178results about How to "Small grain size" patented technology

The invention belongs to the field of sodium ion solid electrolyte manufacturing, and particularly relates to a terbium-doped NASICON type sodium ion conductor material and a preparation method thereof. The stoichiometric formula of the terbium-doped NASICON-type sodium ion conductor material is Na < 3 + x > Zr < 2-x > Tb < x > Si < 2 > PO < 12 >, x is more than 0 and less than or equal to 0.3, and the total ionic conductivity of the terbium-doped NASICON-type sodium ion conductor material is 3.07 * 10 <-4 > S / cm to 1.02 * 10 <-3 > S / cm. Compared with the prior art, a proper amount of terbium ions are used for replacing skeleton ions (such as Zr < 4 + >) in an NASICON structure, so that the concentration of transferable sodium ions is increased, and the ionic conductivity is improved. By doping terbium ions, the size of a sodium ion transmission channel is effectively increased, the transmission energy barrier is reduced, and the ionic conductivity is further improved. The ionic conductivity of the Na < 3.2 > 2Zr < 1.8 > Tb < 0.2 > Si2PO12 electrolyte doped with terbium ions at the room temperature reaches 1.02 * 10 <-3 > S / cm. According to the invention, the selected raw materials are economical and practical oxides, and the raw materials are easy to purchase and low in price, so that the production cost can be reduced.

The invention relates to the technical field of lithium ion batteries, and particularly provides a preparation method of a graphite negative electrode material and the graphite negative electrode material. The problems that an existing method for improving the rate capability of a graphite negative electrode is complex in process and limited in improving effect, and high-temperature storage performance is deteriorated are solved. Therefore, the preparation method of the graphite negative electrode material comprises the following steps: S1, mixing aromatic hydrocarbon oil, thiophene and medium-high sulfur asphalt, and performing heat treatment to obtain vulcanized asphalt; s2, carrying out delayed coking on the vulcanized asphalt to obtain high-sulfur green coke; and S3, crushing the high-sulfur green coke, and then carrying out graphitization treatment to obtain the graphite negative electrode material. The graphite negative electrode material prepared by the preparation method provided by the invention has good rate capability and high-temperature storage performance.

The invention relates to a flexible production method of low-alloy high-strength steel with yield strength of 420 / 460 MPa. The steel comprises the following chemical components: 0.12-0.16% of C, 0.12-0.16% of Si, 0.12-0.16% of Cr, 0.12-0.16% of Cr, 0.20%-0.3% of Si; mn: 1.2% to 1.5%; p is less than or equal to 0.02%; s < = 0.005%; 0.02% to 0.03% of Nb; 0.02% to 0.03% of V; 0.01%-0.03% of Als; the balance of Fe and impurities; the production process comprises the steps of converter smelting, LF refining, continuous casting, heating, rolling, controlled cooling after rolling and straightening. Through the coupling design of smelting, continuous casting, low-temperature heating, low-temperature rolling and controlled cooling processes, the comprehensive effect of fine grain strengthening, precipitation strengthening and phase change strengthening during rolling of the high-quality continuous casting billet is fully utilized, and flexible and efficient production of the low-alloy high-strength steel with the yield strength of 420 MPa and 460 MPa is achieved.

The invention relates to a metal oxide and application thereof. The metal oxide is of a face-centered cubic structure, the space group is Fd-3m, the lattice constant a of the metal oxide is # imgabs 0 # to # imgabs 1 #, and the tensile residual stress F1 in the metal oxide is 0.105 MPa to 5.51 MPa, or the compressive residual stress F2 in the metal oxide is 1.05 MPa to 8.6 MPa; the metal oxide is prepared by a spray pyrolysis method, and the pyrolysis rate K is 0.361 to 48.611. The metal oxide provided by the invention not only has relatively high crystallinity and stability, but also has high activity, and is beneficial to improving the intercalation of sodium ions or lithium ions when the positive electrode material is prepared, so that the comprehensive electrical property is improved.

The invention discloses a production method of a 5005-H34 aluminum alloy plate strip, and relates to the technical field of aluminum alloy preparation. The production process comprises the steps of casting, saw cutting, surface milling, heating, hot rolling, intermediate annealing, cold rolling, cleaning, stable annealing and finished product flattening. During production, the following parameters are mainly optimized: controlling the following chemical components in percentage by mass: less than or equal to 0.1% of Si, less than or equal to 0.25% of Fe, less than or equal to 0.15% of Cu, less than or equal to 0.15% of Mn, 0.85-1.05% of Mg, less than or equal to 0.08% of Cr, less than or equal to 0.15% of Zn, 0.01-0.05% of Ti, less than or equal to 0.05% of a single impurity element, less than or equal to 0.15% of other impurity elements and the balance of Al; the finish rolling temperature of hot rough rolling is controlled to be 400-460 DEG C, the total machining rate of hot finish rolling is larger than or equal to 75%, and the finish rolling temperature is 240-260 DEG C; the intermediate annealing metal temperature is controlled to be 320-340 DEG C, and heat preservation is conducted for 3-5 h; and the total machining rate of cold rolling is controlled to be 25-35%. The method is suitable for the 5005-H34 aluminum alloy plate strip with the finished product thickness of 2.0-4.0 mm, the technological process is short, the cost is low, the grain size is small, the small bending radius is achieved, and cracking and orange peel are avoided during bending.

The invention discloses a heat treatment process for relieving large-size carbides of a 17CrNiMo6 large-modulus gear. The heat treatment process comprises the following steps: a) first-time heating: heating a workpiece to a carburizing temperature in a gradient heating manner; b) heat-preservation carburizing: carburizing the workpiece by adopting multi-section pulse carbon potential; c) cooling after carburization: carrying out furnace gradient cooling on the workpiece to 660 + / -5 DEG C; d) heat preservation transformation: the workpiece is subjected to heat preservation at 660 + / -5 DEG C for a period of time, so that dispersed cementite precipitation and pearlite transformation are fully carried out; e) heating and preserving heat for the second time: heating the workpiece to 820 + / -5 DEG C, and preserving heat for austenite transformation; and f) quenching. Therefore, large-size carbides in a gear structure after heat treatment can be reduced, martensite needles in a quenched workpiece are effectively promoted to be smaller and thinner, the content of retained austenite is low, the metallographic structure of the workpiece is guaranteed, the use performance of parts is met, and the heat treatment method is particularly suitable for heat treatment of large-modulus gears.

The invention relates to an easily-activated Ti-Fe-Y-Mn-Zr-Co-Zn-based hydrogen storage alloy and a preparation method thereof, belongs to the technical field of hydrogen storage alloy materials, and solves at least one of the problems of high activation difficulty, long activation period, poor hydrogen absorption and desorption dynamic performance and the like of a Ti-Fe-based hydrogen storage alloy in the prior art. The invention provides a Ti-Fe-Y-Mn-Zr-Co-Zn based hydrogen storage alloy easy to activate, the chemical formula of the hydrogen storage alloy is Ti 1.15, Fe 0.8, Y 0.03, Mn 0.35-x-y-z ZrxCoyZnz, x, y and z are atomic ratios, x is larger than or equal to 0.05 and smaller than or equal to 0.15, y is larger than or equal to 0.02 and smaller than or equal to 0.1, and z is larger than or equal to 0.02 and smaller than or equal to 0.1. The Ti-Fe-Y-Mn-Zr-Co-Zn based hydrogen storage alloy provided by the invention obtains good activation performance and hydrogen absorption and desorption performance by means of component design and preparation process improvement, can be activated at one time under the conditions of 30 DEG C and 3 MPa, and has the hydrogen storage capacity of more than or equal to 1.69 wt.%, the hydrogen absorption platform pressure of more than or equal to 0.39 MPa and the hydrogen desorption platform pressure of more than or equal to 0.3 MPa.

The invention provides nanocrystalline barium titanate dielectric ceramic, a preparation method thereof and a ceramic capacitor, and belongs to the technical field of ceramic materials. The preparation method of the nanocrystalline barium titanate dielectric ceramic comprises the following steps: adding barium titanate into a first solvent, and carrying out ultrasonic atomization to obtain barium titanate slurry; adding holmium nitrate, yttrium nitrate, dysprosium nitrate, calcium nitrate, magnesium nitrate, manganese acetate and zinc acetate into an inorganic solvent to obtain an inorganic doped solution, and adding tetraethoxysilane into a second solvent to obtain an organic doped solution; uniformly mixing the barium titanate slurry, the inorganic doping solution and the organic doping solution to obtain mixed slurry; adjusting the pH value of the mixed slurry to be alkaline, standing and precipitating, drying, sieving for the first time, and pre-sintering to obtain powder; sieving the powder for the second time, uniformly mixing the powder with a binder, sieving for the third time, granulating, and carrying out compression molding to obtain a green body; and degumming and sintering the green body to obtain the nanocrystalline barium titanate dielectric ceramic.

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 catalytic decomposition of N2O, in particular to a transition metal oxide catalyst with biomass as a surface structure control agent and application of the transition metal oxide catalyst in low-temperature catalytic decomposition of N2O. The preparation method comprises the following steps: dissolving biomass (agar) in water, adding a transition metal oxide soluble salt, heating and stirring for reaction, and after the reaction is finished, drying, grinding and calcining the obtained product to obtain a target product. The prepared catalyst takes a transition metal oxide as a catalytic main body, takes an improved sol-gel method as a preparation means, and assists the preparation of a high-activity transition metal oxide catalyst by adding low-price agar as a surface structure control agent of the catalyst, so that the performance of the catalyst for catalytically decomposing industrial waste gas N2O pollution is improved. According to the invention, chemical reaction between the agar and the transition metal oxide is utilized to achieve the purposes of increasing the specific surface area of the catalyst, destroying surface lattices and forming a large number of oxygen vacancies and lattice defects, so that the performance of the catalyst for catalytically decomposing N2O is improved.

The invention provides a nickel-chromium alloy target material and a preparation method thereof, and belongs to the technical field of metal target materials. The preparation method of the nickel-chromium alloy target material comprises the following steps that a mold containing nickel-chromium mixed powder is subjected to hot pressing sintering treatment, a nickel-chromium alloy sintered body is obtained, machining is conducted, and the nickel-chromium alloy target material is obtained; wherein the hot pressing sintering treatment comprises three sections of heat preservation, the pressure of the first section of heat preservation is smaller than 1 MPa, the pressure of the second section of heat preservation is 6-10 MPa, and the pressure of the third section of heat preservation is 30-40 MPa. According to the hot pressing sintering treatment process, three-stage heat preservation is adopted, the pressure of each stage in the three-stage heat preservation process is controlled, the oxygen content and the grain size of the nickel-chromium alloy target material are reduced on the basis that the density of the target material is guaranteed, meanwhile, the grain orientation of the nickel-chromium alloy target material is controlled, and the quality of a sputtering film is effectively guaranteed.

The invention discloses a porous carbon-sodium ferric phosphate pyrophosphate composite material and a preparation method and application thereof, the composite material comprises porous carbon and sodium ferric phosphate pyrophosphate, and the sodium ferric phosphate pyrophosphate is distributed on the outer surface of the porous carbon and in porous carbon channels. The preparation method of the porous carbon-sodium ferric phosphate pyrophosphate composite material comprises the following steps: (1) preparing a sodium ferric phosphate pyrophosphate precursor solution; (2) uniformly mixing the ferric sodium pyrophosphate precursor solution obtained in the step (1) with porous carbon to obtain a precursor material flow; and (3) drying and roasting the precursor material flow obtained in the step (2) to obtain the porous carbon-phosphoric acid ferric sodium pyrophosphate composite material. According to the method, the composite electrode material with high rate performance can be obtained, and the energy density can be greatly improved when the composite electrode material is applied to a sodium ion capacitor.

The invention belongs to the technical field of two-dimensional film material growth, and discloses a 2H-phase semiconductor platinum disulfide single crystal and a preparation method thereof. The method comprises the following steps: dropwise adding a metal halide aqueous solution into a Pt-based compound, mixing, heating and drying to obtain a Pt source mixture; reversely buckling the pretreated growth substrate above the Pt source mixture, and placing the growth substrate in a high-temperature area in the quartz tube; sulfur powder is placed in a low-temperature area inside an upstream quartz tube, in a mixed atmosphere, S steam volatilized by heating of the sulfur powder is diffused to a high-temperature area of a tube furnace and chemically reacts with Pt steam generated by volatilization of a Pt source mixture in the high-temperature area, and 2H-phase PtS2 single crystals are deposited on the lower surface of a growth substrate; or placing the ZnS powder in the high-temperature area, in the inert gas atmosphere, enabling S vapor decomposed from the ZnS powder to chemically react with Pt vapor generated by volatilization of the Pt source mixture, and depositing on the lower surface of the growth substrate to generate the 2H-phase PtS2 single crystal.

The invention relates to a CO2 catalytic conversion catalyst and a preparation method and application thereof.The preparation method of the catalyst comprises the steps that a silicon source, an aluminum source and an inorganic acid aqueous solution are weighed to form white sol, then centrifugation, washing and drying are conducted, white silicon-aluminum composite oxide powder is obtained, a binder is added, rolling ball forming is conducted, and a silicon-aluminum composite oxide carrier precursor is obtained; and weighing the first active component precursor, the second active component precursor and the auxiliary component precursor, loading the precursors on the silicon-aluminum composite oxide carrier precursor in a dipping manner, drying, and roasting to obtain the CO2 catalytic conversion catalyst. Compared with the prior art, the catalyst provided by the invention has the advantages of high activity, high selectivity, high stability and the like in the CO2 reverse water gas shift reaction.

The invention discloses a beryllium-copper alloy and a production process thereof, and belongs to the technical field of copper alloy materials, the beryllium-copper alloy comprises the following raw materials by weight: 2-2.5% of beryllium, 1.3-2% of nickel, 0.05-0.1% of titanium, 1.2-1.5% of a covering agent, and the balance of copper and inevitable impurities; the preparation method comprises the following steps: adding beryllium, nickel, titanium and copper into a medium-frequency induction melting furnace, heating to 1360-1460 DEG C under a protective atmosphere to prepare a melt, adding a covering agent, smelting for 2-4 hours, standing, slagging off, and cooling to room temperature to prepare a beryllium-copper alloy; after the covering agent is added into a melt, on one hand, beryllium can be fully protected from being oxidized to cause loss, on the other hand, the special hollow structure of mullite can play a role in heat preservation and guarantee smooth proceeding of the smelting process, magnesium chloride, europium oxide and yttrium vanadate introduced to the surface can participate in refining of the melt, and the comprehensive performance of the alloy is further improved.

The invention discloses an aluminum-scandium alloy and a preparation method and application thereof, and belongs to the technical field of rare earth alloy sputtering target materials, metal aluminum particles and metal scandium particles are used as raw materials, high vacuum is extracted, inert gas is introduced for multiple times of electric arc melting, aluminum-scandium alloy melt with uniform components is obtained, and after the aluminum-scandium alloy melt is cooled, the aluminum-scandium alloy is obtained. The method comprises the following steps: preparing an aluminum-scandium alloy ingot, carrying out induction heating on the aluminum-scandium alloy ingot prepared by electric arc melting to completely melt the alloy so as to obtain an alloy melt, guiding the alloy melt to be injected into a mold through an argon pressure difference, naturally cooling to form a primary alloy, and carrying out homogenizing annealing on the primary alloy under a vacuum condition to obtain the aluminum-scandium alloy. And eliminating the residual internal stress of the primary alloy to obtain the aluminum-scandium alloy. The aluminum-scandium alloy prepared through the method is low in oxygen content, high in density, fine in crystal grain, uniform in structure and good in machining performance.

The invention provides welding wire steel for welding ultralow-temperature high manganese steel, a welding wire, a preparation method of the welding wire and a welding method. The welding wire steel for welding the ultralow-temperature high manganese steel comprises the following components in percentage by mass: 0.05 to 0.1 percent of C; 0.5 to 0.6 percent of Si; 24% to 25% of Mn; p is less than or equal to 0.01%; s is less than or equal to 0.01%; 0.05% to 0.1% of Al; 0.12 to 0.2 percent of Ni; 0.02% to 0.06% of N; 0.08% to 0.15% of Ti; v, 0.08% to 0.15%; 0.08% to 0.15% of Nb; 0.05% to 0.1% of Mo; and the balance of Fe and inevitable impurities. The welding wire composition design is optimized, only a small amount of Ni element is added, W and other high-melting-point elements are not added, and a small amount of C, N, Ti, V, Nb and other alloy elements are transited to a welding seam through the welding wire, so that nitride, carbide and other pinning grain boundaries are formed in the welding seam at the high temperature, austenite grain growth is effectively prevented, the austenite grain size is reduced, and the low-temperature impact toughness of the welding seam is improved; in addition, a small amount of Si element is transited to the welding seam through the welding wire, molten pool fluidity is improved, slag floating is promoted, and slag inclusion of the welding seam is avoided.

The invention provides a lithium ion battery positive electrode material, a precursor, a preparation method of the precursor, a lithium ion battery and lithium battery equipment, and relates to the field of lithium ion batteries. The secondary particles of the precursor comprise a plurality of strip-shaped or shuttle-shaped primary particles, and the ratio of the grain size D (100) / D (001) of the precursor is 1.50-2.40. The preparation method comprises the following steps: adding raw materials including a metal salt solution, a precipitator and a complexing agent into a base solution, reacting according to a preset procedure, and adjusting the pH value in the reaction process until a crystal nucleus is obtained; the method comprises the following steps: adding materials including a metal salt solution, a precipitator, a complexing agent and a crystal nucleus into a base solution, reacting according to a preset procedure, and adjusting the pH value in the reaction process. The raw material of the lithium ion battery positive electrode material comprises a lithium ion battery positive electrode material precursor. The precursor provided by the invention gives consideration to both capacity performance and cycle performance by inhibiting growth of a (001) plane.

The invention discloses a method for preparing a silicon monoxide material through photovoltaic silicon waste regeneration and application, and belongs to the field of secondary resource recycling. According to the method, photovoltaic cutting waste silicon sludge and silicon dioxide are taken as raw materials, silicon monoxide (SiO) gas is generated through vacuum disproportionation reaction, and a uniform high-purity SiO material is formed by controlling the temperature of a condensation thermal field. According to the preparation method, by utilizing the characteristics of fine granularity, high purity and high activity of the cut waste silicon sludge, the conversion efficiency and uniformity of the SiO product can be remarkably improved, and the SiO product obtained by the preparation method has the characteristics of high purity, good uniformity and the like, and has excellent long-cycle stability when being used as the anode of the lithium ion battery. According to the preparation method, the waste silicon powder is directly regenerated to prepare the SiO product, so that the production cost of SiO can be reduced, value-added cyclic utilization of the waste silicon powder can be realized, the raw material cost is low, the process operation is simple, the practicability is high, and meanwhile, the preparation method also has huge economic benefits and wide application prospects.

The present invention discloses a metal flux-cored welding wire for laser cladding and a preparation method and application thereof, belonging to the field of additive manufacturing technology. The metal flux-cored welding wire for laser cladding is mainly used for preparing a coating on the surface of a hydraulic support that is resistant to chloride ion corrosion and coal particle wear. The metal wire for laser cladding of the present invention is a flux-cored welding wire, which belongs to a martensitic rust steel type material. By adding alloy elements that improve strength and toughness, the material has good corrosion resistance while having high hardness and plastic toughness, so that it can be prepared into a metal wire by drawing, and the prepared cladding layer can meet the requirements of the hydraulic support for the service environment.

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.

The invention discloses a sensor for detecting C2H2 gas dissolved in power transformer oil, and belongs to the technical field of semiconductor gas sensors. The problem that an existing semiconductor C2H2 gas sensor cannot respond to C2H2 gas under the oxygen-free condition is solved. A base is a cube, a square through hole is formed in the center of the cube, and a supporting film, a heater, an isolation film, an interdigital electrode and a gas-sensitive material layer are attached to the surface, provided with the through hole, of the cube at a time; the centers of the gas sensitive material layer, the interdigital electrode, the isolation film, the heater and the supporting film correspond to the through hole of the cube; the isolation film is used for isolating electrical connection between the interdigital electrode and the heater, the gas-sensitive material layer is attached to the center of the upper surface of the interdigital electrode, and the resistance value of the gas-sensitive material layer changes along with the concentration of detected gas; and the gas sensitive material layer is prepared by doping SnO2 with In and Pt elements. The method is suitable for detecting the C2H2 gas dissolved in the power transformer oil.

The invention discloses a light aluminum alloy material, a preparation method thereof and application of the light aluminum alloy material in a new energy automobile, and belongs to novel aviation aluminum alloy materials. The aluminum alloy comprises the following components: magnesium, manganese, copper, zinc, a transition element combination, chromium, strontium, titanium, nano silicon carbide, a main material aluminum and other inevitable impurities. By optimizing the element composition, adding the inorganic nanoparticles, effectively refining crystal grains and improving the system density and being assisted by an efficient surface treatment means, the obtained aluminum alloy material has good comprehensive mechanical properties and corrosion resistance, is suitable for being used in parts such as a battery shell and a battery protection plate of a new energy automobile, effectively protects a battery, and has a good application prospect. And meanwhile, the device is also suitable for parts such as frames and is light and durable.

The invention provides a system and a process for continuous crystallization synthesis of a molecular sieve, and belongs to the technical field of molecular sieve catalyst preparation methods. According to the system and the process for synthesizing the molecular sieve through continuous crystallization, raw materials for synthesizing the titanium silicalite molecular sieve are added into the long reaction tube, and the titanium silicalite molecular sieve with small grain size and uniform distribution is obtained through a crystallization reaction in a continuous flowing process in the reaction tube. In addition, a regulator is added in batches in the flow reaction process, the internal pore structure of the titanium silicalite molecular sieve is further regulated, and the titanium silicalite molecular sieve with abundant pore structures and large specific surface area is obtained.

The invention discloses a preparation method of a BT14 titanium alloy large-specification bar, and aims to solve the problems of non-uniform structure and mismatching of mechanical property strength and toughness caused by temperature and strain difference of each part of a blank in the existing bar forging process. According to the titanium alloy structure evolution rule and the deformation distribution characteristic in the blank forging process, the optimal forging technology is determined, and the deformation uniformity of the titanium alloy is improved by adopting a deformation mode combining upsetting, conventional drawing, reversing drawing, diagonal drawing and inverted octagonal drawing. And the alloy structure and mechanical properties meeting the requirements are obtained through optimized forging process parameters, and the quality of large-specification bars is guaranteed. According to the BT14 titanium alloy large-size bar prepared through the method, the grain size in a microscopic structure is effectively reduced, meanwhile, a macrostructure is uniform, and the mechanical property meets the technical requirements of ocean engineering materials; in addition, the preparation heating number is small, energy consumption in the process is low, and the method is suitable for industrial production of BT14 titanium alloy bars with the diameter phi ranging from 400 mm to 500 mm.

The invention provides lithium-based ceramic pre-sintered powder and a preparation method thereof. The method comprises the following steps: S1, providing raw materials according to the stoichiometric ratio of lithium-based ceramic; s2, mixing the raw materials with an alcohol solvent, and grinding to obtain slurry; and S3, drying the slurry, and directly carrying out pre-sintering treatment to obtain the lithium-based ceramic pre-sintered powder. The lithium-based ceramic pre-sintered powder obtained by the method is fine and uniform in crystal grain, good in dispersity and good in sintering activity.

The invention relates to the technical field of alloy, and provides a high-strength aluminum product and a preparation method thereof.The high-strength aluminum product is composed of an aluminum matrix and a reinforcing phase, and the aluminum matrix is composed of, by weight, 3%-5% of Mg, 2%-4% of Cu, 0.5%-1.5% of Mn, 1.5%-2.5% of Zn, 0.01%-0.03% of Cr, 0.005%-0.015% of Ti and the balance Al and inevitable impurities; the reinforcing phase comprises rare earth oxide and a carbon nanomaterial; the weight ratio of the reinforcing phase to the aluminum product is (1-2): 1000, and the weight ratio of the rare earth oxide to the carbon nanomaterial is 1: 1. Through the technical scheme, the problem of low strength of aluminum products in related technologies is solved.

The extrusion integrated forming die for the magnesium alloy comprises a pair of forming dies, two pairs of die fastening bolt openings are formed in each of the two forming dies, the two forming dies are fixedly connected through the two pairs of die fastening bolt openings, a forming channel is jointly formed in the two forming dies, and the die fastening bolt openings are formed in the forming channels. The forming channel sequentially comprises a feeding port, a spherical expansion deformation area, a reducing thread torsion deformation area, a discharging port and a discharging channel from top to bottom, a pressing head is arranged at the top end of the feeding port, and the outer edge of the pressing head is attached to the inner wall of the feeding port; the spherical expansion deformation area can conduct spherical upsetting on the blank, dynamic recrystallization is promoted, dislocation rearrangement is accelerated, the material strength is improved, meanwhile, the machining efficiency is improved, meanwhile, traditional reducing extrusion and rotary extrusion deformation are adopted in the reducing thread torsion deformation area, and the machining efficiency is improved. The material strength is improved by intensifying the internal deformation of the material.

The present invention belongs to the technical field of catalyst preparation, and provides an ordered mesoporous carbon-confined nickel phosphide catalyst, a preparation method thereof, and an application of catalytic cellulose to sorbitol. The phytic acid used in the present invention has a strong chelating effect, and each phytic acid molecule can complex six nickel ions, so the ratio of nickel to phosphorus in phytic nickel is relatively fixed. Due to the close complexation of nickel and phosphorus, a high phosphorus utilization rate can be achieved by controlling the volume space velocity of flowing air and flowing hydrogen, so that the generated hydrogenation active center is pure phase Ni2P. In addition, the catalyst precursor is first heat-treated in an atmosphere of flowing air, the purpose is to introduce oxygen, reduce the content of carbon species, and avoid excessive carbon species from burying the metal active center; then switch to an atmosphere of flowing hydrogen, continue to heat up for reduction treatment, the purpose is to reduce the phytic nickel to generate Ni2P active center, and then increase the content of pure phase Ni2P.