the preform of the heat shield to form a green body of the heat shield; S4, placing the green body of the heat shield into the ceramic slurry to densify the green body of the heat shield; and S5, sealing a large port of the green body of the heat shield and performing solution infiltration on the green body of the heat shield by using polytetrafluoroethylene to form the heat shield. The heat shield prepared by the method not only has the functions of bearing and transmitting waves, but also has excellent heat insulation and heat protection functions.

The application discloses a tubular object inner wall double-glow plasma processing device, which comprises an electrode rod and a bottom disc; the bottom disc is connected with a target material tray through a first ceramic support, and the bottom disc is connected with a workpiece tray through a second ceramic support; the target material tray is provided with a target material one and a target material two, and the target material one and the target material two are in a disc shape; a hole with the same inner diameter as the workpiece is reserved on the workpiece tray, and a hollow heat preservation cover is further arranged on the workpiece tray; the workpiece is arranged at the middle position of the target material one and the target material two, and the center lines of the target material one, the target material two, the workpiece and the hollow heat preservation cover are coincident; the target material tray is connected with an electrode rod one, and the workpiece tray is connected with an electrode rod two. The application further discloses a processing method of the tubular object inner wall double-glow plasma processing device. The outer walls of the two metal target materials and the inner wall of the tubular object are at equal intervals and are located on the upper and lower sides of the tubular object, the film layer is uniform and dense, no hole and crack appear, the film layer is combined with the base body in a metallurgical way, and the service life is improved.

The application provides a quartz fiber composite surface high-temperature-resistant waterproof coating and a preparation method thereof. The coating is ytterbium silicate (YbSiO5) ceramic, is prepared by using a low-pressure plasma spraying process, has a thickness of 0.05-0.30 mm, a porosity of not more than 5%, and a thermal expansion coefficient of less than 4*10 ‑6 / K. A laser etching process is selected for a quartz fiber composite pre-spraying treatment process, X-direction and Y-direction fibers are subjected to roughening and densification treatment, and Z-direction fibers are not treated, so as to form a grid. On the one hand, the grid maintains the integrity of the fiber bundle, and on the other hand, the surface roughness is controllable, so that the coating bonding force can be greatly improved. The coating bonding strength is greater than or equal to 1 MPa, the coating has no cracking or peeling in a prepared state, and the surface has super-hydrophobic effect. The ytterbium silicate coating has good durability, can be stored stably for a long time, does not discolor or age and fall off, is resistant to 1600 DEG C ablation, and has a water immersion weight gain rate of not more than 0.02 g / (cm 2 *h) after ablation.

The invention relates to the field of metal material surface treatment, in particular to a light alloy surface green anti-ablation composite coating and a preparation method thereof. The preparation method of the composite coating comprises the following steps: preparing a micro-arc oxidation electrolyte, and preparing a ceramic layer containing a ZrO2 reinforced phase on the surface of a light alloy through a micro-arc oxidation method based on the electrolyte; wherein the electrolyte comprises sodium dihydrogen phosphate, potassium fluozirconate, zirconium sol and hydroxyethyl cellulose; preparing a film-forming agent and a filler of the green coating, uniformly mixing the film-forming agent and the filler, and coating the surface of the ceramic layer with the mixture to obtain a composite coating; wherein the composite coating is green. The composite coating provided by the invention can improve the ablation resistance of the light alloy.

The application provides a manufacturing method of a three-dimensional braided preform with low fiber volume content, which comprises the following steps: selecting fibers, braiding the fibers to form a first three-dimensional braided bundle, and the fiber volume content in the first three-dimensional braided bundle is 40%-60%; braiding the first three-dimensional braided bundle again to form a second three-dimensional braided preform, and the fiber volume content in the second three-dimensional braided preform is 20-35%. The three-dimensional braided bundle with the same thickness is used to replace the fiber bundle composed of single filaments, so that the size and distribution of the gap in the preform are more uniform, which is beneficial to the densification of the subsequent curing process, reduces the porosity, and improves certain structure and physical and chemical performance indexes.

The application relates to the technical field of ablation-resistant materials, in particular to a high-performance composite material and a preparation method thereof, which comprises the following steps: surface modification of coated carbon fibers and carbon nanotubes by using silane coupling agents respectively to obtain modified carbon fibers and modified carbon nanotubes; uniform stirring of polyphenyl ether resin, an antioxidant, anti-precipitation flame-retardant microspheres and the modified carbon nanotubes to obtain a mixture; side feeding of the modified carbon fibers in a double-screw extruder, extrusion granulation and preparation of the high-performance composite material. By adding the coated carbon fibers, the anti-precipitation flame-retardant microspheres and the carbon nanotubes in the resin matrix, the ablation resistance and the friction resistance of the prepared composite material are greatly improved; specifically, the zirconium oxide film is coated on the surface of the carbon fibers, the coated carbon fibers have the characteristics of high-temperature oxidation resistance, corrosion resistance and high hardness, and the coated carbon fibers and the carbon nanotubes jointly act, so that the overall performance of the composite material is enhanced.