41results about How to "Avoid abnormal growth" patented technology

The invention relates to the technical field of powder metallurgy, in particular to a tungsten-copper alloy preparation method and a tungsten-copper alloy. The preparation method of the tungsten-copper alloy comprises the following steps: mixing double-scale compound tungsten powder containing nanocrystals and ultra-fine grains or double-scale compound tungsten-tungsten oxide powder containing nanocrystals and ultra-fine grains with copper oxide powder to obtain precursor slurry; drying the precursor slurry to obtain precursor composite powder; the precursor composite powder is subjected to segmented reduction, tungsten-copper composite powder is obtained, and tungsten crystal grains in the tungsten-copper composite powder are distributed in a double-scale mode of nanocrystals and ultra-fine crystals; and the tungsten-copper composite powder is prepared into a blank and sintered, and the tungsten-copper alloy is obtained. The heat conductivity and density of the tungsten-copper alloy can be improved.

The invention provides platinum-rhodium alloy powder for a nitrogen-oxygen sensor electrode, a preparation method of the platinum-rhodium alloy powder and slurry for the nitrogen-oxygen sensor electrode, and the preparation method of the platinum-rhodium alloy powder for the nitrogen-oxygen sensor electrode comprises the following steps: performing chemical co-reduction on a platinum metal precursor and a rhodium metal precursor to obtain composite powder, the particle size range of the composite powder is 50-100 nm; and carrying out molten salt heat treatment on the composite powder to obtain the submicron platinum-rhodium alloy powder for the nitrogen-oxygen sensor electrode. According to the platinum-rhodium alloy powder prepared through the method, the three-phase interface uniformity of a metal catalytic functional phase and a zirconium oxide ion electrolyte substrate in electrode slurry is improved, the catalytic capacity of an electrode is improved, meanwhile, the particle size of platinum-rhodium alloy particles is properly increased, and therefore the prepared electrode slurry has better flowability, and the service life of the electrode slurry is prolonged. The problem of easy wire breakage in the subsequent sintering process is reduced, and the yield and aging life of the sensor are improved.

The invention relates to the technical field of nano powder material preparation, in particular to a method for preparing molybdenum powder based on a spray granulation precursor and the molybdenum powder. The method for preparing the molybdenum powder comprises the steps that ammonium molybdate and a pore forming agent are dissolved in ultrapure water at the room temperature, and mixed slurry is obtained; carrying out spray granulation treatment on the mixed slurry to obtain composite powder particles containing the pore-forming agent and ammonium molybdate; the composite powder particles are placed in an oxygen-containing atmosphere to be roasted, and superfine nano molybdenum trioxide is obtained; placing the superfine nano molybdenum trioxide in a hydrogen atmosphere for primary reduction treatment to obtain superfine molybdenum dioxide powder; and the superfine molybdenum dioxide powder is subjected to second-stage reduction treatment, the superfine molybdenum powder is obtained, and the reduction conditions of the first-stage reduction treatment and the second-stage reduction treatment are different. According to the preparation method, the superfine molybdenum powder with good uniformity and dispersity can be prepared.

The invention belongs to the technical field of aluminum oxide ceramics, and particularly relates to a high-strength 99 aluminum oxide ceramic as well as a preparation method and application thereof. The boehmite and the hydrotalcite are used as main components of a binder, the boehmite and hydrotalcite composite sol is obtained by adopting a specific preparation method, and the boehmite and hydrotalcite composite sol is applied to a preparation process of aluminum oxide ceramics, so that an aluminum oxide ceramic material with high strength and high density can be obtained. Besides, the sintering aid adopted by the invention can react with MgO and Al2O3 generated by decomposition in the binder to generate a low-melting-point liquid phase, so that redistribution of substances among particles and filling of pores are facilitated, and the density and the dielectric property are further improved.

The invention discloses a silver-coated copper powder preparation method based on nickel layer enhanced palladium catalysis and active hydrogen synergistic deposition, and relates to the technical field of powder surface treatment. The method specifically comprises the following steps that copper powder is soaked in acid liquor, then filtering, washing and drying are conducted, and pretreated copper powder is obtained; immersing the pretreated copper powder into a hydrochloric acid solution of nickel chloride hexahydrate, and then filtering, washing and drying to obtain sensitized copper powder; immersing the sensitized copper powder into a hydrochloric acid solution of palladium chloride, and then filtering, washing and drying to obtain activated copper powder; mixing the activated copper powder with the reduction solution to obtain a solid-liquid mixture, adding a silver-ammonia solution into the solid-liquid mixture, heating for reaction, and filtering after the reaction is finished to obtain a solid product; and washing and drying the solid product to obtain the silver-coated copper powder based on nickel layer enhanced palladium catalysis and active hydrogen synergistic deposition. The silver-coated copper powder with a compact silver layer and high binding force is prepared through the ternary synergistic effect of nickel layer sensitization, palladium nanometer activation and formaldehyde reduction.

The invention relates to the technical field of ceramic cutters, in particular to a SiC whisker toughened aluminum oxide ceramic cutter and a preparation method thereof. The invention relates to a SiC whisker toughened aluminum oxide ceramic cutting tool. The SiC whisker toughened aluminum oxide ceramic cutting tool consists of aluminum oxide ceramic powder, silicon carbide whiskers and toughening auxiliary powder, the toughening auxiliary powder is prepared from the following raw materials in parts by weight: 20 to 30 parts of ferrotitanium slag and 6 to 10 parts of chromium sesquioxide. The SiC whisker toughened aluminum oxide ceramic cutter provided by the invention is compact in structure and has more excellent fracture toughness at the same time.

The invention discloses a tin-silver-copper alloy, a preparation method thereof and solder, and belongs to the technical field of alloy materials, the tin-silver-copper alloy comprises, by mass, 2.8%-3.1% of Ag, 0.3%-0.7% of Cu, 0.01%-0.5% of B, 0.03%-1.0% of P and the balance Sn and impurity elements, and the content of Pb and the content of Fe in the impurity elements are both smaller than or equal to 0.001%. According to the embodiment of the invention, the content of impurity elements in the tin-silver-copper alloy is controlled, the B and P elements are added on the basis of the tin-silver-copper basic elements, the alloy is refined, an oxidation film is formed on the surface of the liquid solder, and the corrosion to a titanium alloy part is reduced.

This invention discloses a method for preparing silicon carbide fibers with an in-situ boron nitride coating. The method involves melt spinning a metal-doped polycarbosilane precursor to obtain doped polycarbosilane precursor fibers. These precursor fibers are then subjected to a non-melting treatment in an oxidizing atmosphere to obtain non-melting fibers. The non-melting fibers are then subjected to inorganic pyrolysis to obtain inorganic fibers. These inorganic fibers are then densified and sintered to obtain boron-containing SiC fibers. Finally, the boron-containing SiC fibers are subjected to high-temperature treatment in a nitrogen atmosphere to obtain silicon carbide fibers with an in-situ boron nitride coating. This invention provides a simple preparation method, resulting in an in-situ self-grown BN coating with high crystallinity, good stability, and excellent uniformity. The coating is tightly bonded to the SiC fibers, is low-cost, and can be mass-produced. Furthermore, it significantly improves the fiber's temperature resistance and high-temperature creep resistance, allowing the fiber to serve for extended periods at higher temperatures.

The present application relates to the technical field of ceramic tools, and more specifically, it relates to a SiC whisker toughened alumina ceramic tool and a preparation method thereof. A SiC whisker toughened alumina ceramic tool, the SiC whisker toughened alumina ceramic tool is composed of alumina ceramic powder, silicon carbide whiskers and toughening auxiliary powder; the toughening auxiliary powder includes the following raw materials in parts by weight: 20-30 parts of ferro-titanium slag and 6-10 parts of chromium trioxide. The SiC whisker toughened alumina ceramic tool of the present application has a dense structure and has better fracture toughness.

The invention belongs to the technical field of precise functional ceramic parts, and particularly relates to multilayer ceramic for an electrostatic chuck and a preparation method of the multilayer ceramic. According to the preparation method of the multilayer ceramic, a ceramic biscuit is formed in a water-based gel tape casting mode, and then the compact aluminum oxide multilayer co-fired ceramic is prepared through the steps of cross-linking curing, lamination, degreasing, sintering and the like. According to the method, the shrinkage rate of the ceramic biscuit in the curing process is reduced by optimizing the components of the ceramic slurry, the abdicating space corresponding to the electrode structure is machined in advance, and the space for compensating the shrinkage of the ceramic in the sintering process is machined in the ceramic substrate in advance by adopting the laser stealth cutting process; the deformation problems of warping, bulging and the like in the multi-layer ceramic sintering process are solved, and then the electrostatic chuck which is high in flatness and uniform in electrode layer distribution is prepared.

The invention discloses a sintering method for effectively reducing the ferromagnetic resonance line width of Bi-substituted garnet ferrite with a high dielectric constant, and belongs to the technical field of ferrite materials, the sintering method is a sintering route of heating-multi-stage high and low temperature alternation-cooling. According to the preparation method, the ferromagnetic resonance line width delta H of the garnet type high-dielectric-constant ferrite is improved, the grain size is increased, abnormal growth of grains after long-time sintering is avoided, the sintering difficulty of the Bi-substituted high-dielectric-constant microwave ferrite is reduced, the sintering quality of the ferrite is improved, and the sintering cost is reduced. The improvement of the batch production reliability and stability of the garnet high-dielectric-constant ferrite is facilitated, the development of a batch production process of high-dielectric-constant products is promoted, and the miniaturization development of microwave ferrite devices in China is assisted.

This invention discloses a two-step oscillating hot-pressing sintering method for WC-Co cemented carbide. Specifically, the method involves: loading WC-Co cemented carbide mixed powder into a mold and pre-pressing it; firstly, holding the powder at 800°C in a vacuum environment to degas and pre-sinter the billet; then applying unidirectional oscillating pressure to the billet through the mold and raising the temperature to 1100°C for solid-state sintering. Dynamic pressure causes WC particles to rearrange, and Co particles undergo severe plastic deformation under the pressure of the WC particles, further increasing the relative density of the billet; finally, the temperature is raised to 1300-1350°C to form a WC-Co eutectic liquid phase. Dynamic pressure drives further particle rearrangement, and the eutectic liquid phase uniformly fills the gaps between WC particles, completing the sintering process. This invention improves the three-dimensional spatial distribution uniformity of the Co phase, eliminates residual porosity, effectively inhibits abnormal growth of WC grains, and produces cemented carbide with excellent strength and toughness.

The invention discloses an ultra-high hardness surface-strengthened GGr15 steel and a preparation method thereof, and belongs to the technical field of heat treatment of metal materials. The invention discloses an ultra-high hardness surface-strengthened GGr15 steel preparation method, which adopts a multi-stage composite carbonitriding process to quickly and efficiently form dispersed granular carbonitriding compounds on the surface of GGr15 bearing steel, which can not only realize high-efficiency carbonitriding on the surface of bearing steel, but also avoid abnormal growth and coarsening of carbonitriding compounds, and significantly improve the surface hardness and wear resistance of steel; the method significantly improves the carbonitriding speed and shortens the processing cycle, thereby realizing the practicality, economy and effectiveness of the carbonitriding treatment process, and the reagent cost used in the method is low, and the processing temperature and processing time are significantly reduced, showing great potential in energy saving, emission reduction and cost reduction.

The application relates to the technical field of metal matrix composites, and particularly discloses a high-entropy alloy binder phase gradient cemented carbide tool material and a preparation method thereof. The high-entropy alloy binder phase gradient cemented carbide tool material comprises a surface layer, a transition layer and a core layer, and the surface layer comprises WC powder 60-70 parts, high-entropy alloy binder phase 0.5-2.0 parts, high-entropy carbide precursor 5-10 parts and composite grain inhibitor 0.3-0.8 parts in terms of mass parts; the transition layer comprises WC powder 45-55 parts and high-entropy alloy binder phase 5-10 parts. In the application, the WC powder, the high-entropy alloy binder phase, the high-entropy carbide precursor, the composite grain inhibitor and the carbon black are matched in the surface layer, the transition layer and the core layer, the carbon black content in each layer presents a gradient distribution, and the high-entropy carbide precursor generates nanoscale high-entropy carbide precipitated phases in situ under the driving of carbon potential, so that the abnormal growth of WC grains is inhibited.

The invention discloses a high-strength alumina-based porcelain insulator, comprising an alumina-based porcelain body, wherein the raw materials of the alumina-based porcelain body include: industrial alumina powder, reinforcing powder, Anyuan clay, potassium feldspar, titanium dioxide, boric acid, phosphorus pentoxide, kaolin and diatomaceous earth. The alumina-based porcelain body prepared by the method of the invention has good bending strength and electrical breakdown strength, can withstand a large load force, is not easy to be damaged; and has high insulation performance, thereby improving the safety of the insulator during use.

This invention relates to the field of high-temperature alloy investment casting technology, and discloses an inert ceramic core for high-temperature alloy hollow castings and its preparation method. The preparation method includes the following steps: using yttrium-stabilized zirconia as the matrix material, yttrium oxide powder as a mineralizer, alumina-toughened zirconia powder as a toughening agent, yttrium aluminum garnet powder as an additive, and thorium oxide as a grain inhibitor, the above powders are mixed evenly, a paraffin-based plasticizer is added, and the mixture is vacuum stirred to form a slurry with fluidity and thermoplasticity; the slurry is added to a hot-pressing core-casting machine, and a core blank is prepared using the hot-pressing method; the core blank is embedded with sand and then sintered at high temperature, and cleaned after sintering to obtain the ceramic core. This invention improves the chemical inertness, high-temperature strength, and dimensional stability of the ceramic core through the synergistic effect of yttrium-stabilized zirconia, yttrium oxide powder, alumina-toughened zirconia powder, yttrium aluminum garnet powder, and thorium oxide, making it suitable for the internal cavity forming of high-temperature alloy hollow castings.

The application discloses a semiconductor-dielectric-conductor type attenuation porcelain and a preparation method thereof, and relates to the technical field of electromagnetic wave absorption and attenuation materials. The attenuation porcelain is composed of a semiconductor phase, a dielectric phase, a conductor phase, a sintering aid and a binder; the conductor phase has a core-shell structure of a nickel-cobalt-cerium alloy solid solution inner core, a nitrogen-doped amorphous carbon intermediate layer and a silicon dioxide shell, and cerium atoms are doped in the nickel-cobalt alloy solid solution lattice in the form of lattice distortion. The preparation method comprises the following steps: preparation of a precursor solution, limited silicon dioxide coating, limited in-situ reduction and defect construction, mixing and forming, and high-temperature sintering. Through the synergistic effect of the semiconductor phase, the dielectric phase and the core-shell conductor phase, the application realizes comprehensive enhancement of impedance matching, interface polarization, conductive loss and multiple scattering attenuation, and can improve the high-temperature stability and electromagnetic wave attenuation performance of the attenuation porcelain.

This invention discloses a preparation process for a high-density tungsten-cobalt cemented carbide, relating to the field of cemented carbide preparation technology. The process includes the following steps: S1: Batching: Tungsten carbide powder, cobalt powder, and a forming agent are precisely weighed according to a preset mass percentage and placed in a high-efficiency mixing device for pre-mixing to ensure that the components are initially and uniformly dispersed, resulting in a stable tungsten-cobalt mixture. This invention employs a multi-stage densification process involving wet ball milling, spray drying, die pressing, and cold isostatic pressing. This not only ensures that the mixture particles are sufficiently refined and uniformly dispersed, producing spherical composite powder with excellent flowability and significantly reducing internal defects in the formed blank, but also further enhances the density and uniformity of the blank through cold isostatic pressing, providing a good foundation for subsequent full densification during sintering, effectively reducing the porosity of the finished alloy and improving the overall structural stability.

The application discloses a method for constructing a multi-enzyme complex engineering strain, and has the characteristics that the method comprises the following steps: S1, constructing a light decarboxylase FAP and an oil-producing yeast fatty acid synthase fusion expression vector; S2, electrically shocking and transforming the constructed target vector into an agrobacterium competent AGL1, and introducing the target vector into a starting strain through an agrobacterium-mediated transformation method to obtain an engineering strain that is back-supplemented with a fatty acid defect; the engineering strain that is back-supplemented with the fatty acid defect is obtained, the FAP-FAS2 fusion expression is realized at the same time as the self-assembly of the intracellular FAS1, and a FAP-FAS synthase complex is obtained. The complex not only back-supplements the fatty acid defect function, so that the strain grows normally, but also can synthesize alkanes in the process of blue light irradiation fermentation culture, and realizes the intracellular assembly of protein macromolecules.

This invention discloses a high specific surface area mesoporous tin oxide powder and its preparation method. The method includes: dissolving a tin source in a mixed solvent of alcohol and deionized water, adding a ketone complexing agent and a nonionic dispersant, and stirring to form a tin-based complex precursor solution; then transferring the solution to a hydrothermal reactor for hydrothermal aging treatment, causing the precursor solution to hydrolyze and condense, forming gel particles in situ; after solid-liquid separation, washing with alternating anhydrous ethanol and dilute ammonia water, and drying to obtain the precursor powder; finally, performing staged heating calcination under an air-nitrogen mixed atmosphere, first removing organic components at low temperature, and then completing the crystal phase transformation at high temperature to obtain rutile phase SnO2 powder. The powder has an average particle size of 8–15 nm and a specific surface area of ​​85–110 m² / g. 2 The powder has a pergola size of 3–6 nm and good dispersibility. This invention effectively suppresses grain agglomeration through complexation regulation, hydrothermal-sol-gel coupling, and gradient atmosphere calcination. The prepared powder is suitable for applications such as gas sensors, lithium-ion battery anodes, or transparent conductive films.

This invention belongs to the field of electrical ceramics technology, and relates to a carbon ceramic composite material, its preparation method, and a resistor sheet. The composite material uses clay and kaolin as the ceramic matrix, introduces submicron graphite as the conductive phase, and incorporates nano-ceramic reinforcing powder. It is prepared through multi-stage wet mixing, spray drying granulation, and pressureless sintering under an inert atmosphere. The preparation method involves first pre-treating the material at medium temperature under vacuum to remove moisture and organic matter, followed by high-temperature sintering under inert gas protection to obtain a uniform and dense carbon ceramic composite matrix, on which electrodes and a high-resistivity layer are formed. Through the dispersion strengthening effect of the nano-ceramic reinforcing powder and the synergistic control of process parameters, the microstructure of the material is effectively improved, significantly increasing the compressive and flexural strength of the resistor sheet, reducing the risk of mechanical failure caused by electro-thermal-mechanical shocks during transportation and service, and making it suitable for use in high-voltage and ultra-high-voltage circuit breaker closing resistors.

The invention relates to the field of aluminum oxide ceramics, in particular to high-strength 95 aluminum oxide ceramics and a preparation method and application thereof.The high-strength 95 aluminum oxide ceramics are prepared by adopting boehmite and hydrotalcite as main components of a binder and adopting the following method: S1, the boehmite and the hydrotalcite are mixed according to the mass ratio of 1: (1-3) and ground till the particle size ranges from 60 nm to 100 nm, and a nano powder mixture is obtained; s2, the ground nano powder mixture is added into a dispersing agent to be evenly mixed, a binder precursor is obtained, and the mass ratio of the nano powder mixture to the dispersing agent is 10: (0.1-0.5); and S3, slowly adding a nitric acid solution with the pH value of 2-3 into the binder precursor to obtain the binder disclosed by the invention. When the binder is applied to an aluminum oxide ceramic preparation process, the defect that pores and cracks appear in aluminum oxide ceramic due to the fact that a traditional binder is decomposed and overflows under the high-temperature condition can be overcome, the compactness of the aluminum oxide ceramic is further improved, and the strength and hardness of the aluminum oxide ceramic are improved.

This invention relates to the field of magnesium alloy smelting technology, and in particular to a smelting process and apparatus for a semi-solid non-dendritic slurry of rare earth AS-based magnesium alloy. Using AS magnesium alloy as the base material and a Ce-La-Nd ternary rare earth mixture as the rare earth modifier, the process involves vacuum melting, electromagnetic stirring, and stepped cooling to obtain an ingot. A three-dimensional curve is plotted based on the JMAK equation to determine the critical temperature. Using a rheological casting apparatus, through internal cooling gradient, stirring-assisted slurry preparation, and ultrasonic-assisted isothermal treatment, combined with three-level quality judgment and defect closed-loop adjustment, a slurry with controllable liquid phase content, fine and rounded grains, and uniform rare earth distribution is prepared. The process exhibits high repeatability and meets the requirements of high-end semi-solid forming.

The invention discloses a preparation method and application of a tungsten-titanium alloy target material, and belongs to the technical field of target materials for diffusion barrier layers of integrated circuits. The prepared tungsten-titanium alloy target material is low in gas content and fine and uniform in grain size, a titanium-rich phase is uniformly distributed in a tungsten-rich phase, and the tungsten-titanium alloy target material has high density and high solid solubility. The preparation method comprises the following steps: carrying out high-energy ball milling and powder mixing on high-purity tungsten powder and titanium powder; performing cold isostatic pressing molding; performing microwave sintering; and carrying out solution treatment. The tungsten-titanium alloy target material prepared by the method can be applied to sputtering of a diffusion barrier layer of a large-scale integrated circuit.

The application relates to the technical field of alloy materials, in particular to a 4341E high-speed steel and a preparation method thereof. The high-speed steel is characterized in that Ti, B and N elements are introduced for ternary micro-alloying and synergistic modification on the basis of a W-Mo-V-Co component system, nanoscale particles generated in-situ by Ti-N are used as heterogeneous cores to significantly refine grains, the grain boundary is strengthened by the grain boundary segregation effect of boron elements, and the reticular carbide is effectively broken. The obtained steel material realizes perfect matching of high hardness, excellent red hardness and excellent impact toughness, solves the problem that the strength and toughness of traditional high-speed steel are difficult to be compatible, and is particularly suitable for manufacturing high-performance cutting tools, cold and hot precision dies and high-temperature wear-resistant parts.

The invention discloses a high-crystallinity titanate perovskite nanocrystalline powder prepared by adopting an oxalate method and two-stage calcination. The chemical general formula of the powder is Ba1-xMexTiO3 (x is greater than or equal to 0 and less than or equal to 0.2), Me is one or more of Ca, Sr and other elements, the average grain size of the powder is 30-120 nm, the grain size dispersion coefficient s is less than or equal to 0.4, and the powder has a high tetragonal distortion ratio (c / a). The novel oxalate method comprises the following steps: complexing a titanium source and oxalic acid in ethanol, adding a surfactant, reacting with a barium / Me salt solution, and curing to obtain an oxalate precursor; after cleaning and ball-milling refinement, carrying out two-stage calcination: firstly decomposing at 580-800 DEG C and preliminarily forming a phase, and then finishing crystallization optimization at 900-1200 DEG C; the method provided by the invention solves the problems of coarse grains, non-uniform distribution or many defects in the traditional method, and realizes controllable preparation of superfine, uniform and high-crystallinity powder; the powder disclosed by the invention is particularly suitable for manufacturing a miniaturized, high-capacity and high-reliability multilayer ceramic capacitor (MLCC) dielectric layer.

The invention discloses a preparation process of high-Br and high-Hcj sintered neodymium iron boron without heavy rare earth, and belongs to the technical field of rare earth magnetic material preparation. The process comprises the following steps: raw material preparation and precursor preparation: weighing a main phase raw material and an Al-Ga-Cu ternary precursor according to a specific proportion; smelting, vacuumizing, filling argon, preserving heat at 1440-1460 DEG C, and adding a precursor; hydrogen decrepitation dehydrogenation reforming, wherein the temperature is increased to 845-855 DEG C for hydrogen decrepitation, and a parallel magnetic field is applied for dehydrogenation; key sintering is carried out, oxygen partial pressure is controlled to be 4-6 ppm, and the temperature is increased to 847-853 DEG C at a specific rate for sintering; low-temperature self-assembly is conducted, after the temperature is reduced to 600 DEG C, the oxygen partial pressure is increased to 14.5-15.5 ppm, heat preservation is conducted, and then the temperature is reduced to 400 DEG C; and the structure is locked, and the oxygen partial pressure is reduced to 4.5-5.5 ppm and then is cooled to 20-30 DEG C. Through a ternary precursor low-temperature self-assembly mechanism driven by an oxygen potential gradient, collaborative improvement of Br > = 1.45 T and Hcj > = 20 kOe under the condition of no heavy rare earth is realized, the grain boundary phase volume fraction is > = 85%, the problem of collaborative improvement of magnetic performance is solved, and the requirement of a high-end motor for a high-performance permanent magnet can be met.

This invention belongs to the field of piezoelectric materials and discloses a lead nickel tungstate-lead zirconate titanate piezoelectric ceramic and its preparation method. The general chemical formula of the lead nickel tungstate-lead zirconate titanate piezoelectric ceramic of this invention is: xPb(Ni 1 / 2 W 1 / 2 )O3-yPbZrO3-(1-x-y)PbTiO3+zwt%MnO2; where, 0.05

The invention relates to the technical field of ceramic materials, in particular to SiC-TiB2-TiC composite ceramic, a preparation method and application thereof, and the preparation method comprises the following steps: respectively weighing raw material powder according to a component design ratio; uniformly mixing and fully drying; and sintering in a vacuum atmosphere by using a discharge plasma sintering furnace at the sintering temperature of 1900-2000 DEG C under the pressure of 40-60 MPa for 10-15 minutes to finally obtain the compact SiC-TiB2-TiC composite ceramic. In order to solve the problem that commercial TiB2 powder is large in particle size and is directly introduced to cause insufficient electrical properties and electrical discharge machining properties of the SiC-TiB2 composite ceramic, TiC is introduced into a SiC-TiB2 system, and in-situ formation and grain pinning effects in a reaction sintering process are utilized, so that a microstructure is refined, and the connectivity of a conductive network is enhanced. Compared with the composite ceramic without TiC, the material prepared by the invention has more excellent conductivity and electrical discharge machining performance, the preparation process is simple, and complicated subsequent treatment is not needed.

The invention discloses a preparation method of an ultra-fine grain hard alloy mixture, which belongs to the technical field of hard alloy manufacturing, and comprises the following steps: weighing raw material powder of WC, Co, Cr3C2, VC and the like, carrying out two-stage grinding and mixing on the raw material powder to obtain a mixture, and then pressing and sintering to obtain the ultra-fine grain WC-Co hard alloy. The two-stage grinding process is adopted, uniform mixing of materials is facilitated, machining strain and lattice distortion in the grinding process are effectively reduced, the integrity and morphology of WC grains are kept, and therefore the crushing efficiency of the materials is improved, and superfine powder with higher dispersity is obtained. According to the prepared ultra-fine grain WC-Co hard alloy, the components are evenly mixed, particle contact and reaction are more sufficient in the sintering process, abnormal growth of WC grains in the alloy can be effectively avoided, the problem of coarse inclusion is solved, and the performance of the alloy is effectively improved.