56 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.

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 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.

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 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 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 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.

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.

The application belongs to the technical field of metal boride materials, and specifically provides high-purity titanium diboride powder and a preparation method thereof, characterized by comprising the following steps: S01. taking TiH2 coarse powder, crushing to obtain TiH2 fine powder; S02. taking NaBH4 coarse powder, crushing to obtain NaBH4 fine powder; S03. taking the TiH2 fine powder and the NaBH4 fine powder, mixing and ball milling, then briquetting, placing, then passing nitrogen, and sintering to obtain sintered material; the sintering treatment is to place the compacted material in an atmosphere furnace with a sodium vapor condensation reaction tank to perform stage heating and heat preservation operation; S04. taking the sintered material, performing airflow crushing, sieving and magnetic separation to obtain the titanium diboride powder. The preparation method can reduce production energy consumption and improve the purity of the prepared titanium diboride powder.

This invention relates to the field of metal boride preparation, and discloses a method for efficiently preparing metal borides using a modified microwave oven apparatus. The method includes the following steps: mixing boron-containing raw materials with metal-containing raw materials to obtain a precursor mixture; placing the precursor mixture in a reaction vessel; placing the reaction vessel in a household microwave oven and starting the microwave oven for a microwave reaction of 3-30 minutes; and post-processing the reaction product to obtain the metal boride. This invention provides a method for efficiently preparing metal borides using a modified microwave oven apparatus. By utilizing the rapid heating characteristic of graphite powder absorbing microwaves, the reaction can be completed within 3-30 minutes, significantly improving the preparation efficiency compared to traditional high-temperature synthesis methods. Furthermore, by employing a vacuum microwave reaction combined with NaCl / KCl flux, only simple washing is required after the reaction to obtain a high-purity product, eliminating the need for acid etching and multiple centrifugal washing processes, thus significantly simplifying the process.

The application discloses application of two-dimensional transition metal boride in a saturable absorber and a laser, and the two-dimensional transition metal boride is Mo 4 / 3 B 2‑x T z The application builds a fiber laser based on two-dimensional Mo 4 / 3 B 2‑x T z , optimizes Mo 4 / 3 B 2‑ x T z saturable absorber and a cavity structure of the fiber laser, and after adjusting pump power and a polarization state in the cavity, self-starting of ultrashort and high-repetition-rate mode-locked pulses is realized.

The application 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: firstly, uniformly mixing nano-Mg alloy powder and B powder in an inert gas atmosphere according to an atomic number ratio of Mg:B=1:2; secondly, compounding a high-purity Nb rod, a CuNi alloy tube and an oxygen-free Cu tube into an Nb / CuNi / Cu alloy rod, processing deep holes, and then making a single-core wire by loading the mixed powder; thirdly, assembling the single-core wire into a Monel alloy tube, processing into a multi-core composite wire, and obtaining the high-performance MgB2 superconducting wire through high-temperature phase formation heat treatment. The metal elements in the nano-Mg alloy powder can generate metal borides, and the CuNi alloy has both constraint and barrier effects, so that the MgB2 grains of the wire are refined, the connectivity between the grains is improved, and the current-carrying performance is improved.

This radio wave-absorbing thermally-conductive composition comprises a silicone resin (A), a radio wave-absorbing material (B), and a thermally-conductive substance (C). The radio wave-absorbing material (B) is a helical structure having a metal plated layer, and is contained in an amount of 0.1-50 parts by mass with respect to 100 parts by mass of the silicone resin (A). The thermally-conductive substance (C) is preferably inorganic particles of a metal oxide, a metal nitride, a metal carbide, a metal boride, an elemental metal, or the like, is contained in an amount of 50-3000 parts by mass with respect to 100 parts by mass of the silicone resin (A), and preferably has a thermal conductivity rate of 0.8 W / mK or more. As a result, provided are: a radio wave-absorbing thermally-conductive composition that achieves both thermal conductivity and radio wave-absorbing ability for terahertz waves; and a sheet of the same.

The present application relates to a kind of anode catalysts for alkaline system direct urea fuel cell, it is with nickel salt, H3BO3 and PVP dispersed in water heating reaction preparation precursor, then under inert atmosphere calcination obtained, by nitrogen-containing carbon material wrapped elemental nickel / nickel oxide / nickel boride nanocrystalline composite material.The present application introduces non-metallic boron and PVP carbon material, after calcination, active substance nickel / nickel oxide / nickel boride replaces traditional noble metal, by forming metal boride and oxide to adjust catalyst electronic structure, improve the catalytic activity and electrode conductivity of catalyst, with it as the anode catalyst for alkaline system direct urea fuel cell, with excellent electrochemical reaction activity.

The radio wave absorbing thermally conductive composition includes a silicone resin (A), a radio wave absorbing material (B), and a thermally conductive material (C), where the radio wave absorbing material (B) has a helical structure with a metal plating layer, and is contained in an amount of 0.1 to 50 parts by mass per 100 parts by mass of the silicone resin (A). The thermally conductive material (C) is preferably inorganic particles such as metal oxides, metal nitrides, metal carbides, metal borides, and elemental metals, and is contained in an amount of 50 to 3,000 parts by mass per 100 parts by mass of the silicone resin (A), and preferably has a thermal conductivity of 0.8 W / mK or higher. This provides a radio wave absorbing thermally conductive composition and a sheet thereof that combine radio wave absorption and thermal conductivity for terahertz waves.