18results about How to "Uniform microstructure" patented technology

The application relates to the technical field of zirconium-niobium alloy material processing, in particular to a preparation method of a large-diameter zirconium-niobium alloy pipe for nuclear industry, which comprises the following steps: S1, mixing nuclear-grade sponge zirconium and niobium scraps, or mixing zirconium-niobium alloy, zirconium dioxide and iron; melting the mixture and preparing a zirconium-niobium alloy ingot; S2, sequentially performing large deformation forging in a beta single-phase zone and an alpha+beta two-phase zone; S3, drilling a central hole in the axial direction of a round-forging blank; quenching in the beta single-phase zone; S4, coating an anti-galling agent on the surface of the central hole and heating to prepare a pipe blank in the mode of cross piercing; S5, performing periodic forging and rolling on the pipe blank; S6, annealing the hot-rolled pipe twice; and straightening the hot-rolled pipe after the second-stage annealing. The zirconium-niobium alloy pipe has uniform microstructure, good mechanical properties and corrosion resistance, the production direction of the brittle hydride is nearly parallel to the circumferential direction of the pipe, and brittle damage of the pipe wall thickness caused by the crack propagation of the hydride is avoided.

The present application relates to core-pulling rivet titanium alloy wire processing technical field, specifically to a kind of preparation method of TB9 titanium alloy large disc round wire for core-pulling rivet.The method first obtains the TB9 titanium alloy ingot with a diameter of 500-700mm, then the TB9 titanium alloy ingot is forged into a bar blank with a diameter of 290-310mm at 1100-1200 ℃, then the TB9 titanium alloy bar blank is rough forged into a bar blank with a diameter of 130-150mm at 1000-1100 ℃, then the TB9 titanium alloy bar blank is precision forged into a bar blank with a diameter of 95-105mm at 850-950 ℃, then the TB9 titanium alloy bar blank is continuously rolled at 780-900 ℃, and then quenched after rolling, to obtain a large disc round wire blank with a diameter of 7.5-15mm, then room temperature drawing, then high-temperature solid solution, then room temperature drawing again, then peeling, polishing and coating treatment.At this time, the alloy cross-section structure is fine and uniform equiaxed structure, the longitudinal section structure is elongated fibrous structure, and after aging treatment, it meets the mechanical property requirements of AMS4957F for TB9 titanium alloy wire.

The invention provides a tape casting method high-transparency polysulfonamide film as well as a preparation method and application thereof. The light transmittance of the high-transparency polysulfonamide film obtained through the tape casting method is larger than or equal to 80% (400-800 nm), and the dimensional change rate at 250 DEG C is smaller than or equal to 1%. The preparation method comprises the following steps: S1, pretreatment of the polysulfonamide fibers: soaking and purifying the polysulfonamide fibers in acetone; then stirring and alkalizing in an alkaline solution; removing the alkaline solution and drying to obtain pretreated polysulfonamide fibers; s2, preparation of a membrane casting solution: dissolving the pretreated polysulfonamide fiber in a solvent to prepare a polymer solution; then adding a salt cosolvent and a polymeric dispersant to prepare a mixed solution, and stirring, filtering and carrying out vacuum defoaming to obtain a membrane casting solution; s3, film forming through a tape casting method, wherein the film casting solution is placed on a substrate, and a wet film is prepared through scraper tape casting; s4, coagulating bath phase inversion: transferring the wet film into a coagulating bath, and coagulating to form a preliminarily shaped film material; and S5, post-treatment: washing the preliminarily shaped membrane material with water, and carrying out gradient drying to obtain the high-transparency polysulfonamide membrane.

This invention discloses a hot pressing method for forming amorphous soft magnetic powder, wherein the amorphous powder is granulated and heat-treated under a protective atmosphere to a specific temperature. T x -150℃ to T x -50℃ and hold for 5–90 minutes; then transfer the powder to a mold, and... T g to T x High-density molded bodies are obtained by hot pressing for 30–180 seconds at a gauge pressure of 100–600 MPa within a temperature range. After sintering, high-density amorphous soft magnetic powder cores can be obtained. This method significantly reduces the gauge pressure, increases the relative density, improves the magnetic permeability, and reduces iron loss. Furthermore, the process is highly adaptable, can be easily modified from conventional powder metallurgy equipment, and offers high controllability, making it suitable for the industrial-scale preparation of high-performance amorphous soft magnetic materials.

The application discloses a gelatin-bacteriocin amino acid-dialdehyde starch composite film and a preparation method and application thereof. The preparation method of the composite film comprises the following steps: adding a crosslinking agent into a gelatin solution, adding N-hydroxysuccinimide into the gelatin solution after activation for a set time, then adding bacteriocin amino acid into the gelatin solution, coupling for a set time under weak acid condition and in the dark, and obtaining Gel-MAAs; dissolving the Gel-MAAs in water to obtain a composite solution; dissolving dialdehyde starch in water, gelatinizing, adjusting to weak alkalinity, and obtaining a dialdehyde starch solution; adding the dialdehyde starch solution into the composite solution, mixing uniformly, reacting at 35-45 DEG C for 1-3 h, adding glycerol with a mass fraction of 1-5%, ultrasonic degassing, pouring the film solution into a mold, and drying, and thus the composite film is obtained. The composite film has excellent mechanical properties, physicochemical properties, ultraviolet resistance, good biocompatibility, and great potential in the field of active composite films.

This invention relates to the field of electronic packaging substrates, and particularly to an alumina ceramic substrate material, its preparation method, and its application. The alumina ceramic substrate comprises 90-99 wt% alumina and 1-10 wt% sintering aids. The sintering aids have the following composition: xB₂O₃·zSiO₂·yBi₂O₃, where 15≦x≦25, 50≦y≦70, 15≦z≦25, and x+y+z=100, where x:y:z is the mass ratio. The density of the alumina ceramic substrate is ≥3.8 g / cm³. 3 The alumina ceramic substrate of this invention has the following characteristics: surface roughness ≤ 0.35 μm, breakdown strength ≥ 35 kV / mm, bending angle ≥ 350 MPa, and thermal conductivity ≥ 25 W / m·K. It also features high density, uniform microstructure, good surface flatness, high mechanical strength, high breakdown strength, low dielectric loss, and high thermal conductivity.

The application belongs to the technical field of refractory materials for blast furnace ironmaking, and particularly relates to a thermal shock cracking resistant taphole clay material and a preparation method thereof. The taphole clay material comprises aggregates, matrix powder and a binder system; the binder system is composed of polysilazane, isocyanate curing agent and B4C micropowder. By introducing polysilazane as the main binder, the application realizes high ceramic yield and low volume shrinkage by using the characteristics of polysilazane being converted into Si-B-C-N ceramic at high temperature. Meanwhile, B4C micropowder is oxidized to generate B2O3 at high temperature, which fills pores, promotes sintering and protects carbon phase, so as to realize volume shrinkage compensation and high temperature strength improvement. The taphole clay material has low shrinkage rate, high cold compressive strength, high high-temperature bending strength and excellent thermal shock cracking resistance, and solves the technical problems of poor volume stability and insufficient high-temperature strength of traditional taphole clay caused by binder carbonization shrinkage.

This invention provides a method for preparing WC-Co cemented carbide based on electron beam selective melting, belonging to the field of cemented carbide additive manufacturing technology. The method includes: 1) mixing tungsten carbide powder and cobalt powder; 2) modeling the component to be printed; 3) setting substrate preheating parameters; 4) setting contour scanning parameters; 5) setting part scanning parameters; 6) setting the part scanning strategy; 7) loading the mixed powder into the hopper of an electron beam selective melting device, leveling the substrate, and evacuating the vacuum; 8) cyclically stacking the powder according to steps 2) to 6) to obtain the WC-Co cemented carbide. The microstructure of this cemented carbide shows that the average size of the WC grains is 50-60 μm, and the Co phase is uniformly distributed between the WC hard phases. Room temperature tribological tests show that the cemented carbide has a friction coefficient of 0.55–0.65 at room temperature, exhibiting excellent room temperature wear resistance, making it suitable for cutting tools, molds, mechanical parts, etc., where room temperature tribological performance is required.

This invention discloses a high-alloy high-performance rotary guide component and its manufacturing method, belonging to the field of stainless steel technology. It solves the problems of poor microstructure uniformity and inability to simultaneously achieve mechanical properties and stress corrosion resistance in existing rotary guide components. The manufacturing method includes: smelting molten steel; preparing ingots; forging the ingots into steel billets using a high-speed forging machine after they are tapped from the furnace; heating and holding the steel billets; forging the steel billets into intermediate billets using a radial forging machine; water cooling the intermediate billets; forging the water-cooled intermediate billets a second time using a radial forging machine, followed by air cooling to obtain finished steel billets; straightening, machining, and shot peening of the finished steel billets to obtain rotary guide components; the composition of the rotary guide components, by mass percentage, includes: 18.00% ≤ Cr < 28.00%, 3.00% ≤ Mo ≤ 6.00%, 14.00% ≤ Ni ≤ 20.00%, 3.00% ≤ Mn ≤ 8.00%, Si ≤ 0.4%, Nb ≤ 0.25%, P ≤ 0.025%, S ≤ 0.02%, C ≤ 0.03%, N ≥ 0.3%, with the balance being Fe and other unavoidable impurities. The rotary guide components of this invention have fine and uniform grains and excellent mechanical and corrosion resistance.

The invention relates to the technical field of preparation of advanced ceramic materials, and provides a high-temperature fast firing method for alumina ceramics in order to solve the problems that a traditional gas furnace is too long in sintering period and cannot meet emergency production requirements and the quality problem occurs when a traditional process is directly transplanted to an electric furnace. The temperature transition from room temperature to the target sintering temperature is ensured to be completed within a short time, meanwhile, the densification, grain growth and other processes of the ceramic material are ensured to be stably carried out through accurate temperature control in each stage, short-period high-quality sintering from a green body to a finished product is achieved, high-quality product preparation can be completed within 72-96 hours, and the production cost is reduced. The method is especially suitable for small-batch, multi-variety and emergency order production modes; parameters are flexibly adjusted and can be quickly optimized according to product requirements; and the adaptability to electric furnace models and specifications is high.

This application relates to a wire rod, an arc-sprayed wire, and a preparation method thereof, belonging to the technical field of arc-sprayed materials. The chemical composition of the wire rod, by mass fraction, is: C: 0.08%~0.14%, Si: 0.10%~0.60%, Mn: 1.50%~2.00%, P≤0.020%, S≤0.020%, Cr≤0.10%, Ni≤0.10%, Mo≤0.05%, Cu≤0.10%, Ti≤0.010%, Al≤0.020%, N≤0.010%, TO≤0.010%, with the remainder being Fe and unavoidable impurities. The wire is prepared by optimizing the chemical composition of the alloy wire rod through processes such as smelting, continuous casting, rolling, surface treatment, rough drawing, copper plating, and fine drawing. The mass fraction of Cu is 0.10%~0.25%, and the other elements are the same as those in the wire rod. This wire material has excellent wear and corrosion resistance and adhesion strength to the aluminum alloy substrate. It can form a stable protective coating on the inner wall of the engine cylinder, taking into account both the advantages of engine lightweighting and high performance requirements, and effectively supporting long-term service.

The application relates to a preparation method of a polyvinyl alcohol composite hydrogel coating and belongs to the field of coating preparation. The polyvinyl alcohol-silicon dioxide composite hydrogel coating is prepared on the surface of a substrate by coating technology and crosslinking treatment, with polyvinyl alcohol, an organic silicon source and polydopamine as main raw materials. The organic silicon source is fully hydrolyzed to obtain uniform silicon dioxide sol; the silicon dioxide sol is mixed with a polyvinyl alcohol solution to obtain a polyvinyl alcohol-silicon dioxide composite sol; the composite sol is uniformly coated on the surface of the substrate which has been modified by polydopamine; and the composite sol on the surface of the substrate is crosslinked to obtain the polyvinyl alcohol-silicon dioxide composite hydrogel coating. The obtained coating has a smooth surface and uniform microstructure, the required equipment is simple, the operation is convenient, the energy consumption and cost are low, the coating is environment-friendly and easy to be industrially produced. The coating can be used in the fields of biomedicine, crop planting, sewage treatment, cosmetics and the like.

The application belongs to the technical field of carbon dioxide mineralization curing concrete, and relates to a carbon dioxide mineralized concrete and carbon fixation device and method, which comprises a reaction kettle, a stirring system and a dry ice powder supply system. A rotating powder spraying arm coaxially connected with a stirring shaft is arranged in the reaction kettle, and powder spraying micropores for upward and horizontal spraying are arranged on the hollow arm body of the powder spraying arm. A flow guide groove penetrating through the upper surface and the lower surface of the stirring blade is arranged on the stirring blade, the inlet of the flow guide groove is located at the root of the upper surface of the blade, and the outlet is located at the middle of the lower surface and faces the powder spraying arm area. An adaptive baffle assembly composed of a movable baffle, a reset spring rod and a centrifugal counterweight is arranged at the inlet of the flow guide groove, which can automatically adjust the inlet opening according to the stirring speed. A cutting grid located below the powder spraying arm is further arranged in the reaction kettle. The application realizes the efficient and uniform mixing of dry ice powder and cement slurry through the space collision of rotating powder spraying and directional jet, centrifugal force adaptive adjustment and forced refinement of the cutting grid.

The invention relates to the field of ceramic materials, in particular to a preparation method of a high-thermal-conductivity aluminum nitride tape-casting green body and a ceramic chip thereof, and the high-thermal-conductivity aluminum nitride tape-casting green body is prepared from the following raw materials in parts by weight: 100 parts of aluminum nitride powder, 1.5-3.5 parts of a dispersing agent, 8-12 parts of a binder, 3-6 parts of a plasticizer, 1-5 parts of a sintering aid and 80-100 parts of water. According to the invention, due to the low hydrolytic property of the slurry, the uniform distribution of the sintering aid and the optimized sintering schedule, the thermal conductivity of the obtained ceramic wafer is stabilized at 200W / (m.K) or above, the ceramic wafer has a uniform and compact microstructure, the bending strength can reach 450MPa or above, and the requirement of high-end application on mechanical reliability is met.

This application belongs to the field of additive manufacturing technology, specifically a high-performance Alnico permanent magnet and its preparation method and system. The preparation method includes the following steps: using Alnico alloy powder as raw material, preparing an Alnico permanent magnet blank using selective laser melting, and controlling the process parameters of selective laser melting to ensure that the temperature gradient of the molten pool in a specific direction is ≤2.0×10⁻⁶. 7 K / m, and cooling rate ≤ 3.0 × 10 6 K / s, a specific direction perpendicular to the laser scanning plane and passing through the center of the molten pool; the Alnico permanent magnet blank is homogenized, subjected to magnetic field heat treatment, and tempered to obtain the Alnico permanent magnet. This application successfully achieved SLM forming of high-density, low-defect Alnico permanent magnets by precisely controlling the thermal history of the molten pool; it also has important reference and promotion value for the SLM forming of other high-entropy alloys, copper alloys, and other multi-component alloys with significant differences in element melting points and prone to segregation.

The invention discloses a core-shell structure mineralizer modification-based photocuring 3D printing aluminum-based ceramic core and a preparation method thereof. The aluminum-based ceramic core comprises the following substances in percentage by weight: 65-75% of aluminum-based ceramic powder, 5-15% of a core-shell structure mineralizer component and 15-25% of a photosensitive resin component. The preparation method comprises the following steps: preparing aluminum-based ceramic core slurry, and vacuumizing the aluminum-based ceramic core slurry; injecting the aluminum-based ceramic core slurry into a trough of 3D printing equipment, and printing an aluminum-based ceramic core blank; the aluminum-based ceramic core green body is subjected to ultrasonic cleaning and drying treatment; and the aluminum-based ceramic core blank is subjected to degreasing treatment and sintering treatment, and the photocuring 3D printing aluminum-based ceramic core based on core-shell structure mineralizer modification is prepared. According to the method, the sintering temperature of the 3D printing aluminum-based ceramic core blank can be effectively adjusted, generation of interlayer cracks in the degreasing and sintering process is reduced, and the aluminum-based ceramic core with excellent comprehensive performance is obtained.

The invention discloses a preparation method of a SiC fiber reinforced BeO crucible, which is used for solving the problem that the toughness, thermal shock resistance and compactness of the existing BeO crucible cannot be considered at the same time, and the preparation method comprises the following steps: respectively pretreating SiC fiber and BeO powder; mixing and ball-milling the pretreated SiC fibers, BeO powder, a dispersant, a binder, a plasticizer and a sintering aid in a solvent to obtain mixed slurry, and granulating the mixed slurry to obtain a mixture; performing cold isostatic pressing on the mixture to obtain a green body; and carrying out heat treatment strengthening on the green body to obtain the SiC fiber reinforced BeO crucible. The SiC fiber reinforced BeO crucible prepared by the method disclosed by the invention is high in density, high in toughness and excellent in thermal shock resistance.

The invention provides a thick-plate narrow-gap titanium alloy double-sided swing laser powder feeding additive process method, which is used for completing high-quality joint of titanium alloy plates with the thickness of 50mm and thicker and eliminating the defects of incomplete fusion, air holes, cracks, oxidation and the like. Welding deformation is reduced, the process stability is improved, and the problems of low efficiency and welding material waste caused by multi-layer and multi-pass traditional surfacing are solved; the heat input and the production cost are reduced, the production period is shortened, and meanwhile it is guaranteed that the mechanical property of a jointed structural part is superior to that of base metal. Through the integrated design of special device customization, accurate parameter matching and double-face symmetrical material adding, the design of a special symmetrical inverted trapezoidal groove, the design of an extensible red copper powder feeding pipe, the design of an extensible material adding protection cover and sectional type accurate process parameter matching are adopted.