57results about How to "Uniform precipitation" patented technology

The invention relates to high-performance low-cost microalloyed steel for an automobile I-shaped front axle and a preparation method of the microalloyed steel, and belongs to the technical field of materials. The steel comprises the following chemical components in percentage by weight: 0.20 to 0.60 percent of C, 0.2 to 1.0 percent of Mn, 0.1 to 0.5 percent of Si, 0.6 to 1.2 percent of Cr, 0.01 to 0.10 percent of Nb, 0.01 to 0.06 percent of Mo and the balance of Plt, 0.01%, Slt; 0.01%, Olt; 0.0040%, and the balance being iron. According to the invention, the contents of Nb and C key alloy elements in the material are accurately controlled, so that Nb can be completely dissolved into a matrix in the smelting process, and the phenomenon of one-time NbC liquation is avoided. Heat treatment is directly carried out after smelting and casting, and the component control strategy is adopted, so that the precipitation of nano-sized dispersed NbC on an original austenite grain boundary is promoted, austenite grains are effectively pinned, and a microstructure with uniform and fine grain size is obtained; a martensitic structure is obtained through quenching, and uniform dispersion and precipitation of NbC carbide are realized in the martensitic structure through a subsequent tempering process, so that the strength and the toughness of the I-shaped front axle are ensured to reach the best match.

The invention discloses a welding material, a welding material, application and a preparation method, and the welding material comprises the following raw materials by weight percent: 1%-3% of Si, 1.2%-3.2% of Mg, 1%-3.6% of Zn, 0.6%-1.6% of Cu, 0.5%-0.8% of Mn, 0.2%-0.45% of Cr, 0.1%-0.25% of Ti, 0.05%-0.1% of Zr, 0.05%-0.1% of Sc, and the balance of Fe. 0.2%, and the balance being Al and inevitable impurities. By regulating and controlling the contents of Zn, Cu, Mg and Si elements, the precipitation enthalpy of a nanoscale strengthening phase is reduced, so that the bake hardening effect of a welding seam is improved, and the problem that the welding seam is excessively softened due to melting of the nanoscale precipitation phase is solved. In addition, the Fe-containing brittle phase characteristic in the weld joint is improved by adding Mn and Cr elements, and the hot crack tendency of the weld joint is reduced by combining Zr, Sc, Ti and other grain refinement elements, so that the strength and toughness of the weld joint are further improved.

The invention discloses a lithium hexafluorophosphate crystallization and separation device, and relates to the technical field of lithium hexafluorophosphate crystallization and separation, the lithium hexafluorophosphate crystallization and separation device comprises a fixed seat and support legs symmetrically fixed on the periphery of the bottom of the fixed seat, the interior of the fixed seat is fixedly connected with an outer box body, and the lithium hexafluorophosphate crystallization and separation device further comprises an air inlet, an air outlet and an air outlet, an air outlet is formed in the other side of the top of the outer box body; the liquid outlet is formed in the middle of the bottom of the outer box body; the outer barrel body is installed in the outer box body, an inner barrel body is connected to the interior of the outer barrel body in a clamped mode, and a cleaning brush is installed on the lower portion of the partition plate; the swing mechanism is arranged on one side of the outer barrel; and the cleaning mechanism is arranged below the partition plate, and the problems that a lithium hexafluorophosphate solution in the device is in direct contact with the barrel for a long time, so that the barrel is easily corroded and damaged, and large lithium hexafluorophosphate crystals are still possibly contained in the device during discharging, so that the subsequent smooth discharging of the lithium hexafluorophosphate crystals is inconvenient are solved.

The invention discloses a preparation method of a low-density high-thermal-conductivity copper-based graphite heat sink material, which comprises the following steps of: 1, selecting one or more than two copper alloy powder of CuZr powder, CuCr powder and CuCrZr powder as matrix powder, and mechanically ball-milling and mixing the matrix powder with graphite powder; 2, sintering the mixed powder to obtain a sintered body; and 3, carrying out aging heat treatment on the sintered body to obtain the low-density high-thermal-conductivity copper-based graphite heat sink material. The reinforced phase raw material graphite powder is added into the copper alloy powder to be mixed and sintered, so that a carbide ceramic phase is generated in situ, a ceramic phase transition layer is formed, the interface bonding capacity between a copper matrix and graphite is improved, the copper alloy powder with different components and sizes is used at the same time, a heterostructure matrix structure is formed, and the performance of the composite material is improved. The strength and plasticity of the copper-based graphite heat sink material are improved, so that the copper-based graphite heat sink material has excellent mechanical properties and thermal conductivity, and is simple in process, low in cost and suitable for the field of heat sink materials.

The invention belongs to the technical field of corrosion-resistant steel bar preparation, and particularly relates to a rolling process of a chloride ion corrosion-resistant steel bar for 500 MPa-grade reinforced concrete. The rolling technology provided by the invention comprises the following steps that molten steel obtained after smelting is subjected to continuous casting, a continuous casting billet is obtained, and the continuous casting billet comprises the following components in percentage by weight: 0.08%-0.09% of C, 1.00%-1.02% of Cr, 0.20%-0.22% of Cu, 0.20%-0.22% of Mo, 0.24%-0.28% of Si, 0.4%-0.42% of Mn, 0.03%-0.035% of V, 0.04%-0.045% of N, smaller than or equal to 0.02% of P, smaller than or equal to 0.01% of S and the balance of iron and inevitable impurities; the continuous casting billet is heated, rough rolling and finish rolling are sequentially conducted on the heated continuous casting billet, cooling is conducted after finish rolling, and the chloride ion corrosion resistant steel bar is obtained; the rough rolling pass is 5-7 times, the reduction rate of the first pass is 10-15%, the reduction rate of the last pass is 10-15%, and the reduction rate of the middle pass is 25-30%. By means of the rolling technology, high strength is achieved, and meanwhile excellent chloride ion corrosion resistance is achieved.

The invention provides an electric arc additive manufacturing high-corrosion-resistance magnesium alloy component and a preparation method and application thereof.The preparation method of the electric arc additive manufacturing high-corrosion-resistance magnesium alloy component comprises the following steps that a magnesium alloy base plate is fixed to a workbench provided with a heating plate, and the heating plate is provided with a thermocouple; the thermocouple is connected with the temperature control box to control the temperature of the heating plate so as to realize constant-temperature heating of the magnesium alloy substrate; and the magnesium alloy wire is fixed to wire feeding equipment, single-channel layer-by-layer reciprocating deposition is carried out along the set track according to the set welding machine technological parameters till the target height is reached, and the high-corrosion-resistance magnesium alloy component is obtained. According to the method, the temperature of the magnesium alloy substrate and the interlayer temperature are controlled at a constant temperature through the external temperature field, the manufacturing process parameters are adjusted, the interlayer binding force and the forming quality of the magnesium alloy component are improved, and the prepared high-corrosion-resistance magnesium alloy is small in grain size and uniform in precipitated phase distribution and shows excellent corrosion resistance compared with a traditional cast magnesium alloy.

The invention relates to the technical field of aluminum alloy materials, in particular to an aluminum alloy material, an aluminum alloy conductor wire core and a preparation method and application of the aluminum alloy conductor wire core. The aluminum alloy material comprises, by mass, 0.3%-1.0% of iron (Fe), 0.03%-0.2% of magnesium (Mg), 0.1%-0.8% of manganese (Mn), 0.08%-0.3% of zirconium (Zr), 0.004%-0.03% of boron (B), 0.015%-0.65% of rare earth (RE), 0-0.12% of silicon (Si) and the balance aluminum (Al) and inevitable impurities, the single impurity is not larger than 0.03%, and the sum of the impurities is not larger than 0.1%. Wherein the rare earth (RE) is prepared from the following components in percentage by mass: 0.003 to 0.1 percent of lanthanum (La), 0.004 to 0.15 percent of cerium (Ce) and 0.008 to 0.4 percent of scandium (Sc). The prepared aluminum alloy material has the characteristics of high conductivity, high strength, heat resistance, corrosion resistance and good fracture and impact toughness, is very suitable for being used as a cable conductor, and is particularly applied to places with high requirements on high temperature, vibration, movement, corrosion and the like, such as power cables, electrical connecting wires, drag chain cables applied to metal smelting places and the like.

The invention discloses a preparation method and application of a lithium ion battery positive electrode material manganese-titanium precursor. The preparation process of the manganese-titanium precursor comprises the following steps: adding a mixed metal salt solution prepared from a manganese-titanium mixed salt solution and a complexing agent and a precipitant solution into a reaction kettle in a parallel flow manner, and carrying out a co-precipitation reaction to prepare the manganese-titanium precursor with uniform manganese-titanium precipitation and uniform morphology. According to the invention, the manganese-titanium precursor with uniform manganese-titanium coprecipitation and uniform morphology can be prepared, the lithium ion battery prepared from the positive electrode material obtained by sintering the manganese-titanium precursor and the lithium source at high temperature has excellent electrochemical properties such as high capacity, high energy density and long cycle service life, and the preparation cost is relatively low.

The invention discloses a preparation method and application of a lithium manganese iron phosphate secondary microsphere with a porous structure, and belongs to the technical field of a lithium ion battery positive electrode material. The chemical formula of the lithium manganese iron phosphate secondary microspheres is LiMn < 0.5 > Fe < 0.5 > PO4, and the lithium manganese iron phosphate secondary microspheres are prepared by spray drying of a plurality of sheet-shaped lithium manganese iron phosphate primary nanoparticles; according to the preparation method, a surfactant is added in the preparation process to induce generation of sheet-shaped lithium manganese iron phosphate nanoparticles, then primary nanoparticles are assembled into lithium manganese iron phosphate secondary microspheres through spray drying, and the formed lithium manganese iron phosphate secondary microspheres are regular in morphology and have a porous structure; electrolyte infiltration and a shorter ion transmission path are facilitated, and the rate capability of the material as a positive electrode material can be effectively improved.

The utility model discloses a brake disc casting mold which comprises a pouring cup and a mold core, the transverse pouring gates comprise the first transverse pouring gate and the second transverse pouring gate, the first transverse pouring gate is connected with the pouring cup and extends outwards in the first direction, the second transverse pouring gate is connected with the pouring cup and extends outwards in the second direction, and a first included angle space is formed between the first transverse pouring gate and the second transverse pouring gate; the cavity is provided with a first inlet and a second inlet, and the first inlet and the second inlet are symmetrically distributed on the two sides of the cavity relative to the center of the cavity; wherein the mold cavity comprises a first mold cavity, the first mold cavity is arranged in the first included angle space, the first cross gate is connected to a first inlet of the first mold cavity through the first flow gate, and the second cross gate is connected to a second inlet of the first mold cavity through the second flow gate. The brake disc casting mold is excellent and stable in mechanical property, the brake performance of a whole vehicle can be improved, meanwhile, defective products can be reduced, and the production and management cost of an enterprise is reduced.

The present invention belongs to the technical field of aluminum alloy wires, and specifically relates to a high-conductivity, heat-resistant, high-elongation aluminum alloy wire and its application. The present invention defines the composition as follows: Zr 0.065-0.075%, Er 0.11-0.14%, B 0.032-0.038%, Fe 0.040-0.048%, Si 0.041-0.045%, (V+Ti+Cr+Mn) 0.012-0.018%, and the balance is aluminum. Through the setting of alloy composition, continuous casting and rolling process and intermediate annealing process, the alloy uniformly precipitates heat-resistant dispersed phase particles during the intermediate annealing process, thereby improving the heat resistance of the aluminum alloy. Through differential temperature drawing, the work hardening of aluminum alloy wire rods can be annealed and recovered online in time, reducing the traditional offline annealing process and facilitating the continuity of drawing. Combined with a single deep cold drawing process, the shape of the finished wire is fully corrected and the surface quality is improved. The conductivity, strength and elongation are then adjusted through annealing of the finished product. Finally, through the synergistic effect of the mechanism, the aluminum alloy wire has the characteristics of high conductivity, high elongation and heat resistance.

A high-alloy steel electroslag ingot and its homogenization method are provided, comprising the following steps: S1, electroslag ingot pretreatment: removing surface oxide scale and crack defects, and grinding to a surface roughness Ra≤6.3μm; S2, staged heating: heating to 800-900℃ at a rate ≤100℃ / h and holding for 2-6h; heating to 1000-1100℃ at a rate ≤100℃ / h and holding for 2-6h; heating to 1200-1300℃ at a rate ≤150℃ / h and holding for 10h. -20h; S3, Stepped cooling: Turn off the heating device and cool with the furnace to 800-1000℃, hold for 2-6h; cool to 500-650℃ at a rate of ≤50℃ / h, hold for 2-6h; open the furnace door and introduce cooling air at a speed of 0.5-3m / s to cool to room temperature, obtaining homogenized high-alloy steel electroslag ingots; S4, Post-homogenization testing: the relative standard deviation of each alloying element is ≤5%; the average grain size is ≤10μm; the Brinell hardness fluctuation range is ≤15HBW. This invention eliminates component segregation, refines grain structure, optimizes process parameters, is highly efficient and energy-saving, easy to promote, and has strong practicality.

This invention discloses a free-machining high-strength aluminum-lithium alloy, its preparation method, and its applications, belonging to the field of alloy materials technology. The free-machining high-strength aluminum-lithium alloy has the following weight percentages of elements: Li: 3.5–5.5%, Cu: 2.6–3.1%, Zn: 6.8–7.1%, Mg: 2.1–3.0%, Y: 1.5–4.0%, Bi: 0.85–1.05%, In: 0.05–0.08%, Cr: 0.05–0.45%, Ti: 0.02–0.04%, with the balance being Al. This invention involves batching, smelting, refining, online refining, online degassing and filtration, casting, homogenization, extrusion, and two-stage aging treatment to finally obtain a free-machining high-strength aluminum-lithium alloy with a uniform microstructure. This invention has a reasonable component ratio, low manufacturing cost, and the resulting product has excellent strength and hardness, and exhibits excellent surface finish after dry machining.

The invention discloses a novel green and environment-friendly magnesium air battery anode material and a preparation method thereof. The anode material comprises the following components: 1.0-5.0% of Ga, 0.5-5.0% of Sn, 0-3.0% of In and the balance of Mg, wherein the content of impurity elements is controlled as follows: less than 0.01% of Fe, less than 0.01% of Ni and less than 0.01% of Cu. The preparation method comprises the following steps: (1) performing alloy preparation in an induction heating furnace, adding Mg and Sn in the form of pure metal, raising the temperature to 690-710 DEG C under the atmosphere of protective gas, adding Mg-Ga and Mg-In intermediate alloy after all additives are molten, continuously stirring, controlling the temperature to 720-740 DEG C, and controlling the stirring time to 10-20 minutes; (2) after stirring is completed, pouring into a mold, further cooling the mold to 600-650 DEG C, then rapidly cooling, controlling the temperature to 350-400 DEG C, and then carrying out heat preservation for 5-24 hours; and after heat preservation is finished, water cooling is rapidly conducted to the room temperature, and a cast ingot is obtained after the mold is removed.

The invention discloses an aluminum beryllium enhanced high-conductivity heat-resistant aluminum alloy material and a preparation method thereof, and belongs to the technical field of metallurgical wire rod processing. The aluminum beryllium enhanced high-conductivity heat-resistant aluminum alloy material is prepared from the following components in percentage by weight: 0.12 to 0.16 percent of Si, 0.15 to 0.35 percent of Fe, 0.005 to 0.10 percent of Cu, 0.35 to 0.85 percent of Zr, 0.2 to 0.45 percent of Y, 0.15 to 0.35 percent of Er, 0.005 to 0.03 percent of B, 0.001 to 0.02 percent of Ti, 0.03 to 0.05 percent of Be, less than or equal to 0.5 percent of other impurities and the balance of Al. According to the aluminum alloy single wire, the specific raw material composition is adopted, namely, multiple elements such as Zr, Y, Er and Be are compositely added, and the proportion of the elements is strictly controlled, so that the prepared aluminum alloy single wire achieves synergistic improvement of high strength, high conductivity and excellent heat resistance.

This invention relates to a crystallization apparatus for preparing lithium hexafluorophosphate, comprising: a tank body, a feeding device provided on the top surface of the tank body, and an array of heat exchange components provided on the inner wall of the tank body. The heat exchange components include several heat exchange plates disposed on the inner wall of the tank body and arranged along the length of the tank body. This apparatus can increase the heat exchange area and enhance the heat exchange efficiency, enabling the uniform and rapid precipitation of lithium hexafluorophosphate crystals, and achieving continuous production with simultaneous crystallization and scale prevention.

The invention provides a preparation method of high-whiteness aluminum hydroxide, and belongs to the field of aluminum hydroxide preparation. The method comprises the following steps: carrying out light burning on aluminum hydroxide to decompose organic matters in the aluminum hydroxide so as to obtain light-burned aluminum oxide; pulping the light calcined alumina and liquid caustic soda to obtain first mixed slurry; under a closed condition, carrying out reaction dissolution on the first mixed slurry to obtain a dissolution solution; carrying out solid-liquid separation on the dissolved solution to obtain a sodium aluminate solution with set alpha k; adding high-whiteness aluminum hydroxide seeds into the sodium aluminate solution for seed decomposition to obtain second mixed slurry; and carrying out solid-liquid separation on the second mixed slurry to obtain the high-whiteness aluminum hydroxide. Compared with the traditional sintering process, the method provided by the invention has the advantages of low energy consumption, small pollution and good decolorization effect, and can reach the whiteness of aluminum hydroxide prepared by the sintering process.

The present application relates to a short process forging method of Ti1100 alloy bar, which is used to solve at least one of the problems of long time, low production efficiency, poor mechanical properties, poor process stability, poor consistency of different batches, high cost and the like in the prior art forging method. The forging method controls the heating times of blooming forging and trans-phase zone forging, and cooperates with gradient air cooling treatment. Specifically, in the organization control, the conventional multi-heating-time beta phase zone upsetting and drawing forging is abandoned, the single-heating-time beta phase zone precise temperature control and dynamic deformation regulation are adopted, the excessive growth of beta grains is avoided, and the needle-like alpha phase lamellar aggregation or equiaxed alpha phase abnormal precipitation is prevented by combining with gradient air cooling, so as to ensure the uniformity of the organization, solve the problems of mechanical property fluctuation exceeding the index and low service reliability.

The invention belongs to the field of sodium-ion batteries, and particularly relates to a sodium-ion battery positive electrode material and a preparation method and application thereof. The preparation method comprises the following steps: S1, carrying out first mixing on a nickel source, a manganese source, a tellurium source and water to obtain a mixed solution, adding a precipitator and a chelating agent, and carrying out reaction, aging and first drying to obtain a precursor; and S2, carrying out second mixing on the precursor, a sodium source and a calcium source, carrying out second drying, compacting, and sintering to obtain the sodium ion battery positive electrode material, the tellurium element is introduced to regulate and control the particle morphology of a precursor microstructure and realize an in-layer Te-Ni-Ni-Te ordered upper layer structure, the ligand level structure is adjusted, and lattice oxygen loss is inhibited; the calcium element is added to maintain the cation content in the sodium layer and relieve O2-O2-rejection in the sodium extraction process, so that the prepared sodium ion battery positive electrode material can maintain a pure P2 type structure and has excellent capacity performance and cycle performance.

This invention discloses a catalyst for the production of ethylene and propylene, its preparation method, and its applications. The catalyst comprises the following components: I) 1%–10% of chemical formula A x B y D z A compound of O4; in the chemical formula, the oxidation states of elements A, B, and D are m, n, and p, respectively, satisfying x·m + y·n + z·p = 8, where m, n, and p are integers not greater than 3; the A x B y D z O4 has a spinel structure; II) 0.5%–10% is selected from at least one oxide of rare earth elements, P, Mo, and W; III) 20.0%–55.0% is selected from at least one zeolite of ZSM-5 and ZSM-11; IV) 10%–30% is a binder; V) 25.0%–60.0% is clay. This catalyst is used in the catalytic cracking of petroleum hydrocarbons to produce ethylene and propylene, and features good catalyst stability, low methane yield, and high ethylene and propylene yields.

This invention relates to the field of high-temperature alloy technology, specifically to a notch-free GH4141 high-temperature alloy forging bar and its preparation method. In the microstructure of this GH4141 high-temperature alloy forging bar, M6C carbides are distributed in spherical granular form at the grain boundaries; the forging bar exhibits a high-temperature notch creep rupture time ≥40h under 732℃ temperature and 603MPa stress conditions, and the fracture locations are all located in the smooth segment.

The application discloses a low-cost high-strength aluminum-lithium alloy for a space cabin body and a preparation method thereof, and belongs to the technical field of aluminum-lithium alloys.The aluminum-lithium alloy comprises the following components in mass fraction: 91.5-94.5 parts of aluminum, 3.9-4.2 parts of copper, 1.0-1.5 parts of lithium, 0.2-1.0 parts of magnesium, 0.2-0.4 parts of silver, 0.3-0.8 parts of zinc, 0.10-0.12 parts of zirconium and 0.15-0.25 parts of mixed rare earth; the mixed rare earth is a mixed rare earth of cerium and lanthanum, and the mass ratio of cerium to lanthanum is (1.5-2.5):1; the total mass of metal impurities in the aluminum-lithium alloy is not more than 0.15 parts, and the single metal impurity is not more than 0.05 parts; through multi-component micro-alloying design and a precise controllable thermal mechanical treatment process, the application solves the technical problems that the existing aluminum-lithium alloy is high in cost due to the dependence on high-content noble metals and is anisotropic in mechanical properties due to strong deformation texture, and provides an ideal material which is excellent in comprehensive performance and economically feasible for a space cabin structure.

The invention relates to the technical field of sodium perchlorate preparation, and discloses a plate net type electrolytic bath for sodium perchlorate preparation, the plate net type electrolytic bath comprises an electrolytic bath body and two top covers, the top covers on the two sides are clamped to the top of the electrolytic bath body, and air outlet pipes are fixedly connected to the middles of the top covers on the two sides; a bubble uniform precipitation triggering assembly used for uniformly regulating and controlling gas precipitated from the cathode and the anode is arranged in the electrolytic bath body; an anode protection adjusting assembly used for releasing the concentration of chlorine around the anode in real time is arranged in the side, close to the anode, of the gas outlet pipe; the positions and forms of hydrogen and chlorine generated in the cathode chamber and the anode chamber are detected through the ultrasonic sensor, the distance between the cathode plate and the anode plate is adjusted, heat in the electrolytic bath is neutralized, bubble aggregation of two gases in the cathode chamber and the anode chamber is avoided, uniform separation of the gases is facilitated, and the production efficiency is improved. And meanwhile, meshes of the nickel wire meshes on the two sides are treated through linkage adjustment, and normal proceeding of the subsequent electrolysis process is guaranteed.

The present invention belongs to the technical field of alkali metal ion batteries, and discloses a negative electrode of a lithium / sodium ion battery with a dual gradient structure and a preparation method thereof. The dual gradient negative electrode is a double gradient sandwich structure constructed by a current collector modified with a strong lithium / sodium-philic conductive layer at the bottom of the negative electrode, an active layer in the middle of the negative electrode, and a lithium / sodium-phobic insulating passivation layer at the top of the negative electrode, wherein the bottom of the negative electrode is lithium / sodium-philic and conductive, the middle negative electrode active layer has moderate lithium / sodium-philicity and conductivity, and the top is lithium / sodium-phobic and insulating. By introducing a conductive and lithium / sodium-philic component at the bottom of the negative electrode with a low lithium / sodium nucleation barrier, after the negative electrode active layer accommodates lithium / sodium, it can induce excess lithium / sodium ions to nucleate and grow from the bottom of the negative electrode, avoid lithium / sodium precipitation on the surface of the negative electrode, effectively utilize the lower layer space of the negative electrode, realize dual-phase lithium / sodium storage, and greatly improve the specific capacity and cycle life of the negative electrode. At the same time, the insulating lithium-repellent passivation layer on the negative electrode surface is not only thin, but also well preserves the original pore structure of the negative electrode active layer, and has little effect on the wettability of the electrolyte and the diffusion process of lithium / sodium ions. Moreover, the insulating lithium-repellent property effectively hinders the reduction growth of lithium / sodium on the electrode surface. The synergistic effect of the dual-gradient structure not only greatly improves the specific capacity of the negative electrode through the dual-phase lithium / sodium storage characteristics, but also prevents the occurrence of lithium / sodium precipitation on the surface, significantly improving the cycle performance of the battery.

The invention relates to the technical field of magnesium phosphate cement materials, and particularly discloses a magnesium potassium phosphate cement-based material with high compactness and high salt corrosion resistance and application of the magnesium potassium phosphate cement-based material. The magnesium potassium phosphate cement-based material is prepared from the following components in parts by weight: 30 to 40 parts of dead burned magnesium oxide, 15 to 20 parts of monopotassium phosphate, 3 to 5 parts of retarder, 0.01 to 0.03 part of crystalline phosphate, 30 to 40 parts of fine aggregate and 8 to 13 parts of mixing water. Wherein the molecular formula of the crystalline phosphate is KNaMg2 (PO4) 2.14 H2O. By introducing the crystalline phosphate in a special structural form, the hydration evolution path and the microstructure of the magnesium potassium phosphate cement-based material in a salt erosion environment are effectively improved, and the salt erosion resistance is remarkably improved.

The invention relates to the field of spherical silicon micropowder preparation, and discloses a method for preparing spherical silicon micropowder for LED display device packaging material. The method comprises the following steps: taking fatty alcohol polyoxyethylene ether, anhydrous ethanol, a sodium silicate solution and ethyl acetate to react to obtain a filter cake; adding PEG1500 to the filter cake to obtain powder A; calcining the powder A in a nitrogen atmosphere and an air atmosphere in sequence to obtain a primary product; taking the primary product and adding sodium chloroacetate to react to obtain a carboxylation primary product; taking the carboxylation primary product and adding thionyl chloride to react to obtain an acyl chloride primary product; and modifying the acyl chloride primary product with an antioxidant to obtain the spherical silicon micropowder. According to the invention, PEG1500 is added and calcined in nitrogen and air atmospheres to block high-temperature hard agglomeration of particles, and an antioxidant is modified on the surface of the primary product, which is beneficial to the dispersion of the spherical silicon micropowder in an organic matrix of an epoxy molding compound, and at the same time, the epoxy molding compound is given more excellent mechanical properties and antioxidant properties.

The invention belongs to the technical field of electronic materials, and discloses a magnesium-strontium double-doped calcium fluoride crystal and a preparation method and application thereof.The method comprises the steps that firstly, disodium ethylene diamine tetraacetate is chelated with calcium and magnesium ions, and the calcium and magnesium ions and villiaumite are subjected to a coordination exchange reaction to prepare a magnesium-doped calcium fluoride microsphere precursor; regulating and controlling hydrolysis of 3-aminopropyltriethoxysilane through an absolute ethyl alcohol-deionized water mixed solvent, and realizing uniform anchoring and deposition of strontium ions by virtue of an interface connection effect of the 3-aminopropyltriethoxysilane, so as to construct a magnesium-strontium double-doped precursor with a core-shell structure; carrying out hot pressed sintering in a CF4 / Ar mixed atmosphere to obtain a high-density polycrystalline blank; and finally, finishing crystal oriented growth by adopting a Bridgman-Stockbarger method. Through the synergistic effect of the components in the whole process, gradient uniform doping of magnesium and strontium ions is achieved, lattice distortion is effectively eliminated, the optical uniformity, the anti-laser-damage threshold value and the mechanical stability of the crystal are improved, and the prepared crystal can be widely applied to manufacturing of special electronic materials such as semiconductor wafers and the like and has good industrialization prospects.

This invention relates to the field of hot extrusion manufacturing technology, specifically to a high-strength weldable 6xxx series aluminum alloy profile, its manufacturing method, and its application. The aluminum alloy profile is composed of the following weight percentages: Si: 0.80%~1.2%, Fe≤0.20%, Cu: 0.40%~0.80%, Mn: 0.30%~0.70%, Mg: 0.70%~1.1%, Cr≤0.25%, Zn≤0.10%, Ti≤0.10%, Zr: 0.05%-0.20%, Pb<0.01%, with the balance being Al and unavoidable impurities. The profile meets the following performance requirements: tensile properties, R... m ≥420MPa, R p0.2 ≥330MPa, A 50mm ≥8.0%; Fatigue performance: at r=0.1, N=1×10 7 Under the same conditions, the fatigue strength σ of the smooth sample is ≥145MPa, realizing the lightweight manufacturing of high-speed trains.

The invention discloses a high-performance Cu-Ni-Si-Cr alloy vacuum precision die-casting part and a production method thereof, the steps S0 to S4 are completed within 5 minutes, copper alloy melt is poured into vacuum auxiliary die-casting equipment and injected into a die cavity of the vacuum auxiliary die-casting equipment, the injection pressure maintaining time is 20-30 seconds, then demolding is performed, and the high-performance Cu-Ni-Si-Cr alloy vacuum precision die-casting part is obtained. According to the method, the high-performance Cu-Ni-Si-Cr alloy vacuum precision part is directly obtained, near-net forming of the high-performance Cu-Ni-Si-Cr alloy vacuum precision part is achieved, cold rolling treatment and solution treatment are omitted, the preparation speed and the production efficiency are greatly improved, the size of a second phase is decreased, distribution is more uniform, crystal grains are in a quasi-equiaxed crystal shape and are fine, and the high-performance Cu-Ni-Si-Cr alloy vacuum precision part is obtained. And the size of the second phase is reduced, the distribution is more uniform, and the mechanical property is greatly improved on the premise of keeping no loss of the electric conductivity.

The application provides a high-strength aluminum alloy for 3C electronic products and a preparation method thereof, which comprises six steps of smelting, refining, casting forming, homogenization treatment, quenching and aging. The preparation process of the aluminum alloy is optimized by strictly reducing the content of Fe and Cu, improving the atomic ratio of Mg and Si, guaranteeing the synergistic effect of Al, Mg and Si, and promoting the uniform and stable precipitation of the strengthening phase. The coarse G.P. zone formed after the aluminum alloy is quenched and stored at room temperature can be avoided, the demand for high dispersion of the strengthening phase is met, and the mechanical properties of the aluminum alloy are significantly improved. The yield strength of the aluminum alloy is 288 MPa-305 MPa, the tensile strength is 302 MPa-313 MPa, the precision range of the accessory after the aluminum alloy is processed into 3C product accessories is ±0.009 mm-±0.02 mm, the surface color difference value ΔE of the accessory after anodic oxidation is 0.31-0.45, and the tolerance fluctuation rate and the color difference fluctuation rate are both lower than 7%. The aluminum alloy does not need to add expensive metals, the crystal phase structure is uniform, has high strength and high plasticity, is easy to popularize and implement, and can meet the processing requirements of 3C electronic products and ultra-high-precision medical devices.