11results about How to "Reduce composition segregation" patented technology

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 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 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 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 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 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.