349 results about "Mixed crystal" patented technology

The invention relates to the technical field of water treatment agent preparation and environmental governance material processing, in particular to polymeric ferric sulfate and a preparation method thereof.The preparation method comprises the steps that steam condensation recycled water of a thermal power plant of an aluminum factory is mixed with ferrous sulfate and concentrated sulfuric acid to form a reaction solution, oxygen is introduced for an oxidative polymerization reaction, and a liquid intermediate is generated; gradient cooling is carried out on the liquid intermediate to control the molar ratio of ferric ions to hydroxyl, and a porous solid precursor is formed through concentration and closed aging; crushing the precursor, performing graded drying by adopting a rotary kiln and flash drying, and synchronously spraying a hydrophobic modifier to reduce the surface hydroxyl activity; the powdery product is secondarily dried in a nitrogen inert environment, and moisture absorption and agglomeration are inhibited. The invention solves the problems of mixed crystal forms, delayed release of effective components and secondary pollution in the traditional process. The obtained product is uniform in crystal form, concentrated in particle size distribution, remarkably improved in dissolution rate and storage stability, and suitable for black and odorous water body treatment and industrial sewage treatment.

The invention discloses a heat treatment method for optimizing a gear steel structure and refining grains, and belongs to the technical field of heat treatment process control. The method is particularly suitable for a production scene of cold forging gear parts such as three pin shafts; according to the method, a pre-normalizing or annealing heat treatment process with specific parameters is added after cold forging forming and before carburizing, so that an AlN precipitated phase in the steel forms segregation again at a grain boundary, the grain boundary is effectively pinned, and austenite grain growth is inhibited, and therefore the phenomenon of mixed crystals is avoided, the structure is refined, and the fatigue performance is improved. Experiments prove that after normalizing pretreatment at the temperature of 900 DEG C or above or annealing pretreatment at the temperature of 720 DEG C is adopted, the original cold forging mixed crystal area with the grain size of 0-4 grade can be increased to 7 grade or above, grains are uniform and compact, and the structure property is remarkably improved. The process parameters are clear, the flow is controllable, and the method is suitable for optimization and application of the batch gear steel heat treatment process.

The invention belongs to the technical field of aluminum alloys, and particularly relates to a high-toughness anti-fatigue aluminum alloy and a preparation method thereof. The alloy comprises the following components in percentage by mass: 0.6-1.4% of Mg, 0.6-1.4% of Si, 0.5-1% of Mn, 0.3-0.8% of Cu, 0.1-0.4% of Cr, 0.1-0.3% of Mo, less than or equal to 0.15% of Fe, less than or equal to 0.05% of Ti, less than or equal to 0.05% of other impurities and the balance of Al. In the alloy, the ratio of Mn to (Cr + Mo) is 2-5, and Cr + Mo is less than or equal to 0.4. The aluminum alloy is subjected to synergistic microalloying of elements Mn, Cr and Mo and three-stage homogenization treatment, then a high-density'core-shell 'structure dispersed phase is separated out, and the deformation structure regulation and control effect is effectively improved; through hot forging and multi-stage solution treatment, a mixed crystal structure in which sub-crystals and recrystallization coexist is obtained, the fatigue crack propagation rate is remarkably reduced, and the obdurability and the fatigue resistance are synchronously improved.

The invention discloses a forging method for effectively eliminating a mixed crystal structure at the edge of a difficult-to-deform high-temperature alloy bar, which mainly comprises the following steps of: firstly, carrying out cogging forging on a cast ingot for 2-4 times in total, enabling the deformation temperature to be 1000-1180 DEG C, and enabling the cogging heating number to adopt a mode of combining upsetting and drawing; alternately obtaining an intermediate billet with tetragonal and octagonal section characteristics; and secondly, the intermediate blank is subjected to forming forging for 3-6 times in total, the deformation temperature ranges from 900 DEG C to 1080 DEG C, and in the deformation process, the mode that a square is drawn from all directions firstly, and then the square is drawn from all directions is adopted. Particularly, the eight-direction drawing-out of the forming heating number mainly adopts a mode of large eight directions, middle square directions and small eight directions, an eight-direction and four-direction repeated alternating type forging deformation thought is designed, a high-strain cross area in the eight-direction deformation process is utilized to eliminate a strain dead area in the four-direction deformation process, the grain size of the high-temperature alloy is refined through the method, and the high-temperature alloy yield is improved. And the strain dead zone in the traditional flat anvil forging process is solved.

The invention discloses a casting method crystal growth control method, device and equipment and a medium, and relates to the field of crystal preparation. The casting method crystal growth control method comprises the following steps: acquiring an area curve of a crystal; according to the area curve, adopting a growth neuron network model to obtain a heating power curve in the crystal growth process, controlling a casting crystal growth module to perform crystal growth, and obtaining an image of the crystal in the growth process in real time; analyzing the image to obtain parameter data of the crystal in the growth process, and obtaining the quality of the crystal in the growth process by using a quality neural network model; if the mixed crystal exists in the crystal, controlling the casting crystal growth module to melt the crystal until the mixed crystal region is melted; and correcting the heating power curve according to the area of the crystal after the mixed crystal region is melted, and continuing the crystal growth process. According to the invention, the heating power curve required by crystal growth control can be rapidly generated, and the crystal quality can be monitored in real time.

The invention provides a method for synthesizing high-valued amorphous calcium carbonate through carbon sequestration of carbide slag, and belongs to the technical field of carbon sequestration and high-valued utilization of industrial solid waste resources. The method comprises the following steps: carrying out active calcium extraction reaction on a dried and ball-milled carbide slag aqueous solution through ammonium chloride, stirring and filtering to obtain a calcium-containing solution; the method comprises the following steps: adding a certain amount of absolute ethyl alcohol and magnesium chloride into a calcium-containing solution, fully stirring, adjusting the pH value to a certain value, and introducing CO2 gas for mineralization reaction to obtain a turbid liquid containing calcium carbonate precipitate; and carrying out centrifugal separation, alcohol washing and drying on the turbid liquid to obtain powder calcium carbonate. According to the method disclosed by the invention, the calcium carbide slag active calcium liquid is extracted by adopting ammonium chloride, and absolute ethyl alcohol-magnesium chloride is added to precisely regulate and control the reaction steps of CO2 and the extracted calcium liquid, so that the CO2 is efficiently fixed, and meanwhile, mineralization is performed to obtain a mixed crystal type amorphous nano calcium carbonate product. According to the technology, double targets of synthesizing high-valued calcium carbonate through carbide slag carbon sequestration are achieved, and an innovative technical path is invented for current solid waste resource utilization.

The invention discloses a hafnium-zirconium-oxygen-doped multi-bit ferroelectric storage unit and a preparation method thereof. The storage unit comprises a first electrode, a second electrode and a multi-state ferroelectric layer arranged between the first electrode and the second electrode, the polymorphic ferroelectric layer comprises a hafnium-zirconium-oxygen solid solution and doping elements. And carrying out high-temperature annealing treatment on the device, and enabling the material of the multi-state ferroelectric layer to be subjected to phase transformation under the combined action of doped elements and electrode stress so as to form a mixed crystal of a ferroelectric phase, an anti-ferroelectric phase and a non-ferroelectric phase, thereby realizing multi-bit information storage. The polymorphic ferroelectric layer has stable polymorphisms for storing multi-bit data, and can be quickly switched among different storage states. The electrode layer is used for providing electric field driving force and regulating stress and oxygen vacancy space distribution of the electrode-ferroelectric interface layer at the same time; and the distribution between the material phase components and the oxygen vacancies in the ferroelectric layer is adjusted by controlling the distribution and the concentration of the elements by doping the elements and under the combined action of the electrodes.

The invention discloses a single crystal blade directional solidification process real-time closed-loop optimization method and casting equipment, and the method comprises the steps: S1, constructing a multi-physical field numerical simulation model to simulate a simulation temperature field in a directional solidification process; s2, arranging a temperature sensor at a key part of the actually poured single crystal blade to obtain an actually measured temperature field; s3, inputting the simulated temperature field and the actually measured temperature field into an extended Kalman filter to update model parameters of the multi-physical field numerical simulation model; s4, extracting solidification process characteristic parameters from the corrected multi-physical field numerical simulation model, inputting the solidification process characteristic parameters into a pre-trained machine learning model, and predicting a mixed crystal tendency probability; s5, optimizing process parameters of directional solidification by adopting a self-adaptive genetic algorithm by taking miscellaneous crystal tendency probability minimization as a target function; and S6, the optimized technological parameter set is issued to an execution mechanism, the directional solidification process is controlled to achieve closed-loop adjustment, and the steps S2 to S6 are executed circularly.

The invention relates to a heat treatment process for eliminating forge piece mixed crystals after warm forging or hot forging of low-carbon gear steel, which comprises the following steps: annealing a forge piece blank with mixed crystals, preserving heat for 3-3.5 hours, cooling to below 500 DEG C along with a furnace, discharging and cooling in air, determining the annealing temperature according to the A1 temperature and the Al / N ratio of the steel grade, and determining the specific annealing temperature according to an empirical formula t = A1-K.Al / N, wherein K represents a constant, is suitable for Al refined grain steel, and is usually 25-35. The forging blank with the mixed crystal structure can be eliminated through a re-heat treatment process, so that the structure and the grain size after subsequent carburizing heat treatment meet the standard requirements.

The invention discloses a post-forging heat treatment method for improving the structure uniformity of hot-work die steel, which comprises the following steps: (1) returning the forged hot-work die steel to a furnace, supplementing the temperature to 980-1020 DEG C, preserving the heat for 4-6 hours, discharging the hot-work die steel, alternately cooling the hot-work die steel to 150-300 DEG C by water and air, and loading the hot-work die steel into a heating furnace; (2) the temperature is increased to 650-750 DEG C along with the furnace, heat preservation is conducted for 2-4 h, and the mixture is discharged out of the furnace, air-cooled to 150-300 DEG C and loaded into a (3) the temperature is increased to 800-850 DEG C along with the furnace for preheating and heat preservation, and the heat preservation time is 2-4 Raising the temperature to 1020-1050 DEG C, and keeping the temperature for 4-6 hours; and discharging from the furnace, alternately cooling to 150-300 DEG C by water and air, loading into a heating furnace, and carrying out isothermal spheroidizing annealing. According to the method, the forging structure can be refined, the forging coarse grain and mixed crystal defects are eliminated, chain carbide precipitation of the annealing structure is inhibited, and the uniformity of the annealing structure and the transverse core impact toughness of the material can be remarkably improved.

The invention discloses a method for preparing an ultra-fine grain Ti-6Al-4V titanium alloy. The method comprises the following steps: pretreating a coarse-grain Ti-6Al-4V titanium alloy plate, processing the coarse-grain Ti-6Al-4V titanium alloy plate into square blocks with a specific proportion, and carrying out surface smoothing treatment; and then, forging deformation is implemented through multidirectional isothermal closed die forging, and the forging direction, the pressure and the deformation pass are controlled, so that the mixed crystal Ti-6Al-4V titanium alloy with the ultra-fine grain structure is prepared. After forging, the surface of a sample is cleaned, rolling preparation is conducted at the proper rolling temperature, and the thickness of the sample is reduced through rolling of multiple passes. The maximum grain size is smaller than 5 micrometers, the average grain size is smaller than 1 micrometer, and the proportion of grains within 1 micrometer reaches 75% or above. According to the method, the uniformity of a material structure is effectively improved, meanwhile, the service life of a mold is prolonged, the process efficiency and surface quality control are optimized, the mechanical property of the material is remarkably improved, and a new technical approach is provided for preparation of the titanium alloy material.

The invention discloses a method for eliminating a mixed crystal structure of medium-carbon alloy steel, and belongs to the technical field of heat treatment of steel. The mixed crystal structure eliminating method comprises the following steps: S1, heating to-be-treated medium-carbon alloy steel to Ac1-Ac3, and then preserving heat; s2, the steel obtained after heat preservation is completed is rapidly cooled to the room temperature; s3, repeating the operation for multiple times according to the steps S1 to S2; and S4, the steel treated in the step S3 is heated to be subjected to high-temperature tempering treatment and then air-cooled to the room temperature, and the medium-carbon alloy steel with the uniform grain structure is obtained. According to the method, the defects in production can be overcome, the problem of crystal mixing easily caused by large size, deformation and uneven cooling in the large die steel production process is particularly solved, and a mixed crystal structure with the original grain size level of 4-8 can be adjusted into a uniform structure with the grain size level of about 8.

The invention discloses a flexible PDLC (Polymer Dispersed Liquid Crystal) dimming film based on dichroic dye as well as a preparation method and application thereof, and belongs to the technical field of photoelectric materials. The problems that the current PDLC dimming film preparation process is not environment-friendly, the operation is complicated, the flexibility is poor and the like are solved. The preparation method of the flexible PDLC dimming film comprises the following steps: (1) mixing an ultraviolet curing adhesive, a nematic phase mixed crystal, a rigid spacer and a dichroic dye to obtain a mixture; (2) substrate treatment; and (3) filling the mixture between two flexible substrates, and curing with ultraviolet light. Volatile resin and ester plasticizers in a traditional formula are replaced with the ultraviolet curing adhesive, toxic and harmful substances are prevented from being used, the preparation process is environmentally friendly and safe, meanwhile, the conductive flexible substrate is combined with the ultraviolet curing adhesive, the limitation of a rigid substrate is broken through by means of high toughness of the ultraviolet curing adhesive, and the conductivity of the conductive flexible substrate is improved. By introducing the dichroic dye, the off-state transmittance is reduced, the contrast ratio is improved, and the long-term stability of the PDLC dimming film is enhanced.

The invention provides a method for preparing a lithium iron manganese phosphate composite positive electrode material by utilizing multi-stage negative pressure evaporation, and belongs to the technical field of lithium ion battery positive electrode materials. The method comprises the following steps: placing manganese acetate, ferrous sulfate and an antioxidant in the same reaction kettle, and adding deionized water to form a ferromanganese salt mixed solution; the ferromanganese salt mixed solution is controlled to be kept at the constant temperature of 5-40 DEG C; performing multi-stage negative pressure evaporation to obtain mixed crystals of manganese acetate and ferrous sulfate; mixing the mixed crystal with a lithium salt, a phosphorus-containing compound and a carbon source, and carrying out ball milling to obtain precursor powder of lithium iron manganese phosphate; putting the precursor powder into a sintering furnace, carrying out two-stage sintering in a flowing inert atmosphere, and cooling along with the furnace to obtain the lithium iron manganese phosphate composite positive electrode material; according to the method, crystals which are uniformly mixed and small in particle size are separated out through negative-pressure evaporation and concentration, meanwhile, the whole production process is fast in reaction and free of waste materials and waste residues, and the prepared lithium manganese iron phosphate material is good in stability and high in electron and ion conductivity.

The invention relates to the technical field of wrought superalloy processing, in particular to a GH4169 superalloy bar and a preparation method and application thereof. Through the design of triple smelting, twice homogenization treatment, forging, hot rolling and cold drawing processes, the GH4169 high-temperature alloy bar is prepared, the specification of the obtained bar can be as small as phi8mm-phi12mm, the structure from the center to the edge is uniform, strip segregation is avoided, the grain size can be stably controlled to 7-8 grades, namely, the grain size is 20-30 microns, the grade difference is smaller than or equal to 1 grade, and mixed crystals are avoided; the room-temperature tensile strength is greater than or equal to 1300MPa; the high-temperature tensile strength at 650 DEG C is larger than or equal to 1000 MPa, the high-temperature lasting time at 650 DEG C / 690 MPa is larger than or equal to 23 h, the high-temperature lasting elongation rate is larger than or equal to 4%, the comprehensive mechanical property is excellent, and the technical problems that the grain size of a small-specification GH4169 alloy bar prepared through an existing technology is 10 levels or above, grains are too fine, and mixed crystals are likely to happen are solved.

The invention relates to a cerium ion doped high-entropy fluoride scintillation crystal and a preparation method and application thereof. The preparation method comprises the following steps: taking single crystal particles or powder of LaF3, GdF3, CaF2, SrF2, BaF2 and CeF3 as raw materials, doping Ce ions, uniformly grinding to obtain a matrix material, vacuumizing, carrying out high-temperature sintering, ensuring that the matrix material is completely melted and impurities are removed, slowly cooling, carrying out crystal growth, and cooling to room temperature to obtain the cerium ion doped high-entropy fluoride scintillation crystal. The chemical formula of the high-entropy fluoride scintillation crystal is Ce: M1M2CaSrBaF12, wherein M1 and M2 are any two of Y, Lu, Gd, La, Lu, Sc and Ce. Compared with the prior art, the LaGdCaSrBaF12 high-entropy crystal prepared by the invention has lower phonon energy and smaller 5d energy level cleavage, and can greatly reduce the non-radiative transition probability of the 5d energy level of Ce < 3 + > ions. In addition, the disorderly distributed mixed crystal also regulates and controls the local coordination structure of Ce < 3 + > ions on the scales of atoms, molecules and groups, so that true disorder is achieved.

The invention belongs to the technical field of additive preparation, and particularly relates to an inner hole laser cladding composite powder material and a preparation method thereof. The invention provides an inner hole laser cladding composite powder material and a preparation method thereof in order to solve the problems that in the prior art, an inner hole laser cladding composite powder material is poor in uniformity and flowability and has limitation in the aspects of hardness, abrasion resistance and corrosion resistance. The material comprises tungsten carbide powder, NiCr alloy powder, silver and calcium fluoride-barium fluoride mixed crystals, mixed ball milling is conducted, ball milling is conducted again after presintering, then gas atomization treatment and laser pretreatment are conducted, and finally a nickel coating is formed on the surface of the powder through a chemical coating. The composite powder material has high hardness, high wear resistance, good corrosion resistance and high-temperature stability and is suitable for inner hole laser cladding, the service life of a workpiece is remarkably prolonged, and the performance of the workpiece is remarkably improved.

The invention provides a preparation method of a hollow directional solidification blade, and relates to the technical field of precision casting. Specifically, a pouring cup, a first composite wax mold and a second composite wax mold are configured; wherein the first composite wax mould comprises a blade wax mould, a seeding straight section wax mould and a seeding draft section wax mould which are integrally pressed, and the second composite wax mould comprises a seeding stepped draft section wax mould and a base plate which are integrally pressed; and then the procedures of wax mold welding, mold shell preparation, pouring and crystal pulling, shell cleaning and cutting, depoling, checking and heat treatment are conducted in sequence, and the hollow directional solidification blade is obtained. The invention designs and provides a draft stepped seeding section module, which is combined with a pouring process with an underneath blade tip of the blade and can be assisted by a special-shaped heat screen to improve the local temperature gradient, so that the high-quality blade with refined grains, few cracks and few mixed crystals or monotectic is prepared, and the draft stepped seeding section module is particularly suitable for preparation of large-size complex hollow blades. The method has a good application prospect in the aspect of heavy-duty gas turbines.

The invention relates to the technical field of rod and wire rod production, in particular to a titanium alloy and high-temperature alloy rod and wire rod continuous rolling production line and a production process. The production line comprises a first heating stepping furnace, a second heating stepping furnace, a first pinch roll, a roughing mill unit, a head removing rail, a second pinch roll, an intermediate mill unit, a finishing mill unit and a rod and wire production line which are sequentially connected in the longitudinal direction. A feeding port of the first heating stepping furnace is connected with the automatic feeding machine, the automatic feeding machine comprises a first feeding frame and a second feeding frame, the discharging end of the second feeding frame is connected with a feeding port of the second heating stepping furnace, and the feeding end of the second feeding frame is connected with the discharging end of the first feeding frame in a staggered mode. According to the production line, rapid switching can be achieved, continuous rolling can be efficiently and stably conducted, a rolled titanium alloy structure is uniform, and a high-temperature alloy structure is free of mixed crystals.

The invention relates to a heat treatment process for EN26 shaft products, which combines the multi-step and large-section size shape of an EN26 shaft, takes the large step at the tail end as a symmetric base point before heat treatment, is designed according to the double-length size, and adopts the modes of low-temperature preheating, high-temperature normalizing, air cooling after normalizing and tempering after forging to effectively cut off the structure inheritance. The method solves the problem of mixed crystal or coarse crystal grains caused by non-equilibrium structures due to weaving inheritance, promotes pearlite with small interlamellar spacing to be converted into austenite structures through a rapid heating and repeated austenitizing mode, improves the nucleation rate so as to achieve the effect of refining the grain size, and improves the grain size through reasonable quenching cooling strength. According to the method, the structural transformation from high-temperature austenite to martensite is guaranteed, the risk of product cracking caused by overlarge thermal stress and structural stress is avoided, the overall stability of a forge piece is guaranteed through high-temperature tempering, the strength, plasticity, toughness and hardness are well matched, the overall quality and production efficiency of the EN26 shaft produced through the method are improved, and the production cost is reduced. And after finish machining, single-length sawing and delivery are carried out.

The invention relates to the field of oxygen-containing compound adsorption and removal, and discloses a molecular sieve adsorbent as well as a preparation method and application thereof. The method comprises the following steps: mixing a silicon source and an aluminum source, carrying out preliminary crystallization, aging and crystallizing in a gel-like mother solution containing the silicon source and the aluminum source to obtain an FAU molecular sieve seed crystal, and carrying out mixed crystallization on the FAU molecular sieve seed crystal, various molecular sieves and the aluminum source, forming and roasting the obtained molecular sieve mixed crystal, the sodium metaaluminate modified carbon nanotube, an aluminum source and an auxiliary component; and finally, carrying out surface modification by adopting anhydrous amino acid ionic liquid. The molecular sieve adsorbent has a hierarchical pore structure composed of abundant micropores and mesopores and a relatively high specific surface area, the adsorption performance is improved through modification of the amino acid ionic liquid and addition of the modified carbon nanotubes, and when the molecular sieve adsorbent is used for adsorbing and removing oxygen-containing compounds in olefins, the molecular sieve adsorbent shows a relatively good removal rate and a relatively long adsorption period, and the molecular sieve adsorbent has relatively good application prospects. The production cost can be effectively reduced, and the method has high production and application value.

The present invention relates to a method for improving the mixed crystal structure of a 17CrNiMo6 material. The method comprises the following steps: S1, placing a forging in a heating furnace, heating it to 930-950°C, and then holding the temperature for 4-5 hours; S2, normalizing and air-cooling the forging after holding the temperature to 600-620°C, placing the forging again in the heating furnace and isothermally tempering and holding the temperature at 530-560°C for 4-5 hours; S3, placing the forging after tempering and holding the temperature in a heating furnace, raising the temperature of the heating furnace to 850-860°C and holding the temperature for 2-3 hours; S4, normalizing and air-cooling the forging after holding the temperature to 600-620°C, placing the forging again in the heating furnace and isothermally holding the temperature at 530-560°C for 4-5 hours; and S5, air-cooling the forging to room temperature, machining the forging, and then carburizing and quenching the forging. The method for improving the mixed crystal structure of 17CrNiMo6 material of the present invention can effectively improve the mixed crystal situation of 17CrNiMo6 material and ensure the stability of the 17CrNiMo6 material after it is made into products.

The invention relates to the technical field of pharmaceutical crystal structures, in particular to a preparation method of a high-purity pravastatin sodium D-type crystal, the preparation method comprises the steps of crystallization liquid pretreatment, first nitrogen drying, washing, second nitrogen drying and vacuum drying, the vacuum drying is a programmed drying process, the pravastatin sodium crystallization material is pumped or pressed to dry by utilizing different nitrogen pressures, so that accelerated separation and programmed vacuum drying of mother liquor in crystallization liquid can be promoted, generation of amorphous pravastatin sodium or pravastatin sodium of other crystal forms is reduced, and the technical problems that pravastatin sodium is easy to cake in the drying process, the drying time is long, mixed crystal forms are generated and the like are solved; the bulk density of the finally obtained high-purity pravastatin sodium D-type crystal is 0.3-0.5 g / mL, the hardness is proper, the subsequent crushing operation is convenient, and the pravastatin sodium D-type crystal is very suitable for being applied to medicines and preparations.

The invention discloses a production method for improving the structure uniformity of a 304 austenitic stainless steel medium-thickness plate, belongs to the field of stainless steel production, and solves the problem that mixed crystal structures often appear in the structure of the 304 austenitic stainless steel medium-thickness plate produced by an existing method. The method comprises the following steps: producing a 304 austenitic stainless steel continuous casting sheet billet; the plate blank is heated for the first time, the temperature of a heating furnace is set to be 1280-1300 DEG C, the heating time is 300-360 min, and natural cooling is conducted; the plate blank is remelted, heated and rolled again, the heating temperature is set to be 1250-1270 DEG C, the heating time is 240-300 min, and the remelted and reheated plate blank is rolled to the target thickness; and solution treatment is conducted, the solution treatment temperature ranges from 1050 DEG C to 1080 DEG C, the solution treatment time coefficient ranges from 1.0 min / mm to 2.0 min / mm, and water cooling is conducted to the room temperature. The structure uniformity of the 304 austenitic stainless steel medium plate produced by the method is obviously superior to that of a traditional method.

The present application belongs to the technical field of steel smelting and hot working, and particularly relates to a microstructure uniformity regulation method for hot work die steel, comprising: obtaining the hot work die steel through initial smelting by an electric furnace, LF refining purification, VD refining degassing and impurity removal; the present application adopts special smelting, forging and heat treatment processes, so that the prepared product has excellent microstructure uniformity, no banded structure and no mixed crystal structure in the finished product structure, and the carbide is uniformly distributed in a dispersion state; according to the annealing structure rating, annealing structure banded segregation rating and heat treatment structure rating diagrams of the North American Die Casting Association NADCA #207-2016 standard, AS1 level, SA1 level and HS1 level can be respectively reached. The hot work die steel of the present application has excellent wear resistance and impact toughness. The die prepared from the material has a longer service life and can better adapt to the demand of modern industrial production for high-end dies.

The invention discloses a method and device for preparing a mixed crystal structure material through friction stir solid-phase deposition, and belongs to the technical field of heterostructure material preparation. According to the method, firstly, a deposition head is used for carrying out single-layer friction stir solid-phase deposition on a needed material, then a special corrugated roller is used for carrying out cold rolling to enable different positions of the surface of the deposition material to be subjected to different degrees of cold deformation, and therefore uneven high dislocation density is introduced into a deposition layer, and then next-layer friction stir solid-phase deposition is carried out on the surface of the deposition layer. In the friction-stir solid-phase deposition process, static recrystallization and static recovery rapidly occur in a local high-dislocation-density area to maintain fine grains, and grain growth rapidly occurs in a low-dislocation-density area due to heating, so that the whole deposition layer shows the mixed crystal structure characteristic that fine grains and coarse grains coexist; the block mixed crystal structure material can be prepared through stirring friction solid phase deposition and cold rolling circulation.

A kind of multi-wavelength selection laser based on Ho doped crystal and its wavelength tuning method belong to the field of optoelectronic device manufacturing and optical engineering laser technology.To solve the function of multi-wavelength output of multi-wavelength selection laser, the pump source of 1940nm is connected with fiber coupler through fiber, the fiber coupler is arranged with fiber coupling lens group, polaroid, input plane mirror, Ho doped mixed crystal, output plane mirror and 1900nm narrow band filter in sequence along the light path;The Ho doped mixed crystal is composed of first square doped crystal, second square doped crystal, third square doped crystal and fourth square doped crystal, and the combination includes Ho: LLF crystal, Ho: YAP crystal and Ho: YLF crystal cut in different axial directions.The present application can efficiently realize tunable multi-wavelength output.By combining Ho doped crystals with different substrates, a laser is used to realize multi-wavelength output in a wide wavelength range.

The invention discloses an organic compound and application thereof. The organic compound has a structure as shown in a formula I. In the formula I, R1 and R2 represent C1-C15 straight-chain, branched-chain alkyl or alkoxy in a same or different manner at each occurrence, and R1 and R2 represent C1-C15 straight-chain, branched-chain alkyl or alkoxy at each occurrence. Wherein any one or more disconnected-CH2-can be replaced by cyclopropylidene, cyclobutyl, cyclopentadiene or cyclopentadiene,-CH = CH-,-N (Re)-,-O-,-S-,-CO-,-CO-O-and-O-CO-in a form that O-or S-is not connected with each other, and at least one-CH2-in R1 and R2 is replaced by cyclopropylidene, cyclobutyl, cyclopentadiene or cyclopentadiene. The organic compound structure has the characteristics of low melting point, good low-temperature solubility and small normal temperature-high temperature contrast change rate. The liquid crystal material can be uniformly mixed with mixed crystals and completely dissolved at a relatively low processing temperature, and the risk of thermal decomposition or phase change of the liquid crystal material can be reduced. # imgabs0 #

The invention belongs to the technical field of powder metallurgy, and particularly relates to a preparation method of a high-density molybdenum-rhenium alloy. The compactness of the molybdenum-rhenium alloy mainly refers to the number and the size of internal pores, cracks and other defects of the molybdenum-rhenium alloy. The high compactness means that the internal structure of the molybdenum-rhenium alloy is uniform and continuous, the number of defects is extremely small, the strength, plasticity, toughness, thermal conductivity, electrical conductivity, corrosion resistance, high-temperature stability and fatigue life are improved, and premature failure, leakage, corrosion and performance degradation caused by pores are avoided. According to the preparation method of the high-density molybdenum-rhenium alloy, on one hand, in the preparation process of mixed crystals of rhenium salt and molybdenum salt, the particle size and particle size distribution of the mixed crystals are controlled through technical means, and the problem that the mixed crystals are distributed unevenly is avoided; and on the other hand, formation of internal pores and cracks is eliminated through technical means in the molybdenum-rhenium alloy powder compression molding process. And finally, the high-density molybdenum-rhenium alloy is prepared.

A component having a solid structure of an alloy which, as a main component, contains a refractory metal (RM) from the group of molybdenum and tungsten and, as a further component, boron (B) and optionally carbon (C). The solid structure is manufactured additively by laser beam or electron beam, and the solid structure has regions made of the RM or a mixed crystal of the RM and the regions are at least partially delimited by (RM)2B, where B in (RM)2B can be partially replaced by C.