342 results about "Boron carbides" patented technology

The invention discloses a high-strength silicon carbide ceramic material and a preparation method thereof, and relates to the technical field of ceramic material preparation. The silicon carbide ceramic material is prepared from the following raw materials in parts by weight: 70-85 parts of silicon carbide powder, 5-15 parts of B4Cw-coated BN, 3-5 parts of a sintering aid, 0.5-1 part of a dispersing agent and 0.5-2 parts of carbon black, the B4Cw-coated BN is prepared by the following steps: pretreating a boron carbide whisker with a silane coupling agent, adding the pretreated boron carbide whisker into a precursor solution containing boric acid and urea, and reacting to obtain the boron carbide whisker with a BN coating; the sintering aid is formed by mixing Y2O3 and Al2O3; the dispersing agent is ammonium polyacrylate. The preparation method of the high-strength silicon carbide ceramic material comprises the following steps: pretreating boron carbide whiskers, synthesizing B4Cw-coated BN, preparing composite powder, and preparing the silicon carbide ceramic material. The high-strength silicon carbide ceramic material disclosed by the invention has relatively high bending strength and elasticity modulus.

The invention relates to the technical field of powder metallurgy materials, and discloses rare earth microalloyed ultrahigh-strength high-toughness hot work die steel and a preparation method thereof.The die steel is prepared from 4Cr5MoSiV1 pre-alloyed powder, rare earth hydride, boron carbide and porous amorphous carbon powder loaded with a nickel catalyst. The preparation method comprises the steps of material mixing, sheath packaging, graded dynamic reaction thermal devolatilization, hot isostatic pressing densification and heat treatment, in the graded dynamic reaction thermal devolatilization, active hydrogen generated by decomposition of rare earth hydride is used for reducing oxide on the surface of powder, and nickel catalyzed carbon powder is used for capturing water vapor at low temperature to generate CO to be discharged. An oxide film on the surface of the powder is thoroughly removed through in-situ chemical reaction, original particle boundaries are eliminated, meanwhile, a nano strengthening phase with high thermal stability is generated in situ, and the high-temperature strength, impact toughness and tissue compactness of the die steel are remarkably improved.

The invention belongs to the technical field of textile material processing, and particularly discloses a preparation method of high-strength low-shrinkage composite yarn for spinning. A preparation method of a high-strength low-shrinkage composite yarn for spinning comprises the following steps: (1) respectively drying ultra-high molecular weight polyethylene and PET polyester, adding maleic anhydride grafted PE, a treated metal organic framework material, boron carbide nanoparticles, cellulose acetate and a silane coupling agent KH550, uniformly mixing, and carrying out melt extrusion to obtain nascent fibers; (2) performing first-stage pre-drafting, second-stage high-temperature tension field drafting and third-stage low-temperature relaxation treatment on the nascent fiber to obtain treated fiber; and (3) dipping the treated fiber in an ethanol solution containing nano SiO, and performing infrared radiation curing to obtain the high-strength low-shrinkage composite yarn for spinning. The composite yarn has good mechanical strength, wear resistance and low contractibility, and the yarn has wide application due to the high breaking strength.

The invention belongs to the technical field of tungsten alloy, and particularly discloses a tungsten alloy electrode material and a preparation method thereof.The tungsten alloy electrode material comprises, by weight, 0.1%-0.2% of lanthanum boride, 0.2%-0.5% of zirconium oxide, 0.2%-0.6% of boron carbide, 0.4%-0.8% of cerium oxide, 0.5%-1.2% of tantalum carbide, 1.4%-1.8% of modified carbon nanotubes and the balance tungsten powder. The lanthanum boride, the zirconium oxide, the boron carbide, the cerium oxide, the tantalum carbide and the modified carbon nanotubes are added into the tungsten powder, under the combined action of the lanthanum boride, the zirconium oxide, the boron carbide, the cerium oxide, the tantalum carbide and the modified carbon nanotubes, the tensile strength and the electrical conductivity are effectively improved, and the high-temperature stability tungsten powder has excellent high-temperature stability and wide application prospects.

The invention relates to the technical field of titanium alloy pipes, in particular to a titanium alloy pipe preparation method which comprises the following steps: S1, base material preparation, S2, base material pretreatment, S3, cladding material preparation, S4, cladding treatment and S5, post-treatment. According to the method, after the cladding layer is formed on the surface of the titanium alloy pipe by matching the basic powder, the reinforced phase powder and the additive with the cladding treatment process, the basic powder forms a tough metal collective to provide stable support for the reinforced phase, and the reinforced phase powder treated by the silane coupling agent forms a multi-scale reinforced network in a matrix; boron carbide serves as a superhard phase to directly resist abrasion, nano yttrium oxide refines grains through a pinning effect, crack propagation is prevented, the abrasion-resistant life of the pipe is remarkably prolonged, and the service reliability of the pipe is remarkably improved.

The invention relates to the technical field of solar photovoltaic backboards, in particular to a high-water-resistance solar cell backboard and a preparation method thereof. The solar cell backboard structurally comprises a weather-proof layer, a nano-composite waterproof layer, a substrate supporting layer and a bonding layer from bottom to top in sequence, the preparation raw materials of the nanometer composite waterproof layer comprise a nanometer material, multilayer graphene, saturated aliphatic polyester polyol and a curing agent. The nano material comprises at least one of nano silicon dioxide, nano clay, single-walled carbon nanotubes, multi-walled carbon nanotubes, nano aluminum oxide, nano boron carbide, nano cellulose, nano zinc oxide, nano titanium oxide and nano molybdenum disulfide. The invention has the advantages of better water resistance and weather resistance and simpler preparation process.

The invention relates to a preparation method of a double-layer high-temperature adhesive for connecting brass and aluminum oxide, which comprises the following steps: reacting aluminum hydroxide, zirconium hydroxide and dilute phosphoric acid to prepare an aluminum zirconium phosphate adhesive base solution, and compounding silicon powder, boron carbide, titanium powder, nickel powder and the adhesive base solution to prepare a special adhesive for coating a brass surface. And compounding silicon powder, boron carbide, titanium powder, nickel powder, aluminum oxide and the gum base solution to prepare the special adhesive for aluminum oxide surface coating. The brass surface coating special glue is brushed on the brass surface and cured, then the aluminum oxide surface coating special glue is brushed on the aluminum oxide surface, the brass coated with the adhesive and the aluminum oxide coated with the adhesive are attached together in the mode that the bonding surfaces are opposite, and the brass / aluminum oxide double-layer bonding piece is obtained after pressing and curing and can serve in the high-temperature environment. The method has the advantages that the special glue for brass surface coating and the special glue for aluminum oxide surface coating have high thermal expansion coefficient matching with brass and aluminum oxide, and thermal stress can be relieved; the double-layer adhesive can provide the bonding strength which can reach 1.3 MPa at the temperature of 500 DEG C.

The invention discloses a composite shielding collimator suitable for a complex mixed radiation field, belongs to the technical field of radiation shielding and measurement, and mainly solves the problems of low signal-to-noise ratio, high space background and mixed energy spectrum caused by the mixed radiation field of high-energy neutrons, gamma rays and the like in a fusion device and the problem that traditional equipment is heavy and difficult to flexibly adjust. The composite shielding collimator adopts a cylindrical shielding structure formed by aluminum oxide, boron-containing polyethylene, boron carbide and lead from outside to inside, and background interference and secondary radiation are remarkably inhibited by moderating and absorbing neutrons step by step and effectively shielding gamma rays; the neutron and gamma ray detector is integrally integrated on a rotatable supporting mechanism, unification of excellent radiation shielding performance and detection flexibility is achieved, and the neutron and gamma ray detector is mainly used for high-precision neutron and gamma ray diagnosis in complex radiation environments such as a magnetic confinement fusion device.

The invention discloses a graphite sagger preparation method based on a secondary isostatic pressing process. According to the method, natural crystalline flake graphite and artificial graphite powder are selected as raw materials, coal pitch is selected as a binder, and boron carbide micro powder is selected as a filler. The preparation method comprises the following steps: dry-mixing a graphite raw material, preparing crushed and molten coal pitch and boron carbide into a suspension, and mixing and kneading the coal pitch and the boron carbide into paste; the paste is pre-pressed into a biscuit through a hydraulic machine, the biscuit is sealed in a rubber sheath and then subjected to primary cold isostatic pressing, then primary roasting is carried out, the blank is subjected to vacuum impregnation in a suspension liquid after primary roasting, secondary cold isostatic pressing and secondary roasting treatment are carried out after impregnation is completed, graphitization treatment and cutting shaping are sequentially carried out after roasting, and the finished graphite saggar is obtained. The degree of dependence on equipment is effectively reduced through a secondary isostatic pressing process, so that the prepared graphite saggar has good performance, and the density, bending strength, porosity, thermal shock performance and other indexes of the graphite saggar all meet the specialized operation requirements in the fields of photovoltaics, new energy and the like.

This invention provides a high-hardness, crack-free flux-cored welding wire and its preparation method. The flux-cored welding wire includes an outer sheath and a flux core. By weight, the flux core comprises the following components: boron carbide 5.6-8.6 parts; 75% ferrosilicon 3.1-4.6 parts; electrolytic manganese 0.6-1.6 parts; 80% ferrovanadium 0.3-1.2 parts; nickel powder 0.3-1.0 parts; 68% high-carbon ferrochrome 67.5-94.5 parts; and iron powder 6-6.5 parts. The preparation method of the flux-cored welding wire is as follows: [The following components are listed:] boron carbide, 75% ferrosilicon, electrolytic manganese, 80% ferrovanadium... Ferrovanadium, nickel powder, 68% high-carbon ferrochrome, and iron powder are added sequentially to a dryer and dried for 2-3 hours. The mixture is then thoroughly mixed using a three-dimensional motion mixer and placed in an insulated box for later use. The outer sheath is placed on a forming machine, which rolls the outer steel strip into a U-shaped groove. Flux-cored powder is added to the U-shaped groove, and the forming machine closes and pulls the groove to obtain the flux-cored welding wire. The flux-cored welding wire of this invention features high hardness, no cracks, high temperature resistance, and corrosion resistance. Furthermore, the low production cost of the flux-cored welding wire facilitates industrial production.

The application discloses a method for preparing a carbon-carbon heater by means of pitch impregnation, and the carbon-carbon composite material prepared through the process steps of preform preparation, pitch impregnation and solidification, high-pressure pitch impregnation, low-temperature carbonization, repeated impregnation and carbonization and high-temperature graphitization has the advantages of high density and low resistivity, and the photovoltaic single crystal furnace heater is further machined. First, micron composite powder of boron carbide-tungsten carbide is uniformly applied on the surface of the heater and is subjected to high-temperature treatment, so as to form a dense ceramic coating, and then a mixed pyrolytic graphite layer is deposited in a methane-argon atmosphere, and through the above two coating processes, the silicon vapor corrosion resistance of the carbon-carbon heater is significantly enhanced, so that the service stability and service life of the carbon-carbon heater are improved.

The application belongs to the technical field of carbon / ceramic composite material preparation, and provides an impregnation sealing liquid for carbon / ceramic friction discs, an impregnation sealing method, a densified carbon / ceramic friction disc and application thereof. The impregnation sealing liquid comprises 2-5% of an interface reinforcing metal component, 3-6% of a friction and wear resistant ceramic component, 2-5% of a metal oxide component and the balance of a polymer. The polymer comprises liquid polycarbosilane and liquid polyborosilazane, and the mass ratio of the liquid polycarbosilane to the liquid polyborosilazane is 7-9:1-3. The interface reinforcing metal component comprises one or more of titanium powder, chromium powder, nickel powder, cobalt powder and molybdenum powder. The friction and wear resistant ceramic component comprises one or more of silicon carbide, zirconium boride, boron carbide and zirconium carbide. The metal oxide component comprises one or more of cerium oxide, yttrium oxide and lanthanum oxide. The impregnation sealing liquid can realize the triple improvement of the interface bonding force, the friction stability and the high-temperature oxidation resistance of the carbon / ceramic friction disc.

Carbon particles comprising at least 97 wt% carbon, based on the total weight of the carbon particle, at most 0.2 wt% impurities, based on the total weight of the carbon particle, at least 0.08 wt% boron, based on the total weight of the carbon particle, and at most 0.05 wt% boron carbide, based on the total weight of the carbon particle.

The application relates to the technical field of ceramic materials, and provides boron carbide ceramic material resistant to plasma etching, a preparation method thereof and etching equipment. The boron carbide ceramic material comprises boron carbide and etching-resistant intergranular phases. The etching-resistant intergranular phases are at least dispersed at the grain boundaries of the boron carbide, and the etching-resistant intergranular phases comprise Y3Al5O 12 , and rare earth elements are doped in at least part of the Y3Al5O 12 . In the etching process, the etching-resistant intergranular phases can inhibit corrosion at the grain boundaries of the boron carbide, can not only maintain the mechanical properties of the boron carbide, but also can significantly enhance the etching resistance of the boron carbide ceramic, prolong the service life of the etching equipment, and reduce the replacement cost of etching-damaged consumables.

The application relates to a high-cycle-stability lithium iron phosphate positive electrode material and a preparation method thereof. 1‑x‑y V x Al y PO4 of an olivine structure, wherein 0.02<=x<=0.05 and 0.01<=y<=0.04; the lithium iron phosphate positive electrode material core surface further contains a gradient coating layer, the coating layer close to the core is a mixed layer of nano boron carbide and amorphous carbon, and the outer layer is a pure amorphous carbon layer. Through double-layer coating and addition of the components Al and V in the core, the cycle performance and the electrochemical performance are effectively improved, the compaction density of the lithium iron phosphate positive electrode material is 2.61-2.81 g / cm 3 , the initial discharge specific capacity is 163.1-169.3 mAh / g at 0.1 C, and the capacity retention rate is 94.1-95.8% after 1000 cycles.

The application relates to the technical field of ceramic materials, in particular to a boron carbide composite ceramic material and a preparation method and an etching component thereof. The preparation method comprises the following steps: forming granular materials containing boron carbide, titanium boride and silicon carbide, the granular materials have a spherical structure, the mass proportion of the boron carbide in the granular materials is 70%-90%, the mass proportion of the titanium boride is 5%-25%, and the mass proportion of the silicon carbide is 5%-25%; and the granular materials are sequentially subjected to pre-sintering and hot-press sintering to prepare the boron carbide composite ceramic material; wherein the temperature of the pre-sintering is 1200 DEG C-1500 DEG C. The application can promote the three-dimensional communication growth of sintering necks in the hot-press sintering process, effectively improve the material density, ensure the good uniformity of the material, and synergistically improve the etching resistance of the boron carbide ceramic material.

The invention relates to the technical field of high polymer materials and component potting, in particular to a two-component high-thermal-conductivity low-thermal-expansion epoxy resin potting adhesive and a preparation method thereof.The preparation method comprises the following steps that 1, after epoxy resin, a diluent and a defoaming agent are mixed and stirred to be uniform, heat-conducting filler, a heat stabilizer and an anti-settling agent are added, mixed and stirred, vacuumized and stirred, and a mixture is obtained; defoaming to obtain a component A; step 2, uniformly mixing and stirring a curing agent and a curing accelerator, vacuumizing and stirring, and defoaming to obtain a component B; and step 3, when the pouring sealant is used for pouring, mixing and stirring the component A and the component B according to the proportion, and carrying out vacuum defoaming to obtain the double-component epoxy resin pouring sealant with high thermal conductivity and low thermal expansion. According to the prepared epoxy pouring sealant, aluminum oxide and the anti-settling agent are utilized to form a uniform heat conduction network, the thermal expansion coefficient is reduced by adding boron carbide, the problems of heat dissipation, thermal stress and micro-crack filling are solved, and the epoxy pouring sealant is suitable for pouring of large complex special motors.

The application provides a flame-retardant composite shielding material and a preparation method and application thereof, and belongs to the technical field of nuclear radiation shielding materials. The flame-retardant composite shielding material comprises the following components in parts by mass: 10-20 parts of high-density polyethylene, 68-81 parts of lead, 0.5-4 parts of boron carbide and 9-20 parts of a flame retardant. By adopting high-density polyethylene, lead, boron carbide and a flame retardant and controlling the mass fraction of each component, the heat resistance, flame retardance and shielding performance of the flame-retardant composite shielding material can be improved.

The invention belongs to the technical field of bulletproof ceramic material preparation, and discloses a preparation method of a granite-imitated structure boron carbide bulletproof ceramic. According to the invention, the technical problems of how to construct the boron carbide anti-bullet ceramic with the granite organization structure and how to ensure that the boron carbide anti-bullet ceramic can be sintered compactly are solved. By simulating the organization structure of granite, on one hand, the overall hardness of the material is not reduced, and it is guaranteed that the material has the good projectile breaking capacity; and on the other hand, the fracture toughness of the material is greatly improved through the effects of crack deflection of particles, pulling-out of the flaky material, microcrack toughening and the like, so that the damaged area is greatly reduced after the ceramic is hit, and the ceramic has good multi-bullet resistance.

To provide a new boron preparation.SOLUTION: A modified boron carbide particle powder contains boron carbide particles, wherein at least part of the surface of at least some of the boron carbide particles in the boron carbide particles is modified with polyglycerol. The polyglycerol-modified boron carbide particle powder is inherently less toxic and can be administered in a shorter time, and can be suitably used in boron neutron capture therapy applications.SELECTED DRAWING: None

The invention relates to a part (100) comprising a part made of a SiC / SiC ceramic matrix composite material (11), at least part of the external surface of which has been machined, and at least the part of the external surface that has been machined being directly covered with a healing layer, the healing layer (20) being made of a material selected from among silicon nitride Si3N4, boron carbide B4C, a ternary Si-B-C system, silicon carbide SiC, or a mixture of two or more of these compounds.

This invention discloses a wire drawing die polishing paste and its preparation process. The polishing paste comprises the following components: 25-40% composite abrasive, 3-8% modified dispersant, 5-12% elastic binder, 2-6% lubricant, 1-4% polishing aid, and the balance being deionized water. The composite abrasive is composed of nano-diamond powder and boron carbide powder in a mass ratio of (1-3):1. This invention utilizes a composite abrasive of nano-diamond and boron carbide, which improves polishing efficiency and precision. The use of the modified dispersant significantly enhances the dispersion stability of the composite abrasive, reduces abrasive agglomeration, and ensures polishing uniformity. The use of the elastic binder reduces surface damage to the wire drawing die, extending its service life. The preparation process of this invention ensures full fusion of the components, thereby allowing precise control of the particle size distribution of the polishing paste, removing air bubbles and impurities, and significantly improving the stability and service life of the polishing paste.

The invention discloses a blast furnace slag runner castable and a preparation method thereof, and relates to the technical field of refractory materials, and the blast furnace slag runner castable comprises the following raw material components in percentage by mass: 6-9% of 15-8mm brown aluminum oxide, 14-16% of 8-5mm brown aluminum oxide, 17-19% of 5-3mm brown aluminum oxide, 13-15% of 3-1mm brown aluminum oxide, 8-11% of 1-0mm compact corundum, 6-8% of 1-0mm silicon carbide, 3-8% of 1-0mm silicon carbide, and the balance of water. The invention relates to a high-strength wear-resistant ceramic material, which is prepared from the following raw materials in percentage by weight: 8 to 12 percent of 200-mesh silicon carbide, 3 to 5 percent of zirconite-silicon carbide composite powder, 6 to 8 percent of aluminum oxide micro powder, 2 to 3 percent of silicon micro powder, 2 to 2.5 percent of cement, 1 to 3 percent of ball pitch, 0.5 to 2 percent of carbon black, 0.2 to 0.5 percent of boron carbide, 1 to 1.5 percent of metal silicon powder, 0.3 to 0.6 percent of zirconium boride, 0.03 to 0.05 percent of metal aluminum powder, 0.05 to 0.08 percent of organic fiber and 0.1 to 0.2 percent of water reducing agent. The oxidation resistance, slag corrosion resistance and scouring resistance of the blast furnace slag runner castable are improved, the cost is reduced, and the service life is prolonged.

This disclosure relates to the field of functional polymer composite materials technology, specifically to composite materials and their preparation methods, storage containers and their preparation methods, and preparation apparatus. The composite material is composed of epoxy resin, a curing agent, and boron carbide, wherein the mass ratio of the epoxy resin, the curing agent, and the boron carbide is 100:(20~50):(5~35); wherein the epoxy resin is a multifunctional epoxy resin, and the curing agent is a room temperature curing agent; the composite material of this disclosure possesses excellent neutron absorption capacity, significant thermal stability, good corrosion resistance, and feasible engineering implementation performance.

The application belongs to the field of detection and analysis, and particularly relates to a method for detecting free carbon in cemented carbide mixture based on pretreatment, which comprises the following steps: S1, obtaining cemented carbide mixture, the components of the cemented carbide mixture including at least one of chromium carbide, silicon carbide and boron carbide, and grinding the cemented carbide mixture into cemented carbide mixture powder; S2, mixing, stirring and centrifugally separating the cemented carbide mixture powder and heavy liquid to obtain a mixture; taking out the upper layer liquid containing elemental carbon of the mixture and washing and solid-liquid separating to obtain an initial sample to be detected; S3, rinsing and drying the initial sample to be detected to obtain a final sample to be detected, and detecting the final sample to be detected to obtain the content of free carbon. Through the improved pretreatment detection method of free carbon in cemented carbide mixture, the accuracy and efficiency of detection are improved, the range of detection of free carbon in cemented carbide is expanded, and the method is suitable for more kinds of carbides.

The present invention developed a composite having a novel structure containing, in a high content, a powder having a radiation-shielding function.　Provided is a composite having a radiation-shielding function and a method for producing the same. The composite comprises a preform made from a mixture containing a liquid silica-based binder and one or more radiation-shielding powders selected from gadolinium oxide, boron carbide, boron oxide, boron, barium sulfate, strontium oxide, tungsten, tungsten oxide, tungsten carbide, molybdenum, molybdenum oxide, iron powder, iron oxide powder, and ferrite powder, the radiation-shielding powder(s) being contained in the range from 3% to 85% in total. All of the voids in the preform are impregnated and filled with molten aluminum and solidification is allowed to occur to form a composite, or 25% or more of the voids in the preform are impregnated with a liquid organic / inorganic sealing agent and solidification is allowed to occur to form a composite. The liquid silica-based binder has properties that allow the preform to be formed at a temperature at which the radiation-shielding powder(s) does not decompose.

The invention discloses a high-temperature-resistant polycrystalline wire-drawing die and a preparation method thereof, and relates to the technical field of wire-drawing dies, the die comprises a boron carbide whisker reinforced silicon carbide ceramic matrix, a modified composite polycrystalline working layer and a titanium carbide-tungsten carbide-cobalt multiphase gradient transition layer between the boron carbide whisker reinforced silicon carbide ceramic matrix and the modified composite polycrystalline working layer; the working layer contains coarse and fine graded diamond particles, tungsten carbide-titanium carbide composite particles and a rare earth modified cobalt-nickel alloy binding agent. The preparation method comprises the steps of matrix preparation, pretreatment, gradient transition layer spraying, rare earth modified binding agent preparation, polycrystalline material mixing, compression molding and step-by-step sintering. According to the invention, the matrix toughness is enhanced by the whiskers, the wear resistance and high temperature resistance of the working layer are enhanced by the graded particles and the modified binding agent, and the interface combination is optimized by the gradient transition layer, so that the problems of fragile matrix, easy damage of the working layer and easy stripping of the interface of the traditional mold are solved, the overall service performance of the mold is obviously improved, and the mold is suitable for industrial production.

The invention relates to the field of ultrahigh-temperature ceramic materials, and discloses rare earth element doped quinary high-entropy boride powder and a preparation method thereof. The preparation method of the rare earth element doped quinary high-entropy boride powder comprises the following steps: 1) taking metal oxide powder, boron carbide powder and graphite powder as raw materials, and performing wet mixing to prepare mixed powder, 2) briquetting the mixed powder to prepare a green body, putting the green body into a high-temperature carbon tube furnace into which protective gas is introduced, heating, and carrying out pressureless sintering to obtain clinker; and 3) grinding the clinker to obtain the rare earth element doped high-entropy boride powder. The rare earth element doped quinary high-entropy boride powder prepared by the method has the advantages of high purity, no impurity phase, uniform metal element distribution and high rare earth element content, the preparation process is simple, the cost is low, the reaction temperature is lower, and large-scale production is facilitated.

The invention discloses a flame-retardant lead-boron modified polyethylene composite shielding material and a preparation method thereof. The flame-retardant lead-boron modified polyethylene composite shielding material is prepared from the following components in percentage by weight: 14 to 16 percent of ultrahigh molecular weight polyethylene powder, 0.5 to 3 percent of boron carbide powder, 70 to 80 percent of lead powder of which the purity is greater than or equal to 99.5 percent, 5 to 10 percent of modified aluminum diethylphosphinate, 0.1 to 0.2 percent of antioxidant and 0.1 to 0.2 percent of lubricant, wherein the lead powder comprises 200-mesh granular lead powder and 300-500-mesh spherical lead powder, the mass ratio of the 200-mesh granular lead powder to the 300-500-mesh spherical lead powder is 1: 1, and the modified aluminum diethyl phosphinate is silane coupling agent modified aluminum diethyl phosphinate. The shielding performance of the prepared flame-retardant lead-boron modified polyethylene composite shielding material is equivalent to that of a conventional lead-boron polyethylene material, and the flame-retardant lead-boron modified polyethylene composite shielding material has excellent flame retardance and physical and chemical properties, the oxygen index of the flame-retardant lead-boron modified polyethylene composite shielding material is greater than or equal to 32, and the vertical combustion method reaches V0 level.