377 results about "Boride" patented technology

The invention belongs to the technical field of ceramic materials, and discloses a high-entropy boride composite silicon carbide ceramic with a controllable microstructure and a preparation method and application thereof. The method comprises the following steps: carrying out ball milling, drying and sieving on Zr, Ta, Nb, W, Cr, B4C and SiB6 to obtain mixed powder; the preparation method comprises the following steps: putting a boron carbide powder into a graphite mold of which the inner surface is coated with a BN layer, heating to 1850-2050 DEG C, carrying out SPS sintering, and preparing the high-entropy boride composite silicon carbide ceramic with controllable microstructure under 20-35 MPa and a vacuum degree of 10 Pa, and the molecular formula of the high-entropy boride composite silicon carbide ceramic is (Zr0. 2Ta0. 2Nb0. 2W0. 2Cr0. 2) B2-SiC. The ceramic has good mechanical properties, the hardness at room temperature is 27-32 GPa, the fracture toughness is 4.5-6 MPa.m < 1 / 2 >, the bending strength is 450-600 MPa, and the ceramic can be applied to extreme environments or the field of radiation protection.

The invention relates to the technical field of anti-oxidation coatings, and particularly discloses a tantalum-tungsten alloy anti-oxidation coating and a preparation process thereof. The tantalum-tungsten alloy anti-oxidation coating comprises a transition layer, an inner layer, a barrier layer and an outer layer which are stacked in sequence, the transition layer is prepared from the following raw materials: an Ir target, a Ta target and an Re target are adopted for co-sputtering; the inner layer is prepared from the following raw materials in parts by mass: Si, MoSi2, Y and Ta-W alloy powder; the barrier layer is prepared from the following raw materials in parts by mass: Al2O3, Yb2O3 and 3YZrO2; the outer layer is prepared from the following raw materials in parts by mass: a compound: Yb2O3, La2O3, Gd2O3, SiC and B4C; and the multi-element borides comprise ZrB2 and HfB2. The tantalum-tungsten alloy anti-oxidation coating prepared in the invention has relatively good high-temperature oxidation resistance.

The invention discloses a modified lithium-rich manganese-based positive electrode material and a preparation method thereof, and relates to the technical field of lithium ion battery positive electrode materials. On the basis of a traditional metal modified lithium-rich manganese-based material, boride and MBene are further introduced for synergistic modification, so that the conductivity can be remarkably improved, the specific capacity and rate capability of the battery can be improved, the spinel structure of the lithium-rich manganese-based positive electrode material can be stabilized, the cycle performance of the material can be improved, and the service life of the battery can be prolonged.

The embodiment of the utility model provides a cathode assembly and an electron emission device. The cathode assembly comprises a cathode emitter, the first end of the cathode emitter is used for emitting electrons outwards, and the material of the cathode emitter at least comprises boride; the first heating part is used for irradiating the cathode emitter with laser so as to heat the cathode emitter; the second heating part is connected to the second end of the cathode emitter, and the second heating part heats the cathode emitter by generating joule heat; and the second heating component is used for heating the cathode emitter together with the first heating component after the first heating component heats the cathode emitter to a first temperature threshold value.

A magnetic memory device may include a pinned magnetic pattern and a free magnetic pattern which are stacked on a substrate, a tunnel barrier pattern between the pinned magnetic pattern and the free magnetic pattern, a capping pattern on the free magnetic pattern, and a non-magnetic pattern between the free magnetic pattern and the capping pattern. The free magnetic pattern may be between the tunnel barrier pattern and the capping pattern. The non-magnetic pattern may include a first non-magnetic metal and boron, and the capping pattern includes a second non-magnetic metal. A boride formation energy of the second non-magnetic metal may be higher than a boride formation energy of the first non-magnetic metal.

The invention provides a method for preparing a zirconium boride ceramic material through pressureless sintering, and belongs to the technical field of zirconium boride ceramics. The method comprises the steps of preparing zirconium boride composite powder, modifying silicon carbide nanowires and mixing and sintering. The method for modifying the silicon carbide nanowire comprises the steps of acid treatment and modification, the modification step comprises the following steps: adding aluminum isopropoxide into absolute ethyl alcohol, adding a nitric acid solution, stirring for 1.5-2.0 hours at the temperature of 60-63 DEG C, adding the acid-treated silicon carbide nanowire, carrying out ultrasonic dispersion and water bath evaporation, then drying, putting into a muffle furnace, and carrying out heat preservation for 2.0-2.2 hours at the temperature of 490-500 DEG C to obtain a modified silicon carbide nanowire; the ceramic material prepared by adopting the method disclosed by the invention is high in density, good in mechanical property and excellent in high-temperature oxidation resistance and stability in a complex environment.

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 relates to a process for preparing a phosphor copper rod by using a phosphonate-amide composite purifying agent as a quenching aid, and belongs to the technical field of non-ferrous metallurgy. Phosphorus pentoxide and sodium carbonate are mixed and decocted into fused salt, the fused salt is cooled and ground and then added into a corundum crucible together with scrap copper to be rapidly heated, compressed air is blown in, and slagging-off is conducted after heat preservation and standing; blowing mixed gas into the melt for reduction refining; adding calcium boride into the melt for refining; the refined copper liquid is subjected to continuous casting and continuous rolling; rapidly immersing the phosphorus copper rod subjected to continuous casting and rolling into a quenching aid solution, and carrying out quenching treatment; and the quenched phosphor copper rod is blow-dried and dried, and the high-conductivity phosphor copper rod is obtained. The high-purity phosphorus copper rod prepared by the method is excellent in key indexes of copper content, phosphorus content and conductivity, and meets the expected requirements of high purity and high conductivity.

The present invention discloses an alkali-resistant castable for a lime rotary kiln working lining, as well as its preparation method and application. The present invention comprises the following raw materials in parts by mass: 100 parts premixed granular material; 50-55 parts premixed fine powder; and 9-13 parts potassium dihydrogen phosphate solution. The premixed granular material comprises magnesia aluminate spinel particles and calcium hexaaluminate particles; and the premixed fine powder comprises magnesia rhodonite fine powder, enstatite fine powder, zirconium boride fine powder, and amorphous Al2O3 fine powder. The alkali-resistant castable for the lime rotary kiln working lining prepared by the present invention has excellent construction performance. After being cast into the lime rotary kiln working lining, it does not require additional heat treatment or firing, thus saving energy. The castable has high high-temperature strength, low bulk density, low thermal conductivity, high alkalinity, strong resistance to alkali corrosion, and is non-ringing and slag-resistant. The castable has good fluidity, ensuring good overall sealing of the lime rotary kiln working lining. The alkali-resistant castable produces no toxic components before and after construction, making it environmentally friendly.

The invention relates to the technical field of ceramic material preparation, in particular to core-shell structure ceramic powder and a preparation method and application thereof.The surface of boride ceramic powder is coated with a uniform carbon layer, then the carbon layer is mixed with silicon powder, thermal treatment is conducted through Joule thermal equipment, and the boride ceramic powder coated with a silicon carbide layer is obtained; the prepared composite ceramic powder has good sinterability and oxidation resistance, a composite ceramic block or a ceramic-based composite material is prepared by sintering the composite ceramic powder as a raw material, and the long-acting oxidation / ablation resistance can be effectively improved, so that the composite ceramic powder can be used as a thermal structure component on a remote high-speed aircraft; the preparation process is simple, the reaction condition is mild, the period is short, the cost is low, and the problems that in the prior art, the boride and silicon carbide composite ceramic powder preparation process is complex, and the service requirement in an extreme environment cannot be met are solved.

The application belongs to the technical field of ceramics, and particularly relates to a preparation method of high-entropy boride-silicon carbide composite ceramics, which comprises the following steps: mixing high-entropy boride powder and carbon source powder, and then adopting a ceramic forming method to prepare a ceramic green body; embedding the ceramic green body with silicon powder, and performing liquid silicon infiltration treatment in a vacuum environment to obtain high-entropy boride-silicon carbide composite ceramics. The application mixes high-entropy boride and carbon source, and then performs liquid phase silicon infiltration, so that the process is simpler, the residual Si content is relatively less, and high-entropy boride-silicon carbide composite ceramics with a density of more than 99% can be obtained, which is suitable for large-scale production and application.

The invention provides a refractory ceramic-based material for a smelting furnace lining and a preparation method of the refractory ceramic-based material, and belongs to the technical field of ceramic refractory materials. The material comprises coated modified fused magnesite main aggregate, ceramic sand main aggregate, surface coated magnesium oxide fine powder, gamma-phase aluminum oxide micro powder, an aluminum dihydrogen phosphate solution, alkaline silica sol, a pre-reaction spinel precursor and zirconium boride micro powder. The coated modified fused magnesite main aggregate is prepared by mixing and sintering fused magnesite, silicon carbide composite powder, chromium sesquioxide powder and phenolic resin powder. And mixing the silicon carbide powder and the magnesium oxide powder, and depositing a silicon nitride layer on the particle surface to prepare the silicon carbide composite powder. The surface-coated magnesium oxide fine powder is formed by coating the surfaces of magnesium oxide fine powder particles with aluminum oxide. The pre-reaction spinel precursor is prepared by the following steps: preparing a mixed salt solution from magnesium nitrate hexahydrate and aluminum nitrate nonahydrate by using deionized water, reacting, aging and carrying out heat treatment. And the ceramic sand main aggregate is made of zirconium oxide. And all the layers are matched for use to realize balanced improvement of performance.

The invention belongs to the technical field of special ceramic preparation, and particularly relates to high-strength special ceramic and a preparation method thereof. The high-strength special ceramic is prepared from the following raw materials: alumina powder, quartz powder, serpentine, phosphorus slag, eucryptite, barium borate, nano yttrium trifluoride, nano hafnium boride, nano strontium zirconate, nano lanthanum titanate and polyborosilazane. According to the high-strength special ceramic disclosed by the invention, the aluminum oxide powder, the quartz powder, the serpentine and the phosphorus slag are taken as matrix raw materials, eucryptite, barium borate and yttrium trifluoride are taken as fluxing agents, and nano hafnium boride, nano strontium zirconate, nano lanthanum titanate and polyborosilazane are taken as fillers, so that the prepared special ceramic has excellent bending strength and fracture toughness.

The invention provides a high-temperature-resistant creep-resistant tungsten alloy, and relates to the technical field of powder metallurgy, the tungsten alloy comprises, by mass, 3-8 wt% of Re, 0.2-1 wt% of carbide, 0.1-0.5 wt% of boride, and the balance tungsten and inevitable impurities; the carbide is selected from one or more of TiC, ZrC, TaC and HfC; the boride is selected from one or more of TiB2 (titanium diboride), HfB2 (hafnium diboride) and ZrB2 (zirconium diboride). The high-temperature-resistant creep-resistant tungsten alloy is prepared by adding low-content rhenium, carbide and boride into pure tungsten and adopting a unique preparation method, and the technical defects that an existing tungsten-rhenium alloy is insufficient in strength and creep resistance at the ultrahigh temperature (larger than or equal to 2000 DEG C), and a traditional multi-pass processing technology is complex are overcome.

The invention provides a micron-scale high-melting-point oxide sheet layer enhanced ultra-high-temperature ceramic-based anti-ablation composite coating and a preparation method thereof.The preparation method comprises the steps that ultra-high-temperature carbide / boride ceramic powder, silicide powder and high-melting-point metal oxide powder are mechanically mixed, and spraying mixed powder with uniform components is obtained; the mixed powder is sprayed on the surface of a base body in a plasma spraying mode, and the ultra-high-temperature ceramic-based anti-ablation composite coating containing a micron-scale oxide lamellar structure is obtained; the lamellar high-melting-point oxide phase is introduced into the ultrahigh-temperature ceramic-based composite silicide coating, so that the problem that the silicon-containing glass phase is easy to lose and splash under high-heat-flow scouring is effectively solved. The high-melting-point oxide sheet layer serves as a physical barrier, can effectively limit flowing of a silicon-containing glass liquid phase in the ablation process and allows gaseous oxidation products to escape at the same time, so that a firmly-attached composite oxide layer is formed, and the oxidation resistance and the anti-scouring and anti-stripping capacity of the coating are greatly improved.

The invention discloses 5-hydroxymethylfurfural and a preparation method thereof, and belongs to the technical field of chemical engineering. The preparation method comprises the following steps: reacting a homogeneous aqueous solution containing fructose, inorganic salt and an acid catalyst in a multi-kettle series reactor to obtain the 5-hydroxymethylfurfural, the inorganic salt is selected from at least one of halogen compounds, borides, silicate, aluminate, phosphate and borate; the acidic catalyst comprises at least one of water-soluble acids. The specific inorganic salt and the specific acid catalyst are added and can play a synergistic role, the reaction is carried out under multi-kettle series connection, the backmixing degree of the reaction materials in the reactor is maximized, side reactions can be effectively controlled, black rot is avoided, the reaction production efficiency and conversion rate are effectively improved, the reaction selectivity is improved, and the method is suitable for industrial production. And the equipment maintenance and labor cost is greatly reduced.

The invention relates to a preparation method of a low-density boride aerogel material, and aims to solve the problems of high density, large pore diameter and poor heat insulation performance of the existing boride ceramic material with a porous structure, the method comprises the following steps: 1) preparing tannic acid-formaldehyde sol, and pre-gelling at a constant temperature; 2) preparing M / B precursor sol, and carrying out pregelation at a constant temperature; 3) mixing the tannic acid-formaldehyde sol and the M / B precursor sol, and fully and uniformly stirring to obtain mixed sol; 4) sealing and storing the mixed sol at a constant temperature to obtain boride precursor wet gel; (5) carrying out absolute ethyl alcohol replacement on the boride precursor wet gel, and drying at normal pressure to obtain boride precursor aerogel; and 6) carrying out high-temperature sintering on the boride precursor aerogel in a tubular furnace to obtain the pure-phase boride aerogel. The low-density boride aerogel material with a complete structure can be obtained, the material phase purity is high, the density and aperture are adjustable, the light absorption performance is excellent, the maximum porosity is-95%, and the low-density boride aerogel material has wide application prospects in the field of thermal protection of aircrafts as a light thermal insulation material.

The invention relates to the technical field of dissimilar material connection, in particular to a method for regulating and controlling molybdenum steel brazed joint intermetallic compounds based on transition elements. According to the technical scheme, the method comprises the following steps that a transition element coating is deposited on the surface of a molybdenum matrix, transition elements are selected from one or more of Ti, V, Nb, Zr, Hf and Ta, and the molybdenum matrix and a steel matrix are brazed through boron-containing Ni-based brazing filler metal; in the brazing process, the transition element and the boron element preferentially react to generate a transition element boride, and therefore generation of MoNiBintermetallic compounds is inhibited. According to the method, the transition element coating is introduced, a brazing interface reaction path is actively intervened and reconstructed from the thermodynamic angle, and the problem of continuous generation of the brittle MoNiBintermetallic compound in the molybdenum / steel brazing joint is fundamentally solved.

The invention discloses a high-performance corundum-based repairing material and a preparation method thereof, and belongs to the technical field of furnace lining repairing materials, the high-performance corundum-based repairing material comprises the following preparation raw materials by mass: 60-80 parts of aggregate, 10-30 parts of powder, 8-20 parts of a binder and 0.5-2 parts of an additive; the aggregate comprises fused white corundum and fused magnesium aluminate spinel; the powder comprises white corundum powder, rare earth modified alumina powder and boride. The preparation method of the high-performance corundum-based repairing material comprises the following steps: adding the powder into the aggregate, carrying out uniform dry mixing, adding the organic binding agent, then adding the silica sol, and finally adding the additive. The high-performance corundum-based repairing material disclosed by the invention is high in early strength and still has relatively long service life in a high-temperature environment.

The invention discloses an anti-crack nickel-based superalloy and a preparation method and application thereof, and belongs to the technical field of nickel-based alloys. The anti-crack nickel-based superalloy comprises, by mass, 12%-18% of Cr, 10%-20% of Ni, 10%-20% of Ni and the balance Ni; 8%-15% of Co; 3 to 6 percent of Mo; 2 to 4 percent of W; 1 to 3 percent of Al; 2 to 4 percent of Ti; 0.5 to 2 percent of Ru; 0.3%-1% of Y; b: 0.002 to 0.01% of the total weight of the raw materials; and the balance of Ni and inevitable impurities. According to the invention, aluminum is passivated by the rare earth oxide to form a Y2O3 passivation layer, so that the precipitation of a low-melting-point phase is effectively inhibited, the crack propagation rate under high-temperature cyclic load is remarkably reduced, the grain boundary binding energy is optimized, and the long-term service stability of the alloy in an oxidation-hot corrosion coupling environment is improved. Through a Ni-B intermediate alloy preparation process and carbon thermal reduction and liquid filtration technologies, boron element segregation and brittle boride formation are avoided, a grain boundary stress concentration source is eliminated, and boron elements are uniformly distributed on a matrix, so that the intergranular fracture tendency is inhibited under high-temperature and high-stress conditions, and the service life of the alloy is prolonged.

The invention relates to an amorphous reconstruction hydrogen evolution catalyst and a preparation method and application thereof. The amorphous reconstruction hydrogen evolution catalyst is of a heterostructure, the surface layer of the amorphous reconstruction hydrogen evolution catalyst is a transition metal oxide, and the inner layer of the amorphous reconstruction hydrogen evolution catalyst is a transition metal boride or a transition metal boron-phosphorus co-doped compound; the transition metal oxide, the transition metal boride and the transition metal boron-phosphorus co-doped compound are all in an amorphous state; transition metals in the amorphous state reconstruction hydrogen evolution catalyst are at least two of Fe, Co, Ni, Ce, Cu, Mn, V, W and Mo.

The invention discloses a tungsten-containing ultrahigh-temperature high-entropy rare earth boride ceramic material as well as a preparation method and application thereof. The preparation method of the tungsten-containing ultrahigh-temperature high-entropy rare earth boride ceramic material comprises the following steps: 1) preparing a green body from metal oxide powder and boron carbide powder; 2) performing electric field sintering, crushing and screening on the green body to prepare tungsten-containing ultrahigh-temperature high-entropy rare earth boride ceramic powder; and 3) pressing the tungsten-containing ultrahigh-temperature high-entropy rare earth boride ceramic powder into a green body, and then carrying out spark plasma sintering. The tungsten-containing ultra-high-temperature high-entropy rare earth boride ceramic material has excellent ultra-high-temperature oxidation resistance, is wide in component space range and low in cost, has a very wide application prospect in ultra-high-temperature thermal protection components such as the leading edge, the nose cone and the control surface of a hypersonic aircraft, and has a wide application prospect. And the preparation method has the advantages of simple operation and process flow, short reaction time, low synthesis cost and the like, and is suitable for large-scale industrial production.

The present application belongs to the technical field of the synthesis of chiral boron compounds, and in particular relates to an MOF-Cu(II) / CMC composite material, and a preparation method therefor and the use thereof. The preparation method for an MOF-Cu(II) / CMC composite material of the present application comprises: dropwise adding an aqueous solution of sodium carboxymethyl cellulose to an aqueous solution of a bivalent copper salt, performing solid-liquid separation, mixing obtained composite microspheres with an organic solution of trimesic acid, heating the resulting mixture, and subjecting same to solid-liquid separation, so as to obtain an MOF-Cu(II) / CMC composite material. The MOF-Cu(II) / CMC composite material is used in an asymmetric chiral boron addition reaction. The reaction is performed at room temperature, involves mild conditions, is applicable to a wide range of substrates and has a high yield and enantioselectivity. Moreover, the method can achieve the synthesis of a chiral organic boride in a solvent having simple components, providing an efficient new method for the preparation of drug molecules and active intermediates, and also broadening the range of substrates used for the preparation of chiral organic borides.

The invention belongs to the technical field of ceramic materials, and particularly relates to a composite ceramic material as well as a preparation method and application thereof. The composite ceramic material comprises a matrix and silicon carbide, the substrate coats silicon carbide, and the substrate comprises high-entropy carbide and high-entropy boride. According to the invention, through the design of components of the high-entropy material and the optimization of a preparation process, the composite ceramic material with a matrix being high-entropy carbide and high-entropy boride and SiC being a main second phase is obtained, the SiC is wrapped by the high-entropy carbide and the high-entropy boride in a dual-phase manner, the high-entropy carbide and the high-entropy boride are used in a combined manner, and the high-entropy material can be used for preparing the composite ceramic material. According to the present invention, the SiC particles are introduced into the ultra-high temperature ceramic, such that the mechanical property, the thermal stability and the chemical stability of the material can be improved, the toughening can be achieved by introducing the SiC particles into the ultra-high temperature ceramic, and the oxidation resistance and the ablation resistance of the material at the medium-high temperature can be effectively improved so as to provide the good mechanical property and the good ablation resistance of the ceramic material, and the certain wave absorbing property is hopeful.

The invention provides an insulating high-thermal-conductivity flexible silica gel sheet and a preparation method thereof. The silica gel sheet comprises the following components in parts by weight: 1-5 parts of organic boride; 1 to 5 parts of a polysilazane compound; 1-5 parts of hydrogen-containing silicone oil; 5 to 10 parts of dimethyl silicone oil; 20 to 30 parts of vinyl silicone oil; 50-80 parts of a heat-conducting filler; 0.01 to 0.1 part of a platinum catalyst; the heat-conducting filler comprises a heat-conducting filler 1 and a heat-conducting filler 2, the heat-conducting filler 1 is selected from any one of boron nitride, aluminum oxide and magnesium oxide, and the heat-conducting filler 2 is selected from any one of graphene, silicon carbide and silicon nitride. The flexible silica gel sheet provided by the invention realizes comprehensive optimization of high heat-conducting property, excellent electrical insulating property, thermal mechanical stability and surface flatness.

The invention relates to the technical field of metal material connection and surface engineering, in particular to MAB phase reinforced Cu-Sn-Ti active brazing filler metal and a preparation method thereof. According to the MAB phase enhanced Cu-Sn-Ti active brazing filler metal, an MAB phase serves as a strengthening phase and is layered ternary boride ceramic, M is Mo or Cr, A is Al, and the brazing filler metal comprises, by mass, 60%-65% of Cu powder, 15%-18% of Sn powder, 10%-12% of Ti powder and the balance MAB powder. The MAB phase ceramic with a unique layered structure and chemical activity is introduced, the interface reaction of a diamond / steel substrate can be actively regulated and controlled while dispersion strengthening of the brazing filler metal substrate is achieved, a tough and tough combined gradient interface is formed, and therefore the diamond composite wear-resistant coating with excellent comprehensive performance is obtained.

The invention discloses a zirconium boride-carbon hybrid aerogel composite material and a preparation method thereof, and belongs to the technical field of aerogel materials. In order to solve the problem of insufficient oxidation resistance of a carbon aerogel material, a co-gel method is mainly adopted to introduce a zirconium boride precursor network, zirconium boride is generated in situ through pyrolysis reduction, and matrix oxidation resistance modification of carbon aerogel is realized. A stable anti-oxidation protection layer can be formed in a high-temperature aerobic environment, the high-temperature-resistant and anti-oxidation performance of the material is improved, and the material can be applied to the field of light thermal protection.

The invention belongs to the technical field of high-entropy ceramic materials, and particularly relates to a high-entropy boride ceramic material and a preparation method and application thereof. The invention provides a preparation method of a high-entropy boride ceramic material, which comprises the following steps: mixing high-entropy boride and silicon carbide to obtain a mixed material; the high-entropy boride is (Ti < 0.2 > Zr < 0.2 > Nb < 0.2 > Mo < 0.2 > Ta < 0.2 >) B2; the silicon carbide comprises silicon carbide whiskers and / or silicon carbide particles; and sintering the mixed material to obtain the high-entropy boride ceramic material. The high-entropy boride ceramic material prepared by introducing the silicon carbide whiskers and / or the silicon carbide particles into the high-entropy boride (Ti0. 2Zr0. 2Nb0. 2Mo0. 2Ta0. 2) B2 has relatively high density, fracture toughness and bending strength, and the high-temperature tribology performance of the high-entropy boride ceramic material can be effectively improved.

The invention relates to a memristor and a preparation method and application thereof. The memristor structurally comprises a bottom electrode, a tunneling layer, a nanoparticle layer, a resistive layer and a top electrode from bottom to top, the nano-particle layer is made of metal nano-particles; and the resistive layer is made of a low-dimensional rare earth boride nano material. According to the memristor with the specific structure, the dynamic electron release and capture process between the metal nanoparticles in the nanoparticle layer and the low-dimensional rare earth boride nanomaterial of the resistive layer is used as a physical entropy source to enable current signals to maintain binary distribution for a long time; therefore, the memristor generates a random telegraph noise current signal with high stability, and the memristor can be used as a random entropy source of a true random number generator to generate an unpredictable binary number in a real-time transmission process of a hardware encryption system.

The invention relates to the technical field of graphite-based ceramic coating materials, in particular to a preparation method of a graphite-based boride ceramic modified Si-SiC ceramic coating material. Metal oxide powder of TiO2, ZrO and Ta2O5, B4C and C powder are subjected to ball milling and mixing and then subjected to two times of vacuum heat treatment to obtain single-phase medium-entropy boride ceramic, then the single-phase medium-entropy boride ceramic serves as a modifier to be mixed with Si and SiC and then subjected to spark plasma sintering, and the graphite-based (Ti1 / 3Zr1 / 3Ta1 / 3) B2-Si-SiC ceramic coating material is obtained. The medium-entropy boride ceramic with excellent high-temperature oxidation resistance is prepared by adopting a boron / carbon thermal reduction method and a discharge plasma sintering method, the molecular formula of the medium-entropy boride ceramic is (Ti1 / 3Zr1 / 3Ta1 / 3) B2, the medium-entropy boride ceramic has a close-packed hexagonal structure, and when the medium-entropy boride ceramic is used for doping modification of a Si-SiC coating, the density and the high-temperature oxidation resistance of the Si-SiC coating can be remarkably improved, and the high-temperature oxidation resistance of the Si-SiC coating can be remarkably improved. Wide application prospects are realized.