25results about How to "Small grain size" patented technology

The application provides a method for microwave-assisted preparation of tetragonal barium titanate powder, comprising the following steps: mixing a barium source and a titanium source to obtain a non-hydrolytic sol; performing a microwave-assisted gelation reaction on the non-hydrolytic sol to obtain a wet gel; drying the wet gel to obtain a dry gel; performing heat treatment on the dry gel in a protective atmosphere to obtain a pre-sintered powder; performing microwave-assisted calcination on the pre-sintered powder to obtain a calcined powder; and performing washing and drying on the calcined powder to obtain the barium titanate powder. The method provided by the application performs a microwave-assisted gelation reaction on a sol, and through the microwave effect in the two steps of gelation and calcination, the gelation time can be shortened and the calcination temperature can be reduced, and the synergistic regulation of high purity, ultra-fine particle size and high tetragonal phase content of the barium titanate powder is realized simultaneously. The method provided by the application is simple and controllable, low in energy consumption, suitable for industrial large-scale production, and the prepared barium titanate powder can be widely applied to the preparation of ceramic capacitors, and the reliability and miniaturization capability of the device are significantly improved.

This invention discloses a 440MPa grade steel plate with ultra-low temperature toughness and its preparation method, belonging to the field of steel materials technology. It solves the contradiction between insufficient strength and toughness grades and excessive nickel content in existing low-temperature steels. The composition of the 440MPa grade steel plate with ultra-low temperature toughness, by mass percentage, includes: C: 0.030%–0.085%, Si: 0.18%–0.38%, Mn: 0.95%–1.35%, P: ≤0.010%, S: ≤0.003%, Cr: 0.01%–0.25%, Mo: 0.01%–0.15%, Ni: 3.20%–4.25%, Cu: 0.12%–0.85%, Nb: 0.008%–0.035%, Al: 0.02%–0.036%, Ti: 0.008%–0.022%, with the balance being Fe and other unavoidable impurities. The steel plate of this invention exhibits excellent strength and low-temperature toughness.

This invention discloses a heat- and impact-resistant protective conduit for MPP cables and its preparation method, relating to the field of polymer materials technology. The components, by weight, include: 20-22 parts of a toughening dispersion made from anhydrous ethanol and terminally epoxy-terminated hyperbranched polysiloxane; 33-35 parts of a boron-nitrogen co-doped carbon dot made from citric acid, boric acid, and urea, first compounded with phytic acid and piperazine, then compounded with modified zirconium phosphate prepared by hexadecyltrimethylammonium bromide intercalation, and then modified with silane coupling agent KH-560 to form a flame retardant synergist; 12-14 parts of polyolefin elastomer; 2-2.5 parts of magnesium aluminum hydrotalcite; 0.2-0.24 parts of antioxidant; 0.2-0.3 parts of calcium stearate; 0.2-0.3 parts of polyethylene wax; and 100-120 parts of polypropylene. The introduction of the flame retardant synergist and other raw materials in this invention effectively improves flame retardancy, aging resistance, impact resistance, low-temperature resistance, and heat resistance.

This application proposes a layered cathode material, its preparation method, and a lithium-ion battery. The layered cathode material includes a lithium source, a manganese source, and a grain refiner. By adding a grain refiner to the raw materials, the layered cathode material has a larger half-maximum width at half-maximum (FWHM) and a smaller grain size, or an I(010) / I(021) intensity ratio in the range of 0.3 to 0.85. This shortens the lithium-ion diffusion path, which is beneficial for lithium-ion diffusion, thereby improving the rate performance, capacity utilization, and cycle stability of the material. The layered cathode material of this application is a primary particle and a single-crystal material. Compared with conventional polycrystalline materials, single-crystal materials do not have the anisotropic stress problem of polycrystalline materials. The stress distribution of single-crystal materials is uniform, and the mechanical stress is stable. Therefore, it has less expansion stress and less volume deformation during charge and discharge, which can reduce the generation of particle cracks and effectively delay the occurrence of failure.

The invention provides an ultrafast laser in-situ composite cladding repair method, and relates to the field of metal material repair. The ultrafast laser in-situ composite cladding repair method comprises the following steps: pretreating a to-be-repaired area of a titanium alloy defect part; cladding repair is conducted on the pretreated titanium alloy defect part through cladding laser, and a molten pool is formed; and the ultrafast impact laser acts on the molten pool so as to induce to generate impact waves to conduct impact forging on the molten pool. According to the method, the microscopic structure of the repairing layer can be remarkably refined, the Widmannstatten needle-shaped alpha phase is short, small and uniformly distributed, the grain size is obviously reduced, and the structure is more compact and uniform; and the microhardness of the repairing layer is effectively improved through the refined microscopic structure, and the mechanical property of the material is enhanced. According to the method, the structure uniformity and hardness of the repairing layer can be remarkably improved, and the requirement for high-performance repairing of the titanium alloy defect part is met.

The application provides a high-entropy niobate ceramic with high-temperature water vapor sintering resistance and high fracture toughness, a preparation method and application thereof, and belongs to the technical field of thermal barrier coating materials for hydrogen hybrid combustion engines.The high-entropy niobate ceramic prepared by the application can promote crack deflection and bridging through ferroelastic domain and super-dense dislocation, consume crack propagation energy, and thus improve the fracture toughness of the coating, so that the fracture toughness of the coating is comparable to that of YSZ; on the other hand, the high-entropy niobate ceramic can form a covalent bond with water vapor adsorbed on the surface, the covalent bond has strong binding force, and the hydroxyl group cannot move; meanwhile, high-temperature water vapor can reduce the surface energy of the high-entropy niobate ceramic, promote the diffusion of particles to the neck, increase the curvature radius of the neck, and reduce the diffusion driving force, so as to inhibit sintering; the high-entropy niobate ceramic is doped with multi-element rare earth elements to obtain an "entropy-stable" high-entropy niobate, so that the high-entropy niobate ceramic material has high-temperature phase stability, high-temperature water vapor sintering resistance, high-temperature thermal insulation performance and high fracture toughness.

This invention discloses a 5052 aluminum alloy cavity for semiconductor devices and its preparation method, relating to the field of aluminum alloy material technology. Specifically, it includes the following steps: S1: First, the 5052 aluminum alloy ingot undergoes a two-stage homogenization treatment, followed by a three-stage free forging process, and finally, spray cooling and air drying to obtain a shaped cavity substrate; S2: After plasma cleaning, the shaped cavity substrate is subjected to magnetron sputtering technology to sequentially deposit a transition layer, a barrier layer, and a functional layer on its inner surface to obtain the 5052 aluminum alloy cavity for semiconductor devices. The 5052 aluminum alloy cavity prepared by this invention can greatly ensure the stability and purity of the prepared aerospace semiconductors, meeting the manufacturing needs of high-performance chips for aerospace applications, and is of great significance.

The application relates to the field of metallurgical and plastic processing of biomaterials, and provides a biodegradable Zn-Mg binary alloy and a preparation method and application thereof. The biodegradable Zn-Mg binary alloy is prepared by adopting a method of smelting-semi-continuous casting-forging-rolling-reverse extrusion and taking metal Zn and Zn-Mg intermediate alloy as raw materials. The Zn-Mg binary alloy prepared by the application has good mechanical properties, and the strength and ductility can meet the requirements of medical implant devices. Meanwhile, the Mg is added in the form of Zn-Mg intermediate alloy, so that the burning loss of the Mg can be effectively controlled, and the uniformity of the alloy composition and structure is improved. Further, high-purity raw materials are selected, and high-purity graphite crucibles are adopted for smelting, so that the heavy metal content in the Zn-Mg binary alloy is effectively controlled, the contents of Pb, As and Cd reach the standard of drinking water, and the safety of the Zn-Mg binary alloy implant in the body is ensured.

This invention discloses an electrical graphene-aluminum rod and its preparation method, belonging to the field of materials processing technology. The method includes the following steps: S1, solution treatment and quenching of an Al-Mg-Si alloy to obtain a solution-treated Al-Mg-Si alloy; S2, processing grooves on the surface of the solution-treated Al-Mg-Si alloy, filling the grooves with graphene powder, and performing rotary friction extrusion processing under low-temperature rapid cooling in a cooling medium; S3, performing aging treatment after rotary friction extrusion processing to obtain the electrical graphene-aluminum rod. This invention, using the above-mentioned electrical graphene-aluminum rod and its preparation method, optimizes the process sequence and controls the rotary friction extrusion process, not only ensuring uniform dispersion of graphene in the aluminum matrix and sufficient suppression of interfacial reactions, but also forming ultrafine crystals and extremely fine nano-Mg2Si precipitates in the matrix. The resulting graphene-aluminum rod possesses both high strength and high conductivity.

This invention belongs to the field of ceramic materials technology and discloses a high-temperature, high-insulation 96 alumina ceramic and its preparation method. The material is made by mixing α-Al₂O₃ powder with a dopant, wherein the dopant is composed of TiO₂ and CaO mixed in a mass ratio of (1-3):(3-1). Its average volume resistivity at room temperature is higher than 10 Ω·cm. 15 The optimal component insulation resistivity can reach 1.75 × 10⁻⁶ Ω·cm at a high temperature of 500°C. 12 The preparation method involves mixing α-Al₂O₃ powder with dopants TiO₂ and CaO according to their doping content; mixing the raw material powder with anhydrous ethanol and then ball-milling; drying and sieving the ball-milled slurry; adding a binder to the obtained powder, sieving it again, granulating it, and pressing it into a green body; firing the green body after debinding to obtain the final ceramic sample. This invention utilizes Ca... 2+ Ti 4+ By doping and modifying the material, 96 alumina ceramics that meet the properties of coulombic electrostatic chucks were prepared. While reducing the sintering temperature, the resistivity was maintained, thus better meeting the practical application requirements.

The invention discloses a freeze-drying preparation method of second-phase particle dispersion nano tungsten-nickel-iron composite powder, which comprises the following steps: 1, adding rare earth nitrate, a salt solution and a surfactant into deionized water, and carrying out ultrasonic treatment to form a uniform precursor mixed solution; 2, performing freeze drying after pre-freezing treatment to obtain precursor powder; and thirdly, the precursor powder is subjected to calcination treatment and a two-step reduction process, and second-phase particle dispersion nanometer tungsten-nickel-iron composite powder is obtained. According to the preparation method, the precursor powder with the submicron particle size and highly concentrated particle size distribution is prepared by combining rapid pre-freezing with a freeze-drying process, and high-purity and high-uniformity compounding of tungsten-nickel-iron and second-phase particles is realized by combining subsequent calcination and reduction; the second-phase oxide particle dispersion nano tungsten-based composite powder with high purity and good uniformity is obtained, controllable preparation of superfine nano powder is achieved, and the method has good process amplification potential and is suitable for the field of powder preparation engineering.

The application discloses a 785MPa-grade steel plate with ultralow-temperature toughness and a preparation method thereof, and belongs to the technical field of steel materials, and solves the contradiction between the insufficient toughness level of the ultrahigh-strength steel and the excessive matching of the nickel content in the prior art.The 785MPa-grade steel plate with ultralow-temperature toughness comprises the following components in percentage by mass: C: 0.08% to 0.15%, Si: 0.02% to 0.18%, Mn: 0.60% to 1.63%, P: ≤0.010%, S: ≤0.004%, Cr: 0.35% to 0.95%, Mo: 0.32% to 0.60%, Ni: 3.15% to 4.35%, Cu: 0.75% to 1.85%, V: 0.04 to 0.12%, Nb: 0.008% to 0.035%, Al: 0.017% to 0.036%, Ti: 0.008% to 0.022%, and the balance of Fe and other inevitable impurities.The 785MPa-grade steel plate with ultralow-temperature toughness has excellent strength and low-temperature toughness.

The invention provides a ZSM-23 molecular sieve, a preparation method thereof and a catalyst. The preparation method comprises the following steps: mixing a silicon source, an aluminum source, an alkali source, an organic structure-directing agent, a mesoporous template agent, a crystal growth inhibitor and water to form a raw material solution, crystallizing, washing, drying and roasting to obtain the ZSM-23 molecular sieve, the crystal growth inhibitor comprises one or a combination of more than two of trimethoxy [3-(phenylamino) propyl] silane, lauryl sodium sulfate, tetradecyl phosphoric acid and glutamic acid. According to the method, the ZSM-23 molecular sieve with small crystal grains and a hierarchical pore structure can be synthesized in one step, and the catalytic performance of the molecular sieve is improved.

This invention relates to the field of cement building materials, specifically disclosing a cement-based protective material with both ion trapping and induced passivation functions and its application. The cement-based protective material comprises the following components: 95-100 parts by weight of magnesium phosphate cement, 4-6 parts by weight of retarder, and 20-25 parts by weight of composite modifier. The composite modifier comprises modified dry powder, calcium-containing dry powder, mixing water, and a dispersant, and the modified dry powder is obtained by calcining a layered bimetallic hydroxide with an aluminum source. The cement-based protective material of this invention exhibits high Cl- content... ‑ SO4 2‑ In addition to its excellent impermeability in CO2 environments, it can also actively capture corrosive ions, promote the formation and maintenance of a stable passivation film on the steel surface, thereby providing more long-lasting and reliable protection for marine steel structures.

This invention relates to a forging method for stepped gear shafts from continuously cast billets with diameters of φ600~φ785mm. The method involves loading the continuously cast billet into a heating furnace, holding it at 700~800℃, and then raising it to 1230℃±10℃. The billet is then upset with the tail end facing upwards using a concave upsetting plate, with an upsetting height-to-diameter ratio of 0.6~0.7. The billet is then drawn on an upper and lower flat plate, with a reduction of 13~18% per pass, and rotated 90° per pass. Finally, the billet is drawn on upper and lower flat anvils, with a reduction of 18~22%, and fed into the anvils at full capacity, ensuring at least one [unclear unit] per two anvils. With a 5% anvil loading, the anvil is rotated 90° per pass. A 3150-ton hydraulic press is used to upset the riser end with a concave upsetting plate, resulting in a height-to-diameter ratio of 0.6 to 0.8. The billet is drawn to be 20 to 30 mm larger than the maximum step diameter of the stepped gear shaft. After scoring, the billet is kept at a furnace temperature of 1030±10℃. The small steps at both ends are forged into finished products, and the large steps are forged into finished products within the range of 760℃ to 790℃. This improves the actual grain size and banded structure qualification rate of the stepped gear shaft, reduces the need for one normalizing step, and improves the low-magnification structure.

The application discloses a preparation method of a high-strain-energy-density CoCrNi medium-entropy alloy with a biomimetic brick clay structure, mainly comprising the following steps: firstly, cold-rolling a bulk CoCrNi alloy raw material, then annealing and water quenching to room temperature; and then, adopting high-speed rolling to perform multi-pass surface nanocrystallization treatment on the front and back surfaces of the annealed bulk CoCrNi alloy, so that the grain size has gradient structure and layered structure in two-dimensional space, respectively, and the prepared CoCrNi medium-entropy alloy comprises two layers of unevenly distributed gradient nanocrystalline layers and a uniformly distributed coarse-grained layer between the two layers, and has a very high strain energy density (strong plastic product). The application can prepare alloy plates with different sizes of transverse and longitudinal alternating brick clay structures to realize different heterogeneous strengthening effects. The application has simple process and strong universality, and can be popularized to other metal material processing fields.

The application relates to a kind of molybdenum dioxide-nano carbon fiber composite and its preparation method and application, and relates to the technical field of lithium ion battery negative electrode material, molybdenum disulfide nanosheet and polyacrylonitrile are dispersed in organic solvent with the mass ratio of 0.1-2:1, to obtain mixed solution;The mixed solution is electrospun to obtain molybdenum disulfide-polyacrylonitrile nanofiber;Molybdenum disulfide-polyacrylonitrile nanofiber is oxidized at 400-600 DEG C, to obtain molybdenum dioxide-polyacrylonitrile composite material;Molybdenum dioxide-polyacrylonitrile composite material is carbonized under the condition of protective atmosphere and 700-900 DEG C, to obtain molybdenum dioxide-nano carbon fiber composite.The product of the application slows down the volume expansion of molybdenum dioxide in the charging and discharging process, has good cycle performance, larger specific capacity and excellent rate performance.

The invention provides a magnesium-aluminum composite oxide carrier and a preparation method thereof as well as a methane dry reforming catalyst and a preparation method and application thereof. The preparation method of the magnesium-aluminum composite oxide carrier comprises the following steps: dissolving magnesium salt in deionized water to form a magnesium salt solution; dissolving an aluminum source in an acid solution to form aluminum sol; mixing the magnesium salt solution and the aluminum sol, adjusting the pH value to 3-4 by using an acid solution, and continuously stirring to obtain a turbid liquid; in the turbid liquid, the molar ratio of aluminum to magnesium is (1: 1)-(3: 1); and drying and roasting the turbid liquid to obtain the magnesium-aluminum composite oxide carrier. The preparation method of the magnesium-aluminum composite oxide carrier is simple in process, environment-friendly and convenient for large-scale production, meanwhile, the obtained carrier has a relatively high specific surface area, and the dispersion degree of active metal nickel can be improved by preparing the supported nickel-based methane dry reforming catalyst by taking the magnesium-aluminum composite oxide as the carrier, so that the grain size of the active metal nickel is reduced, and the catalytic activity of the catalyst is improved. The high-temperature sintering resistance of the catalyst is improved; the activity stability is enhanced.

The invention discloses a method for improving the high-temperature oxidation resistance of a molybdenum-rhenium alloy, a product and application of the product, belongs to the field of rhenium-molybdenum high-temperature alloys, and aims to solve the problem of how to reduce segregation of impurity elements in a high-temperature environment and particularly reduce the influence of a high-temperature oxygen environment on the performance of the Mo-Re alloy. The molybdenum-rhenium alloy resistant to high-temperature oxidation comprises the following alloy elements in percentage by mass: 4.89%-4.95% of Re, 0.05%-0.11% of Zr and the balance of Mo and inevitable impurities. On the premise that the Re content is reduced, the composition design thought of alloying Mo-Re is optimized, on the basis of the Mo-5Re alloy, Zr is used for replacing part of Re, the reduction amount of the Re content is made to be equal to the adding amount of the Zr content, and finally the high-temperature oxidation resistance superior to that of the Mo-5Re alloy is obtained. Test results show that after the Re content is reduced and a trace amount of Zr is added, the oxidation resistance of the molybdenum-rhenium alloy resistant to high-temperature oxidation is superior to that of a Mo-5Re alloy, and a large amount of segregation of oxides basically does not occur at the grain boundary.

This invention belongs to the field of target material technology and discloses a method for preparing large-size AZO rotating targets with high density, low resistivity, and minimal white skin. The method includes: spray granulation of a mixed slurry of zinc oxide and aluminum oxide to obtain a mixed powder; cold isostatic pressing of the mixed powder into a mold to obtain a green body; the cold isostatic pressing is performed in 4-6 stages, with the pressure of each subsequent stage being 30-60 MPa higher than the previous stage; sintering the green body in an inert atmosphere, heating it to 1300-1550℃ at a rate of 0.3℃ / min-2℃ / min and holding it at that temperature for 0.5-1 h, then cooling it to 1200-1350℃ at a rate of 2℃-5℃ / min and holding it at that temperature for 10-20 h to obtain the AZO rotating target. By modifying the cold isostatic pressing method and sintering regime in the existing preparation process, it is possible to obtain rotating targets with a length greater than 500 mm, an outer diameter greater than 150 mm, and a thickness greater than 20 mm. Furthermore, the relative density of these rotating targets can be greater than 99.86%, and their resistivity less than 7%. ‑4 It has a high surface quality (Ωcm), low white skin, uniform color inside and out, and a grain size of less than 15μm.

The present application relates to a kind of low carbon equivalent ultra-high strength steel plate and its preparation method, belong to ultra-high strength steel technical field.The low carbon equivalent ultra-high strength steel plate includes C:0.32-0.40%, Si:0.10-0.50%, Mn:0.3-1.5%, P≤0.010%, S≤0.005%, Cr≤1.0%, Mo:0.20-0.50%, Ti:0.04-0.10%, Nb≤0.06%, Al:0.01-0.04%, N≤0.005%, B:0.001-0.004%, and satisfy 1.0%≤Mn+Cr≤1.5%, 0.05%≤Nb+Ti≤0.10%, the rest is Fe.The carbon equivalent CEV of obtained steel plate is ≤0.70%, tensile strength is ≥1900MPa, yield strength is ≥1600MPa, low temperature impact absorption energy KV2 (-40 DEG C) is ≥32J.

The invention relates to the field of molecular sieves, and particularly discloses a nano H-Beta molecular sieve, the grain size of which is less than 40nm. The XRD spectrum of the molecular sieve shows that the molecular sieve has the strongest peak at the 2theta angle of 23 degrees; the nano H-Beta molecular sieve disclosed by the invention is uniform in particle size, can improve diffusion of reactant molecules, and has good selectivity; the molecular sieve also has more exposed catalytic activity sites, so that the molecular sieve is good in catalytic activity and high in stability, the carbon deposition generation rate can be remarkably reduced, the catalytic efficiency of the molecular sieve is improved, and the molecular sieve is particularly suitable for being used as a catalyst and is particularly suitable for being used as a catalyst in preparation of diisopropylbenzene.

This invention discloses a method for preparing a highly textured high-purity copper target. The method includes: annealing a polycrystalline copper block to prepare a high-purity single-crystal copper block; cold rolling the high-purity single-crystal copper block with the rolling direction parallel to the rolling surface, a thinning amount of 80%–98%, and a deformation amount of 5%–20% per pass; quenching the cold-rolled high-purity single-crystal copper block, followed by polishing, to obtain a highly textured high-purity copper target. The grain size of the highly textured high-purity copper target is less than 30 μm, and the proportion of the main texture is greater than 50%. The preparation method disclosed in this invention involves annealing a polycrystalline copper block to prepare a high-purity single-crystal copper block, and then controlling the cold rolling and quenching conditions to regulate the texture and grain size of the high-purity single-crystal copper block, resulting in a highly textured high-purity copper target with a small grain size and a high proportion of the main texture. The magnetron sputtering film formation rate of the strongly textured high-purity copper target disclosed in this invention is high, and the film quality and thickness distribution are uniform.

The application discloses a vacuum rapid condensing furnace integrating regulation and control of rapid cooling and polishing, which comprises a furnace body, a vacuum subsystem connected to the furnace body, an induction melting crucible, a rapid cooling copper roller, a tundish, a flow baffle and a rough cooling turntable arranged in the furnace body, a sleeve horizontally arranged on the inner wall of the furnace body and located above the rough cooling turntable, a first motor arranged on the outer wall of the furnace body, the rapid cooling copper roller located directly below the tundish, the tundish located on the side of the induction melting crucible, the flow baffle arranged between the induction melting crucible and the tundish, the rough cooling turntable rotatably arranged directly below the rapid cooling copper roller, the rough cooling turntable connected to a second motor arranged at the bottom of the furnace body, an extendable polishing structure arranged on the inner wall of the furnace body, and an adjustable fine cooling mechanism arranged below the rough cooling turntable and used for recooling the materials in the rough cooling turntable. The application is used to regulate and control the cooling speed of alloy sheets, so that the alloy sheets can rapidly complete the cooling at a cooling speed suitable for the preparation of high-performance materials, and the agglomeration and caking of the alloy sheets can be avoided. Meanwhile, the rapid cooling copper roller can be automatically polished.

This invention discloses a Ca2Nb2O7 glass-ceramic material with excellent energy storage efficiency and its preparation method. The method includes: Step 1, mixing Na2CO3, K2CO3, BaCO3, SrCO3, CaCO3, Bi2O3, TiO2, Nb2O5 and SiO2 evenly to obtain mixture A; Step 2, adding mixture A into a crucible preheated to 1100-1300℃, then raising the temperature to 1450℃ and holding it at that temperature to completely melt mixture A. The process continues until no more bubbles are generated, resulting in a melt. This melt is then poured into a mold preheated to 200°C, and after molding, product B is obtained. Step 3: Product B is transferred to an annealing furnace preheated to 500–600°C and held at that temperature. After cooling in the furnace, a glass sample is obtained. Step 4: The glass sample is placed in a muffle furnace and heated from room temperature to 800–1000°C at a rate of 5°C / min, and held at that temperature to crystallize the glass sample. After cooling in the furnace, Ca2Nb2O7 glass-ceramic material is obtained. This invention not only has a simple preparation process, but also produces Ca2Nb2O7 glass-ceramic with high breakdown strength and high energy storage efficiency.