22 results about "Diboride" patented technology

The present application relates to a protective coating for ultra-high-temperature ceramics based on diborides and a method for producing this coating. The coating is applied as an aluminum oxide mixture, i.e., as a mixture of elemental aluminum and aluminum oxide, and can be applied as a slurry directly onto the diboride-based ceramic materials, preferably zirconium diboride, hafnium diboride, or mixtures thereof, for ultra-high-temperature applications.

The invention relates to the technical field of high-entropy ceramic powder, in particular to diboride high-entropy ceramic powder and a preparation method thereof.The preparation method comprises the following steps that five transition metal oxides, boron powder and fused salt serve as raw materials, are evenly mixed through a mixer and then are dried at the temperature of 60-200 DEG C, and a mixture is obtained; then, the mixture is put into a corundum crucible, and heat preservation is conducted for 1-20 h at the temperature interval of 700-1600 DEG C and under the protective atmosphere; and after the reaction is completed, cooling, washing, carrying out suction filtration, and drying at 60-200 DEG C to finally prepare the diboride high-entropy ceramic powder. The method has the advantages of low synthesis temperature, small product particle size, uniform element distribution, environment friendliness and the like, and the prepared diboride high-entropy ceramic powder shows excellent electromagnetic wave absorption performance.

The invention discloses an environment-friendly magnesia carbon brick and a preparation method thereof, and relates to the technical field of magnesia carbon brick production, and the environment-friendly magnesia carbon brick comprises the following preparation raw materials: a magnesia material, a carbon source, graphite, a fiber body, steel particles, coal ash, quartz powder, clay, vanadium diboride, silicon oxide, aluminum oxide, phenolic resin and an antioxidant; the refractory material is prepared from the following components in parts by weight: 40-80 parts of magnesia material, 8-15 parts of carbon source, 8-15 parts of graphite, 4-12 parts of fiber body, 2-6 parts of steel particle, 1-10 parts of coal ash, 1-10 parts of quartz powder, 1-8 parts of clay, 1-6 parts of vanadium diboride, 1-6 parts of silicon oxide, 1-5 parts of aluminum oxide, 1-10 parts of phenolic resin and 1-8 parts of antioxidant. According to the environment-friendly magnesia carbon brick and the preparation method thereof, the magnesia waste separated from the waste magnesia carbon brick can be used as the main raw material, the recycling of the magnesia carbon refractory raw material is facilitated, the solid waste resource recycling rate is high, the environment-friendly magnesia carbon brick has the characteristics of energy conservation and environmental protection, the whole processing technology is simple, and the cost is relatively low.

The invention relates to the technical field of metal surface engineering, and particularly provides a composite material, a preparation method and a spraying method. The composite material comprises a nickel-based alloy matrix and a high-entropy diboride reinforcement phase dispersed in the nickel-based alloy matrix, and the high-entropy diboride reinforcement phase is provided with metal cation vacancies and lattice distortion structures. The preparation method of the composite material is used for preparing the composite material. According to the composite material, the preparation method and the spraying method, the composite coating is not prone to failure due to falling of a certain material when the composite material is used for a long time in a boiler.

The invention discloses a method for preparing high-entropy diboride ceramic through ultrahigh pressure-strong electric field coupling sintering. The preparation method of the high-entropy diboride ceramic comprises the following steps: mixing at least five kinds of transition metal powder with boron powder to obtain mixed powder, and carrying out vacuum sintering on the mixed powder at 1200-2000 DEG C to obtain high-entropy diboride powder; and the high-entropy diboride powder is pre-pressed into a green body, the green body is gradually pressurized to 5-20 GPa under the vacuum condition, pressure maintaining is conducted, an electric field of 300-1000 V / cm is applied while pressure maintaining is conducted, and cooling is conducted after 1-2 min. The high-entropy diboride ceramic prepared by the preparation method disclosed by the invention has higher density, and the hardness is up to 30 GPa or above. Compared with a traditional SPS sintering method, the sintering temperature is reduced by 300-500 DEG C, the whole sintering process can be completed within 5 min, and the sintering time is shortened by about 90% compared with the traditional method.

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.

This invention provides a corrosion-resistant, low-friction protective coating, its preparation method, and its application, relating to the field of medical implant protective materials. The invention involves micro-arc oxidation of a titanium alloy substrate to form a micro-arc oxidation layer on the substrate surface. The electrolyte used in the micro-arc oxidation comprises the following components at concentrations: sodium phosphate 5-30 g / L, sodium silicate 5-30 g / L, sodium hydroxide 1-5 g / L, with the balance being water. Using a transition metal diboride as the target material, magnetron sputtering is performed on the surface of the micro-arc oxidation layer to obtain the corrosion-resistant, low-friction protective coating. The protective coating prepared by this invention exhibits excellent corrosion resistance in simulated body fluid environments, effectively adsorbing proteins in the body fluid and utilizing the lubricating function of proteins, thereby reducing the coefficient of friction between the coating and the friction pair, achieving a low wear rate. Furthermore, it possesses good biocompatibility, facilitating cell adsorption and growth.

The invention belongs to the technical field of metal material preparation, and particularly relates to a laser cladding method for preparing a copper-based composite material coating on a copper alloy substrate. Comprising the following steps that chromium diboride and graphite serve as strengthening phases and are mixed with Cu powder, and Cu-based composite powder is obtained in a powder mixing and ball milling mode in sequence; the Cu-based composite powder comprises the following components in percentage by volume: 0vol.%-1vol.% of graphite, 1vol.%-5vol.% of chromium diboride and the balance of Cu, and the total amount is 100%; and the Cu-based composite powder is cladded on the surface of the copper alloy in a laser cladding mode, and the copper-based composite material coating is obtained. According to the method, the copper-coated graphite powder, the chromium diboride powder and the Cu powder serve as raw materials, the copper-based composite material coating is successfully prepared on the copper alloy substrate through the laser cladding technology, the performance of the surface of the copper alloy can be improved, and a more economical scheme can be provided for repairing a damaged mobile electric contact part.

The application provides a high-pressure corrosion-resistant hard alloy material and a preparation method and application thereof, and belongs to the technical field of alloy materials. The application improves the strength, toughness and corrosion resistance of the material by constructing titanium boride, silicon carbide and chromium diboride hard phases, introduces a multiphase composite binder composed of aluminum-iron alloy, high-entropy alloy and cerium hexaboride to realize high-temperature dense coating, and adopts asymmetric gradient paving and sintering process to construct a gradient structure with high surface hardness, high toughness in the core and stress concentration reduction in the transition layer. Meanwhile, the surface hardness and sealing property are strengthened by powder embedding and calcination, and the wear resistance, corrosion resistance and impact resistance of the material are comprehensively improved.

The invention discloses a wide-temperature-range anti-attrition wear-resistant tungsten diboride-based composite film as well as a preparation method and application thereof. The wide-temperature-range anti-attrition and wear-resistant tungsten diboride-based composite film comprises a chromium transition layer, a chromium / tungsten diboride layer and a tungsten diboride / carbon / nitrogen doped layer which are sequentially stacked on the surface of a base body in the thickness direction of the wide-temperature-range anti-attrition and wear-resistant tungsten diboride-based composite film, the chromium transition layer is adjacent to the surface of the base body, and the tungsten diboride / carbon / nitrogen doped layer is arranged at the top end of the tungsten diboride-based composite film. The preparation method comprises the following steps: sequentially depositing the chromium transition layer, the chromium / tungsten diboride layer and the tungsten diboride / carbon / nitrogen doped layer on the surface of the substrate by adopting a magnetron sputtering technology to prepare the wide-temperature-range anti-attrition wear-resistant tungsten diboride-based composite film. The tungsten diboride-based composite film still keeps a low friction coefficient and a low wear rate under a high-temperature condition, and synchronous improvement of structural toughness and high-temperature lubricating performance is realized.

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 discloses a wear-resistant and corrosion-resistant nanometer multilayer ceramic-based film and a preparation method and application thereof. The wear-resistant and corrosion-resistant nanometer multilayer ceramic-based film comprises a chromium transition layer and a nanometer multilayer composite structure which are sequentially stacked in the thickness direction of the film. The nanometer multilayer composite structure comprises a plurality of period units which are stacked and arranged. Each period unit comprises a tungsten diboride / carbon nanometer layer and a carbon nanometer layer. The tungsten diboride / carbon nanometer layer in the period unit adjacent to the chromium transition layer is arranged adjacent to the chromium transition layer. The top end of the nanometer multilayer composite structure is the carbon nanometer layer. The wear-resistant and corrosion-resistant nanometer multilayer ceramic-based film has high bonding force, low atmospheric environment friction coefficient, good antifriction and wear resistance, good seawater corrosion resistance, can meet the lubrication stability and long service life requirements of a ship transmission system component, and makes up the shortcomings of poor salt mist resistance of a carbon-based film.

The application relates to a high-oxidation-resistance high-entropy metal diboride composite phase material, and belongs to the technical field of ultrahigh-temperature ceramic materials. The high-oxidation-resistance high-entropy metal diboride composite phase material has a chemical formula of (Hf 0.2 Zr 0.2 Ta 0.2 Nb 0.2 Tm 0.2 )B2 / TmB4. The (Hf 0.2 Zr 0.2 Ta 0.2 Nb 0.2 Tm 0.2 )B2 / TmB4 powder and block prepared by the application contain (Hf 0.2 Zr 0.2 Ta 0.2 Nb 0.2 Tm 0.2 )B2 and TmB4 two phase structures. The obtained material is subjected to static oxidation test, the oxides generated by Tm and other metal elements form a continuous oxidation layer, fill the gaps, and a high-density oxidation layer is obtained, which can effectively prevent oxygen from entering and reduce the oxidation rate. Therefore, the high-entropy metal diboride composite phase material prepared by the application has excellent oxidation resistance.

Disclosed is a ceramic sintered body which can give consideration to both toughness and wear resistance. This ceramic sintered body contains a first compound and a second compound. The first compound is silicon carbide, and the second compound is a diboride of a Group 4 element. The proportion of the second compound in the ceramic sintered body is 50% by mass to 70% by mass. When a 300 [mu] m * 300 [mu] m region of the polished surface of the ceramic sintered body is divided into 400 sections of 15 [mu] m * 15 [mu] m, and the area ratio of the first compound is determined for each of the sections, the coefficient of variation CV of the area ratio of the first compound is greater than 0.14 and less than 0.23.

The present application refers to a protective coating for diboride based Ultra-High Temperature Ceramics and a method for preparing said coating. The coating is applied as alumina mixture, i.e. a mixture of elemental aluminum and aluminum oxide, and may be applied as a slurry directly on the diboride based ceramic materials, preferably zirconium diboride, hafnium diboride or mixtures thereof, for ultra-high temperature applications.

The invention belongs to the field of ultrahigh-temperature ceramic materials, and particularly relates to high-temperature-resistant antioxidant multi-component diboride ceramic powder as well as a preparation method and application thereof. The chemical formula of the high-temperature-resistant antioxidant multi-component diboride ceramic powder is (Ti < 0.2 > Zr < 0.2 > Hf < 0.2 > Nb < 0.2 > Sc < 0.2 >) B2 or (Zr < 0.2 > Hf < 0.2 > Nb < 0.2 > Sc < 0.2 > Lu < 0.2 >) B2 or (Zr < 0.2 > Hf < 0.2 > Nb < 0.2 > Sc < 0.2 > Yb < 0.2 >) B2. The prepared high-temperature-resistant antioxidant multi-component diboride powder is of a single-phase hexagonal structure, and the initial oxidation temperature is effectively increased through the synergistic effect of multiple elements. Experimental results show that the initial oxidation temperature of the high-temperature-resistant antioxidant multi-component diboride ceramic powder disclosed by the invention is 687.1-788.0 DEG C, which is higher than the initial oxidation temperature of typical single-component diboride powder. Therefore, the multi-component diboride ceramic powder prepared by the preparation method disclosed by the invention has excellent oxidation resistance.

The invention belongs to the technical field of alloy materials, and particularly discloses a tungsten alloy material for a pantograph and a preparation method thereof.The tungsten alloy material comprises, by weight, 68-75 parts of spherical tungsten powder, 8-15 parts of flaky copper powder, 4-8 parts of high-entropy alloy powder, 2-6 parts of modified carbon nanotubes, 1-4 parts of spherical carbon powder, 1-3 parts of chromium powder, 0.5-2 parts of manganese powder and 0.2-0.6 part of zinc stearate; the high-entropy alloy powder comprises titanium aluminum carbide, molybdenum powder, tungsten diboride powder, cobalt powder, hafnium powder and zirconium powder, and the mass ratio of the titanium aluminum carbide to the cobalt powder to the hafnium powder to the molybdenum powder to the tungsten diboride powder to the zirconium powder is (25-35): (20-30): (10-20): (10-20): (8-15): (2-6). The tungsten alloy material provided by the invention has excellent impact toughness and wear resistance, is very suitable for preparing the pantograph, and has a wide application prospect.

The invention relates to the technical field of ceramic materials, and discloses an antioxidant high-entropy diboride ceramic material (HfZrTaCr) B2 with double protective layers as well as a preparation method and application of the antioxidant high-entropy diboride ceramic material. In order to solve the problems that an existing five-element high-entropy diboride (HfZrTaTiNb) B2 high-temperature oxidation layer is porous and poor in continuity, a quaternary system (HfZrTaCr) B2 capable of forming a single-phase solid solution is screened out through a Pall electronegativity difference factor. The preparation method comprises the following steps: adopting HfB2, ZrB2, TaB2 and CrB2 as raw materials, carrying out ball milling with absolute ethyl alcohol, drying, and carrying out spark plasma sintering to prepare the high-density (gt; according to the invention, Cr is introduced to realize element synergism, so that a unique CrTaO4 (at) (Hf, Zr) O2 / B2O3 double-layer protection structure is formed in situ during high-temperature oxidation. Pores of a (Hf, Zr) O2 framework of the inner layer are filled with CrTaO4 to form a compact barrier, and the surface of the outer layer is covered with molten B2O3 to cooperatively block oxygen diffusion. A thermogravimetric analysis experiment at the temperature of 1400 DEG C verifies that the weight gain rate of the (HfZrTaCr) B2 material is only 2.573%, is far superior to that of a contrast group (HfZrTaV) B2 and an existing (HfZrTaTiNb) B2 system, and has excellent oxidation resistance. In addition, the alloy also has single-phase stability and high density, and is suitable for ultra-high-temperature extreme environments such as aerospace engine hot end parts and nuclear reactor jackets.

The application provides a molybdenum disulfide tungsten diboride nanocomposite multilayer film and a preparation method and application thereof, and the molybdenum disulfide / tungsten diboride nanocomposite multilayer film is prepared by using a non-equilibrium magnetron sputtering technology, and comprises a titanium transition layer, a titanium / molybdenum disulfide / tungsten diboride multilayer gradient transition layer and a molybdenum disulfide / tungsten diboride multilayer doped layer which are sequentially stacked in the thickness direction, so as to obtain the molybdenum disulfide / tungsten diboride nanocomposite multilayer film. The molybdenum disulfide / tungsten diboride nanocomposite multilayer film has good substrate bonding strength, hardness and high hardness / elasticity ratio, the main phase molybdenum disulfide grows along the (002) crystal plane parallel to the substrate, the moisture resistance and high-temperature oxidation resistance of the molybdenum disulfide are greatly improved, the molybdenum disulfide exhibits excellent friction and wear performance under atmospheric normal temperature and high-temperature environment, and can meet the requirements of stable lubricating performance and long service life of key components of aerospace and nuclear energy machinery under harsh environment.

A method for preparing an ablation-resistant high-entropy carbide-high-entropy diboride-silicon carbide (SiC) multiphase ceramic, including: (S1) mixing a transition metal oxide mixed powder, nano carbon black and a silicon hexaboride (SiB6) powder to obtain a precursor powder; and (S2) subjecting the precursor powder to pressureless sintering to obtain the high-entropy carbide-high-entropy diboride-SiC multiphase ceramic with a relative density of 96% or more.

This invention belongs to the field of ceramic preparation technology and provides a hot-pressed sintered multiphase boron carbide ceramic and its preparation method. The ceramic is based on boron carbide, with the addition of high-entropy diboride phases containing titanium, zirconium, hafnium, niobium, tungsten, and molybdenum, as well as a carbon phase. The ceramic may further contain corresponding high-entropy carbides. In the preparation process, multi-metal powder, amorphous boron powder, cobalt powder, and a process control agent are first subjected to high-energy ball milling and heat treatment under an inert atmosphere to obtain high-entropy diborides. Then, nanodiamond and cobalt powder are dispersed in ethanol, followed by ultrasonication, drying, and heat treatment to obtain the carbon phase. Subsequently, this carbon phase is mixed with boron carbide and granulated to obtain composite particle powder. Finally, it is hot-pressed and sintered in segments under vacuum conditions, with pressure pulses and pressure relief cycles applied during the high-temperature stage to obtain a dense multiphase ceramic, which can be applied to ceramic valves and ceramic cylinder valve plates.

This invention discloses a boron-doped vanadium diboride-based multiphase ceramic and its high-pressure, high-temperature preparation method. The ceramic consists of vanadium diboride and a boron-doped phase, with a boron doping amount of 15–50 vol%, preferably 50 vol%. The preparation method involves weighing VB2 powder and boron powder according to a specified ratio, ball-milling them together, pressing them into a blank, and then sintering under high pressure and high temperature (1000–2000℃) for 60–180 minutes. This invention, through the synergistic effect of controllable excess boron doping and high-pressure, high-temperature sintering, allows excess boron to form a nanoscale second phase in situ at the VB2 grain boundaries, inducing high-angle, multi-level crack deflection and promoting grain pull-out, thus significantly improving fracture toughness while maintaining high hardness. The obtained 50 vol% boron-doped multiphase ceramic exhibits a Vickers hardness of 21.27 ± 1.11 GPa and a fracture toughness of 9.41 ± 0.58 MPa·m. 1 / 2 This method achieves approximately 135% improvement in hardness and toughness compared to pure VB2 ceramics, realizing a synergistic enhancement of both. The process is simple, requires no additional sintering aids, and is suitable for preparing high-strength, high-toughness ultra-high temperature ceramic components.