128results about How to "Improve bending strength" patented technology

The invention relates to a zirconia-based all-ceramic false tooth and a preparation method thereof. A core layer of the zirconia-based all-ceramic false tooth is prepared from the following components in parts by mass: 90 to 94 parts of ZrO2, 5 to 9 parts of Y2O3, 0.1 to 0.5 part of Al2O3, 0.01 to 0.5 part of Fe2O3, 0.01 to 0.5 part of Er2O3 and 0 to 0.2 part of MnO2, and a shell layer of the zirconia-based all-ceramic false tooth is prepared from the following components in parts by mass: 24.5 to 49.5 parts of CaCO3, 45 to 50 parts of SiO2, 0 to 25 parts of MgO, 0.01 to 0.5 part of Fe2O3, 0.01 to 0.5 part of Er2O3 and 0 to 0.2 part of MnO2. The preparation process comprises the following steps: performing dry pressing and isostatic pressing on raw materials of the core layer, presintering, and carving to obtain a zirconia-based false tooth biscuit; meanwhile, calcining raw materials of a shell layer, then adding deionized water, a dispersing agent and an adhesive, and carrying out ball milling and mixing to obtain calcium-magnesium-silicon-based ceramic slurry; and coating the calcium-magnesium-silicon-based ceramic slurry on the surface of the zirconium oxide-based false tooth biscuit, and sintering to obtain the zirconium oxide-based all-ceramic false tooth provided by the invention. The zirconia-based all-ceramic false tooth has good jade texture and is closer to the natural color of natural teeth.

The invention discloses pressureless sintered aluminum nitride ceramic as well as a preparation method and application thereof. The preparation method comprises the following steps: ball-milling and mixing micron-sized aluminum nitride, a sintering aid, nano-sized molybdenum powder, a dispersing agent, a binder and an organic solvent to prepare slurry; and drying the slurry, granulating, forming, dumping and sintering to obtain the pressureless sintered aluminum nitride ceramic. Wherein the sintering aid is a combination of samarium fluoride and yttrium fluoride. According to the preparation method, oxygen is removed at a low temperature by virtue of strong affinity of the nanoscale molybdenum powder and oxygen, the nanoscale molybdenum powder and the sintering aid jointly play a role in liquid-phase sintering assistance at a high temperature, densified sintering is realized and grain growth is inhibited by adopting pressureless sintering at a relatively low sintering temperature, the aluminum nitride ceramic with both heat conduction and strength is obtained, and meanwhile, a low-resistance second phase is generated; the resistivity of the aluminum nitride ceramic is adjusted while the heat conduction characteristic of the aluminum nitride ceramic is improved, the electrical conductivity of the aluminum nitride material is improved, and finally the aluminum nitride ceramic with high heat conduction and bending strength and moderate resistivity is obtained to meet the use requirements of electrostatic chucks.

The invention provides a lightweight insulation composite cross arm. The lightweight insulation composite cross arm comprises an insulation core rod, a filler filled in the insulation core rod and an insulation umbrella skirt located outside the insulation core rod, the structure of the insulating core rod is a pipe body formed by modified continuous basalt fibers which are spirally arranged in multiple layers, and resin is adhered to the surfaces of the modified continuous basalt fibers; the structure of the modified continuous basalt fiber is as follows: basalt fiber chips are connected to the surface of the continuous basalt fiber through silica sol; the resin comprises the following raw materials: 100 parts of epoxy resin, 1-5 parts of a silane coupling agent, 5-8 parts of an auxiliary agent, 8-10 parts of basalt fiber chippings, 20-30 parts of a curing agent and 30-50 parts of a solvent. According to the invention, the continuous basalt fibers are modified by the basalt chips, and the basalt chips are used as a bridge, so that the interaction between the continuous basalt fibers and a resin matrix is increased, and the bending modulus and bending strength of the insulating core rod are improved.

The invention relates to the technical field of polypropylene, and discloses a high-strength impact-resistant modified polypropylene plastic and application thereof in durable toys, the high-strength impact-resistant modified polypropylene plastic comprises 100 parts by weight of polypropylene, 10-30 parts by weight of hyperbranched polyurethane elastomer, 2-8 parts by weight of a filler, and 0.3-0.5 part by weight of an antioxidant; the hyperbranched polyurethane elastomer contains an alkyl long chain with good compatibility with polypropylene, and meanwhile, in the high-temperature melt extrusion process, the alkyl long chain and a polypropylene molecular chain form a physical chain winding effect, so that the compatibility between the polyurethane elastomer and the polypropylene is remarkably improved, and the interfacial force between the polyurethane elastomer and the polypropylene is improved; the hyperbranched polyurethane elastomer has a better toughening effect, and the tensile property, the bending strength and the impact strength are obviously improved.

The invention belongs to the technical field of epoxy resin, and particularly relates to a flame-retardant epoxy resin system, application thereof and a pultrusion composite material. The flame-retardant epoxy resin system provided by the invention comprises a material A and a material B which are independently subpackaged, the material A comprises the following components in parts by mass: 70 parts of flame-retardant epoxy resin; 22 to 26 parts of epoxy diluent; 5-7 parts of a toughening agent; the material B comprises the following components in parts by mass: 95-97 parts of an anhydride curing agent; 0.3 to 2 parts of accelerant; 0.5 to 1.5 parts of an antioxidant; and 0.1 to 0.6 part of a release agent. The material A and the material B in the flame-retardant epoxy resin system provided by the invention select proper components and mass ratios of the components, so that the pultrusion material product has a flame-retardant effect while the modulus advantage, the lightweight characteristic, the high fiber volume content and the excellent mechanical property requirements of the pultrusion material product are maintained, and the flame-retardant epoxy resin system can be suitable for places with relatively high fireproof grades.

The invention discloses a straw powder filled biodegradable composite material and a preparation method thereof, and relates to the technical field of biodegradable composite materials, the preparation method of the biodegradable composite material comprises the following steps: S1, pretreating straw; s2, impurities are removed through winnowing; s3, removing magnetic impurities; s4, cleaning and drying; s5, performing high-pressure steam treatment; s6, drying in the oven and crushing again; s7, adding into a high-speed mixer and mixing; s8, extruding the biodegradable composite material, and cooling and shaping the biodegradable composite material; and S9, cutting and polishing are conducted, and performance testing is conducted. The biodegradable composite material is prepared from agricultural waste, waste accumulation is reduced, sustainable development is promoted, the straw powder filled biodegradable composite material has biodegradability, high strength and good processability, and the straw powder filled biodegradable composite material is suitable for large-scale production. The problems of reducing agricultural wastes, enhancing mechanical properties and environmental protection performance, improving processability and reducing raw material cost can be solved.

The invention discloses raw material powder for preparing high-thermal-conductivity silicon nitride ceramic as well as a preparation method and application of the raw material powder. The raw material powder comprises silicon nitride powder; a sintering aid; and zirconium oxide chips falling off from the zirconium oxide grinding ball when the zirconium oxide grinding ball and the silicon nitride grinding ball are used for grinding. The trace doping of zirconium oxide promotes the densification of the silicon nitride ceramic and improves the relative density and the overall density on one hand, and on the other hand, zirconium oxide is mainly distributed in a triangular grain boundary position in a dispersed phase manner and is not dissolved in a silicon nitride grain lattice, so that the thickness of an intergranular phase is not increased, and the thickness of the silicon nitride is increased. The thermal conductivity of the finally obtained silicon nitride ceramic material is more than 100W / (m.K).

The invention belongs to the technical field of resin preparation, and particularly relates to a preparation method of low-temperature curing resin, which comprises the following steps: step 1, selecting raw materials: bisphenol A epoxy resin, a latent curing agent, a carbon nano tube, nano silicon dioxide, glass fiber, aluminum hydroxide, a dispersing agent and a lubricating agent; according to the preparation method of the low-temperature curing resin, the bisphenol A type epoxy resin and the latent curing agent are selected and combined with various fillers such as the carbon nano tube, the nano silicon dioxide, the glass fiber and the aluminum hydroxide, and the low-temperature rapid curing resin with excellent performance is prepared. The cured resin shows excellent mechanical properties, including high tensile strength, bending strength and impact toughness, which are benefited from the reinforcing effect of fillers such as carbon nanotubes, nano silicon dioxide and glass fibers. Meanwhile, the rigidity and the heat conductivity of the resin are remarkably improved, so that the stability and the heat-conducting property of the resin in a high-temperature environment are more excellent.

The invention relates to the technical field of crystalline silicon cells, in particular to a preparation method of a heterojunction cell and the heterojunction cell. The preparation method of the heterojunction cell comprises the following steps of performing texturing and cleaning, depositing each photovoltaic power generation functional film layer, preparing a metal electrode, removing a transparent conductive film layer in an edge region, performing smooth etching on the edge region, and preparing a passivation layer in the edge region of a silicon wafer. The heterojunction cell comprises a silicon wafer, the silicon wafer is divided into an edge area and a middle area, the surface of the edge area of the silicon wafer is a smooth surface covered with a passivation layer or a smooth textured surface, and the front face and the back face of the middle area of the silicon wafer are textured surfaces covered with photovoltaic power generation functional film layers. And the outermost layer of each photovoltaic power generation functional film layer in the middle area is a transparent conductive film layer. The transparent conductive film layer in the edge area is etched and removed, and the edge area is smoothly etched by using the reserved transparent conductive film layer as a mask, so that the preparation process of the heterojunction cell is simple and easy to realize.

The invention relates to the technical field of epoxy molding compounds, in particular to a low-stress low-hygroscopicity epoxy resin composition and application thereof. The low-stress low-hygroscopicity epoxy resin composition is prepared from the following components: epoxy resin, phenolic resin, inorganic filler, a coloring agent, a release agent, a curing accelerator, an ion trapping agent and a coupling agent, the epoxy resin is composed of o-cresol formaldehyde type epoxy resin and branched diphenyl sulfide epoxy resin, and the branched diphenyl sulfide epoxy resin is obtained by crosslinking 4, 4 '-dihydroxy diphenyl sulfide, inositol and epichlorohydrin; by adding the branched diphenyl sulfide epoxy resin into the epoxy resin composition, the mechanical property and the water absorption rate of the epoxy resin composition are remarkably improved, so that the stability and the reliability of a product are improved, and the epoxy resin composition can be used for packaging small and thin integrated circuits.

The invention relates to a high-heat-resistant glass fiber reinforced ABS material and a preparation method thereof, belonging to the technical field of polymer materials. The material comprises the following raw materials: 60-90 parts of ABS resin, 10-20 parts of modified glass fiber, 1-2 parts of lubricant, 1-3 parts of antioxidant and 0.05-0.1 parts of silane coupling agent. In the technical scheme of the invention, the surface of the glass fiber is grafted with KH550, then combined with graphene oxide, and then modified by triethylenetetramine-polyethylene glycol diglycidyl ether, and an intumescent flame retardant is grafted on the surface to obtain the modified glass fiber, which is finally mixed with ABS resin, lubricant, antioxidant and silane coupling agent, and extruded and granulated after melt blending to obtain the high-heat-resistant glass fiber reinforced ABS material. The modified glass fiber not only enhances the interface compatibility between the glass fiber and ABS, but also improves its mechanical properties, heat resistance and flame retardancy, and overall improves the comprehensive performance of the glass fiber reinforced ABS material.

The invention relates to the technical field of mica coiled material production equipment, in particular to a wrinkle-free super-thick mica coiled material and an integrated production system thereof. The integrated production system for the wrinkle-free ultra-thick mica coiled material comprises a mica paper unwinding roller, a guide roller group, a rolling composite roller group, a mica slurry mixing kettle, a first drying oven, a first hot-pressing roller group, a reinforced screen cloth unwinding roller, a second drying oven, a second hot-pressing roller group, a mica composite coiled material storage assembly, a laser cutting assembly and a finished mica composite coiled material storage roller. The mica slurry mixing kettle inputs mica slurry into the rolling composite roller set, and the mica slurry is hot-pressed and cured on the surface of the phlogopite paper to form a mica slurry curing layer; and a reinforced screen cloth layer unwound by the reinforced screen cloth unwinding roller is input into the first hot-pressing roller group and is subjected to hot-pressing compounding with the phlogopite paper of which the surface is subjected to hot-pressing compounding with the mica slurry curing layer. According to the production line, the wrinkle-free super-thick mica coiled material can be integrally and efficiently produced, and the quality and the production efficiency of the super-thick mica coiled material can be improved.

The application discloses a lithium-free high-heat-resistant ceramic mud and a preparation method thereof, and relates to the technical field of ceramic materials. In the preparation of the lithium-free high-heat-resistant ceramic mud, alumina is reacted with 3-(2,3-epoxypropoxy) propyl trimethoxysilane to obtain pre-modified alumina; the pre-modified alumina is reacted with starch to obtain modified alumina; ethyl acetoacetate, isopropyl alcohol, zirconium oxychloride, aluminum sec-butoxide, polyvinylpyrrolidone and N-N dimethylformamide are mixed to form a spinning solution, the spinning solution is electrospun, and then immersed in yttrium oxide sol to obtain alumina-zirconia-yttria composite fibers; the modified alumina, talc, alumina-zirconia-yttria fibers, hydroxypropyl methyl cellulose, glycerol, oleic acid, polyethylene glycol and water are stirred and mixed, and vacuum pugging is carried out to obtain the lithium-free high-heat-resistant ceramic mud. The lithium-free high-heat-resistant ceramic mud prepared by the application has good thermal shock resistance and bending strength after sintering.

A preparation method of a controllable CNTs@PyC interface layer in carbon / carbon composite material, ZIF-67 with different distribution patterns is carried on the surface of carbon fiber; CNTs are in-situ generated from ZIF-67 through chemical vapor deposition, CNTs are distributed on the surface of carbon fiber in different growth patterns; PyC is deposited on the surface of carbon fiber, different shapes of CNTs@PyC interface layer shape are obtained, by controlling the different growth patterns of ZIF-67 on the surface of carbon fiber, the different distribution states of CNTs derived exist, so as to realize the controllable and adjustable interface layer shape, to meet the application requirements under different conditions: the circular ring shape reduces the stress concentration of CNTs@PyC interface layer, avoids a large number of cracks in the composite material. The wave shape is beneficial to the application of carbon / carbon composite material in the service environment under the tensile condition, prolongs the crack propagation path along the interface layer, effectively relieves the PyC ring cracking phenomenon around the fiber, and is more easy to realize the interlocking effect between the interface layer and the carbon matrix, effectively prevents the interface debonding phenomenon, and greatly improves the mechanical properties of carbon / carbon composite material.

The present application relates to the technical field of bamboo fiber composite material, in particular to a purification preparation method of bamboo fiber reinforced natural polymer composite material. The bamboo raw material is crushed and treated by steam explosion to obtain primary bamboo fiber; the primary bamboo fiber is sequentially subjected to organic solvent dewaxing treatment and oxidation system selective delignification treatment to obtain purified bamboo fiber; the purified bamboo fiber is treated in a tannin acid solution to form a polyphenol interface layer on the surface thereof; and a solution containing polyvalent metal ions is added to the treated bamboo fiber to form a coordination cross-linking interface layer on the surface of the bamboo fiber. The present application constructs a stable interface layer between the fiber and the natural polymer matrix. The interface layer can effectively transfer stress, significantly improve the tensile strength, bending strength and shear strength of the composite material, and solve the problem of weak interface and easy delamination of traditional natural composite materials.

The invention relates to the technical field of nylon alloy, and discloses a preparation method of a high-strength PA alloy plastic material, which comprises the following steps: mixing nylon 6, polyphenyl ether, polyphenyl ether amide, an antioxidant and an auxiliary agent, placing in a twin-screw extruder, and carrying out melt extrusion granulation to obtain the high-strength PA alloy plastic material. According to the invention, 2, 6-dimethyl-p-phenylene bis (oxyethylamine), succinyl chloride and the like are subjected to a polymerization reaction to obtain polyphenyl ether amide, and the polyphenyl ether amide contains a 2, 6-dimethyl-p-phenylene diether structural unit similar to polyphenyl ether and an amido bond structural unit similar to nylon 6, so that the polyphenyl ether amide can be used as a compatilizer, and the polyphenyl ether amide can be used as a compatilizer for preparing a composite material. The interface interaction between nylon 6 and polyphenyl ether is improved, and the compatibility of nylon 6 and polyphenyl ether is improved, so that the PA / PPE alloy composite plastic material with better mechanical properties is obtained, and the PA / PPE alloy composite plastic material shows higher bending strength, impact strength, tensile strength and elongation at break.

This invention discloses a low-temperature resistant plastic bucket and its preparation method, belonging to the field of plastic bucket technology. This invention utilizes the synergistic effect of maleic anhydride-grafted ethylene-octene copolymer, nano-aluminum nitride, and cold-resistant toughening agent, combined with gradient injection molding, gradient annealing, and low-temperature aging processes to eliminate internal stress in the product. This allows the product to possess excellent tensile strength, flexural strength, and drop resistance reliability at -10℃. Under full load, the drop height can reach 1.2m without cracking or leakage. The synergistic effect of each component achieves a balance between low-temperature toughness and structural strength, significantly improving the stability and service life of the plastic bucket under low-temperature conditions.

The invention provides a differential friction stir welding method for an aluminum-based material part, and relates to the technical field of friction stir welding of aluminum-based materials. According to the main technical scheme, a set differential friction stir welding tool is adopted, and differential friction stir welding is conducted on an aluminum-based material part to be welded; the differential friction stir welding tool comprises a stirring needle assembly and a shaft shoulder assembly. The stirring needle assembly comprises a stirring needle and a stirring needle connecting handle; the stirring needle is made of tungsten carbide-cobalt alloy; the shaft shoulder assembly comprises a shaft shoulder and a shaft shoulder connecting handle; the shaft shoulder is made of tungsten carbide-cobalt alloy; in the tungsten carbide-cobalt alloy, the content of cobalt is 12-25 wt%. According to the method, the set differential stirring welding tool is utilized, weld nugget reinforced phase particles can be broken, the higher strengthening effect is achieved, coarse grain weld nugget grains are refined, and therefore low-heat-input differential stirring friction welding of the aluminum-based material thick plate can be achieved, coarsening of a weld joint structure is restrained, and the welding quality of the aluminum-based material thick plate is improved. And the mechanical property of the large-thickness structural part joint is obviously improved.

The present disclosure provides a multilayer electronic component and a mounting plate thereof, the multilayer electronic component including a main body including a dielectric layer and internal electrodes alternately disposed with the dielectric layer, the main body having a first surface and a second surface opposite to each other in a thickness direction, a third surface and a fourth surface opposite to each other in a length direction, and a fifth surface and a sixth surface opposite to each other in a width direction, an external electrode disposed on the third surface and the fourth surface and extending to a portion of the first surface and a portion of the second surface, and a metal terminal disposed on the first surface or the second surface and connected to the external electrode, the metal terminal having a recess provided on an outer side surface thereof in the length direction, and an upper hole and a lower hole respectively provided on an upper surface and a lower surface thereof, and the upper hole being not superimposed with the lower hole in the thickness direction.

The application discloses a kind of 3D printing equipment and printing method of magnetic control microsphere space lattice, it is related to printing forming technical field, equipment includes printing station, drive mechanism, sintering mechanism, control mechanism and at least one grabbing head;Printing station is used to stack multiple loose magnetic microspheres as support medium;Grabbing head is used to grab each forming magnetic microsphere, and can be released to the predetermined spatial position above the support medium of printing station;Drive mechanism is connected with grabbing head, and is used to drive grabbing head to move in space;Sintering mechanism is used to sinter the adjacent forming magnetic microsphere on printing station;Control mechanism is connected with grabbing head, drive mechanism and sintering mechanism, and can control the action of grabbing head, drive mechanism and sintering mechanism respectively.The 3D printing equipment and printing method of magnetic control microsphere space lattice provided by the application improve printing efficiency, material utilization and forming piece performance.

This invention discloses a low-temperature thermoplastic composition and the low-temperature thermoplastic material made therefrom, as well as its applications, relating to the field of medical materials technology. The low-temperature thermoplastic composition mainly comprises the following components: thermoplastic resin, reinforcing filler, and radiation crosslinking agent; the thermoplastic resin includes polyurethane, and each 100 parts of the low-temperature thermoplastic composition contains at least 27 parts of a first polyurethane with a flow start temperature of 50-95°C and an open time of at least 6 minutes. Through the selection of polyurethane and the combination of reinforcing filler, the low-temperature thermoplastic composition enables the low-temperature thermoplastic material to have lower shrinkage and a longer operating time, allowing the low-temperature thermoplastic material prepared from the composition to be used for fixation of parts with higher operating time requirements.

This invention provides an epoxy resin-based composite waterproofing material, its preparation method, and its application. After curing, the epoxy resin-based composite waterproofing material exhibits high flexural strength and Shore hardness, as well as excellent oil penetration resistance. It is suitable for coating the tank walls, bottom plates, and floating roof surfaces of oil storage tanks, curing to form a waterproofing layer. This enhances the oil storage tank's resistance to oil leakage, thereby extending its service life and preventing economic losses and environmental hazards caused by oil leakage.

This invention discloses a dielectric ceramic substrate material with a negative capacitance temperature coefficient, its preparation method, and its application, relating to the field of functional ceramics technology. It comprises, by mass percentage, 76wt%~93.5wt% CaTiO. 3 2wt%~15.5wt% SrTiO 3 1wt%~8.5wt% MgTiO 3 The ceramic substrate material contains 1.5wt%~3.2wt% modifier and 2wt%~4.5wt% cooling agent. It possesses excellent flexural strength, good surface roughness, and bonding strength, making it suitable for fabricating miniaturized chip-type microwave monolayer ceramic capacitors with low dielectric loss. It exhibits a negative temperature coefficient of capacitance (-(1500±500)ppm / ℃, (-55~125)℃), which can compensate for capacitance drift caused by temperature changes and prevent signal distortion. Furthermore, it is flat, non-deformable, and has good rectangularity, exhibiting excellent surface properties.

The application discloses a kind of high-performance outdoor full package imitation wood composite board and preparation method thereof, relate to polyurethane composite board technical field, the full package imitation wood composite board includes base board, and the polyurethane material of setting in the lower surface and the four around of base board, and the resin material of setting in upper surface.Its preparation method includes the following steps: pouring polyurethane material in the silica gel mould after surface treatment, place base board, mould pressing, make the polyurethane material with wood texture around and lower surface of base board composite, obtain intermediate product A;Resin material is rolled on the upper surface of intermediate product A, and is dried, to obtain full package imitation wood composite board;The silica gel mould after surface treatment is prepared by transferring real solid wood board texture.

The invention relates to the technical field of polymethyl methacrylate, and discloses a flame-retardant polymethyl methacrylate material and a preparation method thereof.The flame-retardant polymethyl methacrylate material is obtained by reacting polymethyl methacrylate, a hydroxyl-terminated flame retardant and p-toluenesulfonic acid. The linear polymethyl methacrylate is crosslinked into a three-dimensional network structure, so that the crosslinking degree between molecular chains is enhanced, the molecular chains are not easy to slip under stress, good structural stability is maintained, and the polymethyl methacrylate has high tensile strength and bending strength. The flame retardant contains piperazine rings and phosphate structures, forms an intumescent flame-retardant system, generates phosphoric acid substances, nitrogen and other gases during combustion, promotes dehydration of a matrix to form an intumescent carbon layer, isolates oxygen, prevents heat conduction, inhibits the combustion process, remarkably reduces the peak value of the heat release rate and the total heat release amount, and has excellent flame-retardant performance.

The invention relates to the technical field of plastic-coated wires, and discloses a polyester plastic imitation stainless steel plastic-coated wire and a preparation method thereof. The wire is composed of an internal metal wire, an inner plastic-coated layer wrapped around the outer side of the metal wire, and an outer plastic-coated layer wrapped around the outer side of the inner plastic-coated layer; the inner plastic-coated layer is composed of the following components in parts by weight: 87-99.99 parts of PET plastic particles, 1-3 parts of quartz sand, and 0-2 parts of a plastic production aid; the outer plastic-coated layer is composed of the following components in parts by weight: 87-99.99 parts of polyethylene terephthalate / cyclohexane-4-ene-1,2-dimethyl terephthalate copolyester, 0.01-3 parts of a colorant, 0-2 parts of a plastic production aid, and 0-2 parts of a plastic functional aid. The self-made polyethylene terephthalate / cyclohexane-4-ene-1,2-dimethyl terephthalate copolyester was used as the outer plastic coating material, which significantly improved the mechanical properties of the coating layer and greatly improved the tensile strength, impact strength and bending strength of the product.

This invention provides a method and system for preparing fire-resistant rock slabs containing self-healing nanocapsule components, relating to the field of building decoration materials technology. The method includes preparing double-walled self-healing nanocapsules consisting of an inner repair core material, a thermally decomposable polyurea-formaldehyde inner wall, an outer repair core material, and a mesoporous silica outer wall; mixing and uniform dispersion; low-temperature isostatic pressing; three-level response segmented sintering; and post-treatment. The double-walled self-healing nanocapsules of this invention possess a three-level response mechanism (room temperature, medium temperature, and high temperature), enabling active repair of cracks generated throughout the rock slab's lifespan. The melamine cyanurate in the inner core material of the double-walled self-healing nanocapsules decomposes to release nitrogen in the early stages of a fire, diluting oxygen and carrying away heat. Aluminum dihydrogen phosphate reacts with kaolin to form an aluminum phosphate ceramic phase, which can form a dense barrier layer.

The application belongs to the field of high polymer materials, and particularly discloses a modified basic magnesium carbonate and a PA12 composite material and a preparation method thereof.The preparation method of the modified basic magnesium carbonate comprises the following steps: adding sodium carbonate and magnesium chloride into a sodium hydroxide solution to perform a water bath reaction to obtain the basic magnesium carbonate; adding the basic magnesium carbonate and acrylic acid into deionized water to perform a water bath reaction to obtain acrylic acid modified basic magnesium carbonate; and adding the acrylic acid modified basic magnesium carbonate, glycidyl methacrylate and an initiator into an organic solvent aqueous solution to perform a water bath reaction to obtain the modified basic magnesium carbonate.The modified basic magnesium carbonate prepared by the application can decompose and absorb heat at high temperature, release water vapor and carbon dioxide and other non-combustible gases, dilute the oxygen concentration on the surface of the combustion object, and reduce the temperature of the combustion area, so as to play a role in flame retardation.In addition, the magnesium oxide produced by decomposition covers the surface of the material to form a protective layer, and further prevents the combustion.

The present application belongs to the technical field of preparation of multi-curved surface silicon carbide, and discloses a preparation method of reaction sintering multi-curved surface silicon carbide whole plate, comprising: mixing 100 parts of alpha-SiC powder, 15-20 parts of composite carbon source, 1-2 parts of silicon carbide fiber, 2.3-3.8 parts of dispersing agent, 8-12 parts of water-soluble phenolic resin, 2-4 parts of additive and 42-46 parts of water according to weight parts, pre-dispersing, ball-milling, spray granulating, pressing into multi-curved surface green body; the green body is stacked with graphite support parts and filled with graded silicon particles, and is subjected to step-by-step degreasing and step-by-step reaction sintering under vacuum argon, and then is cooled after temperature control to obtain the product. Through the synergistic effect of formula control of composite carbon source, specific ternary additive and fine sintering process, the technical problem of sintering cracking and cracking of multi-curved surface whole plate is eliminated, and the product density, bending strength and fracture toughness are effectively improved.

The application discloses active powder concrete and a preparation method and application thereof, relates to the technical field of concrete materials and marine engineering durability, and realizes the synergistic promotion of crack self-repairing efficiency, chloride ion solidification capacity and fiber-matrix interface bonding performance. The application solves the problems of long-term self-repairing failure caused by premature consumption of repair components in traditional self-repairing technology, the chloride ion solidification efficiency far lower than the theoretical value caused by uneven dispersion and weak interface bonding in traditional ion capturing means, and the problems of accelerated matrix damage caused by poor interface bonding and missing passivation protection of traditional steel fibers.