20results about How to "Reduce composition segregation" patented technology

The invention discloses active brazing filler metal for sealing sapphire and kovar alloy and a preparation method of the active brazing filler metal. The active brazing filler metal comprises 25.0 wt%-27.5 wt% of Cu, 1.0 wt%-6.0 wt% of Ti, 1.0 wt%-5.0 wt% of Al, 0.1 wt%-1.0 wt% of B, 0.1 wt%-0.5 wt% of rare earth element RE, RE is one or more of La, Ce, Sc, Pr, Nd and Er, and the balance is Ag. The preparation method comprises the following steps: preparing silver-based pre-alloying powder by adopting a gas atomization method, mixing the alloy powder with additive element powder in a ball milling manner, sintering by utilizing vacuum pressure to obtain an alloy ingot blank, and carrying out rough rolling, intermediate annealing and finish rolling to obtain an active brazing filler metal strip with the thickness of 0.05-0.2 mm. The active brazing filler metal is well matched with the thermal expansion coefficient of sapphire, direct brazing of sapphire and Kovar alloy can be achieved, the brazing temperature is moderate, and a brazed joint is uniform in structure and free of defects such as air holes and cracks.

The invention discloses a high-entropy alloy structured composite negative electrode material and a preparation method thereof and a lithium metal battery, and belongs to the technical field of lithium batteries, the high-entropy alloy structured composite negative electrode material comprises lithium, non-metallic elements and other metallic elements, the ratio of lithium atoms to total atoms in the composite negative electrode material is 40-80 at%, and the ratio of non-metallic elements to total atoms in the composite negative electrode material is 1-10 at%. The ratio of atoms corresponding to the non-metallic elements to the total atoms is 1-20 at%, the balance is other metallic elements, the atomic ratio of the other metallic elements is equal, the metal lithium and compounds or simple substances of the other metallic elements are smelted to obtain high-entropy alloy liquid, the high-entropy alloy liquid is subjected to heat preservation and poured into a mold, the high-entropy alloy sheet is obtained after cooling, and the composite negative electrode material contains various eutectic phases, the internal composition segregation is weakened, the organization structure is more uniform, the distortion degree and dislocation accumulation of the alloy in the deformation process are reduced, then the effect of improving the ductility is achieved, and the commercial application of the lithium alloy negative electrode is improved.

The invention relates to a high-performance metal injection titanium alloy feed and a preparation method thereof, the high-performance metal injection titanium alloy feed comprises a metal powder mixture and a binder, the ratio of the binder to the metal powder mixture is (1.5-2.5): (7.5-8.5), the metal powder mixture comprises spheroidized titanium alloy powder, spherical reduced iron powder and rare earth metal yttrium powder, a trace amount of rare earth Y (yttrium) element is added, and the metal injection titanium alloy feed is prepared by mixing the spheroidized titanium alloy powder, the spherical reduced iron powder and the rare earth metal yttrium powder. Although the wax-based binder is low in cost and free of pollution, if a small amount of carbon element exists in a sample to influence the plasticity, the rare earth element and Y are added to react with the O element in the titanium alloy to generate Y2O3, the oxygen content in the titanium alloy is reduced, meanwhile, the generated Y2O3 plays a role in refining grains, and the strength and plasticity of the titanium alloy are improved. Therefore, the plasticity of the material is improved, the contradiction between the strength and toughness of the titanium alloy is balanced, and the comprehensive performance requirement of the high-strength and high-toughness titanium alloy is met.

The invention relates to a device and method for preparing a magnesium / aluminum dissimilar metal joint, and relates to the technical field of welding metallurgy technology and material scientificity, the device comprises a welding table, a plate fixing assembly, a magnetic field assembly and a welding tool, a sealing plate is arranged on the welding table in a surrounding mode, and cooling water is poured into the sealing plate; the plate fixing assembly, the magnetic field assembly and a working head of the welding tool are all located below the liquid level. Trapezoid grooves are formed in the welding positions of the magnesium alloy and the aluminum alloy and filled with mixed powder of the magnesium alloy and the aluminum alloy according to a certain proportion, and component optimization is conducted on welding seams; the welding process is carried out underwater, a copper base plate is adopted, the temperature of a weld joint area in the welding process can be rapidly reduced and dispersed, a magnetic field is applied, under the stirring effect of electromagnetic force, molten plastic flowing metal has a better mass transfer effect on the microscale, element segregation is reduced, and therefore generation of magnesium-aluminum intermetallic compounds is restrained; and the cracking behavior in the welding process is reduced, so that the strength and the preparation efficiency of the magnesium / aluminum dissimilar metal joint are improved.

The invention provides a low-N high-purity aluminum-tungsten-niobium ternary intermediate alloy and a preparation method thereof. The alloy is composed of the following components: 25-30 wt% of Al, 30-35 wt% of W, 35-40 wt% of Nb, less than or equal to 0.002 wt% of N, less than or equal to 0.002 wt% of Si, less than or equal to 0.006 wt% of H, less than or equal to 0.03 wt% of O and the balance of other inevitable impurities. Compared with the prior art, the method has the advantages that the completeness and the yield of the reaction can be effectively improved by introducing the heat generating agent and the slag former and controlling vacuum and argon replacement pressure in the preparation process, and the obtained alloy has higher purity and lower impurity content. The alloy can be widely applied to preparation of the high-temperature titanium alloy, the heat resistance, the mechanical property and the component uniformity of the high-temperature titanium alloy are improved, and the alloy is suitable for preparation of the high-temperature titanium alloy under the long-term service environment of 550 DEG C or above.

The invention relates to a preparation method of high-purity and high-toughness hot work die steel, which comprises the following steps: S1, electric furnace smelting; s2, refining in a ladle refining furnace; s3, refining in a vacuum refining furnace; s4, performing die casting on an electrode blank; s5, annealing the electrode blank; 6, electroslag remelting is conducted, specifically, an electrode blank is adopted, surface polishing is conducted, a calcium fluoride, aluminum oxide, magnesium oxide and silicon dioxide quaternary slag system is adopted for smelting, the starting point melting speed value of the electroslag smelting steady-state stage is 7-10 kg / min, the end point melting speed value of the electroslag smelting steady-state stage is 5.0-8.0 kg / min, an electroslag ingot is obtained, and then power-off furnace cooling is conducted for 80-100 min; s7, forging is conducted; s8, pretreatment after forging; and S9, solid solution and spheroidizing final treatment. According to the invention, on the basis of common hot work die steel H13, the prepared product has excellent high hardness, high purity and high toughness through fine adjustment of chemical components and special smelting, forging and heat treatment processes. The anti-cracking performance of a mold made of the material is greatly improved, the service life of the mold is prolonged, and meanwhile the use cost of the mold is greatly reduced.

The invention belongs to the technical field of high-temperature alloy connection, and particularly discloses novel cobalt-based brazing filler metal for high-temperature dissimilar metal connection and a preparation method and application of the novel cobalt-based brazing filler metal. The cobalt-based brazing filler metal is prepared from, by weight, 30%-70% of Co, 14%-27% of Ni, 11%-20% of Cr, 3%-6.5% of Fe, 1%-1.5% of Mn, 3%-6% of Si, 2%-4% of B, 0.3%-0.5% of Sc, 0.2%-0.4% of Y and the balance inevitable impurities. The melting point of the cobalt-based brazing filler metal ranges from 950 DEG C to 1100 DEG C, and the cobalt-based brazing filler metal is suitable for being used in the high-temperature environment of 600 DEG The method focuses on the refining process and performance evaluation of the Co * NiCrFe (Si, B) cobalt-based brazing filler metal, the content of the Co element is systematically adjusted, the brazing strength of the brazing filler metal is guaranteed, meanwhile, the wettability of the brazing filler metal is improved, composition segregation is reduced, and the process requirement for brazing connection of high-temperature dissimilar metal materials can be fully met.

This invention discloses a method for preparing high-entropy ceramic matrix composites using a reactive infiltration process, belonging to the technical field of ceramic matrix composites. The steps are as follows: at least four single-component carbides are ball-milled and mixed with a carbon source, then dispersed in a dispersion liquid to obtain a slurry; continuous fibers are woven into a preform, and an interface layer and a matrix layer are deposited to obtain a semi-dense composite material; the slurry is introduced through vacuum or pressure impregnation; and a high-entropy carbide matrix is ​​generated in situ and densified by reactive infiltration after embedding with a transition metal and its alloy. This invention solves the problems of long process cycles, high porosity, high cost, and insufficient introduction of high-entropy ceramics in existing processes, achieving rapid densification and improving the material's high-temperature stability, oxidation resistance, and ablation resistance. It is suitable for the large-scale production of thermal protection materials for hypersonic vehicles.

The invention relates to carburized bearing steel for a turntable bearing of a large-size petroleum drilling machine and a production method of the carburized bearing steel. The carburized bearing steel comprises the following chemical components: 0.19-0.23% of C, 0.15-0.40% of Si, 0.30-0.55% of Mn, 1.25-1.75% of Cr, less than or equal to 0.08% of Mo, 3.25-3.75% of Ni, 0.01-0.03% of Al, less than or equal to 0.020% of P, less than or equal to 0.010% of S, less than or equal to 0.25% of Cu, less than or equal to 0.0005% of Ca, less than or equal to 0.0015% of Ti, less than or equal to 0.0010% of O, 0.005-0.010% of La and the balance of Fe and inevitable impurities. The production process comprises the steps of molten iron pretreatment, converter or electric arc furnace smelting, LF refining, RH or VD furnace refining, large-section CCM continuous casting of a large round billet, continuous casting of the large round billet, slow cooling of the continuous casting of the large round billet, heating, rolling, slow cooling of a rolled material, annealing and finishing. And the requirements of the steel for the turntable bearing of the large-size petroleum drilling machine are met.

The invention discloses consumable electrode smelting equipment for preparing ODS steel and a preparation method of the consumable electrode smelting equipment, and belongs to the technical field of OSD steel preparation. The equipment comprises a furnace shell, an electrode smelting unit arranged at the lower part of the furnace shell and an atmosphere adjusting device arranged at the upper part of the furnace shell. The atmosphere adjusting device comprises two vent valves, one ends of the two vent valves are connected with an oxygen source and a protective gas source respectively, the other ends of the two vent valves are connected with the gas mixing cavity, and the gas mixing cavity is connected with the mixed gas pressurizing cavity through a gas pressurizing valve. An electrode is placed in the electrode smelting unit, a vent hole penetrating through the upper end face and the lower end face of the electrode is formed in the middle of the electrode, the gas mixing pressurization cavity is connected with the vent hole through a vent pipe, and a gas mixing one-way valve is installed on the vent pipe. According to the method, the equipment is adopted for ODS steel preparation, the atmosphere pressure and the gas content in the cavity can be dynamically adjusted according to the solidification rate of the melt in the smelting process, it is guaranteed that the content of dissolved oxygen elements is stable after the melt is solidified, and the ODS steel uniform in structure and small in segregation is prepared.

The invention relates to the technical field of aluminum alloy semi-solid processing, and provides a semi-solid slurry flow guide device for aluminum alloy, which comprises a shell, the bottom of the shell is fixedly connected with a rack, one end of the shell is fixedly connected with a feeding pipe, the other end of the shell is fixedly connected with a discharging pipe, and a material shifting mechanism is arranged at one end, close to the feeding pipe, of the inner side of the shell. The material stirring mechanism comprises two rotating plates which are arranged in parallel, a plurality of material stirring plates are fixedly connected between the two rotating plates, a plurality of electric heating pipes are arranged between every two adjacent material stirring plates, a first support is fixedly connected to the outer side of the rack, and a first motor is fixedly installed at the top of the first support; a flow guide mechanism is rotationally connected to the middle of the inner side of the shell, a filter screen is fixedly connected to the end, close to the discharging pipe, of the inner side of the shell, a stirring mechanism is arranged on one side of the filter screen, and a cleaning mechanism is arranged on the other side of the filter screen. Through the innovative mechanism design, the key problem in the aluminum alloy semi-solid slurry diversion process is solved.

The present invention discloses a melt processing device and method for preparing super-large aluminum alloy ingots. The device is mainly composed of an annular electromagnetic melt processor, a hot top, a crystallizer, a crystallizer water tank, a graphite ring, an ingot guide and a lifting mechanism; the annular electromagnetic melt processor is placed in the crystallizer, concentric with the crystallizer, and a line port and a connecting mechanism are arranged on its top, and it is connected to the lifting structure, and can be moved up and down in the height direction of the crystallizer through the lifting mechanism, and positioned at a corresponding position in the crystallizer; the lower end of the hot top is sealed and connected to the crystallizer through a graphite ring; the crystallizer water tank is arranged on the periphery of the crystallizer. The device is used for melt processing, and in the semi-continuous casting process, the annular electromagnetic melt processor is applied to the alloy melt to achieve effective uniformity of the temperature field and composition field of the super-large volume alloy melt, and to achieve effective control of the melt flow, so as to prepare high-quality super-large aluminum alloy ingots with uniform and fine structure and uniform composition.

The invention discloses a method for vacuum horizontal continuous casting of a copper-titanium alloy, and relates to the technical field of copper-titanium alloy preparation. Comprising the following steps that powder mixing, pressing, vacuum sintering and vacuum self-consuming electric arc smelting are sequentially conducted through the powder metallurgy technology according to the proportion that the content of Ti ranges from 40 wt% to 60 wt% and the balance Cu, and a copper-titanium master alloy is prepared; the vacuum sintering temperature is 500-900 DEG C; the preparation method comprises the following steps: proportioning 2-6wt% of Ti and the balance of Cu, adding Ti in the form of a copper-titanium master alloy, heating and melting the raw materials through a vacuum induction melting process, and refining to obtain a melt; the refining temperature ranges from 1260 DEG C to 1300 DEG C; and the melt is flatly guided and injected into a crystallizer with the corresponding guiding and pulling size through a vacuum horizontal continuous casting technology, the guiding and pulling speed is controlled to be smaller than or equal to 600 mm / min, continuous casting is conducted, and after cooling, a copper-titanium alloy casting blank is obtained. The horizontal continuous casting process is adopted to produce bar and plate profile raw materials, and the obtained copper-titanium alloy casting blank is fine and uniform in grain structure, good in plasticity and convenient for subsequent deformation processing.

The invention relates to the field of civil air defense door manufacturing, and particularly discloses an integrated machining process for a civil air defense airtight door. The integrated machining technology of the civil air-tight door comprises the steps that aluminum, magnesium and zinc are mixed and melted in proportion, then copper, manganese, chromium, titanium and silicon are added for refining, refined alloy liquid is cooled to obtain an alloy plate, the alloy plate is cut, then heated, extruded and formed, quenching is conducted, and the civil air-tight door is obtained. And the civil defense air-tight door is subjected to surface sand blasting, and then an anti-rust coating is sprayed. The civil air defense air-tight door integrated machining technology has the advantage that the anti-corrosion and anti-impact capacity of the civil air defense air-tight door is improved.

The invention discloses a preparation method of copper-titanium alloy chopsticks, and relates to the technical field of non-ferrous metal alloys. Comprising the following steps: uniformly mixing raw materials to obtain mixed powder; the mixed powder is pressed into a consumable electrode bar, and a bar material is obtained; the bar is subjected to vacuum sintering at the temperature of 500-900 DEG C and then subjected to vacuum consumable electric arc melting, the melting current ranges from 1.5 KA to 3.0 KA, the melting voltage ranges from 18 V to 25 V, and a cast ingot is obtained; the cast ingot is forged, the final forging temperature is controlled to be not lower than 700 DEG C, and a round bar is obtained; the round bar is subjected to hot rolling treatment at the temperature of 830-900 DEG C, and a hot-rolled round bar is obtained; and carrying out solution treatment and aging treatment on the hot-rolled round rod, and then carrying out post-processing to obtain the finished copper-titanium alloy chopsticks. The copper-titanium alloy chopsticks have good mechanical properties, can reduce damage caused by collision in the use process of the chopsticks, and have obvious sterilization and bacteriostasis effects at the same time, so that the safe use performance of the chopsticks is improved.

The invention discloses a production process of a 6-series aluminum alloy profile, and belongs to the technical field of aluminum alloy material preparation. By adding trace Sc and Zr elements and nano TiN particles and combining a multi-stage homogenization heating and temperature control rolling process, crystal grains are effectively refined, recrystallization is inhibited, a dispersion strengthening phase is formed, the final aluminum alloy section keeps good plasticity and toughness, meanwhile, higher strength and corrosion resistance are obtained, a multi-stage heating homogenization treatment system is adopted, and the service life of the aluminum alloy section is prolonged. According to the method, full dissolution and diffusion of 6-series aluminum alloy elements are promoted, composition segregation and internal stress are reduced, subsequent online spray quenching and air cooling are combined, rapid, uniform and controllable cooling is achieved, the performance difference of all parts of the aluminum alloy profile is greatly reduced, and the structure and size stability is ensured. And on the whole, the aluminum alloy profile is endowed with excellent strength and corrosion resistance through precisely controlled chemical components and process optimization.

The invention discloses protective atmosphere spray forming equipment and a spheroidizing agent alloy particle forming method, and relates to the technical field of spray forming equipment, the protective atmosphere spray forming equipment comprises a box body and a crucible, a cooling cavity is formed in the box body, the crucible is located at the top of the box body, the bottom of the crucible is connected with a communicating pipe extending into the cooling cavity, and the communicating pipe is communicated with the cooling cavity. And the bottom of the outer wall of the communicating pipe is rotationally connected with a rotary spray head. According to the protective atmosphere spray forming equipment and the spheroidizing agent alloy particle forming method, the spheroidizing agent alloy particles prepared through a centrifugal method can greatly reduce structure and component segregation of the spheroidizing agent alloy particles, and the quality of a prepared spheroidizing agent is improved; and meanwhile, an argon protective atmosphere exists in the whole forming process, magnesium in the nodulizer alloy is prevented from being oxidized, the magnesium oxide content of a final nodulizer particle product is smaller than 0.5%, and the function of the nodulizer can be played to the maximum extent.

The application discloses an intelligent sustained-release drug carrier screening method based on material microscopic image recognition, integrates nanometer hyperspectral, cryo-EM and Raman spectral data through a multi-modal data synchronous acquisition system, realizes nanoscale spatial alignment of microscopic morphology and component distribution, adopts a non-local mean denoising algorithm to enhance pore structure identification, combines adaptive baseline correction and multi-peak fitting technology, and quantifies chemical bond state changes, constructs a characteristic spectral library, generates a chemical distribution map through spectral angle mapping, combines spatial mutual information entropy to analyze the co-localization of carriers and drugs, innovatively develops a space-spectrum joint encoder, fuses multi-modal features by using a cross attention mechanism, and outputs quantitative indexes such as pore filling rate, crystallinity change and interaction stability score. The method breaks through the static and single-modal limitation of traditional methods, and establishes a complete screening system from microscopic structure analysis to release kinetics prediction.

The invention relates to high-nitrogen cutting tool steel and a preparation method thereof. The steel comprises the following chemical components: 0.75%-0.85% of C, 0.10%-0.20% of Si, 1.50%-1.70% of Mn, less than or equal to 0.015% of P, 0.08%-0.10% of S, 0.60%-0.80% of Cr, 0.12%-0.15% of Ti, 0.015%-0.055% of Alt, 0.026%-0.030% of N, 0.0040%-0.0060% of B, 0.0020%-0.0030% of Nd and the balance of Fe and impurities. The problems that existing cutting tool steel is poor in working stability, uneven in performance and prone to fracture and tooth breakage are solved, component segregation of the cutting tool steel is relieved, the surface quality is improved, and the cutting tool steel has high strength, high toughness, long fatigue life and good abrasion resistance, deformation resistance, impact resistance and welding performance.

The invention discloses an aluminum alloy for an automobile main structural beam and a preparation method of the aluminum alloy. The preparation method comprises the following steps: S01, respectively preparing a cross beam and a towing beam in the automobile torsion beam; s02, the two ends of the cross beam and the position, connected with the cross beam, in the towing beam are subjected to laser hot melting treatment, and the hot melting temperature is controlled to range from 350 DEG C to 400 DEG C; s03, the cross beam and the towing beam in the step S02 are placed in a directional magnetic field and a directional water curtain, and hot melting connection of the cross beam and the towing beam is achieved for 0.2-0.5 h under the action of moving and cooling of the external magnetic field and the directional water curtain; and S04, the directional water curtain in the step S03 is removed, the temperature is controlled to be 80-100 DEG C, and a chromic acid solution is directionally and rotationally sprayed to the connecting position of the cross beam and the towing beam to form a passivation layer. The automobile torsion beam obtained through the preparation method has high strength and high corrosion resistance.