352results about How to "Low density" patented technology

The invention relates to the technical field of preparation of silicon carbide ceramics, in particular to an in-situ reaction sintered silicon carbide ceramic and a preparation method thereof.The preparation method comprises the following technological stages which are conducted in sequence: S1, preparation of silicon carbide slurry, specifically, organic matter precursor raw materials are weighed according to the mass content percentage to form the silicon carbide slurry; s2, vacuum grouting: injecting the silicon carbide slurry in the vacuum grouting tank into the shaping mold from the bottom of the shaping mold to form a silicon carbide green body; and S3, in-situ reaction sintering is conducted, specifically, the silicon carbide green body is placed in a sintering furnace, heating, heat preservation and cooling are conducted on the silicon carbide green body in the argon atmosphere through a segmented temperature control technology, and the silicon carbide ceramic is obtained. The silicon carbide ceramic prepared by the method disclosed by the invention has relatively high density and excellent mechanical properties.

The invention belongs to the technical field of high-voltage electric appliance material preparation, and particularly relates to a zinc oxide resistor disc and a preparation method and application thereof. The preparation method comprises the following steps: (1) pre-sintering zinc oxide powder; (2) mixing the zinc oxide powder obtained in the step (1), an auxiliary agent and a dispersion liquid, and carrying out ball milling to obtain slurry; the particle size D50 of the slurry is 0.8-1.2 [mu] m, and the dispersity is greater than or equal to 95%; (3) performing spray drying and granulation on the slurry to obtain granulation powder; (4) carrying out molding and first sintering on the granulated powder to obtain a resistor disc semi-finished product; the first sintering adopts sectional sintering; and (5) forming an electrode layer on at least one surface of the resistor disc semi-finished product by adopting a vacuum sputtering and / or electrophoretic deposition process, and performing secondary sintering and annealing. The contact resistance of the zinc oxide resistor disc is less than or equal to 5m omega; and after 1000 hours of aging in a 85 DEG C + 85% RH environment, the leakage current increase is less than or equal to 2 [mu] A, and the performance degradation rate is less than or equal to 5%.

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 invention provides a nitrogen-doped hierarchical pore carbon material as well as a preparation method and application thereof, and the preparation method comprises the following steps: sequentially dissolving urea, alkali metal hydroxide and / or a pore-forming agent in water to obtain a mixed solution, cooling the mixed solution, adding cellulose-based biomass, and dissolving the cellulose-based biomass to obtain transparent sol; freezing the transparent sol into a solid, and performing vacuum freeze drying to obtain a white loose solid; mixing and grinding the liquid polymeric monomer and the white loose solid, and performing heat treatment to obtain a solid product; and carbonizing the solid product in an inert atmosphere, and then pickling and washing the carbonized product. According to the preparation method, chain-shaped arrangement in cellulose-based biomass molecules is converted into three-dimensional net-shaped arrangement through dissolution, macropores are formed, a macropore framework is kept stable and does not collapse in the carbonization process through polymerization reaction, and the formed hierarchical pore carbon material has a micropore / mesopore / macropore coexisting three-dimensional structure and controllable specific surface area and pore size distribution; meanwhile, in-situ nitrogen doping can also be realized.

The present application relates to a kind of compositions and applications comprising polyamide.The composition includes polyamide and sheet structure mineral powder, wherein, with 100 mass parts of polyamide, sheet structure mineral powder in the composition is 0.1-10 mass parts.The polyamide material in the present application has lightweight, easy processing, has cost advantage, compared with steel material has obvious advantage.Sheet structure mineral powder is added in polyamide material by intercalation modification, further improve the barrier property of product, effectively avoid "hydrogen embrittlement" risk, with "hydrogen embrittlement" resistance, low hydrogen permeability, and suitable for the temperature range of application, it has high toughness in low temperature environment condition, the performance of polyamide material reaches a good balance, and the comprehensive performance is better.Suitable for hydrogen pipeline, hydrogen storage bottle etc., has advantage in hydrogen energy automobile and other application scenarios.

The invention provides a solid-liquid conversion type polymer-based thermal interface material as well as a preparation method and application thereof, and the solid-liquid conversion type polymer-based thermal interface material is prepared from the following raw materials: vinyl terminated polydimethylsiloxane, active hydrogen group terminated siloxane and inorganic filler, the inorganic filler comprises a spherical filler and a flaky filler, and the weight ratio of the spherical filler to the flaky filler is (1.5-14): 1. Through cooperation of the spherical filler and the flaky filler, the spherical filler can generate a physical adsorption effect on the surface of the flaky filler and is different from a heat conduction channel formed by the spherical filler; a heat conduction channel formed by the flaky filler-spherical filler composite plays a role in integrating the dispersed small-particle-size spherical filler, so that the complete heat conduction channel can be formed at a relatively low filling fraction. The solid-liquid transition type polymer-based thermal interface material disclosed by the invention has low density and high thermal conductivity, and the workability and the lightweight performance in thermal management of optical module equipment are effectively improved.

This invention discloses a method for preparing low-density, high-filler SPC flooring. The method is characterized by a raw material formulation comprising the following components in the indicated weight proportions: 100 parts graft-modified PVC resin, 300-350 parts filler, 9-12 parts heat stabilizer, 3-5 parts melt processing modifier, 3-5 parts reinforcing and toughening modifier, 1-2 parts external lubricant, 1-2 parts internal lubricant, 2-5 parts chemical foaming agent, and 2-5 parts foaming aid. The graft-modified PVC resin is prepared by replacing the chlorine atoms in PVC with p-aminothiophenol, followed by an amidation reaction between a diacid or polyacid and an amino group. Its advantages are: 1) It improves the melt strength and expandability of the PVC resin, ensuring foaming performance under high filler content. Compared with ordinary SPC flooring, the flooring product has lower density and lighter weight, higher hardness, and lower overall formulation cost compared to ordinary low-density SPC flooring. 2) The process is simple, and the product has high controllability.

The utility model provides a high-melting-point graphite pipe for elemental analysis, which belongs to the technical field of spectral analysis and comprises a circular hollow graphite pipe main body and transverse support parts symmetrically arranged on two sides of the graphite pipe main body, an inner pyrolytic carbon layer is deposited on the inner wall of the graphite pipe, a porous structure is arranged in the inner pyrolytic carbon layer, and an outer compact pyrolytic carbon layer is further deposited on the surface of the inner pyrolytic carbon layer. Through the inner pyrolytic carbon layer and the outer compact pyrolytic carbon layer, in the high-temperature working process, the inner wall pyrolytic carbon layer can be selectively consumed to form a compact glassy carbon film, a self-adaptive protection mechanism enables the graphite tube to still keep stable analysis performance under extreme conditions, reaction or permeation of a detected element and graphite at high temperature is reduced, and the analysis accuracy of the graphite tube is improved. The phenomenon of cross contamination is reduced, the memory effect of the graphite pipe is reduced by 70%, but the memory effect of a traditional pyrolytic graphite pipe can only be reduced by 30-40%, and the graphite pipe is particularly suitable for analysis of high-melting-point elements.

The invention relates to a high-impact PC-elastomer composite battery shell and a preparation method thereof, and belongs to the technical field of battery shell manufacturing. The shell adopts a three-layer composite structure design and comprises an outer polycarbonate layer of which the end group is grafted with a hindered amine light stabilizer, a middle thermoplastic polyurethane layer containing a double-crosslinking network and an inner glass fiber reinforced polycarbonate layer. Through material modification, uniform distribution and dense combination of all layers of materials are realized, the impact resistance and the weather resistance of the battery shell are remarkably improved, and the excellent bonding property of an interface is ensured.

This invention discloses a coatable, moldable dual-functional coating material for heat protection and stealth, and its preparation method. The coating material is formed from a SiC-based composite ceramic aerogel slurry, a perovskite / MAX phase composite ceramic absorber, and a high-temperature resistant binder. The composite ceramic aerogel slurry is composed of SiC micro / nano-scale aerogel powder, SiC nanowires, and a high-temperature resistant binder; the perovskite ceramic absorber is lanthanum strontium manganese oxide (La). 1‑x Sr x MnO3), lanthanum strontium iron oxide (La) 1‑ x Sr x FeO3), lanthanum strontium cobalt oxide (La) 1‑x Sr x The MAX phase ceramic absorber is Ti3SiC2, and it contains substances such as CoO3. The technology of this invention enables the rapid application of coating materials to the surface of equipment via brushing, enhancing high-temperature radar absorption stealth and thermal protection capabilities, and facilitating the preparation and efficient repair of high-temperature stealth coatings.

This invention discloses a circuit board processing method and circuit board processing equipment, comprising: processing a first through hole on a multilayer circuit board, the multilayer circuit board including a first solder mask layer and a second solder mask layer respectively disposed on two adjacent circuit boards, the first solder mask layer and the second solder mask layer being disposed opposite to each other, and the first through hole penetrating the first solder mask layer and the second solder mask layer; performing a desmearing process on the multilayer circuit board to form a first space on the first solder mask layer and a second space on the second solder mask layer; depositing a first metal layer on the inner wall of the first through hole, the first space and the second space; removing the first solder mask layer and the second solder mask layer, and electroplating a second metal layer on the first metal layer on the inner wall of the first through hole to obtain a target circuit board including a target metallized hole, so as to completely remove the low-density first metal layer deposited in the first solder mask layer and the second solder mask layer, so as to achieve complete electrical isolation between the two adjacent circuit boards with the first solder mask layer and the second solder mask layer, and achieve zero residual solder.

This invention discloses a method for preparing a novel ultra-high voltage high-performance composite insulating material, belonging to the field of composite insulating material preparation technology. The technical solution includes the following steps: S1, preparing a modified epoxy-silicone rubber composite resin matrix: 40-50 parts by weight of bisphenol A type epoxy resin (E-51) are placed in a reaction vessel, heated to 60-70℃, and continuously stirred at a stirring rate of 300-500 r / min. 10-15 parts by weight of terminal hydroxyl polysiloxane (molecular weight 5000-10000) are added, and the temperature is kept constant for 1.5-2 hours; subsequently, the system temperature is lowered to 40-50℃. The beneficial effects of this invention are: by setting up a resin matrix system of "terminated hydroxyl polysiloxane modified epoxy resin + nano-alumina / boron nitride composite reinforcement," the problem of imbalance between high voltage resistance and aging resistance in existing materials is solved. It exhibits significantly improved dielectric strength, greatly reduced dielectric loss, and excellent high and low temperature cycling performance, meeting the long-life operation requirements of ultra-high voltage equipment.

The utility model discloses a kind of automobile A column reinforcing member based on lightweight design, it is related to the technical field of automobile parts, including external steel body, the inside of external steel body is equipped with main body reinforcing component, the inside of main body reinforcing component is equipped with energy-absorbing member, the side of external steel body away from the surface of main body reinforcing component is equipped with sound insulation cotton.The utility model can make the internal structure of automobile A column more stable by main body reinforcing component, reduce the deformation due to collision, protect front compartment safety, by energy-absorbing member, local shock wave can be offset, ensure that front compartment living space is not deformed, while the material density of energy-absorbing member is smaller, the overall weight of A column can be reduced, so as to reduce the weight of entire vehicle body, reach the effect of reducing fuel consumption, while external steel body is fixed together by hinge hole bolt and angle steel bolt, compared with general welding mode, when maintaining, avoid cutting A column, cause stress concentration of A column, affect the safety of overall A column structure.

The utility model belongs to the technical field of shielding cabinets, particularly relates to a portable shielding cabinet made of lightweight composite materials, and aims to solve the problems that a main body structure of an existing device is integrally made of metal materials, and although the metal materials have excellent electromagnetic shielding performance, the self weight of the metal materials is large, so that in a scene needing frequent movement or temporary construction, the electromagnetic shielding performance of the metal materials is poor. In order to solve the problems that a traditional shielding cabinet is extremely inconvenient to carry and consumes a large amount of manpower and material resources, the utility model provides the following scheme that the portable shielding cabinet made of the lightweight composite material comprises a frame main body which adopts a frame type structure; the utility model has the beneficial effects that the frame main body is formed by splicing high-strength aluminum alloy sections, the density is low, the weight is light, the frame type structure is matched, the frame is stable, the portability is obviously improved, the carrying is easy and labor-saving, the corner connecting pieces are made of high-strength engineering plastics, the weight is reduced, electromagnetic conduction is prevented, and the shielding performance is optimized.

This invention provides a lightweight wear-resistant steel alloyed with Nb, V, and Ti, its preparation method, and its applications, belonging to the technical field of lightweight wear-resistant steel. The lightweight wear-resistant steel of this invention, by mass percentage, comprises: Mn 23.0–26.0%, Al 7.5–8.3%, C 1.12–1.25%, Si 0.20–0.25%, Nb 0.05–0.20%, Ti 0.05–0.15%, V 0.05–0.10%, P ≤ 0.03%, S ≤ 0.01%, and the balance Fe. Experimental results show that the lightweight wear-resistant steel provided by this invention has a density ≤ 7.01 g / cm³. 3 Yield strength is 565–654 MPa, tensile strength is 901–985 MPa, elongation is 50.3–58.7%, and KV at -40℃. 2 The impact energy is 97-134J, and the wear resistance is improved by more than 30% with high impact energy.

The utility model relates to a kind of concrete double T plates, belong to concrete double T plate structure design technical field, specifically a large-span concrete double T plate, including double T plate body, still include;Positioning slot, positioning slot starts at the periphery of double T plate body, and the inside of each positioning slot is inserted with positioning block;Thermal insulation board, thermal insulation board fixed mounting is in the inner top of double T plate body;The utility model reaches the effect of reducing construction difficulty, facilitating worker installation, solves the high complexity of existing mould, difficult to realize mass production, substantially increase the cost of mould processing, and the precision requirement of on-site hoisting is high, increase the construction difficulty of staff, reduce the problem of work efficiency.

The utility model relates to the technical field of downhole geophysical prospecting, specifically a kind of instrument shock absorption type storage device for downhole geophysical prospecting. Including: storage component, the storage component includes box, lid, storage, shock pad and sealing element, the lid rotationally connected on box, storage is set to the inside of box, shock pad is fixedly connected at the bottom of box, the sealing element is set to the outside of box;Protective component, the protective component is set to the inside of box and lid, and protective component includes buffer, foam pad, magic tape, limiting piece and pull rope, buffer is set to the inside of storage, foam pad is set to the inside of box and lid, magic tape is set to the outside of foam pad, limiting piece and pull rope are all set to the outside of buffer. The utility model can avoid that instrument is extruded harm, utilizes lining bushing and is wrapped with instrument protection, can reduce the impact force from each direction, improves the protection effect to instrument.

The utility model discloses a kind of non-submerged ferry modules, it is related to military water boat and boat bridge technical field, non-submerged ferry module includes capsule clothing and support framework, capsule clothing is provided with the accommodation cavity and filling port being communicated, support framework is located in the cavity wall of accommodation cavity;Polyurethane filler is located in accommodation cavity, support framework is coated in polyurethane filler along the outer wall of polyurethane filler. The filling port that capsule clothing has can be used for polyurethane raw material filling into accommodation cavity, after polyurethane raw material reaction expansion and hardening, capsule clothing can be supported, and the polyurethane filler density low specific gravity small, buoyancy in water is larger, even in sea combat encounter cannonball perforation, it also does not enter water and lead to sinking. In addition, the support framework in the inside of capsule clothing is coated polyurethane filler, so that polyurethane filler does not break apart and tear apart after being hit.

The application provides a 3D printing method for preparing a low-cost TA15 part based on a bimodal particle size distribution near-spherical powder and a high-performance low-cost TA15 part. The 3D printing method uses a bimodal particle size distribution near-spherical TA15 alloy powder with good uniformity as a raw material, improves the near-spherical powder bed density through bimodal grading of coarse powder and fine powder, and then prepares a low-cost high-performance TA15 part through an optimized selective laser melting (SLM) process parameter window suitable for bimodal distribution powder, thereby providing a more cost-effective preparation method for TA15 titanium alloy parts in aerospace.

The application provides a composite metal sodium negative electrode material, a preparation method thereof and a sodium metal battery. The composite metal sodium negative electrode material comprises a porous organic film skeleton, an alloy type conductive sodium-philic layer and sodium metal filled in the pores inside the porous organic film skeleton. The application takes the porous organic film skeleton as a base material, constructs a three-dimensional flexible skeleton, and deposits the alloy type conductive sodium-philic layer on the porous organic film skeleton, so that the active sites for sodium ion deposition are increased and the rapid transmission of sodium ions is promoted.

This application relates to a method for preparing high-purity iron, comprising the following steps: forming an electrode rod from pure iron raw material; subjecting the electrode rod to vacuum arc melting; the vacuum arc melting includes an arc initiation stage, a melting stage, and a feeding stage; the melting current in the arc initiation stage is 1.5 kA~3.0 kA, and the arc stabilization current is 4 A~10 A; the melting current in the melting stage is 2.5 kA~3.5 kA, the melting rate is 2.5 cm / min~5.5 cm / min, and the arc stabilization current is 8 A~20 A; the melting current in the feeding stage is 1.2 kA~3.3 kA, the melting rate is 1 cm / min~4.5 cm / min, and the arc stabilization current is 4 A~11 A. This method can effectively reduce the density and refine the size of inclusions in pure iron, while also making the inclusions dispersed in the material. The high-purity iron prepared by this method has a significantly reduced inclusion density, small inclusion size, and is in a dispersed state, which meets the manufacturing requirements of iron-based supports.

The application discloses sound-absorbing material, sound-emitting device and electronic equipment. The sound-absorbing material comprises: a plurality of graphene powders, each of which comprises a plurality of layer structures arranged in a stack, the number of the layer structures is in a range of 2 to 100 layers, each of the layer structures comprises a plurality of hexagonal rings formed by six carbon atoms, and a defect hole formed by more than six carbon atoms is formed on the layer structure, and the average pore size of the defect hole is in a range of 0.5 nm to 10 nm; wherein the hexagonal rings form micropores for air flow, and the defect hole and the gap between the layer structures form micropores and / or mesopores for air flow; and an adhesive used for bonding the plurality of graphene powders to form the sound-absorbing material. The sound-absorbing material can improve the resonance frequency of an acoustic device.

The invention discloses a carbon foam / paraffin composite phase-change material for thermal management of a lithium ion battery and a preparation method and application of the carbon foam / paraffin composite phase-change material. Low-cost commercial melamine foam is used as a template to prepare carbon foam, and the carbon foam and paraffin are compounded through a vacuum impregnation process to obtain the carbon foam / paraffin composite phase-change material; wherein the carbon foam is prepared by heating and carbonizing melamine foam in a stepped manner under the protection of nitrogen, and the compounding of the paraffin and the carbon foam is realized by adopting vacuum impregnation. The problems that a traditional pure paraffin phase-change material is low in heat conductivity and prone to deformation and leakage, and a metal-based composite phase-change material is high in cost, large in density and prone to corrosion are solved, the prepared foamy carbon / paraffin composite phase-change material is low in density and cost, the heat conductivity is remarkably improved compared with that of pure paraffin, and the thermal stability is excellent within the working temperature range of a lithium ion battery. When the lithium ion battery is applied to thermal management of the lithium ion battery, the lithium ion battery can be maintained for a long time in a phase change temperature range, and an economical and efficient solution is provided for thermal management of batteries of electric vehicles and energy storage equipment.

The invention belongs to the technical field of polyurethane compositions, and particularly relates to all-water foaming stone-like polyurethane foam as well as a preparation method and application thereof. The all-water foaming stone-like polyurethane foam is composed of a component A and a component B in a mass ratio of 1: (1-1.15), and the component A comprises the following raw materials: polyether polyol 1, polyether polyol 2, polyether polyol 3, a composite catalyst, a flame retardant, a surfactant and water; and the component B is polymethylene polyphenyl isocyanate. According to the all-water foaming stone-like polyurethane foam provided by the invention, polyethers with different viscosities are combined and cooperate with different types of catalysts, and an all-water foaming mode is adopted, so that the fluidity of a system is improved, the characteristic of rapid curing is maintained, bubbles on the surface of a product can be effectively eliminated, and the performance of the product is improved. The hard polyurethane product with clear texture and flat and stone-like surface is obtained; the invention also provides a preparation method thereof.

This invention relates to the field of semiconductor technology, specifically disclosing a gallium oxide epitaxial wafer and its preparation method. The preparation method of the gallium oxide epitaxial wafer includes the following steps: S1, placing a (011)-plane gallium oxide substrate in a reaction chamber, introducing a carrier gas, and then introducing oxygen, chlorine, and hydrogen for a first growth; S2, introducing oxygen and hydrogen chloride for a second growth on the first-grown gallium oxide substrate to obtain a gallium oxide epitaxial wafer; wherein, in S1, the flow rate ratio of oxygen to chlorine is (2~3):1; in S2, the flow rate of oxygen is 200~400 sccm, and the flow rate ratio of oxygen to hydrogen chloride is (5~20):1. This invention optimizes the number of growth cycles and growth conditions during the preparation of the gallium oxide epitaxial wafer, reduces epitaxial defect density, improves epitaxial film quality, and realizes the preparation of high-thickness gallium oxide epitaxial wafers with low surface defects and nanoscale surfaces.

A low-density, high-stability fluorinated polyimide aerogel is prepared by using TFMB, ODA, and 6FDA as raw materials to prepare a polyamic acid solution. Triethylamine is added to the polyamic acid solution to prepare a fluorinated polyamic acid salt. The fluorinated polyamic acid salt is dissolved in a mixture of water and diphenyl ether, and then triethylamine and N,N-dimethylcyclohexylamine are added to prepare a polyamic acid hydrogel. The hydrogel is then freeze-dried to obtain the polyamic acid aerogel, which is finally subjected to thermal imidization treatment. This invention uses three monomers to form an aerogel, creating a low-density, high-porosity three-dimensional network structure. This structure is stable, has a high heat resistance temperature, and maintains good performance at high temperatures. The aerogel also possesses a certain degree of rigidity and strength, making it resistant to deformation and structural collapse under external forces.

This invention discloses a composite defluoridating agent for deep defluorination of water and its preparation method. The defluoridating agent is an aqueous solution of a metal salt or an aqueous solution of a metal salt dispersed with nanoparticles. The active ingredient of the defluoridating agent contains at least three metal ions: lanthanum, aluminum, and zinc, and the molar ratio of La, Al, and Zn is 1~4:3~5:1~3. The pH of the aqueous solution is 6.0~6.5. Compared with traditional PAC, which requires more than 5 mmol / L to reduce fluoride ions to 1 mg / L, the composite defluoridating agent of this invention only requires 1.2 mmol / L (based on the total concentration of active ingredients) to reduce fluoride ions to below 1.0 mg / L, significantly reducing treatment costs and sludge production. In addition, this invention has a fast settling speed, achieving solid-liquid separation within 10 minutes. In the preferred scheme containing nanoparticles, magnetic adsorption settling can be completed within 5 minutes, greatly shortening the water treatment process cycle.

This invention provides a low-density flame-retardant thermally conductive foam powder filler, composed of the following components in parts by weight: 200-300 parts of boron nitride (80-100 micrometers); 200-300 parts of hollow glass microspheres (50-70 micrometers); 200-300 parts of aluminum hydroxide (8-10 micrometers); 200-300 parts of aluminum hydroxide (1-2 micrometers); and 2-4 parts of coupling agent. Its advantages are: 1. Low density: By introducing low-density hollow glass microspheres, the overall density of the filler is effectively reduced, meeting lightweight design requirements. 2. High thermal conductivity: The compound boron nitride forms a highly efficient thermal conductivity network. 3. Excellent flame-retardant performance: The halogen-free flame retardant aluminum hydroxide works synergistically with the hollow glass microspheres. The hollow glass microspheres form a glassy barrier at high temperatures, isolating oxygen and heat, achieving excellent flame-retardant effects. 4. Good dispersibility and compatibility: By modifying the powder surface with silane coupling agent, a "molecular bridge" is formed between the inorganic powder and the organic polymer matrix, which significantly reduces agglomeration, lowers the interfacial thermal resistance, and significantly reduces the viscosity of the system.

This invention discloses a method for preparing high-temperature resistant polyimide foam material, comprising: preparing a foamable precursor powder using aromatic dianhydride and diamine; performing bilayer extrusion and foaming molding using two single-screw extruders, wherein one extruder extrudes and foams the foamable precursor powder, and the other extrudes fiber-reinforced thermoplastic resin; the two are compounded at a co-extrusion die, and shaped by a shaping die to obtain a polyimide foam composite material with a fiber-reinforced resin layer on the surface; cutting and collecting polyimide foam strips or foam particles of equal length, filling them into a die, and then hot-pressing to obtain the polyimide foam composite material. This invention significantly improves the operability of polyimide foam preparation and simplifies subsequent molding processes. This invention also provides a high-temperature resistant polyimide foam material obtained by the above preparation method, which can simultaneously provide high compressive strength, high modulus, and low density, and is easy to scale up for production.