1094 results about "Hexagonal boron nitride" patented technology

The invention provides a preparation method of an h-BN / PI high-temperature-resistant anticorrosive coating, and relates to the technical field of polymer composites.The preparation method of the h-BN / PI high-temperature-resistant anticorrosive coating comprises the steps that under the protection of inert atmosphere, aromatic diamine containing impurity element five-membered rings and aromatic dianhydride containing ether bonds are taken and subjected to a polymerization reaction in a polar aprotic solvent, and the h-BN / PI high-temperature-resistant anticorrosive coating is obtained. A polyamide acid solution is obtained; performing ultrasonic-assisted liquid phase stripping on the micron-sized hexagonal boron nitride to obtain single-layer hexagonal boron nitride; adding the single-layer hexagonal boron nitride into the polyamide acid solution for multiple times, and uniformly stirring to obtain a hexagonal boron nitride / polyimide composite solution; and coating the hexagonal boron nitride / polyimide composite liquid on a to-be-coated surface, and carrying out gradient heating curing to obtain the h-BN / PI high-temperature-resistant anticorrosive coating. The h-BN / PI high-temperature-resistant anticorrosive coating based on interaction of multiple hydrogen bonds has relatively good high temperature resistance, relatively good resistance mechanical property and excellent corrosion resistance.

The invention relates to a modified chrome corundum ramming material and a preparation and construction process thereof, and belongs to the technical field of chrome corundum ramming materials. The ramming material comprises a material A, a material B and a material C, wherein the material A comprises chrome corundum aggregate, titanium dioxide coated aluminum oxide microspheres, calcium sulfide dehydrate and silicon carbide porous microspheres; the material B comprises chromium oxide-zirconium oxide composite nano powder, sodium thiosulfate pentahydrate, tricalcium phosphate and hexagonal boron nitride flaky crystals; and the material C comprises an aluminum dihydrogen phosphate-magnesium hydroxide compound, a calcium fluoride-aluminum oxide co-melt and a silane coupling agent. The preparation process comprises the steps of pretreatment of all the components, preparation of composite powder and layered preparation. The construction process comprises the steps of pretreatment, wet-process mixing, layered ramming, negative-pressure permeation, medium-temperature reaction, spraying curing, integral firing and the like. Generation of hexavalent chromium can be effectively inhibited, the thermal shock resistance, the mechanical strength and the heat-conducting property of the material are remarkably improved, and the material has the advantages of being good in environment friendliness, long in service life, excellent in construction performance and the like.

The invention discloses an uvioresistant acrylic resin coating and a preparation method thereof, and belongs to the technical field of acrylic resin paints.The uvioresistant acrylic resin coating is characterized in that step-by-step functional design is adopted, a functional polyurethane prepolymer is constructed through prepolymerization reaction and double-bond end capping, fluorosilicone modified acrylate emulsion is prepared through a core-shell emulsion polymerization process, and the uvioresistant acrylic resin coating is obtained. Then carrying out surface silane modification on hexagonal boron nitride and carrying out composite coating to obtain a modified boron nitride auxiliary agent; and finally, carrying out composite emulsification and dispersion compounding on all the components to obtain the anti-ultraviolet acrylic resin coating. Through the synergistic enhancement effect of the fluorosilicone modified core-shell structure and the surface modified boron nitride, the ultraviolet aging resistance and the insulation reliability of the coating are remarkably improved on the basis of keeping high adhesive force, excellent flexibility and impact resistance of the coating; the problems that a traditional acrylic coating is prone to yellowing and pulverization under long-term ultraviolet radiation, and the mechanical property is reduced are effectively solved, and the acrylic coating is suitable for the field of electronic equipment protective coatings with high requirements for weather resistance, mechanical strength and electrical insulating property.

The invention provides a preparation method of a barrier type antimonide infrared detector. The preparation method comprises the following steps: selecting a gallium antimonide substrate; a gallium antimonide buffer layer, an indium arsenide heavily-doped layer, a class II superlattice absorption layer and an aluminum-arsenic-antimony barrier layer are sequentially grown on the substrate in an epitaxial mode through a molecular beam epitaxy method; mechanically stripping the hexagonal boron nitride two-dimensional material, and transferring the stripped hexagonal boron nitride to the aluminum-arsenic-antimony barrier layer to form a Van der Waals heterojunction and composite barrier layer structure; depositing electrodes by using an ultraviolet lithography technology and a thermal evaporation mode to form one electrode arranged on the gallium antimonide buffer layer and the other electrode arranged on the boron nitride; a large-numerical-aperture micro-lens array is processed on a substrate, and the micro-lens array is composed of gallium antimonide cylinders with a phase modulation function; therefore, the antimonide medium-wave infrared detector with the composite barrier layer can be formed, the quantum efficiency is improved, the order of magnitude of dark current is reduced, and room-temperature medium-wave infrared detection can be realized.

The invention discloses a preparation method of modified self-extinguishing insulating oil with flame-retardant and self-repairing functions. Wherein the insulating liquid is mixed oil of mineral oil and palm oil-based modified natural ester, and the inherent high flash point characteristic of the natural ester improves the fireproof safety of the insulating oil. The modified hexagonal boron nitride (h-BN), the magnesium hydroxide nano material and the microcapsule repairing agent are added into the insulating oil, and the h-BN can capture free electrons in the oil, so that the formation and expansion of electric arcs are inhibited, and the breakdown voltage is improved. Magnesium hydroxide is heated to decompose and absorb heat, the fault temperature is reduced, and therefore the arc self-extinguishing effect is achieved. Under the action of a high electric field and a high temperature, the capsule wall of the microcapsule repairing agent is broken, meanwhile, the repairing material is released, a chemical reaction is carried out, and the insulating property of the insulating oil is repaired. The modified insulating oil prepared by the invention has high insulating strength and high flame retardance, and also has a performance self-repairing function, so that the service life of the insulating oil is prolonged.

The invention relates to a preparation method of a high-thermal-conductivity hexagonal boron nitride film in the technical field of new materials, which comprises the following steps: acquiring particle size distribution data of hexagonal boron nitride powder treated by silane, and measuring the distribution condition of hexagonal boron nitride particles with different particle sizes by a particle size analyzer to obtain a particle size distribution curve; the influence of key process parameters on the heat-conducting property, the mechanical strength and the flame-retardant property is verified through experiments, performance data under different process parameters are obtained, and the influence rule of silanization treatment conditions on the surface property of hexagonal boron nitride and the performance of the composite material is focused on; and according to the heat-conducting property, the mechanical strength and the flame-retardant property data, optimizing process parameters by adopting a particle swarm optimization algorithm in a multi-objective optimization algorithm to obtain an optimal process parameter combination.

The invention belongs to the field of functional textile materials, and provides a cool-feeling anti-ultraviolet nylon fabric and a preparation method thereof, and the cool-feeling anti-ultraviolet nylon fabric adopts a design scheme of combining a boron nitride / titanium dioxide composite filler with a beta-hydroxyl ether type ultraviolet absorption silane coupling agent surface modification technology. Uniform loading of hexagonal boron nitride on the surface of anatase type titanium dioxide is realized through an in-situ heat treatment process, a composite structure with heat conduction and ultraviolet shielding functions is constructed, and a complete process flow of master batch preparation, melt spinning, weaving, after-treatment and the like is matched; the ultraviolet protection coefficient UPF of the fabric is not lower than 40, the UPF retention rate after 20 times of household washing cycles is not lower than 80%, and the cool feeling qmax at the contact moment is not lower than 0.20 W / cm, the technical problem that an existing nylon fabric is insufficient in ultraviolet resistance and cool feeling function is solved, and the fabric has wide industrial application value.

The invention discloses a graphite crucible silicon infiltration resistant coating based on a gradient boron nitride-silicon carbide composite structure and a preparation method thereof. The coating is composed of hexagonal boron nitride nanosheets, beta-type silicon carbide nanowires, yttrium aluminum garnet precursor sol and the like, and effective blocking of 1500-1600 DEG C silicon melt is achieved through gradient structural design and an in-situ self-repairing mechanism. The preparation process comprises the steps of h-BN activation, S C carbon layer deposition, slurry mixing and spraying and segmented heat treatment. The molten silicon contact angle of the coating reaches 158 + / -2 degrees at the temperature of 1550 DEG C, through cracks do not exist after 50 times of thermal shock circulation, the coating is effective after being continuously used for 48 batches under the industrial working condition, the problems of silicon infiltration interface adhesion and thermal shock failure of a traditional graphite crucible are solved, and the coating has remarkable industrial application value.

The invention provides a microwave-transmitting and infrared-compatible low-emissivity coating, and belongs to the technical field of camouflage materials. The microwave-transmitting and infrared-compatible low-emissivity coating is of a double-layer structure composed of a bottom microwave transparent layer and a surface infrared functional layer. The microwave transparent layer is made of hollow dielectric microbeads and polyvinylidene fluoride; the infrared functional layer is made of modified flaky aluminum powder, modified hexagonal boron nitride nanosheets and polyvinylidene fluoride. The microwave-transmitting compatible infrared low-emissivity coating provided by the invention has an infrared radiation inhibition effect in two atmospheric window wave bands of 3-5 microns and 8-14 microns, and has high transmissivity in an electromagnetic wave band of 2-18 GHz; the method is especially suitable for the scenes, such as stealth unmanned aerial vehicles, ship decks and 5G base station shells, where infrared characteristics need to be suppressed and microwave signal transmission needs to be kept at the same time.

The invention provides a composite diaphragm, a preparation method thereof and a lithium ion battery. The composite diaphragm comprises a base diaphragm and a solid electrolyte-water-soluble gel electrolyte composite coating, wherein the surface of the base diaphragm is coated with the solid electrolyte-water-soluble gel electrolyte composite coating by utilizing a roller coating process; the water-soluble gel electrolyte is obtained by co-polymerizing an intermediate I prepared from methyl methacrylate and N-isopropylacrylamide and neopentyl glycol diglycidyl ether. In the composite diaphragm provided by the invention, the water-soluble gel electrolyte can effectively improve the adhesion of the solid electrolyte on the base membrane, and ensure that the solid electrolyte can be effectively adhered to the surface of the base membrane; lithium titanium aluminum phosphate and the like can effectively promote transmission of lithium ions through the solid electrolyte, the hexagonal boron nitride composite coating can prevent direct contact between the lithium titanium aluminum phosphate solid electrolyte and the like and lithium, and the solid electrolyte is protected. And the interface stability of the composite diaphragm is relatively good, and a compact phase formed in the circulation process can effectively inhibit the permeation of lithium dendrites, so that the safety of the battery is improved.

The invention provides a preparation method of a wurtzite boron nitride material, which comprises the following steps: performing high-temperature and high-pressure treatment on hexagonal phase boron nitride powder at the pressure of 10-15 GPa and the temperature of 900-1300 DEG C, keeping the pressure for 120-240 minutes, and keeping the temperature for 40-120 minutes, thereby obtaining the wurtzite boron nitride material. According to the method provided by the invention, the pure-phase wurtzite boron nitride block material is prepared by taking low-cost hexagonal boron nitride powder as a starting material, and synthesis of the high-purity and high-performance wurtzite boron nitride block material is realized under relatively mild conditions by optimizing high-temperature and high-pressure synthesis parameters and an experimental assembly structure. The Vickers hardness of the obtained material reaches 46 + / -2.3 GPa under the loading of 1 kg, the thermal stability reaches 1085 DEG C, and excellent superhardness and high temperature resistance are shown. The method is simple in process, raw materials are easy to obtain, the dependence of a traditional method on a high-cost precursor and a complex process is broken through, and the method has a good industrial application prospect.

The invention relates to the technical field of polymer composite materials, and discloses a nano-ceramic-based composite insulating coating and a preparation method thereof, and the coating is prepared from a composite resin matrix, a composite functional ceramic filler, a double-reactivity organosilicon linker and an initiator. Wherein the composite resin matrix is composed of vinyl-terminated polydimethylsiloxane and a vinyl ether functionalized fluorocarbon copolymer, and a soft and rigid interpenetrating network structure is formed. The composite functional ceramic filler is prepared from needle-shaped silicon nitride, flaky hexagonal boron nitride, nano silicon dioxide, nano cerium oxide and nano barium titanate. According to the invention, a chemical bonding interface is constructed between the inorganic filler and the organic resin, and the synergistic effect of the composite matrix and the multifunctional filler is optimized, so that the coating has excellent adhesive force, flexibility and thermal shock resistance, obtains high volume resistivity and breakdown strength, and meets the insulation protection requirements under harsh working conditions.

The invention provides a preparation process of an environment-friendly film coating, and belongs to the technical field of coatings, the preparation process comprises the following steps: S1, mixing 3-4 parts of epoxy resin, 25-28 parts of polyurethane emulsion, 35-38 parts of water-based acrylic resin emulsion, 0.5-1 part of a curing agent, 0.5-1 part of an accelerant, 2-2.5 parts of a dispersing agent, 0.3-0.5 part of a wetting agent and 6-8 parts of PVA emulsion to obtain a first mixture; s2, adding 4-5 parts of fluorine-doped hexagonal boron nitride and 10-12 parts of nano aluminum oxide into the first mixture, and stirring to obtain a second mixture; adding 2-3 parts of polyoxyethylene, 0.4-0.5 part of citric acid, 2-4 parts of a coalescing agent and 0.5-1 part of a defoaming agent into the second mixture, and stirring to obtain a coating; s3, performing plasma activation on the PET film to obtain a pretreated PET film; and S4, uniformly coating the pretreated PET film with the coating, and curing to obtain the environment-friendly film coating. The ink-jet adhesive force is improved, and meanwhile, the mechanical property of a PET film coated with a coating is improved.

Composite multilayered material compositions are provided which contain one or more hexagonal boron nitride (hBN)-containing layers, together with layers comprising optional polymeric binders, glass fibers, magneto-ceramic materials, and a super-hydrophobic outer coating. Methods are provided for making the composite materials and products containing them. The composite materials are useful for making radomes and other coverings for electronic components and equipment.

The invention discloses a resin aluminum cover plate for circuit board drilling and a preparation method thereof.The preparation method comprises the steps that modified polyurethane is dissolved in water and then evenly mixed with modified filler, modified paint is prepared, the surface of aluminum foil is coated with the modified paint, drying is conducted, and the resin aluminum cover plate is prepared. Compared with traditional polyethylene oxide and polyethylene glycol, the high temperature resistance and the stability are better, large-area surface coating melting caused by overheating in the drilling process is avoided, the drilling precision is guaranteed, meanwhile, a polyurethane molecule side chain contains a long-chain ester group, the lubricating property between a drill bit and resin can be improved, and when the drill bit makes contact with modified filler, the service life of the drill bit is prolonged. When the drill bit is in use, polyethylene glycol on the surface of the modified filler melts, palm oil in pore diameters of the bamboo fibers is released under extrusion of the drill bit, the bamboo fibers can extrude hexagonal boron nitride in the bamboo fibers to form sliding, and then friction between the drill bit and resin is greatly reduced.

The invention discloses a protective coating for an aluminum alloy heat exchange tube and a preparation method of the protective coating, and relates to the technical field of coating materials. The protective coating for the aluminum alloy heat exchange tube at least comprises the following raw materials in parts by mass: 100 parts of bisphenol A epoxy resin; 28 to 32 parts of polyether amine D230; 8 to 12 parts of a modified MgAlCe-BTC-LDH filling material; 4 to 6 parts of polydopamine modified hexagonal boron nitride; 35 to 45 parts of propylene glycol methyl ether acetate; and 1-2 parts of a dispersant. The modified MgAlCe-BTC-LDH filler prepared by the invention realizes triple functions of Ce element oxidation resistance, BTC corrosion inhibition and layered barrier, and the polydopamine modified hexagonal boron nitride prepared by the invention effectively improves the heat-conducting property, solves the contradiction between insulation and heat conduction, and adapts to the protection requirement of an aluminum alloy heat exchange tube.

The invention discloses a high-temperature-resistant and corrosion-resistant coating for an aluminum alloy heat exchange tube and a preparation method thereof, and relates to the technical field of coating materials. The method comprises the following steps that the aluminum alloy heat exchange tube is cleaned and deoiled, then a treating agent is sprayed, composite coating slurry is sprayed to the surface of the aluminum alloy heat exchange tube after curing, and the high-temperature-resistant and corrosion-resistant coating for the aluminum alloy heat exchange tube is obtained after curing treatment. Wherein the treating agent is prepared from NS-30 silica sol, deionized water and methyltrimethoxysilane; the composite coating slurry is prepared from a polyamide acid solution, a synergist, functionalized boron nitride nanosheets, modified hexagonal boron nitride, a flatting agent and a defoaming agent. The silane film introduced into the treating agent and the synergist, the functionalized boron nitride nanosheet and the modified hexagonal boron nitride introduced into the composite coating slurry effectively improve the high temperature resistance, the corrosion resistance, the adhesive force, the thermal conductivity, the aging resistance and the toughness of the coating. Therefore, the method has a wider application prospect.

The invention discloses an insulating heat-conducting glass fiber reinforced polyphenylene sulfide composite material and a preparation method thereof. The composite material comprises the following raw material components: 30-50 parts by mass of polyphenylene sulfide, 10-20 parts by mass of glass fiber, 30-50 parts by mass of a heat-conducting filler, 5-10 parts by mass of a compatilizer and 0.3-1 part by mass of a coupling agent, and the heat-conducting filler is selected from one or more of graphite, silicon carbide, aluminum oxide, magnesium oxide, aluminum nitride and hexagonal boron nitride; the compatilizer is selected from a glycidyl methacrylate graft polymer. The polyphenylene sulfide composite material prepared by the preparation method disclosed by the invention has high insulativity, high thermal conductivity and good mechanical properties.

The present invention relates to the field of cable technology, and discloses a flame-retardant and wear-resistant charging pile cable and a preparation method thereof. The charging pile cable prepared by the present invention comprises a cable core, a heat insulation layer, a shielding layer, and an outer sheath layer. The outer sheath layer is made of thermoplastic polyurethane elastomer as the main raw material, with the addition of maleic anhydride grafted POE, reinforcing fillers, and composite flame retardants and other functional additives, so that the cable has excellent flame retardant and wear resistance. Among them, the reinforcing filler utilizes the synergistic effect between hexagonal boron nitride and polyimide containing siloxane segments and long-chain fluorocarbon structures to improve the wear resistance of the outer sheath layer. The composite flame retardant has higher flame retardant efficiency than traditional inorganic flame retardants.

The invention discloses a radiation refrigeration coating as well as a preparation method and application thereof, and relates to the technical field of material preparation. The preparation method comprises the following steps: sintering hexagonal boron nitride, and removing boron oxide to obtain modified boron nitride powder; the preparation method comprises the following steps: reacting supramolecular polysiloxane with methoxypolyethylene glycol to obtain hyperbranched polysiloxane; the modified boron nitride powder and hyperbranched polysiloxane are subjected to hydrolysis on boron nitride under the alkaline condition, and silane modified boron nitride is obtained; the silane modified boron nitride is added into a polyurethane coating matrix to form the radiation refrigeration coating. The silicon-oxygen modified group is introduced to the surface of the boron nitride, so that the interaction between the boron nitride and the coating group is greatly improved, and the stability of the coating is improved; the coating can be cured under different environmental conditions, and construction on power equipment is facilitated; the formed radiation refrigeration coating is high in sunlight reflectivity, high in mid-infrared emissivity and high in heat dissipation capacity for power equipment.

The invention provides a preparation method of a novel cable sheath layer. The novel cable sheath layer comprises silicone rubber, a heat-conducting insulating material, a flame-retardant material, white carbon black, a silane coupling agent, dicumyl peroxide, silicone oil, an antioxidant, a light stabilizer and the like. The preparation method comprises the following steps: firstly, modifying a heat-conducting insulating material and a flame-retardant material to improve the dispersity and interfacial compatibility, and then uniformly dispersing filler in a silicone rubber matrix through banburying, open milling and vulcanization processes to finally form a high-performance cable sheath layer. Nanometer spherical aluminum oxide grafted hexagonal boron nitride is used as a heat-conducting insulating material, so that the heat conductivity of the sheath layer is remarkably improved, and excellent electrical insulation performance is kept. Besides, modified magnesium-rich silicate is used as a flame-retardant material, so that the cable has an excellent flame-retardant effect, and an antioxidant and a light stabilizer are combined, so that the weather resistance and the aging resistance of the sheath layer are improved. The prepared cable sheath layer is suitable for the fields of high-voltage cables, 5G communication, power transmission, aerospace, military use, rail transit and the like, and has a good application prospect.

An exemplary embodiment of the present disclosure provides a method for making an electrolyte, comprising: providing a solid polymer electrolyte (SPE); incorporating boron nitride with the SPE to form a composite polymer electrolyte (CPE), wherein the boron nitride is at least one of exfoliated hexagonal boron nitride (ex-BN) or fluorine-fimctionalized hexagonal boron nitride (BN-F).

Thin polymer films may comprise a first polymer layer comprising poly(vinylidene fluoride); a second polymer layer comprising poly(vinylidene fluoride); and a nanofiller-polymer layer interposed between the first polymer layer and the second polymer layer, the nanofiller-polymer layer comprising poly(methyl methacrylate) and nanosheets dispersed in the poly(methyl methacrylate); the nanosheets comprising mica nanosheets and / or hexagonal boron-nitride nanosheets; wherein 50-99% of the nanosheets in the nanofiller-polymer layer are oriented parallel to a width dimension of the first polymer layer.

The present invention relates to a thermally conductive rubber material and a rubber track. The preparation method of the rubber material comprises the steps of mixing a raw material composition; wherein, by weight, the raw material composition comprises: 100 parts of a rubber raw material; 20-30 parts of carbon fibers subjected to a first pretreatment; 25-35 parts of hexagonal boron nitride powder subjected to a second pretreatment; and 25-35 parts of nano powder subjected to a third pretreatment; wherein the average length of the carbon fibers is 3 mm to 10 mm; wherein the average particle size of the hexagonal boron nitride powder is 10 μm to 200 μm; wherein the average particle size of the nano powder is 5 nm to 100 nm, and the nano powder is selected from one or more of metal powder and metal oxide powder; wherein the first pretreatment comprises treating the carbon fibers with a silane coupling agent and then etching with CO2 plasma; wherein the second pretreatment comprises treating the hexagonal boron nitride powder with a silane coupling agent; and wherein the third pretreatment comprises treating the nano powder with a solution containing octadecylamine and stearic acid.

The invention relates to the technical field of ceramic materials, and discloses a preparation process for producing hexagonal boron nitride by a low-temperature method, which comprises the following specific steps: mixing borax and urea according to a certain mass ratio, and adding into a ball mill for ball milling to obtain a material A with uniform particle size; adding a modified material with a proper mass ratio into the material A, and continuing ball milling to uniformly disperse the modified material to obtain a material B; transferring the material B into a tubular furnace into which high-purity ammonia gas is introduced, heating to about 900 DEG C at a proper rate, and preserving heat for several hours to complete the reaction; and after the reaction is completed, cooling along with the furnace, washing the product with deionized water until the product is neutral, sieving with a 300-mesh sieve, and carrying out vacuum drying at 70-90 DEG C for a certain time to finally prepare the high-crystallinity hexagonal boron nitride. According to the process, boron-nitrogen reaction kinetics is promoted through the modified material, generation of cubic boron nitride impure phases is inhibited, compared with a traditional high-temperature method, energy consumption is remarkably reduced, product purity and crystallinity are improved, and the process is suitable for large-scale production.

The invention relates to the technical field of cables, and discloses a flame-retardant wear-resistant charging pile cable and a preparation method thereof. The charging pile cable prepared by the invention comprises the cable core, the heat insulation layer, the shielding layer and the outer sheath layer, the outer sheath layer is prepared by taking a thermoplastic polyurethane elastomer as a main raw material and adding functional aids such as maleic anhydride grafted POE, a reinforcing filler and a composite flame retardant, so that the cable has excellent flame retardance and wear resistance; wherein the reinforcing filler utilizes the synergistic effect between hexagonal boron nitride and polyimide containing a siloxane chain segment and a long-chain fluoroalkyl structure, so that the wear resistance of the outer sheath layer is improved; compared with a traditional inorganic flame retardant, the composite flame retardant is higher in flame retardant efficiency.

The invention relates to the field of nylon materials, in particular to a high-temperature-resistant nylon / PTFE composite material and a preparation method and application thereof. The high-temperature-resistant nylon / PTFE composite material is prepared from the following raw materials in parts by weight: 40 to 90 parts of modified nylon, 0.5 to 15 parts of polytetrafluoroethylene, 5 to 15 parts of composite filler, 1 to 3 parts of compatilizer and 0.1 to 0.3 part of antioxidant, the composite filler comprises modified calcium fluoride whiskers, modified glass beads and modified hexagonal boron nitride. Through collaborative design of multiple performance dimensions such as interface, heat resistance, wear resistance, mechanics and the like, the composite material has excellent high-temperature stability, low-friction wear resistance and high-strength mechanical performance at the same time, has remarkable breakthrough in comprehensive performance and service life compared with a traditional nylon-based composite material, and has extremely high technical innovation and practical value.

The invention relates to the field of composite coatings, and discloses a wave-absorbing high-entropy alloy composite coating and a preparation method thereof.According to the wave-absorbing high-entropy alloy composite coating, mixed powder is deposited on the surface of a base body in a laser cladding mode to form a pre-coating, then ion nitriding treatment is conducted on the pre-coating, and the wave-absorbing high-entropy alloy composite coating is obtained. The mixed powder comprises high-entropy alloy powder, a functional additive, core-shell antifriction powder and a binder; the functional additive is prepared by taking halloysite, biomass chitosan and ferric chloride hexahydrate as raw materials, adopting a hydrothermal method to obtain an iron modified halloysite / carbon material, and then performing carbon thermal reduction reaction; the core-shell antifriction powder is prepared by uniformly stacking outer-layer aluminum oxide on the surface of nano hexagonal boron nitride by using a non-uniform nucleation method; the ion nitriding treatment process parameters are as follows: nitriding is performed for 58-62 h at the temperature of 540-560 DEG C, flow velocity thermal decomposition ammonia is adopted as a nitrogen source, and the prepared composite coating is high in hardness and good in wear resistance, corrosion resistance and wave absorbing performance.

The invention discloses high-toughness and high-thermal-conductivity aluminum nitride ceramic and a production process, and relates to the related field of aluminum nitride ceramic. Hexagonal boron nitride and Ti3SiC2 composite particles with the surfaces coated with titanium nitride are introduced into aluminum nitride ceramic, a cerium oxide sintering aid and a reasonable organic adding system are supplemented, synergistic improvement of thermal conductivity and toughness is achieved, Ti3SiC2 is subjected to TiN nanometer coating, interface stability and oxidation resistance are enhanced, combination of Ti3SiC2 and a matrix is improved, and the thermal conductivity and toughness of the aluminum nitride ceramic are improved. The fracture toughness and the mechanical strength of the ceramic are obviously improved; meanwhile, aluminum nitride and hexagonal boron nitride construct an efficient thermal conductivity network, so that the material keeps excellent thermal conductivity, the overall scheme is reasonable in structural design and scientific in component matching, and the obtained ceramic is high in density, high in thermal conductivity, excellent in mechanical property and high in thermal shock resistance.

The invention discloses a flame-retardant coating and a preparation method thereof, and relates to the technical field of coatings, the flame-retardant coating comprises the following raw materials: 100 parts of epoxy resin, 25-50 parts of hexagonal boron nitride functional modified ammonium polyphosphate, 20-30 parts of cerium-cobalt-iron layered double hydroxide, 10-15 parts of hafnium diboride, 8-16 parts of a fireproof filler, 18-30 parts of a fluxing agent, and 20-25 parts of a curing agent; the hexagonal boron nitride functionalized modified ammonium polyphosphate is prepared from the following raw materials in parts by weight: 1-3 parts of functionalized boron nitride nanosheets, 5-10 parts of ammonium polyphosphate, 70-90 parts of ethanol and 7-9 parts of water. The cerium-cobalt-iron layered double hydroxide comprises the following raw materials: 3-4 parts of cerium nitrate hexahydrate, 2-4 parts of cobalt nitrate hexahydrate, 16-20 parts of iron nitrate nonahydrate, 80-100 parts of deionized water, 20-30 parts of a sodium hydroxide solution and 60-80 parts of a sodium carbonate solution. The flame retardant provided by the invention has excellent flame retardant property.