843 results about "Boron carbides" patented technology

Systems and methods for forming an oxidation protection system on a composite structure are provided. In various embodiments, the oxidation protection system comprises a boron-glass layer formed on the composite substrate and a silicon-glass layer formed over the boron-glass layer. Each of the boron-glass layer and the silicon-glass layer include a glass former and a glass modifier. The boron-glass layer includes a boron compound comprising a mixture of boron carbide (B4C) powder and cubic boron nitride (BN) powder.

The invention relates to the technical field of ceramic substrates, and provides a high-toughness multilayer ceramic substrate and a preparation method thereof. Raw materials of the high-toughness multilayer ceramic substrate comprise the following components in parts by weight: 90-95 parts of aluminum oxide, 13-17 parts of a sintering aid, 2-5 parts of a plasticizer, 1-3 parts of a dispersant, 3-5 parts of a binder, 10-12 parts of an aid and 55-65 parts of water, the auxiliaries comprise boron carbide, copper-tin alloy powder and graphene oxide. According to the technical scheme, the problem of poor toughness of the multi-layer ceramic substrate in the prior art is solved.

The invention discloses a spray drying device for boron carbide production, the spray drying device comprises a spray drying tower, a hot blast stove, a cyclone separator and a system controller, an atomizer and an online detection module are arranged in the spray drying tower, and the online detection module is used for monitoring temperature parameters in the spray drying process; comprising a first temperature sensor, a second temperature sensor and a temperature signal processing unit, the temperature signal processing unit adopts a multi-stage filtering and error compensation technology, noise and interference are effectively suppressed, and the accuracy of detection data is ensured. The air inlet temperature and the air outlet temperature are monitored in real time through the online detection module, the fuzzy-PID control algorithm is combined, the temperature control precision and the response speed are remarkably improved, and temperature fluctuation is reduced. The device dynamically adjusts the heating power of the hot blast stove according to real-time working conditions, the energy utilization efficiency is optimized, and the energy consumption is reduced.

The invention provides a high-temperature-resistant magnesia-carbon composite refractory brick and a preparation method thereof, and belongs to the technical field of magnesium oxide refractory wall bricks, the refractory brick comprises the following raw materials: double-layer modified magnesium oxide, modified crystalline flake graphite, zircon powder, modified liquid phenolic resin and a benzoxazine cross-linking agent; the double-layer modified magnesium oxide is obtained by firstly coating magnesium oxide with powder phenolic resin, aluminum oxide and zirconium oxide and then coating magnesium oxide with asphalt, micron magnesium oxide, zirconium oxide and calcium oxide; the modified crystalline flake graphite is obtained by coating crystalline flake graphite with strontium hydroxide, asphalt and boron carbide; the modified liquid phenolic resin is formed by mixing liquid phenolic resin with a silane coupling agent and a polyacrylate cross-linked polymer. Double-layer modified magnesium oxide, modified crystalline flake graphite and modified liquid phenolic resin are prepared by adopting special components and a method and are matched with zircon powder and a benzoxazine cross-linking agent for use, and a reasonable forming and sintering process is designed, so that the refractory brick has good high-temperature stability, oxidation resistance, thermal shock resistance and the like.

The invention discloses a preparation process of a high-temperature-resistant and wear-resistant polymer composite material, which comprises the following preparation steps: (1) selecting polyether-ether-ketone as matrix resin, and drying the matrix resin at 150 DEG C for 4 hours; (2) preparing porous sphere-like boron carbide ceramic powder; (3) carrying out surface treatment on the prepared porous sphere-like boron carbide ceramic powder; and (4) uniformly mixing the boron carbide ceramic powder subjected to surface treatment in the step (3) and polyether-ether-ketone in a mild mixing manner, compounding with carbon fibers, and extruding and granulating by using a double-screw extruder to obtain the high-temperature-resistant and wear-resistant polymer composite material. Through the mode, the composite material prepared by the method does not contain PFAS chemical substances, is superior to the existing PTFE material in the aspects of wear resistance, environmental protection property, high temperature resistance and the like, and is an ideal reliable PTFE substitute material.

The invention discloses an iron alloy electrode paste and a preparation process, and belongs to the technical field of electrode paste preparation, the iron alloy electrode paste comprises a composite aggregate system and a composite binder system, the composite aggregate system comprises the following components by mass: 40-60% of anthracite aggregate, 15-25% of artificial graphite flake, and 3-8% of silicon carbide whisker; the composite binder system comprises the following components in percentage by mass: 70-80% of medium-temperature modified coal pitch, 10-15% of furan resin and 5-10% of dispersion liquid containing nano boron carbide, and the composite binder system is combined with the composite aggregate system through a gradient permeation process to form a three-dimensional conductive network and an enhanced interface; the composite aggregate system and the composite binder system are optimally proportioned, and gradient permeation and gradient kneading processes are combined, so that the comprehensive performance of the electrode paste is remarkably improved, the thermal shock resistance is greatly improved and the linear shrinkage rate is reduced while low resistivity is maintained, the electrode paste is suitable for smelting ferroalloys such as silicomanganese and ferrochromium, and the service life is remarkably prolonged.

The invention discloses a preparation method of a polydopamine modified boron carbide-zinc methacrylate coordination reinforced rubber-based radiation protection composite material, and relates to the technical field of radiation protection materials. The method comprises the following steps: dispersing boron carbide in a triaminomethane buffer solution containing dopamine, and carrying out surface polymerization reaction to obtain polydopamine modified boron carbide; and mixing the polydopamine modified boron carbide, zinc methacrylate and a rubber matrix, and vulcanizing to obtain the polydopamine modified boron carbide-zinc methacrylate coordination enhanced (zinc is coordinated with nitrogen / oxygen and the like on the surface of the modified boron carbide) rubber-based radiation protection composite material. Through multiple effects of coordination enhancement, chemical crosslinking and the like, the material has excellent neutron shielding performance and tensile property, the preparation method is simple, the cost is low, and the material has a wide application prospect in the field of nuclear radiation protection.

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 belongs to the technical field of coatings, and particularly relates to an irradiation-resistant fireproof coating and a preparation method thereof. The radiation-resistant fireproof coating comprises a component A and a component B. The component A comprises, by weight, 15-35 parts of organosilicon modified epoxy resin, 5-10 parts of an active diluent, 20-50 parts of a dehydration char-forming catalyst, 3-10 parts of a foaming agent, 5-10 parts of a flame retardant, 0.1-0.5 part of expanded graphite, 5-10 parts of refractory fibers and 3-15 parts of a radiation-resistant filler. The radiation-resistant filler comprises silane coupling agent modified nano barium sulfate and micron boron carbide; and the component B is an amine curing agent. According to the radiation-resistant fireproof coating and the preparation method thereof, by adopting the specific silane coupling agent modified micro-nano radiation-resistant filler, the radiation-proof performance uniformity and the fire resistance after radiation resistance of the coating are effectively improved, and the radiation-resistant fireproof coating can be widely applied to nuclear power plants and various nuclear industry facilities.

The invention relates to the technical field of grading devices, in particular to a boron carbide powder grading device which comprises a base, a sorting assembly is rotationally arranged on the base, a power assembly used for driving the sorting assembly to rotate is arranged on the base, and the sorting assembly comprises a cylinder rotationally arranged on the base and provided with a power assembly used for driving the sorting assembly to rotate. The barrel is driven to rotate through the power assembly; the screening barrel I is fixedly connected to the interior of the barrel body and is used for carrying out primary screening on the boron carbide powder material; the second screening barrel is arranged in the barrel body, arranged outside the first screening barrel in a sleeving mode and used for conducting second-stage screening on the screen underflow obtained after first-stage screening; the base is provided with a driving module used for driving the second screening barrel to rotate and move up and down. The screening device has the beneficial effects that the height of the second screening barrel can be adjusted through the driving module according to the actual condition of the material amount, and the situation that when the material amount is large, due to the small distance, materials enter the upper layer for screening operation again is avoided.

The invention discloses a die steel additive material for forming a die-casting die core and a manufacturing method of the die steel additive material, and belongs to the technical field of laser advanced manufacturing, and the manufacturing method comprises the following steps: Al powder, Ti powder and boron carbide are mixed, coated and pre-pressed to obtain a pressing block, and the pressing block is heated to generate a combustion synthesis reaction to obtain a TiC + TiB2 / Al intermediate alloy; heating and remelting die steel, adding the TiC + TiB2 / Al intermediate alloy to obtain molten steel, and pouring the molten steel to obtain nano-particle die steel; heating and remelting the nano-particle die steel to obtain a nano-particle die steel solution, and introducing nitrogen for atomization to obtain nano-particle reinforced powder; the nano-particle reinforced powder is prepared through selective laser melting, and the die steel additive is obtained; the die steel disclosed by the invention has high compactness forming and high strength and toughness.

The invention relates to the technical field of refractory materials, and discloses a rotary kiln lining refractory material and a preparation method thereof, the raw materials comprise mullite, boron carbide, calcium hexaluminate, silicon carbide, silica powder, alpha-alumina micro powder, coating powder, modified refractory fiber, and a binder. The mullite and the boron carbide are selected as base materials and have excellent acid corrosion resistance, the titanium dioxide and the aluminum oxide are used for treating the refractory fibers, so that a compact enrichment layer is formed, low-temperature sintering is promoted by adding the yttrium oxide, the titanium dioxide is introduced into the refractory fibers, and the corrosion resistance of the refractory fibers is improved. And micropores in the fiber surface can be blocked, so that the porosity of the refractory material is reduced, and the diffusion path of acid steam is prolonged. The refractory material provided by the invention has excellent high-temperature stability and corrosion resistance.

The present invention relates to the field of carbon-carbon composite materials, and discloses a carbon-carbon composite material, a carbon-ceramic composite material, an anti-oxidation coating, and an aircraft brake disc. The anti-oxidation coating comprises components by weight: 150 parts of an aqueous solution of aluminum dihydrogen phosphate with a content of 37-43%, 70-130 parts of tin powder, 60-120 parts of silicon carbide powder, 15-60 parts of glass powder with a softening point of 600°C-900°C, 15-50 parts of kaolin, and 10-30 parts of boron carbide powder. The anti-oxidation coating can form a coating with good thermal stability and chemical stability by accurately proportioning and mixing a plurality of materials, and can protect the carbon-carbon composite material from oxidation under a high temperature environment.

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 relates to the technical field of boron carbide coarse abrasive particle crushing, in particular to a self-adaptive target type airflow crusher for boron carbide coarse abrasive particles, which comprises an air compressor, a Laval nozzle, a feed distributor, a crusher, a target material, a cyclone collector, a dust remover, an image acquisition assembly, an analysis assembly and a regulation and control assembly, the analysis assembly determines the accumulation degree of the coarse-particle boron carbide powder according to the powder distribution image so as to adjust the vibration feeding frequency of the feeding distributor, and determines the coarse-particle ratio and the coarse-particle duration according to the powder particle size image and the coarse-particle threshold value; and the regulation and control assembly adjusts the air pressure of the high-pressure airflow according to the coarseness ratio, the preset first ratio, the coarseness duration time, the preset time threshold value and the target granularity, and adjusts the angle of the target material or the air outlet angle of the Laval nozzle according to the position of the impact area, the ratio of the impact area and the preset second ratio. According to the method, the qualified rate of crushing of the boron carbide coarse abrasive particles is effectively improved.

The invention relates to a SiOC modified boron carbide-aluminum oxide composite material and a preparation method thereof. The SiOC modified boron carbide-aluminum oxide composite material comprises a porous structure boron carbide-aluminum oxide material and a SiOC layer coating and modifying the porous structure of the boron carbide-aluminum oxide material and the surfaces of boron carbide and aluminum oxide particles, the porosity of the boron carbide-aluminum oxide material with the porous structure is 20 to 40 percent.

The invention discloses clamping equipment capable of clamping irregular boron carbide pellets, relates to the technical field of clamping equipment, and provides the following scheme that the clamping equipment comprises a mounting frame, a motor is arranged at the end of the mounting frame, the output end of the motor is connected with a screw rod, a sliding frame is arranged in the screw rod, and the sliding frame is connected with the motor; a fixing frame is installed at the bottom of the sliding frame, a guide groove is formed in the fixing frame, a telescopic mechanism is slidably connected into the guide groove, butt clamps are arranged on the opposite sides of the sliding frame, an angle iron frame is welded to the outer side of the top of the mounting frame, and a mounting hole is formed in the outer side of the angle iron frame. A mounting bolt penetrates through the middle part of the mounting hole; by arranging the telescopic mechanism, three groups of telescopic blocks are respectively adapted to the outer surfaces of the special-shaped boron carbide pellets, so that the clamping force can be more uniform, the clamping contact points are effectively increased, the irregular boron carbide pellets are clamped in a self-adaptive manner, and the clamping stability and flexibility are better ensured.

The invention discloses a method for manufacturing a high-wear-resistant composite swing hammer head, which comprises the following steps: washing and drying ceramic particles with an oxalic acid solution, uniformly mixing boron carbide ceramic powder and an alcohol adhesive in proportion into a slurry, and drying to remove the alcohol adhesive; then mixing the ceramic particles with NiCrBSi powder and a sodium silicate solution and filling the mixture into a honeycomb mold, taking the mixture out after microwave curing, thereby obtaining a honeycomb ceramic preform with high strength at room temperature, wherein a conical preformed hole is formed on the honeycomb ceramic preform, placing the honeycomb ceramic preform into a casting cavity of a swing hammer head metal mold, and then pouring molten high-chromium cast iron into a runner of the casting mold, wherein the high-chromium cast iron water infiltrates into gaps between ceramic preform particles under high pressure to form a reactive interface, thereby obtaining a high-wear-resistant composite swing hammer head. The method can manufacture a composite swing hammer head with a reactive interface and high wear resistance.

The invention discloses a modified PPS fiber filter material and a preparation method thereof, and belongs to the technical field of filter materials. Comprising the following raw materials in parts by weight: 60-80 parts of PPS resin, 6-18 parts of modified boron carbide and 10-20 parts of an ethylene-octylene copolymer. The filter material prepared by the invention takes polyphenylene sulfide as a matrix, so that the filter material is endowed with excellent strength, high temperature resistance and corrosion resistance; wherein the ethylene-octylene copolymer can improve the toughness of the filter material; wherein the modified boron carbide is good in compatibility with a matrix, the oxidation resistance, the heat resistance and a certain degree of mechanical properties of the filter material can be remarkably enhanced, and the properties are long and stable; therefore, the filter material prepared by the invention is excellent in corrosion resistance, also has stable and efficient oxidation resistance, heat resistance and mechanical properties, and has important application value in the technical field of filter materials.

The invention relates to the technical field of ferrous metallurgy, in particular to low-reactivity Al-Ti inhibition type casting powder for continuous casting based on premelted hollow particles and a preparation technology of the low-reactivity Al-Ti inhibition type casting powder. Wherein the water-quenched melt particles comprise an Al-Ti inhibitor, a melt, aluminum oxide short fibers and carbon black, pre-sintered aluminum oxide and titanium dioxide serve as the Al-Ti inhibitor, a stable Al-Ti-O network structure is formed in the melt, the reaction activity of the slag and the high-activity Al-Ti molten steel is effectively reduced, the aluminum oxide short fibers are introduced to form an enhanced network, and the high-activity Al-Ti molten steel is obtained. According to the casting powder, nano silicon carbide and boron carbide are matched to form synergistic reinforcement, ethyl silicate hydrolysate, water glass and sodium carboxymethyl cellulose are adopted to construct a dual-bonding system, the casting powder of the hollow structure is prepared, and the mechanical strength of the casting powder is effectively improved.

The invention relates to the technical field of silicon carbide ceramics, in particular to a preparation method and a sintering device of a large-sized pressureless sintered silicon carbide ceramic tubing, and the preparation method comprises the following steps: uniformly mixing beta-type silicon carbide whiskers, graphite powder, boron carbide, a sintering aid, a dispersing agent, a binder and silicon carbide micro powder, then adding water, and stirring to prepare pug with the water content of 32-38%; pugging is conducted till pug with the water content being 8%-11% is obtained, and then the pug obtained after pugging is sealed and aged at the room temperature; carrying out extrusion molding on the aged pug through a vacuum extruder to obtain a ceramic tube blank; the ceramic blank pipe is fed into drying equipment to be dried; and sintering the ceramic blank tube in a nitrogen atmosphere at 1900-2150 DEG C to obtain the silicon carbide ceramic tube. By adding the beta-type silicon carbide whiskers, the silicon carbide micro powder, the sintering aid and other substances, the toughness and strength of the silicon carbide ceramic pipe can be enhanced, the wall thickness of the pipe can be reduced on the premise of keeping the same strength level, thermal resistance can be reduced, and the heat exchange efficiency of a heat exchanger can be improved.

A ceramic component included in a plasma etching apparatus, wherein a surface of the ceramic component may include a base material and a composite material disposed in contact with the base material, wherein a resistivity of the ceramic component may be 10−1 Ω·cm to 20 Ω·cm, and wherein the base material may include a first boron carbide-based material and the composite material may include at least one selected from the group consisting of a second boron carbide-based material, a carbon-based material, and combinations thereof, is disclosed.

The present invention belongs to the technical field of ceramic preparation, and relates to a preparation method and device for a high-purity porous boron carbide nuclear control rod. The present invention uses boron trichloride gas as the boron source, methane as the carbon source, argon as the carrier gas and protective gas, and hydrogen as the catalytic gas and reducing gas to prepare a high-purity porous boron carbide nuclear control rod. The method of increasing the deposition temperature of boron carbide step by step and region by region from the back to the front is adopted, which can not only improve the deposition rate of boron carbide, but also ensure that the physical and mechanical properties of each part of the prepared high-purity porous boron carbide nuclear control rod are consistent. By changing the particle size of the boron carbide powder for preparing the boron carbide blank and coordinating the adjustment of temperature, flow rate, pressure and deposition time, the porosity and pore size of the prepared high-purity porous boron carbide can be regulated and a high total boron and carbon content can be obtained, so as to meet various actual requirements.

The invention relates to the technical field of ceramic glaze preparation, in particular to a formula of ceramic glaze, which comprises the following components in percentage by mass: 25-30% of modified zircon sand; 20 to 25% of spodumene; 15 to 20 percent of nano aluminum oxide; 10 to 15% of petalite; 8-12% of kaolin; 3-5% of a silver-loaded zeolite antibacterial agent; 5-8% of boron carbide-silicon nitride composite powder; 2-3% of zinc borate; and 10-15% of a composite frit. A three-dimensional grid structure (the Vickers hardness is greater than or equal to 1800 HV) is formed through boron carbide-silicon nitride composite powder, and the wear resistance is improved by 40% in combination with a potassium feldspar modification technology; the silver-loaded zeolite realizes slow release of Ag, the antibacterial rate is greater than 99.9%, a gradient sintering process enables a glaze layer to form a gradient density structure, the porosity of a surface layer is less than 0.5%, the porosity of a bottom layer is 3-5%, the oxidation defect of the copper red glaze is avoided through CO / N atmosphere control, and the color development uniformity delta E is less than or equal to 0.8; the firing temperature is reduced by 150 DEG C, and the energy consumption is reduced.

The invention belongs to the field of light low-carbon concrete, and discloses hydraulic low-carbon concrete containing barium sulfate barite as well as a preparation method and application of the hydraulic low-carbon concrete. The concrete is prepared from 42.5-grade Portland cement, barium sulfate barite powder, modified polypropylene fiber, industrial waste residue lightweight aggregate, boron carbide powder, nano silicon dioxide, a polycarboxylate superplasticizer, a composite exciting agent and water according to specific parts by weight. Wherein the barium sulfate barite powder is subjected to graded proportioning and calcination activation, the modified polypropylene fiber is treated by plasma and a silane coupling agent, the industrial waste residue lightweight aggregate is formed by compounding fly ash ceramsite and steel slag microbeads, and the composite exciting agent is composed of specific components. The concrete is high in compressive strength, low in dry density, excellent in neutron shielding and gamma ray attenuation performance and low in chloride ion diffusion coefficient. The preparation method comprises the steps of premixing modification, gradient stirring, vibration compaction and steam curing. The concrete is suitable for construction of a nuclear reactor containment, a radioactive waste repository and a nuclear medicine protection wall.

The invention relates to a refractory castable for a blast furnace tapping main channel. The refractory castable is prepared from the following raw materials in parts by mass: 35-45 parts of compact corundum, 25-35 parts of white corundum, 12-18 parts of silicon carbide, 4-7 parts of alpha-Al2O3 micro powder, 2-5 parts of rho-Al2O3 micro powder, 6-10 parts of modified graphite, 1-5 parts of an antioxidant, 0.1-0.3 part of organic fibers and 0.05-0.2 part of a water reducing agent, the modified graphite is obtained by carrying out interface chemical deposition reaction on graphite oxide to form Mg (OH) 2 / Al (OH) 3 coated graphite particles, then calcining in an inert atmosphere to form MgO / Al2O3 coated graphite particles, and then carrying out surface modification by carboxyl-terminated polyethylene glycol silane. The antioxidant is a compound of magnesium carbide, boron carbide and silicon powder. The refractory castable for the blast furnace tapping main channel has excellent slag corrosion resistance, high temperature resistance and thermal shock resistance.

The invention discloses a high-strength tungsten-boron silicone rubber radiation shielding material, which is prepared from the following ingredients in parts by weight: 100 parts of methyl vinyl silicone rubber raw rubber, 30 to 50 parts of white carbon black, 90 to 240 parts of tungsten oxide coated boron carbide heterostructure particles, 4 to 10 parts of hydroxyl silicone oil and 1 to 2.5 parts of 2, 5-dimethyl-2, 5-bis-(tert-butylperoxy) hexane. The preparation method comprises the following steps: 1, surface modification of tungsten oxide particles; 2, boron carbide surface modification; 3, grafting the surfaces of the two; and 4, mixing and vulcanizing the raw materials. White carbon black and tungsten oxide coated boron carbide heterostructure particles are introduced into the material, so that the dispersity of tungsten oxide particles in a silicon rubber matrix is improved, the interface interaction between boron carbide and the silicon rubber matrix is enhanced, the high strength of the material is ensured, and the material has excellent mechanical strength and neutron / gamma ray comprehensive shielding performance; the method is easy for mass production and can be used in the field of radiation protection.

The invention relates to the technical field of high-entropy boride ceramic materials, in particular to a high-entropy boride ceramic material and a preparation method and application thereof. The invention provides a preparation method of a high-entropy boride ceramic material, which comprises the following steps: mixing transition metal oxide and boron carbide to obtain mixed powder; and sequentially carrying out heat treatment and sintering on the mixed powder to obtain the high-entropy boride ceramic material, the mass percent of the boron carbide in the transition metal oxide is 15-40%. The preparation method can solve the problem of abnormal grain size growth caused by high-temperature sintering, and meanwhile, the prepared high-entropy boride ceramic material is small in grain size, high in density, excellent in fracture toughness and bending strength and good in mechanical property.

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 boron carbide ceramics, and relates to a preparation method of boron carbide ceramics with a rare earth silicon carbon compound as a sintering aid. The invention discloses a preparation method of boron carbide ceramic taking a rare earth silicon carbon compound as a sintering aid, which comprises the following steps: mixing the sintering aid rare earth silicon carbon compound RExSiyCz and B4C according to the mass ratio of (0.1-10): (90-99.9), drying, sieving, pre-pressing and sintering to obtain the boron carbide ceramic taking the rare earth silicon carbon compound as the sintering aid. According to the invention, the rare earth silicon carbon compound is added into B4C as a sintering aid, and a liquid phase is formed by using the rare earth silicon carbon compound, so that the particle rearrangement and mass transfer process of the ceramic raw material can be promoted, the ceramic sintering temperature is reduced, and the sintering densification degree is improved.