53results about How to "Uniform grain size distribution" patented technology

The invention relates to a method for rolling fine-grained magnesium alloy with superplastic deformability. The method comprises the steps of low-rolling-reduction transverse rolling, high-rolling-reduction longitudinal asynchronous rolling, longitudinal reversed-direction rolling, low-temperature longitudinal rolling and annealing, and comprises the specific steps of heating a commercial magnesium alloy blank in a heating box, standing to preserve heat for a period of time after heating to a preset temperature, firstly pushing the magnesium alloy blank to an entrance of a rolling roller along the transverse direction, carrying out transverse rolling firstly, then, carrying out high-rolling-reduction longitudinal asynchronous rolling, then, carrying out longitudinal 180-degree-reversed rolling, then, carrying out low-temperature longitudinal rolling, and finally, carrying out low-temperature long-time annealing treatment or high-temperature short-time annealing treatment. According to the method, cracking during the rolling of the magnesium alloy can be reduced, the crystal grain of the magnesium alloy is refined, the texture is weakened, and the high-temperature plasticity of the magnesium alloy is improved; moreover, the process is simple and easy to operate, large-sized wide-width sheet materials can be prepared, and the formability of the magnesium alloy is improved remarkably, so that the method is applicable to the mass production of superplastic magnesium alloy and is prone to popularization and application.

The invention relates to a production method of a high-purity tantalum target material, which comprises the following steps: (1) placing a tantalum block of which the size is 5-10mm*5-10mm in a hydrogenation furnace, and performing hydrogen absorption; and (2) crushing the tantalum subjected to hydrogen absorption into 200-mesh powder, placing in a steel capsule, heating and performing air extraction at certain rates by stages, then placing the steel capsule in a hot isostatic press, sintering under the conditions that the sintering temperature is 1100-1500 DEG C and the atmosphere pressure is 50-200 MPa, and finally machining to cut into a specified shape. According to the invention, a powder metallurgy method is adopted, and specific process conditions are combined, so that the tantalum target material which is uniform in texture distribution, uniform in grain size distribution and small in grain size can be obtained; and the target material has high deposition speed, fine film uniformity and favorable film-forming property, and produces fewer electric arcs and particles. Above all, the method provided by the invention is simple in process and low in cost.

The invention discloses a Cu-doped ZnO/graphene composite photocatalyst and a preparation method thereof. The method comprises the following steps: mixing graphite oxide and a surfactant CTAB (cetyl trimethyl ammonium bromide) in distilled water and carrying out ultrasonic treatment to obtain a first precursor reactant; dissolving zinc acetate and cupric acetate in the distilled water and carrying out ultrasonic treatment to obtain a second precursor reactant; dissolving hexamethylenetetramine and sodium citrate in the distilled water and carrying out ultrasonic treatment to obtain a third precursor reactant; after mixing the first precursor reactant and the second precursor reactant, carrying out ultrasonic treatment, then mixing the obtained product and the third precursor reactant, controlling reaction temperature in the range of 70 DEG C to 120 DEG C and performing reaction; sealing, naturally cooling, standing and carrying out extraction filtration to obtain filter residues; and after drying the filter residues, carrying out annealing treatment. According to the invention, addition of graphene reduces electron-hole compounding possibility; and meanwhile, introduction of Cu ions can be used as an ion trap to temporarily capture a charge carrier and inhibit electron-hole compounding so as to obviously improve photocatalytic efficiency of the product.

The invention discloses a strontium titanate-based ceramic material with high energy storage density and low dielectric loss and a preparation method thereof. The method comprises the following steps: preparing materials according to a chemical formula which is expressed as (1-x)SrTiO[3-x]Bi0.48La0.02Na0.48Li0.02Ti0.98Zr0.02O3, mixing uniformly to obtain raw material powder, uniformly mixing organic solvents and emulsifiers, then adding the raw material powder, adhesives, dispersants and plasticizers, mixing uniformly, carrying out tape casting, then cutting and stacking, then pressurizing, discharging glue and sintering to obtain the strontium titanate-based ceramic material with high energy storage density and low dielectric loss. The ceramic material is simple in preparation process and mature in preparation technique, and is suitable for industrial production; the energy storage density calculated on the basis of ferroelectric hysteresis loop is 1.98-2.59j/cm<3>, the energy storage efficiency is 69-87%, and the electric field intensity is 200kV/cm or more; the ceramic material is excellent in energy storage characteristic and low in dielectric loss.

The invention discloses a preparation method of a low-cost and high-density ITO target material. The preparation method comprises the following steps that a dispersing agent and an adhesive are added into water and stirred evenly, the pH value is adjusted to be 8-11 with ammonium hydroxide, and a pre-mixed solution is obtained; the weight ratio of the dispersing agent to a mixture of citric acid and polyacrylamide is 1-2:1; ITO powder prepared through a chemical co-precipitation method and a sintering agent are added into the pre-mixed solution, then the pre-mixed solution is subjected to ball milling in a ball mill, mixed slurry is obtained after ball milling and stirred, and bubbles in the slurry are removed through vacuumizing; the sintering agent is composed of rare earth oxide, titanium nitride and nano GeO2; an aluminum mold is installed on a gypsum board, and the obtained slurry is poured into the aluminum mold; demolding and drying are conducted after the slurry is absorbed and molded, and an ITO blank is obtained; and the dried ITO blank is sintered in the normal-pressure pure oxygen atmosphere, and the ITO target material is obtained. Compared with the prior art, the product obtained through the preparation method is high in density, low in cost, low in electrical resistivity and uniform in grain dimension distribution.

The invention relates to an nanocrystalline rapid quenching rare-earth permanent magnet material, a minishing method of the grain size of the rare-earth permanent magnet material and a bonded permanent magnet. According to the method, a proper amount of Y, Ho or Gd and the like is added in the alloy smelting process, the feature that the enthalpy generated by (Y, Ho, Gd)-Fe is lower than that generated by Nd-Fe14 is made used of, the grain size of the nanocrystalline rapid quenching rare-earth permanent magnet material is effectively minished, the grain size distribution is more uniform, and the exchange coupling enhancement effect brought by grain size minishing achieves the improvement of residual magnetization; at the same time, since the magnetocrystalline anisotropy field of (Y, Ho, Gd)2Fe14B is larger than 0, coercive force losses caused by the exchange coupling effect can be compensated to a certain extent. Moreover, the uniform grain size distribution and the optimized grain boundary state also contribute to the increase of coercivity.

The invention provides a preparing method of a nanocrystal Sm<2>Co<17>/Co double-phase composite permanent magnetic alloy, and belongs to the technical field of double-phase composite permanent magnetic alloys. The method includes smelting a pure Sm block, a Co block and an elementary substance of an added element under the protection of argon to obtain a multi-component parent phase alloy; allowing phases and component distribution of the parent phase alloy to be uniform by a plurality of times of remelting and homogenizing annealing; preparing the parent phase alloy into amorphous powder by utilization of high-energy ball milling under the protection of an inert gas; preparing the amorphous powder into an initial nanocrystal alloy block which is a metastable phase alloy by spark plasma sintering; and preparing the nanocrystal Sm<2>Co<17>/Co double-phase composite permanent magnetic alloy by a thermal treatment process. The method has advantages of uniform crystal grain size distribution, controllable crystal grain size, controllable phase composition, controllable phase stability, and the like.

The invention discloses a continuous casting technology of a belt material aluminum pipe and aluminum alloy rotating target materials. The method comprises the steps of screened pipe preparing, aluminum or aluminum alloy melting and metal liquid casting and molding. By means of the technology, the micro-structure of the surface of the screened pipe is improved, the binding force between the metal aluminum and a steel pipe is increased, it is guaranteed that the metal aluminum in the liquid phase is combined with the steel pipe completely and firmly in the solidification process, and in the subsequent using process, it is guaranteed that the metal aluminum in the liquid phase is not separated from the steel pipe; all the elements are mixed uniformly, by controlling the atmosphere of a casting furnace body, the pouring speed and the cooling speed, it is guaranteed that the great micro-structure is obtained by the target materials, the combination degree between the target materials and the steel pipe is guaranteed, and air pores are prevented from occurring. The utilization rate of the target materials is improved, and the service lives of the target materials are prolonged; the production cost is reduced, the compactness of the target materials is high, gains are uniform in size and distribution, and the technology is applicable to the manufacturing of connecting membranes of flat display panels.

The invention discloses a temperature-controlled rolling technology of magnesium alloy coiled sheets. The steps comprise: (1) performing heating compensation on a magnesium coiled sheet and uncoiling the magnesium coiled sheet; (2) performing sheet heating compensation and adjusting turning directions of the magnesium alloy sheets; (3) measuring tension of the sheet and controlling a crimp force value; (4) performing integrated temperature control on a part which is to bite into the sheet; (5) performing gradient temperature control on the width direction of the part which is to bite into the sheet; (6) through a temperature-controlled roll, performing finishing rolling on the sheet and the sheet deforming; (7) measuring tension of the sheet and controlling a crimp force; (8) performing sheet heating compensation and adjusting turning directions of the magnesium alloy sheets; (9) performing sheet heating compensation and coiling the sheet in rolls; (10) if the thickness of the magnesium plate coil sheet does not reach the thickness (t0) of a target magnesium plate, reversely repeating the steps (1)-(9) on magnesium coiled sheets on a reversible temperature-controlled rolling mill according to the process steps, performing next temperature-controlled finish rolling processing; (11) if the thickness of the magnesium sheet reaches the thickness (t0) of the target magnesium plate, obtaining the magnesium alloy coiled sheet satisfying the thickness requirements.

The invention discloses a lead-free ceramic material with high energy storage density and energy storage efficiency and a preparation method thereof. The preparation method comprises the following steps of mixing materials according to a chemical formula (1-x)SrTiO3-x(0.93Bi0.5Na0.5TiO3-0.07Ba0.94La0.04Zr0.02Ti0.98O3), uniformly mixing, so as to obtain raw-material powder, uniformly mixing an organic solvent and an emulsifier, then adding the raw-material powder, a binder, a dispersant and a plasticizer, then uniformly mixing, carrying out tape casing, and then cutting, superposing, pressurizing, discharging glue and sintering, so that a strontium titanate based lead-free high-pressure-resistant ceramic energy storage material is obtained. The ceramic material provided by the invention is simple in preparation process, mature in technique, suitable for industrialized production and excellent in energy storage property, and has the energy storage density of 1.80J/cm<3> to 2.83J/cm<3>, the energy storage efficiency of 74 to 87 percent and the electric field intensity of 175kV/cm to 326kV/cm, which are calculated based on an electric hysteresis loop.

The invention relates to a propenyl ethanoate catalyst and a preparation method of the propenyl ethanoate catalyst, in order to mainly solve the problem of low space time yield and selectivity of the catalyst in the prior art. According to the invention, a catalyst for synthesizing propenyl ethanoate is adopted, and SiO2, Al2O3 or the mixture of the SiO2 and Al2O3 are taken as carriers; load active components comprises metal palladium, metal copper and alkali metal acetate; in the catalyst, the content of palladium is 1-12g/L, the content of copper is 0.1-10g/L, and the content of alkali metal acetate is 10-100g/L, wherein the average particle size of palladium copper is 4-10nm, and the number of crystalline grains within the range of -20% to 20% of the average particle size is 60-80% of all the crystalline particles. The technical scheme of the preparation method solves the problem well, and can be used for the industrial production of propenyl ethanoate.

The invention discloses a method for producing an iron-zinc alloy coated steel plate with the yield strength being equal to or higher than 220 MPa. The method comprises the steps that molten iron desulphurization, smelting through a converter and continuous casting are conducted, so that a billet is formed; hot rolling is conducted; rolling is conducted; cold rolling is conducted till the billet reaches the required thickness; continuous hot galvanizing is conducted; rapid cooling is conducted; aerial fog is used for cooling after zinc and iron are alloyed; finishing is conducted; oiling treatment is conducted; and sampling, performance testing and subsequence procedure treatment are conducted. According to the method for producing the iron-zinc alloy coated steel plate with the yield strength being equal to or higher than 220 MPa, on the premise that the yield strength ranges from 220 MPa to 260 MPa, the tensile strength ranges from 300 MPa to 380 MPa, and the elongation is equal to or higher than 43%, grains on the surface of a zinc-iron alloy coating are fine and are even in size distribution, the area ratio of holes in the surface of the coating is equal to or smaller than 5%, no microcrack exists on the surface, and the phenomena of pulverization and falling of the coating are unlikely to occur during stamping forming, namely the 90-degree V bending test grade reaches the level 2.

The invention discloses a non-uniform hard alloy prepared by adopting a close-packed batching mode, and relates to the technical field of hard alloys. The hard alloy is prepared from the following rawmaterials: coarse-particle tungsten carbide, medium-particle tungsten carbide and nano-particle tungsten carbide powder. The invention further provides a preparation technology process method of thehard alloy. The non-uniform hard alloy has the beneficial effects that the average grain size of the prepared hard alloy is 5-10 microns, the coarse grain size reaches 10-20 microns, the Vickers hardness is 1050 or above, the bending strength TRS is 2200MPa or above, the metallographic structure of alloy grains is thick and large, the heat conductivity is extremely high, the thermal fatigue resistance and the thermal impact resistance are good, and the non-uniform hard alloy can be used for continuous exploitation of soft rock under extreme working conditions and the like.

The invention discloses copper and silver co-doped nano-zinc oxide used as a photocatalyst, and a preparation method of the copper and silver co-doped nano-zinc oxide. A sol-gel method is adopted, metal alkoxides (copper acetate and zinc acetate) and acid salt (silver nitrate) are used as raw materials and dissolved in a solvent to form gel with a certain spatial structure, finally drying and heattreatment processes are carried out, and thus the copper and silver co-doped nano-zinc oxide uniform in particle size and high in purity can be prepared. Copper and sliver are doped in zinc oxide, sothat the production cost is reduced and industrial production is achieved while the catalytic activity of the nano-zinc oxide is improved.