1284 results about "Boron carbides" patented technology

The invention provides a heat-conduction heat-dissipation interface material and a manufacturing method thereof, wherein the heat-conduction heat-dissipation interface material is applied to the field of heat dissipation of electronic products. The heat-conduction heat-dissipation interface material comprises a heat-conduction heat-dissipation layer and a surface protective material layer, wherein the heat-conduction heat-dissipation layer consists of one or more of graphite, nano graphite, crystalline flake graphite, graphene, pyrolytic carbon, pyrolytic graphite, graphite powder, carbon nano tubes, carbon fibers, graphite fibers, resin, ceramic fibers, quartz fibers, metal fibers, zirconia, boron nitride, silicon nitride, boron carbide, silicon carbide, magnesia powder, metasillicio acid fibers, calcium silicate aluminum fibers, aluminium oxide fibres, copper power, aluminium power, silver power, tungsten power and molybdenum power; and the surface protective material layer is a polymeric membrane. The heat-conduction heat-dissipation interface material manufactured according to the materials and the method provided by the invention has the advantages of effectively improved heat-dissipation performance, small volume, light weight and small thickness, can be used for prolonging the service life of an electronic component, and simultaneously is easy to produce and process.

The invention relates to a method for preparing a B4C-Al composite material, which is characterized by comprising the following steps of: 1, uniformly mixing a certain proportion of raw material boron carbide powder with aluminum alloy powder in a high-energy ball milling way; 2, compressing the uniformly-mixed power for molding; 3, sintering compression-molded compact in the step 2 at certain temperatures; 4, extruding sintered compact sintered in the step 3 at certain temperatures; and 5, conducting multiple-time hot rolling for the extruding-molded material in the step 4 at certain temperatures to obtain B4C-Al composite boards. By adopting the preparation method in the invention, the ball milling efficiency is high, the preparation process almost has no material loss, and the prepared B4C-Al composite boards have the characteristics of uniform distribution of boron carbide and good mechanical property and can be applied to neutron absorption/shielding.

The invention relates to a method for manufacturing a self-healing silicon carbide ceramic matrix composite. The method comprises the following steps: preparing fiber preform; filtrating a pyrolytic carbon interface layer by chemical gas phase; carrying out thermal treatment on the interface layer; infiltrating silicon carbide and boron carbide substrate by chemical gas phase alternately; and depositing three silicon carbide coatings by the chemical gas phase. The method has strong designability, simple process and good repeatability. The ceramic matrix composite manufactured by the method has good high temperature resistance and oxidation resistance, has excellent mechanical performance and thermal performance, and can meet the use requirement of a sealing strip/an adjustment sheet, an interior cone and other components of a high thrust-weight ratio aeroengine.

The present invention relates to dry refractory compositions having excellent thermal insulation values. The dry refractory composition also has excellent resistance to molten metal and slag. The composition comprises a lightweight filler material selected from the group consisting of perlite, vermiculite, expanded shale, expanded fire clay, expanded silica-alumina hollow spheres, vesicular alumina, sintered porous alumina, alumina spinel Stone insulating aggregate, ettringite insulating aggregate, expanded mullite, cordierite and anorthite, and a matrix material selected from the group consisting of calcined alumina, fused alumina, sintered magnesia, fused magnesia, Silicon fume, fused silica, corundum, boron carbide, titanium diboride, zirconium boride, boron nitride, aluminum nitride, silicon nitride, sialonite, titanium dioxide, barium sulfate, zircon, sillimanite Group of minerals, pyrophyllite, fire clay, carbon and calcium fluoride. The composition may also contain dense refractory aggregates selected from the group consisting of calcined clay, calcined clinker, minerals of the sillimanite group, calcined bauxite, pyrophyllite, silica, zircon, baddeleyite, cordierite , corundum, sintered alumina, fused alumina, fused quartz, sintered mullite, fused mullite, fused zirconia, sintered zirconia mullite, fused zirconia mullite, sintered magnesia, Fused magnesia, sintered spinel and fused spinel refractory clinker. The composition also contains a heat activated binder and a dust suppressant.

This invention relates to a saw bit belonging to mechanical working field, which comprises metal base being alloy steel or carbon steel, with Phi8-Phi10mm radiating holes equispaced on its surface; Carcass including alumina, zircite, quartz, tungsten carbide, zirconium diboride, molybdenum disilicide; common abradant including brown fused alumina, carbofrax, green silicon carbide, cubic carbofrax, boron carbide; superhard abradant including diamond and cubic boron nitride. The produce process includes mixing carcass flour, working layered material batching-mixing process, welding layered material batching-mixing process, koldflo, thermal pressing-sintering formation, arc milling, welding, dressing and making edge. The invention has improved working efficiency, lowered product cost, and is suitable for cutting metal tube, plate such as this materials.

The present invention relates to novel lubricant additives for improving the tribological properties, novel lubricants containing these additives, processes for the preparation thereof and the use thereof. Lubricant comprises ceramic nanoparticles as additives comprising aluminum oxide, aluminum nitride, silicon dioxide, titanium dioxide, zirconium oxide, yttrium oxide, tungsten oxide, tantalum pentoxide, vanadium pentoxide, niobium pentoxide, cerium dioxide, boron carbide, aluminum titanate, boron nitride, molybdenum disilicide, silicon carbide, silicon nitride, titanium carbide, titanium nitride, zirconium diboride and/or clay minerals, and thermally stable carbonates and/or sulfates. The nanoparticles represent an ellipsoid with three semi-axes a, b and c, which are not equal to each other, or equal to each other. The ratio of a and b is 1-100, a and c is 1-1000, and b and c is 1:100.

The invention relates to a light-weight Al2O3-SiC-C refractory casting material and a preparation method thereof. The light-weight Al2O3-SiC-C refractory casting material comprises the following raw materials: 40-55 wt% of porous corundum particle, 8-12 wt% of corundum particle, 6-12 wt% of SiC particle, 6-10 wt% of SiC fine powder, 5-8 wt% of corundum fine powder, 8-12 wt% of active aluminum oxide micropowder, 3-5 wt% of calcium aluminate cement, 2-4 wt% of silicon oxide micropowder, 2-4 wt% of ball asphalt, 1.5-2.0 wt% of silicon powder, 0.1-0.3 wt% of aluminum powder and 0.1-0.3 wt% of boron carbide powder. The preparation method comprises the following steps: mixing the raw materials with 8-15 wt% of water, 0.2-0.6 wt% of water reducing agent and 0.02-0.04 wt% of organic explosion-proof fiber, stirring, casting, molding, and naturally drying at 110 DEG C for 12-48 hours to obtain the light-weight Al2O3-SiC-C refractory casting material. According to the invention, the process is simple; and the prepared product has the characteristics of high strength, excellent thermal shock stability, low heat conductivity and high medium erosion resistance, and also has the advantage that the apparent porosity and pore size can be controlled.

The invention discloses an abrasion-resistant composite material and a preparation method thereof. The composite material disclosed by the invention consists of the following components in parts by weight: 100 parts of plastic resin, 5-30 parts of filler, 0.1-2 parts of coupling agent and 0.1-2 parts of processing aid. The composite material disclosed by the invention has excellent abrasion-resistant property, so that the application field of B4C (boron carbide) is expanded; the composite material with excellent abrasion-resistant property can be prepared by compounding the abrasion-resistant composite material with polytetrafluoroethylene powder; the abrasion-resistant property thereof is better than the effect of independent utilization of B4C or polytetrafluoroethylene; the application field is board; and the composite material is applied to the fields of automobiles, electron and electric, aerospace, weaponry and the like.

The invention discloses a wearing-resistant high-hardness ceramic glaze and a preparation method thereof and relates to the technical field of ceramic glazes. The wearing-resistant high-hardness ceramic glaze comprises the following raw materials: albite, potassium feldspar, kaolin, quartz sand, zinc white, high-aluminum clay, calcite, talc, lithium porcelain, cordierite, zirconium sand, mullite powder, wollastonite, boron carbide, niobium pentoxide, zinc oxide and frit. Both the Vickers hardness and the wearing resistance of a full polish glaze brick made of the glaze disclosed by the invention can be improved, and market requirements on full polish glaze bricks with high hardness and wearing resistance can be met; when a glaze surface is sintered, a great number of bubbles are not generated, and the product is good in antifouling performance and high in glossiness after polishing; expansion coefficients of the full polish brick and a glaze layer are approximate to those of a porcelain blank, the glaze layer is subjected to small inner stress, polishing omission or partial exposure phenomena can be avoided in polishing, and thus product quality can be ensured.

The invention relates to an oxidation resistant coating for aluminum electrolytic carbon anode and a coating method thereof. The method is characterized in that the surface of the aluminum electrolytic carbon anode is provided with an anti-oxidation coating formed by dried and mixed coat which is sprayed on the surface of the electrode, wherein the mixed coat comprises the following compositions in weight percentage: 1 to 25 percent of bisphenol A-type waterborne epoxy resin, 0.1 to 16 percent of boron carbide, 2 to 13 percent of boric acid and/or boric oxide, 15 to 50 percent of alumina, 0 to 20 percent of pseudo-boehmite, 10 to 30 percent of alumina sol, 0.1 to 0.3 percent of foam suppressor, and the balance being water. The coating and the method adopt an alumina-based gradient boron carbide oxidation resistant coating with a multilayer structure, and effectively blocks the contact of air and CO2 with carbon anode carbon, thereby avoiding or reducing excessive consumption of the carbon anode carbon. The method can realize carbon conservation by aluminum electrolytic prebaked anode by 10 to 20 kilogram/ton-Al.

The production of ultrafine boron carbide powders from liquid boron-containing precursors and/or liquid carbon-containing precursors is disclosed. The liquid precursors are fed together or separately to a plasma system where the precursor materials react to form boron carbide in the form of ultrafine particles.

The invention discloses a boron carbide based composite ceramic and a preparation method thereof. The boron carbide based composite ceramic comprises the following compositions by weight percentage: 45 to 50 percent of boron carbide powder, 5 to 8 percent of phenolic resin, and 42 to 50 percent of metallic silicon. After the compositions are weighed, the phenolic resin is dissolved by alcohol first, and the boron carbide powder is added for mechanical ball milling to be mixed evenly; a granulator is used for granulation, and a green body with a shape of the needed product is obtained through compression molding; the compressed green body is placed into a baking oven for drying solidification; the weighed metallic silicon is added into a graphite crucible, the solidified green body is placed on the metallic silicon and is placed into a high-temperature vacuum sintering furnace for sintering along with the crucible, the sintering temperature is between 1,550 and 1,700 DEG C, and the green body is cooled with the furnace after the thermal insulation for 1 to 3 hours to obtain the boron carbide based composite ceramic. The phenolic resin plays a role in an adhesive and a carbon source during the preparation of the composite ceramic, and can also play a role in providing the green body with excessive air holes during the sintering, so that the infiltrability of silicon is improved.

The invention provides a chemical-mechanical polishing composition comprising: (a) an abrasive comprising α-alumina, (b) about 0.05 to about 50 mmol/kg of ions of at least one metal selected from the group consisting of calcium, strontium, barium, and mixtures thereof, based on the total weight of the polishing composition, and (c) a liquid carrier comprising water. The invention also provides a chemical-mechanical polishing composition comprising: (a) an abrasive selected from the group consisting of α-alumina, γ-alumina, δ-alumina, θ-alumina, diamond, boron carbide, silicon carbide, tungsten carbide, titanium nitride, and mixtures thereof, (b) about 0.05 to about 3.5 mmol/kg of ions of at least one metal selected from the group consisting of calcium, strontium, barium, magnesium, zinc, and mixtures thereof, based on the total weight of the polishing composition, and (c) a liquid carrier comprising water. The invention further provides methods of polishing a substrate using each of the above-described chemical-mechanical polishing compositions.

The invention discloses a foamed neutron absorber material. The foaming neutron absorber material is prepared from the mixture of 10-60% of neutron absorber and 40-90% of matrix material through foaming, wherein the neutron absorber is one or more than one of boron carbide, ferrite, rare earth compound, lithium hydride and paraffin wax, and the matrix material is cement, or macromolecular polymer or their mixture. 'Foaming' process is innovatively applied, massive synthesized neutron absorber are dispersed on walls of the pores formed by foaming. The matrix cellular caves greatly expand capacity for capturing neutron rays, neutron rays in the interior of foamed body are diffused by virtue of electromagnetic vortex pore wall, and the scattered neutron waves are gradually attenuated and absorbed.

The invention discloses a laminated neutron radiation shielding composite material and a preparation method thereof; the laminated neutron radiation shielding composite material is in a three-layer composite structure, wherein a bottom layer is a polyethylene fiber reinforced epoxy resin matrix, a middle layer is a boron fiber reinforced epoxy resin matrix, and an upper layer is a polyethylene fiber reinforced epoxy resin matrix which is grafted with acrylic lead. The epoxy resin matrixes comprise materials basically in the following weight portions: 100 portions of bisphenol A epoxy resin, 8 portions to 15 portions of imidazole curing agent and 3 portions to 7 portions of silane coupling agent. In addition, boron carbide (B4C) which occupies 5 weight percent to 20 weight percent of the total weight of the epoxy resin is added into the epoxy resin matrix on the bottom layer; and lead oxide which occupies 10 weight percent to 30 weight percent of the total weight of the epoxy resin is added into the epoxy resin matrix on the upper layer. The laminated neutron radiation shielding composite material is specially manufactured to overcome the defects of a traditional neutron radiation shielding composite material that slowing and absorption functions are not separated so that the functions of an absorbing body cannot be displayed well.

The present invention relates to a high-purity ultrafine zirconium diboride powder material and its preparation method. It is characterized by that the described powder material contains zirconium oxychloride, boron carbide powder and active carbon powder, their mole ratio is ZrOcl2:B4C:C=1:0.4-0.8:1.4-1.8. Its preparation method includes the following steps: firstly, mixing boron carbide powder, active carbon powder and water according to mixing ratio, regulating pH value to obtain mixed suspension; dissolving zirconium oxychloride in deionized water to obtain the zirconium oxychloride solution; mixing the above-mentioned suspension and zirconium oxychloride solution, adding ammonia water, making the zirconium oxychloride be fully hydrolyzed and precipitated; making suspension undergo the processes of solid-liquor separation, waster-washing, removing NH4+ and Cl-, drying and sieving; then placing the powder material into a vacuum furnace to make reaction synthesis, its synthesis temperature is 1500-1600 deg.C, heat-insulating for 0.5-4 h; grinding powder and sieving so as to obtain the invented powder material.

The invention discloses a raw material composition for a graphite-silicon carbide crucible. The raw material composition comprises the following raw materials in percentage by weight: 40% to 50% of flake graphite, 20% to 50% of silicon carbide, 4% to 10% of elemental silicon powder, 1% to 5% of boron carbide powder, and 5% to 15% of clay. The manufacturing process of the graphite-silicon carbide crucible comprises the following steps: mixing raw materials evenly, and manufacturing qualified mud materials; loading the qualified mud materials into moulds, putting the moulds into an isostatic press cylinder, and pressing and shaping; demoulding, drying blanks, and coating anti-oxidation glaze when the blanks are hot; then burning the blanks in a naked manner so that the glaze is melted into glass glaze; inspecting, and when burned blanks are qualified, obtaining finished products. The process disclosed by the invention is simple; the prepared crucible is uniform in texture, large in density, low in air hole rates, high in heat conduction, and strong in corrosion resistance; in addition, the clay is used as bonding agents, so that the situation that phenolic resin or tar, as the bonding agents, is decomposed to release harmful smoke in the course of sintering to pollute environment is avoided.

The invention discloses a preparation method of a composite hard alloy used as a cutter material. The composite hard alloy material is prepared from the following components in parts by weight: 35-40 parts of nano titanium carbide, 5-15 parts of nano titanium nitride, 7-9 parts of tungsten carbide, 5-8 parts of niobium carbide, 3-7 parts of silicon carbide, 3-5 parts of cobalt powder, 1-3 parts of yttrium oxide, 1-3 parts of boron carbide and 1-5 parts of copper powder. The method comprises the following steps: preparing materials, preparing carbon-depleted alloy powder, preparing a presintering matrix, carrying out carbonization and carrying out firing step by step. The composite hard alloy prepared by the preparation method has high strength, good toughness and good wear resistance and thermal shock resistance.

A method for preparing nano boron carbide powder, characterized in that: carbon source and boron source are uniformly mixed according to the molar ratio of 0.1 to 10:1, and placed in a crucible; wherein the carbon source is graphene, and the boron source is boron powder, One or more arbitrary mixtures of boron oxide, boric acid or borate; under an inert protective atmosphere, heating is carried out at a heating rate of 1-16°C/min, and the carbothermal reduction reaction is carried out at a temperature of 900-2500°C , The constant temperature time is 0.3~6h, and the cooling rate is 1~16°C/min. Compared with the prior art, the method involved in the present invention has the following characteristics and advantages: graphene is used as a carbon source, and the characteristics of high specific surface area and abundant edges of graphene are utilized to provide a large number of active sites for boron carbide nucleation, It is beneficial to fully contact the carbon source and the boron source, and the reaction is complete; the prepared product is B ₄ C nano powder does not need secondary crushing in the later ceramic sintering process, which reduces production costs and improves ceramic performance; no additives are required, and the post-processing process is simplified.

The invention discloses a processing technic of a sapphire substrate slice special for a patterned substrate. The processing technic comprises the following steps: A, chamfering; B, performing two-sided rough grinding on the sapphire substrate slice by using boron carbide of which the specification is W14-W20; C, cleaning the sapphire substrate slice by using an ultrasonic wave cleaning machine; D, performing two-sided fine grinding on the sapphire substrate slice by using boron carbide of which the specification is W5-W7; E, cleaning the sapphire substrate slice by using the ultrasonic wave cleaning machine; F, annealing the sapphire substrate slice; G, performing single-sided grinding on the front side of the sapphire substrate slice; H, cleaning the sapphire substrate slice by using the ultrasonic wave cleaning machine; I, preforming the single-sided rough polishing on the front side of the sapphire substrate slice; J, performing single-side fine polishing on the front side of the sapphire substrate slice; and K, cleaning the sapphire substrate slice by using the ultrasonic wave cleaning machine. Due to the adoption of the processing technic, all grinding and polishing processes in the machining process of the sapphire substrate slice special for the patterned substrate can be performed on a two-sided grinding-polishing machine, and the processing accuracy of a product is increased.