75 results about "Metal boride" patented technology

This invention discloses a coating for sand casting of aluminum-lithium alloys and its preparation method. The coating comprises a surface layer in contact with the sand mold and a top layer in contact with the melt. The surface layer material is an alcohol-based zirconium oxide coating containing graphene, and the top layer coating is an alcohol-based boride coating containing titanium diboride and zirconium diboride. This invention effectively improves the coating density and heat transfer rate by doping graphene with metal boride nanoparticles. Using graphene, ceramic materials, and metal borides as aggregates and dopants effectively suppresses the burn-off of light elements such as Li, reducing subcutaneous pinholes and porosity defects in the casting. Using zirconium oxide powder as aggregate increases nucleation sites, effectively improving the quality of non-ferrous metal castings.

The invention discloses a monatomic doped M-B-C material and a preparation method and application thereof.The preparation method comprises the following steps that metal boride, hydrogen peroxide and graphene are mixed according to a certain proportion, and the obtained mixture serves as a monatomic doped M-B-C precursor; and placing the precursor in a tubular furnace, carrying out annealing reduction in an Ar-H2 atmosphere, heating to a set temperature, carrying out heat preservation, and finally cooling to obtain the monatomic doped M-B-C material. The monatomic doped M-B-C material has a layered structure, and metal atoms are highly dispersed, so that the monatomic doped M-B-C material shows excellent battery performance.

Disclosed herein are compounds, methods, and tools which comprise tungsten borides and mixed transition metal borides.

The invention belongs to the technical field of electronic paste, and particularly relates to resistance paste and a preparation method thereof. The resistance paste comprises an inorganic component and an organic component; the inorganic component comprises a conductive material and a glass material; the organic component comprises organic silver and resin; the conductive material comprises at least one of ruthenium-containing oxide, copper, nickel, copper-nickel alloy, palladium, platinum and metal boride. The organic silver is introduced into the resistance paste, so that the dispersion effect of the organic silver in the resistance paste is improved; in the sintering process of the resistance paste, organic silver is decomposed in situ to generate nano-silver, and the nano-silver can be attached to a conductive material to cover a core and grow to form a co-melt, so that the sintering activity of the conductive material is improved, and the sintering temperature sensitivity and shape retention of the resistance paste are effectively improved; and the resistor paste can meet the application requirements of resistors with small sizes and wide resistance value intervals.

The invention provides a metal boride nano particle for diagnosing and treating cancer, the metal boride nano particle has dual functions of diagnosing and treating tumor, the surface of the metal boride nano particle is modified with an antibody and a biological probe or is coated with a biological cell membrane, and the antibody or the probe has specificity of being combined with a receiver of a specific tumor cell.

The invention belongs to the technical field of photocatalyst composite materials, and particularly relates to a covalent bond bonded MoBTx / CdS composite material and a preparation method and application thereof.According to the MoBTx / CdS composite material, rod-shaped CdS and two-dimensional layered MoBTx are compounded through an in-situ growth strategy, covalent bonding between Mo atoms and S atoms is achieved at an interface, and the MoBTx / CdS composite material is obtained. Therefore, a strong-coupling heterogeneous interface is constructed. The covalent bond mediated composite structure can significantly enhance visible light absorption and optimize carrier separation and transmission kinetics, thereby improving the activity and stability of hydrogen production by photocatalytic decomposition of water. The material is excellent in environmental adaptability and can keep good hydrogen evolution performance under complex water quality and low-temperature conditions. The research provides a new interface engineering idea for designing an efficient and stable semiconductor-metal boride photocatalyst.

A cBN-based ultra-high pressure sintered body contains cBN particles and a binder phase. The binder phase contains at least one of a nitride or oxide of Al or a nitride, carbide, or carbonitride of Ti, and a metal boride having an average particle diameter of 20 to 300 nm is dispersed in an amount of 0.1 to 5.0 vol % in the binder phase. The metal boride includes a metal boride (B) containing at least one of Nb, Ta, Cr, Mo, and W as a metal component and containing no Ti and a metal boride (A) containing only Ti as a metal component. In a case where a ratio (vol %) of the metal boride (A) in the metal boride is represented by Va and a ratio (vol %) of the metal boride (B) is represented by Vb, a ratio of Vb / Va is 0.1 to 1.0.

The application provides a preparation method of high-purity superfine diboride powder and relates to the field of metal borides. The preparation method comprises the following steps: introducing BCl3 and H2 into a vacuum environment to obtain a mixed gas; mixing the mixed gas and metal wires and performing electric explosion treatment to obtain a reaction powder; and performing passivation ball milling treatment on the reaction powder in a mixed atmosphere of argon and oxygen to obtain the high-purity superfine diboride powder; and the metal wires comprise at least one of titanium wires, magnesium wires and aluminum wires. The method does not introduce by-products and impurities in the whole process, the obtained diboride powder is small in particle size, uniform in distribution and free of agglomeration, the preparation method is short in process and high in efficiency, and the method has a good industrialization prospect.

The invention discloses a preparation method of two-dimensional boron hydride alkene, and belongs to the technical field of preparation of two-dimensional nano materials. The method comprises the following steps: dispersing metal boride and purified hydrogen type ion exchange resin in an organic solvent with a DN value of less than 19, and carrying out a sealed reaction under the protection of inert gas; according to the method, through the synergistic effect of the low-DN-value solvent and the purified resin, the ion exchange efficiency is effectively improved, competitive adsorption is avoided, the yield of the two-dimensional boron hydride is made to exceed 70%, and the method is mild in reaction condition, easy and convenient to operate, environmentally friendly and suitable for large-scale preparation.

The present invention provides a borate and metal boride composite coated positive electrode material and a preparation method thereof, belonging to the technical field of sodium ion batteries. The present invention directly mixes positive electrode particles, metal boride and non-metallic boron source to obtain a coated mixture and then calcines it in stages. The first stage of calcination: boric acid or boron oxide has a low melting point and has good fluidity after melting at low temperature, so that the metal boride can be evenly distributed on the surface of the positive electrode particles; the second stage of calcination: high temperature promotes the reaction wettability of the metal boride and the surface of the layered oxide positive electrode material, ensuring the close bonding and complete coverage of the coating layer, and slowing down the side reaction between the positive electrode material and the electrolyte. The preparation process of the present invention is simple, does not use dangerous boron hydride compounds, is simple and safe to operate, is low in cost, and is easy to mass produce. The sodium ion battery obtained by using the positive electrode material prepared by the present invention has a high specific capacity and excellent cycle performance.

The application provides a method for preparing boronene by vacuum thermal decomposition, which comprises the following steps: ball milling a metal boride block in an inert atmosphere to obtain a metal boride powder; tabletting the metal boride powder to obtain a metal boride flake; vacuum thermal decomposition of the metal boride flake in a vacuum reaction environment; solid-liquid separation of the obtained product after mixing with water to obtain a solid; washing the solid with an acidic solution until neutralization; and freeze-drying to obtain boronene; wherein the metal boride comprises MgB2 and / or AlB2. The method has a low vacuum thermal decomposition temperature, low preparation cost and high production efficiency. The preparation method occurs in a closed vacuum environment, and there is no secondary oxidation problem of raw materials and products, no solid impurity pollution, and the method is green and safe. The prepared boronene has high purity, high yield and uniform size.

The invention belongs to the technical field of water electrolysis hydrogen production, and relates to a bimetal boride water splitting electro-catalysis material and a preparation method and application thereof.The preparation method comprises the following steps that S1, metal boride, metal chloride and magnesium powder are weighed according to the molar ratio of 2: 1: (1-5), ground and mixed, and the mixture is sealed in a quartz tube in a vacuum mode; s2, calcining the quartz tube at the temperature of 800 DEG C to 1000 DEG C; and S3, grinding the solid sample, dispersing into a sulfuric acid solution, soaking to remove impurities, centrifugally cleaning with water and ethanol, and drying to obtain the bimetallic boride material. According to the invention, the metal diboride is used as a basis, the metal chloride is added as a second metal source, the magnesium powder is added as an auxiliary, the heat released by the magnesiothermic reduction reaction is used for assisting solid-phase synthesis, the reaction temperature is low, and the synthesis steps are simple; the prepared bimetallic boride material has extremely high purity and crystallinity; and has Nigt; cogt; the regular water electrolysis hydrogen production performance of Fe is beneficial to research on the structure-function relationship between an electronic structure and catalytic performance.

Short-arc discharge lamp, comprising a pair of electrodes opposite each other in a light-emitting tube, a scale-like structure formed on an outer surface of at least one of the electrodes of the pair of electrodes, and a coating film that covers the outer surface along with the scale-like structure formed on the outer surface, wherein the scale-like structure has a plurality of plate-like projections that project beyond the outer surface in a direction inclined with respect to a direction perpendicular to the outer surface, wherein each plate-like projection has an outer surface facing away from the rest of the electrode, the angle of which formed with the outer surface being an obtuse angle, and a back surface, the angle of which formed with the outer surface being an acute angle, wherein the coating film comprises at least one compound selected from the group consisting of metal oxides, metal carbides, metal borides, metal silicides and metal nitrides and mixtures thereof, and Part of the coating film lies in a space between the back surface and the outer surface.

The embodiment of the invention provides a nano-porous monatomic catalyst for ammonia synthesis, a preparation method of the nano-porous monatomic catalyst and an electrode, and the nano-porous monatomic catalyst for ammonia synthesis comprises a transition metal boride carrier and a platinum group metal monatomic loaded on the transition metal boride carrier, the transition metal boride carrier is internally provided with three-dimensionally communicated nano-porous channels. The technical problems of poor selectivity, poor stability and limited mass transfer when an electro-catalysis nitrate reduction catalyst is used for synthesizing ammonia are solved. According to the invention, strong interaction between the transition metal boride and an anchored platinum group metal monatomic metal active center is utilized, hydrogen evolution side reaction is inhibited, and the selectivity of a target product is improved; and the transition metal boride has high melting point, strong covalent bond and excellent chemical inertness, so that a stable anchoring site is provided for platinum group metal single atoms, the active metal is prevented from being agglomerated or leached, and the long-term stable operation of the catalyst is ensured.

The invention belongs to the technical field of superconducting materials, and discloses a high-performance MgB2 superconducting wire and a preparation method thereof. The method comprises the following steps: uniformly mixing nano Mg alloy powder and B powder in an inert gas atmosphere according to the atomic number ratio of Mg to B being 1: 2; then compounding the high-purity Nb rod, the CuNi alloy pipe and the anaerobic Cu pipe into an Nb / CuNi / Cu alloy rod, processing a deep hole, and filling mixed powder to prepare a single core wire; and then assembling the single-core wire into a Monel alloy tube, processing the single-core wire into a multi-core composite wire, and performing high-temperature phase forming heat treatment to obtain the high-performance MgB2 superconducting wire. Metal boride can be generated by metal elements in the adopted nano Mg alloy powder, CuNi alloy has constraining force and barrier effects, and finally MgB2 grains of the wire are refined, the connectivity between the grains is improved, and the current-carrying performance is improved.

A workpiece includes a substrate and a hard material layer disposed over the substrate. The hard material layer comprises a metal boride layer having a composition ((TixAl1-x)1-ySiy)B2+z with 0.3 ≤ x ≤ 0.6, 0 < y ≤ 0.2, and -0.3 ≤ z ≤ 0.3.

The application discloses a method for improving high-temperature chemical stability and mechanical compatibility of a transition metal silicon boride coating, which comprises the following steps: obtaining a boride layer on the surface of a transition metal by chemical vapor deposition; obtaining a boron-doped transition metal silicide layer by chemical vapor deposition; and finally obtaining a boron-doped silicon dioxide layer through pre-oxidation treatment, thereby obtaining a composite structure of three-layer boron-doped transition metal silicide layer, two-layer transition metal boride layer and a molybdenum matrix. The application introduces a dense and continuous boride layer by two-step chemical vapor deposition technology, and the boride layer is matched with a subsequent ordered multilayer structure formed by silicon-boron co-deposition and pre-oxidation to improve mechanical compatibility. In addition, the application provides abundant boron sources and a silicide layer to form a transition metal silicon boride layer with good element diffusion resistance, so as to improve the chemical stability of the coating.

The present application is a sliding contact material for a motor brush, the sliding contact material having dispersed in a matrix composed of pure Ag a metal boride at a content of 0.3% by volume or more and 12% by volume or less. The metal boride as the dispersed particles is specifically preferably a boride of Hf, Ta, Nb, Ti, Zr, Mo, Cr, or V. Furthermore, the matrix composed of pure Ag can contain inevitable impurity elements having a solid solubility limit with respect to Ag, but the content thereof is preferably 0.5% by mass or less. The sliding contact material according to the present application is suitable as a constituent material of a motor brush of a small DC motor. The present application is a sliding contact material that is excellent in mechanical wear resistance and spark erosion resistance and is cost-replaceable with respect to an Ag-Pd-based alloy.

The application provides a preparation method of high-purity superfine diboride powder and relates to the field of metal borides. The preparation method comprises the following steps: introducing BCl3 and H2 into a vacuum environment to obtain a mixed gas; mixing the mixed gas and metal wires and performing electric explosion treatment to obtain a reaction powder; and performing passivation ball milling treatment on the reaction powder in a mixed atmosphere of argon and oxygen to obtain the high-purity superfine diboride powder; and the metal wires comprise at least one of titanium wires, magnesium wires and aluminum wires. The method does not introduce by-products and impurities in the whole process, the obtained diboride powder is small in particle size, uniform in distribution and free of agglomeration, the preparation method is short in process and high in efficiency, and the method has a good industrialization prospect.

The invention discloses a TiB2-based ultrahigh-temperature high-toughness ceramic and a screening method and a preparation method thereof, and relates to the technical field of ultrahigh-temperature ceramics, the TiB2-based ultrahigh-temperature high-toughness ceramic material is composed of Ti, B and one or more of Nb, Hf, Ta, Mo, W, Zr, V, Sc and Al, according to the screening method, the elasticity, mechanics and toughness of the TiB2-based ceramic doped with different types of alloy elements are calculated and obtained by adopting a high-throughput first principle, and mechanical properties changing along with components are established through component-property fitting based on CALPHAD; according to the preparation method, metal boride ceramic powder is subjected to high-energy ball milling and powder mixing and then is subjected to electric arc melting to prepare a ceramic block. Based on the screening and preparation method, the problems of high cost and long period caused by element screening in a traditional experiment can be reduced, and meanwhile, by adjusting the smelting temperature and the smelting time in the smelting process, the preparation of the single-phase TiB2-based ceramic block with uniform element distribution and high hardness and toughness can be realized.

The application belongs to the technical field of inorganic nonmetallic hard material, and discloses a method for promoting densification sintering of transition metal boride and improving hardness of the transition metal boride by adding trace silicon dioxide. The application synthesizes B2O3-SiO2 glass phase by adding a small amount of silicon dioxide in the process of preparing the transition metal boride, effectively refines the crystal grains, and prepares a submicron transition metal boride powder with good sintering performance, so that the transition metal boride ceramic with high density and high hardness can be prepared; the transition metal boride ceramic after sintering has a density of about 98%, and still has high hardness under high load.

This method for producing a metal boride comprises preparing: a first unheated raw material containing a metal source that is a metal, a metal oxide, a metal-containing carbonate or a metal-containing hydroxide, boron oxide or boric acid, silicon dioxide, and metallic sodium; or a second unheated raw material containing the metal source, boron oxide or boric acid, and silicon dioxide. Further, this method for producing a metal boride further comprises: heating the first unheated raw material if the first unheated raw material has been prepared; and heating the second unheated raw material in Na vapor if the second unheated raw material has been prepared.

The invention belongs to the technical field of water electrolysis, and discloses an oxygen evolution catalyst, a preparation method thereof, an electrode and a water electrolysis device. The oxygen evolution catalyst comprises a metal boride and a noble metal oxide, the noble metal oxide is loaded on the metal boride, and the specific surface area of the metal boride is 79m < 2 > / g-90m < 2 > / g. The oxygen evolution catalyst provided by the invention has excellent catalytic activity and stability.

The present invention is a sliding contact material for a motor brush which is formed by dispersing a metal boride in a matrix made of pure Ag, wherein the content of the metal boride is 0.3 vol% to 12 vol%, inclusive. Specifically, a boride of Hf, Ta, Nb, Ti, Zr, Mo, Cr, and V is preferable for the metal boride that becomes dispersed particles. The matrix made of pure Ag may contain unavoidable impurity elements having a solid solubility limit with respect to Ag, but the content thereof is preferably 0.5 mass% or less. The sliding contact material according to the present invention is suitable as a constituent material for the motor brush of a small-sized DC motor. The sliding contact material of the present invention is excellent in mechanical abrasion resistance and spark wear resistance, and can be replaced with an Ag-Pd based alloy in terms of cost.

The invention relates to a method for producing a metal borohydride from a metal boron oxide. A process for preparing a metal borohydride Me (BH4) n from a metal boron oxide Me (BO2) n, where Me is a metal or a molecule that exhibits metalloid behavior and can be used as a metal, and n is an integer that can correlate with the valence of the metal, where in a first fluidized bed step, the metal boron oxide is provided in a first fluidized bed. In a subsequent second fluidized bed step, the metal boride particles are provided in a second fluidized bed which is fluidized using hydrogen H2 gas in such an environment in which hydrogen chemically reacts with the metal boride particles to provide the metal borohydride.

The present application relates to a gadolinium-containing high specific gravity tungsten alloy shielding material and a preparation method and application thereof, and the preparation raw material of the gadolinium-containing high specific gravity tungsten alloy shielding material comprises a gadolinium source; the gadolinium source comprises gadolinium oxide and / or surface-modified gadolinium oxide. As a neutron absorption material additive, the gadolinium oxide has a higher boron equivalent than metal boride, that is, the required addition amount of the gadolinium oxide in the shielding material for achieving the same neutron shielding effect is significantly lower than that of the metal boride, and the adverse effect on the mechanical properties of the shielding material can be significantly reduced; from another angle, the allowed addition amount of the gadolinium oxide is significantly higher than that of the metal boride when having the same mechanical properties. Therefore, the shielding material can achieve the combined shielding effect of gamma rays and neutrons, and the microstructure of the shielding material is similar to that of the conventional high specific gravity tungsten alloy material, no new phase is generated, and the shielding material has good mechanical properties, the ultimate tensile strength at room temperature is greater than or equal to 950 MPa, and the elongation after fracture at room temperature is greater than or equal to 15%.

A method of forming a three-dimensional structure comprises forming a layer of a precursor material on a substrate using an additive manufacturing process, the precursor material comprising one or more of a metal oxide, a metal sub-oxide, a metal carbide, a metal nitride, a metal boride, a metal hydride, a metal silicide, a metal salt, and a pre-ceramic polymer; forming one or more additional layers of the precursor material on the layer of the precursor material; and exposing the layers of precursor material to an energy source to reduce the precursor material to form a three-dimensional structure comprising an elemental metal, a metal alloy, a ceramic, or a composite.

This invention relates to the field of surface coating materials technology, and in particular to a wear-resistant transition metal boride coating and its application. The wear-resistant transition metal boride coating is prepared by the following steps: (1) placing a clean and dry substrate on a magnetron sputtering deposition site, placing an HfB2 target on an RF target site, and a TiB2 target on a DC target site; then evacuating and heating the equipment chamber, and then introducing Ar gas as the working gas; (2) controlling the atomic ratio of Hf to Ti by adjusting the sputtering power ratio of HfB2 and TiB2 targets to form a (Ti) composite with adjustable composition. 1‑x ,Hf x The B2 coating was deposited at a controlled temperature of 300~600 ℃. The (Ti) coating developed in this invention... 1‑x ,Hf x The B2 coating has advantages such as high hardness, excellent friction performance and wear resistance, and has broad application prospects. It is especially suitable for use as a protective coating for cutting tools.

The invention relates to a surface modification method for in-situ transition metal boride-coated semiconductor silicon carbide, boron carbide and silicon carbide-boron carbide composite granules ( 2 ) and to composite material s having a segregated network structure and thermoelectric properties. The production method for composite materials with thermoelectric properties includes mechanical alloying, grinding and sieving of the coating material mixture ( 1 ), preparing a surface activating liquid phase solution and dispersing the said solution on the surface of the granules, coating of the coating material mixture ( 1 ) on the surface of the composite granules ( 2 ) and sintering of the material. The final product has a conductive segregated network structure.

Aspects and embodiments disclosed herein include a bulk acoustic wave (BAW) device comprising a first electrode and a second electrode, at least one of the first electrode and the second electrode including at least one of a binary intermetallic compound, a metal nitride, a metal carbide, a metal carbonitride, a metal boride, a MXene, a MAX phase, or a MAB phase, and a piezoelectric material layer positioned between the first electrode and the second electrode.