106results about How to "Promote sintering" patented technology

The invention relates to the technical field of nano ceramic materials, and discloses a high-strength nano aluminum oxide ceramic product and a preparation process thereof.The preparation process comprises the following preparation steps that aluminum oxide powder, a composite binder, composite gel, a plasticizer and a solvent are mixed and subjected to ball milling, and composite slurry is obtained; placing the composite slurry in a mold, and performing mold pressing and drying to obtain a green body; and putting the green body into a high-temperature sintering furnace, carrying out high-temperature sintering, and cooling to room temperature to obtain the nano aluminum oxide ceramic product. Nano zirconium oxide and nano magnesium oxide are formed on the surfaces of the pretreated silicon carbide whiskers, and can form a solid solution with nano aluminum oxide in the sintering process to serve as a bridge of the silicon carbide whiskers and nano aluminum oxide particles, so that the binding force of the silicon carbide whiskers in a nano aluminum oxide ceramic matrix is remarkably enhanced; phosphoric acid and aluminum ammonium sulfate are firmly combined on the surfaces of nanometer aluminum oxide particles through carboxymethyl cellulose, and the situation that phosphoric acid and aluminum ammonium sulfate are not firmly combined with the nanometer aluminum oxide particles is avoided.

The invention relates to a high-temperature ablation resistant ceramic matrix composite material and a preparation method thereof. The method comprises the following steps: preparing a rare earth acetylacetone complex from hexahydrate of rare earth chloride (rare earth nitrate) and acetylacetone; uniformly mixing the rare earth acetylacetone complex with poly (hafnium) oxane by using xylene to obtain a zirconium (hafnium)-rare earth ceramic precursor solution; densifying the porous carbon fiber preform by using a zirconium (hafnium)-rare earth ceramic precursor solution through a precursor impregnation and pyrolysis process to obtain a carbon fiber reinforced carbide ceramic-rare earth zirconium (hafnium) acid salt ceramic-based composite material; and densifying the carbon fiber reinforced carbide ceramic-rare earth zirconium (hafnium) acid salt ceramic-based composite material by using molybdenum chloride and silicon chloride through a chemical vapor infiltration method to prepare the high-temperature ablation resistant ceramic-based composite material. The prepared ceramic-based composite material has excellent high-temperature oxidation ablation resistance and excellent high-temperature mechanical properties at the temperature of 2000 DEG C or above.

The invention relates to a preparation method of high-strength and high-toughness composite silicon carbide ceramic, which comprises the following steps: mixing 70-82 parts of micron-sized alpha-silicon carbide powder, 5-15 parts of a mixed reinforced phase, 5-10 parts of a sintering aid, 1.9-2.1 parts of a dispersant and 0.9-1.1 parts of a binder to obtain a powder raw material, adding deionized water into the powder raw material, and carrying out ball milling to obtain water-based slurry; carrying out spray granulation on the water-based slurry to prepare spherical granulation powder; and adding the spherical granulation powder into a graphite mold, putting the graphite mold into a hot-pressing sintering furnace, heating to a sintering temperature, and carrying out hot-pressing sintering to obtain the high-strength and high-toughness composite silicon carbide ceramic. By adopting the method disclosed by the invention, the high-performance silicon carbide ceramic material with higher mechanical property and higher toughness can be obtained.

The invention discloses a lithium iron phosphate carbon nanotube composite material and a preparation method thereof, and belongs to the technical field of battery materials. The polydopamine is used as a carbon source to coat the lithium iron phosphate, so that the direct contact between the lithium iron phosphate and the electrolyte is avoided; meanwhile, the compatibility of the carbon nanotube composite material and the lithium iron phosphate is enhanced due to the strong adhesion, so that the carbon nanotube composite material is favorably adsorbed on the lithium iron phosphate to be sintered; a carbon coating layer formed by polydopamine and the carbon nanotubes are beneficial to permeation of an electrolyte and exposure of surface active sites, and metal ions are introduced into the carbon nanotubes of the carbon nanotube composite material, so that the electrochemical performance of the material is improved, and meanwhile, the carbon nanotubes are supported; the condition that the cyclicity of the material is reduced due to collapse of the carbon nano tube in the reaction process is prevented; cobalt is introduced outside the carbon nano tube, so that the energy density of the battery can be improved, the structures of the carbon nano tube and the positive electrode material can be stabilized, and the degradation of the material is reduced.

The invention discloses silver powder and a preparation method and application thereof, and the preparation method of the silver powder comprises the following steps: dispersing a silver source in an alcohol amine compound solution, adding a dispersing agent, and then reacting with a C3-C27 fatty amine solution to prepare the silver powder. The micron silver powder is prepared through the hydrothermal method, the powder can be heated more evenly, the method is simple in process, short in reaction time and high in efficiency, the obtained micron silver powder is good in dispersity, and the tap density of the silver powder can reach about 7 g / cm < 3 >.

The invention relates to a solar cell and a preparation method thereof, a conductive device and laser-assisted sintering equipment, and the preparation method of the solar cell comprises the steps: forming a grid line pattern on a cell main body, and the grid line pattern comprises N auxiliary grid lines which are arranged in parallel at intervals; bias voltage is applied to the N auxiliary grid lines, and the bias voltage on each auxiliary grid line is in positive correlation with the conductive resistance of the auxiliary grid line; and carrying out laser-assisted sintering treatment on the N auxiliary grid lines. Therefore, Joule heat generated by local current flowing through each auxiliary grid line is beneficial to sintering of the auxiliary grid line, so that the N auxiliary grid lines can be in good contact with the semiconductor layer of the cell main body, and the conversion efficiency of the solar cell can be improved.

The invention provides a method for preparing a high-coercivity sintered neodymium-iron-boron magnet, and belongs to the technical field of rare earth permanent magnet material preparation, and the method comprises the following steps: 1, taking the sintered neodymium-iron-boron magnet as a base material, and removing an oxide layer through alkali washing deoiling, ultrasonic water washing and acid pickling cleaning; 2, taking the Pr-Dy-Cu-Ga quaternary alloy as a diffusion source, and cutting the Pr-Dy-Cu-Ga quaternary alloy into slices; 3, attaching the thin sheet to the surface of a base material for diffusion heat treatment; fourthly, low-temperature tempering is conducted; 5, testing a room temperature demagnetization curve of the sample; light rare earth Pr replaces a part of heavy rare earth Dy and is matched with Cu and Ga elements in a certain proportion to be smelted to obtain quaternary alloy, the quaternary alloy with low heavy rare earth serves as a diffusion source, the microscopic characteristics of the magnet are improved, grain boundary phase distribution is optimized, and under the condition that residual magnetism and the maximum magnetic energy product are slightly reduced, the coercive force of the sintered neodymium-iron-boron magnet is improved; and terbium and dysprosium are not used, so that the use amount of heavy rare earth elements and the production cost are reduced.

The invention relates to a silicon-based ceramic, a preparation method and application thereof, and a removal method of a ceramic core for titanium alloy casting, the raw materials of the silicon-based ceramic comprise solid powder and a binder, the solid powder comprises 60-100 wt% of silicon dioxide, 0-10 wt% of mullite, 0-10 wt% of kaolin and 0-20 wt% of yttrium oxide; the mass ratio of the solid powder to the binder is 1: (0.01-0.05); the contents of mullite, kaolin and yttrium oxide are all greater than 0; the silicon-based ceramic provided by the invention has excellent room high temperature mechanical properties and good dissolution performance.

The invention discloses a conductive paste low-temperature laser sintering method and application thereof, and the method specifically comprises the steps: applying a low-temperature laser sintering technology to the sintering process of low-silver or silver-free conductive paste, and achieving the efficient and uniform molding of a conductive layer at a lower temperature through the control of the frequency, power density and wavelength of laser. The damage of high-temperature sintering to the material structure is avoided, the conductivity of the conductive paste is effectively improved, the use of silver is reduced, and the cost is reduced; besides, the conductive paste is modified by adding a modifier, and in practical application, the photovoltaic conductive paste with the silver content of 8.5% shows excellent conductivity after being subjected to laser-assisted sintering.

The invention belongs to the technical field of photovoltaic target materials, and particularly relates to an indium titanium cerium niobium oxide ceramic target material, a preparation method and application thereof, and a transparent conductive oxide film. The indium titanium cerium niobium oxide ceramic target material comprises the following components: indium oxide, titanium oxide, cerium oxide and niobium oxide, the mass ratio of indium oxide to titanium oxide to cerium oxide to niobium oxide is 97-99: 1-0.3: 1-0.3: 1-0.2, the transparent conductive oxide film has high density, high purity and high strength, and the transparent conductive oxide film prepared from the transparent conductive oxide film has high carrier mobility, high conductivity and high light transmittance.

The invention provides a long-service-life magnesium-aluminum-carbon ladle wall brick for a steel ladle and a preparation method of the long-service-life magnesium-aluminum-carbon ladle wall brick. The long-service-life magnesium-aluminum-carbon ladle wall brick comprises the following raw materials in percentage by mass: 29%-63% of waste magnesium-aluminum-carbon bricks, 10%-20% of waste magnesium-carbon bricks, 10%-25% of fused magnesite, 2%-5% of white corundum, 3%-5% of alpha-alumina micro powder, 3% of liquid phenolic resin, 1%-3% of fused magnesite dust removal powder, 0.1%-3% of a CeSi2-SiC multiphase material and 1%-3% of high-temperature asphalt. And 1%-5% of graphite. The long-life magnesium-aluminum-carbon ladle wall brick prepared by the method has the advantages of favorable oxidation resistance, favorable molten steel scouring resistance, high thermal shock resistance, long service life and excellent use effect.

The invention provides a high-porosity and high-strength silicon-based ceramic, a preparation method and application thereof, and a removal method of a ceramic core for a titanium alloy casting, the silicon-based ceramic comprises the following raw materials: solid powder and a binder, the solid powder comprises 60-100 wt% of silicon dioxide, 0-20 wt% of kaolin, and 0-20 wt% of calcium hydroxide; wherein the content of kaolin is greater than 0, and the content of calcium hydroxide is greater than 0; the mass ratio of the solid powder to the binder is 1: (0.01-0.05); the silicon dioxide is taken as a raw material, and the kaolin and calcium hydroxide powder are taken as mineralizers, so that the sintering of the material and the generation of christobalite can be effectively promoted, the open porosity of the silicon-based ceramic is improved, the collapsibility is improved, and meanwhile, a new phase is formed and is mutually combined to form a framework so as to enhance the mechanical property of the silicon-based ceramic.

The invention discloses a preparation method of a CuAlO2-phase-based alumina-based conductive ceramic, and belongs to the technical field of preparation of nano conductive ceramics. The invention relates to a method for converting aluminum oxide ceramic into a novel electric heating element from an insulator by adding a semiconductor component CuAlO2 phase in the aluminum oxide ceramic and continuously distributing the CuAlO2 phase along an aluminum oxide crystal boundary through a process to form a conductive path, which comprises the following steps of: mixing CuO, SiO2, Al2O3 and the like according to a certain proportion, and carrying out ball milling; and the novel aluminum oxide electric heating body is formed after tabletting and sintering. According to the method, the sintering temperature of the aluminum oxide ceramic can be greatly reduced, and complicated processes and equipment are not needed, so that the novel aluminum oxide conductive heating ceramic is low in energy consumption, simple in process, low in equipment requirement and excellent in product performance, and the price of a novel heating body is expected to be greatly reduced.

The invention relates to a hollow nickel alloy breathable porous material and a preparation method thereof, and belongs to the technical field of breathable sweating metal materials. The method comprises the following steps: drying absorbent cotton, and carbonizing; then carrying out nickel plating treatment on the absorbent cotton carbonized fibers; and then carrying out dry-process blank making, wet hydrogen sintering and solid-phase infiltration, and finally rolling to obtain the hollow nickel alloy breathable porous material. The material has low density, has good permeability while ensuring the strength, and has good application prospects in the field of aerospace.

The utility model discloses a sintering system for recycling sintering ring cooling waste gas, which comprises a sintering machine and a ring cooling machine which are sequentially connected in series, a main body fan cover (1) is arranged above the sintering machine in a covering manner, and a cooling fan cover (9) is arranged on the ring cooling machine in a covering manner. And a medium-temperature waste gas outlet of the cooling fan cover (9) is respectively communicated with a front-section air inlet (201), a middle-section air inlet (301) and a rear-section air inlet (401) of the main body fan cover (1) through three independent waste gas recycling pipelines (901). According to the sintering ring cooling waste heat recovery device, waste heat recovery of sintering ring cooling medium-temperature and low-temperature waste gas is achieved at low cost and high efficiency, meanwhile, the discharge amount of the waste gas is remarkably reduced, meanwhile, the sintering working condition is greatly enhanced, and the quality of sintered ore products is remarkably improved.

The invention relates to the technical field of ceramic production, in particular to an automatic powder burying device for special ceramic production, which comprises a stamping table, an automatic feeding device and a powder burying table, the powder burying table is arranged on the stamping table, the automatic powder burying device further comprises a plurality of vertical knocking blocks, and the vertical knocking blocks are positioned on the powder burying table; the horizontal knocking blocks are located on the powder burying table, the multiple horizontal knocking blocks are divided into two groups and located on the two sides of the powder burying table respectively, and when the automatic powder burying device for special ceramic production is used, different from the prior art, gaps between powder particles are effectively compressed through knocking, and therefore the powder particles are prevented from being damaged; compared with the prior art, the powder burying table has the advantages that the compactness of the powder is improved, the higher compactness is favorable for reducing pores and defects in the product and improving the mechanical strength of the product, and meanwhile, the knocking effect can promote powder particles to be redistributed in the powder burying table, so that the local gap or accumulation phenomenon is avoided, and the uniform powder distribution is favorable for obtaining more consistent product quality.

The invention discloses an H2 and CO erosion resistant Al2O3-Cr2O3 refractory material for a hydrogen-based shaft furnace and a preparation method of the H2 and CO erosion resistant Al2O3-Cr2O3 refractory material. The H2 and CO erosion resistant Al2O3-Cr2O3 refractory material comprises the following raw materials in parts by weight: 30-40 parts of chrome corundum particles with the particle size of 4-1mm; 10-15 parts of aluminum chromium slag particles with the particle size of 1-0 mm; 10-20 parts of fused brown aluminum oxide particles with the particle size of 3-1 mm; 20-30 parts of fused white corundum powder with the particle size of less than 0.074 mm; 5-10 parts of alumina micro powder with a particle size of less than 6 [mu] m; 3-5 parts of chromium oxide green with a particle size of less than 0.074 mm; 3-4 parts of phosphoric acid; and 3-10 parts of erbium oxide. The invention has good H2 and CO gas erosion resistance, slag corrosion resistance and stable high-temperature performance, and is convenient for construction and use, so that the overall service life of the hydrogen-based shaft furnace is prolonged.

The invention discloses a coal gas injection method in a limonite sintering process, which comprises the following steps of: integrally imaging a sintering charge level according to a thermal imager above the charge level of a sintering machine to obtain the predicted temperature of the charge level, and dividing the charge level into a preheating area, a low-temperature reaction area, a medium-temperature reaction area, a high-temperature sintering area and a cooling area according to the predicted temperature of the charge level; blowing coal gas and mist water drops to the preheating area, the low-temperature reaction area, the medium-temperature reaction area, the high-temperature sintering area and the cooling area according to the coal gas injection amount and pressure and the mist water drop injection amount and pressure of the corresponding areas, and sintering; local overheating or supercooling can be avoided, and the sintering quality is powerfully guaranteed; the gas permeability of a material layer can be optimized through partitioned injection of water vapor, gas circulation and reaction development are facilitated, according to different sintering stages, coal gas and fog drop water are injected at a certain flow rate and pressure, various working conditions can be well adapted, solid fuel consumption in the sintering process is reduced, and the sintered ore yield is increased.

The invention discloses a preparation method of low-temperature sintered ceramic. The preparation method comprises the following steps: S1, pretreating kaolin; s2, modifying kaolin; s3, preparing a ceramic green body; s4, preparing a glaze material; and S5, preparing the low-temperature sintered ceramic. According to the low-temperature sintered ceramic provided by the invention, the kaolin is pretreated and modified, and the special grinding aid is added in the preparation process of the ceramic green body, so that the sintering temperature of the ceramic is effectively reduced, the sintering process is optimized, low-temperature sintering of the ceramic is realized, the energy consumption is reduced, and the production efficiency is also improved; the method has remarkable economic benefits and environmental protection significance, and the prepared ceramic has good mechanical properties.

The preparation method comprises the following steps: firstly, taking 20 to 30 weight percent of 85 alumina clinker, 15 to 25 weight percent of forsterite, 11 to 24 weight percent of fused magnesite, 4 to 6 weight percent of pyrophyllite, 6 to 8 weight percent of 95 silicon carbide, 5 to 7 weight percent of 90 silicon carbide, 22 to 27 weight percent of ferro-silicon nitride, 9 to 13 weight percent of coke powder, 6 to 8 weight percent of metal Si powder, 5 to 7 weight percent of aluminum oxide micro powder, 7 to 8 weight percent of bentonite and 14 to 20 weight percent of white mud as raw materials; and adding 2-4wt% of high-temperature asphalt, 1-2wt% of carbon black and 15-18wt% of stemming oil, and mixing in a mixer for 20-30 minutes to obtain the additive for the anhydrous stemming. The invention has the advantages of environmental protection, no pollution, effective improvement of strength and stability, and improvement of oxidation resistance and erosion resistance.

The invention discloses a low-expansion ceramic cookware blank with low water absorption and high thermal shock resistance and a preparation method of a cookware product. The blank is prepared from the following raw materials: 25 to 45 weight percent of fused quartz, 5 to 10 weight percent of potassium feldspar powder, 15 to 25 weight percent of washing mud, 10 to 20 weight percent of knar clay, 8 to 12 weight percent of chlorite, 3 to 7 weight percent of ball clay, 5 to 10 weight percent of microcrystalline glass leftover material and 5 to 10 weight percent of activated aluminum oxide. The ceramic blank is sintered at the temperature of 1240-1260 DEG C. The water absorption rate of the obtained cookware product is 4.5-5.8%, the expansion coefficient alpha (800-20 DEG C) is less than or equal to 1.6 * 10 <-6 > / DEG C, and the thermal shock resistance is that the cookware product does not crack after being cooled by water for five times at the temperature of 460-20 DEG C. Through formula design, the technical problem that in the prior art, a fused quartz formula system is large in water absorption is solved, the prepared ceramic pot product is low in water absorption, thermal shock resistance and other properties are remarkably improved, the use requirements of low-expansion ceramic products such as a heat-resistant pot can be well met, and the requirements for matched use of electric appliances, high-temperature resistance and the like can be met. And the technical progress and application development of the low-expansion ceramic industry can be promoted.

The present invention relates to the field of ceramic manufacturing technology, specifically to a high-hardness alumina-based ceramic and a preparation method thereof. The high-hardness alumina-based ceramic includes the following raw materials in parts by mass: 88 to 90 parts of alumina, 5 to 7 parts of zirconium oxide, 2 to 4 parts of lanthanum boride-modified barium titanate, 1 to 3 parts of zirconium oxide-modified silicon carbide, 6 to 8 parts of sintering aids, 1 to 2 parts of polyacrylic acid, 1 to 2 parts of sodium alginate, 0.5 to 1.0 parts of triammonium citrate, and 15 to 20 parts of solvent. The sintering aid includes a composition of magnesium oxide, nano-titanium dioxide, glass powder, and niobium pentoxide. In the scheme, alumina is used as the main body, zirconium oxide is added as a toughening agent, lanthanum boride-modified barium titanate and zirconium oxide-modified silicon carbide are used as toughening agents, and a sintering aid is introduced to improve the sintering performance, effectively improve the density of alumina-based ceramics, and increase mechanical properties such as hardness and fracture toughness.

The present application belongs to the technical field of silicon nitride ceramic production, and in particular, relates to a silicon nitride ceramic sintering production device and a production method thereof, comprising a sintering cylinder and a guide rail arranged inside the sintering cylinder, a moving frame is arranged inside the guide rail, two fixed connecting rods arranged in parallel are arranged on the moving frame, the fixed connecting rods are provided with clamps rotating around the fixed connecting rods, the two clamps on the two fixed connecting rods cooperate to clamp the silicon nitride ceramics, the fixed connecting rods are provided with torsion springs, the sintering cylinder comprises an upper straight section, a lower straight section and a central inclined section located between the upper straight section and the lower straight section, the partition of the sintering cylinder can divide the sintering cylinder into different sintering spaces and make each sintering space have a different sintering temperature, and the silicon nitride ceramics are sintered and produced by first installing the silicon nitride ceramics, then exhausting, and then sintering in different areas.

The invention discloses a processing method for a copper-clad ceramic substrate, which relates to the technical field of copper-clad ceramic substrate processing, and comprises the following steps of: taking a pre-treated copper-clad ceramic substrate, introducing nitrogen, and carrying out layered progressive micropore processing on an exposed aluminum oxide ceramic substrate of the pre-treated copper-clad ceramic substrate through picosecond laser to form micropores; each micropore is divided into an inlet layer, a middle layer and an outlet layer from top to bottom; the layer number of the micropores, the thickness of each layer of the micropores and the pulse width are controlled, and a light spot and long-focal-depth lens is adopted; adjusting monopulse energy and frequency parameters of picosecond laser, and punching an inlet layer; adjusting monopulse energy and frequency parameters of picosecond laser, and punching the middle layer; and adjusting monopulse energy and frequency parameters of the picosecond laser, and punching the outlet layer to obtain the copper-clad ceramic substrate. In the middle layer, the monopulse energy is gradually increased, and it is ensured that the material is evenly removed; at the inlet layer and the outlet layer, energy is reduced, and cracks caused by stress generated instantly when the material is punctured are avoided.

The invention discloses an intermediate of a sulfide electrolyte, a preparation method of the intermediate, the sulfide electrolyte and a preparation method of the sulfide electrolyte, the fluidity of the intermediate is 30s / 50g-75s / 50g, the preparation method of the sulfide electrolyte is characterized in that the intermediate is sintered to obtain the sulfide electrolyte, the grain size and material distribution of the sulfide electrolyte intermediate are uniform, the grain size is relatively fine, and the sulfide electrolyte intermediate has relatively high fluidity. According to the method, the intermediate of the sulfide electrolyte is adopted to prepare the sulfide electrolyte, and the improvement proportion of the ionic conductivity of the sulfide electrolyte is relatively high.

The invention discloses a purification process of high-purity magnesia, which is characterized by comprising the following steps: (1) raw material selection: firstly selecting magnesite as a raw material, and then putting the magnesite raw material into a grinding machine for grinding to obtain mineral powder; by adopting the purification process designed by the invention, high-purity magnesite can be obtained, and in the grinding and ball pressing process, the magnesium oxide material is ground until the granularity is greater than or equal to 90% in 12 microns and greater than or equal to 50% in 5 microns, the illusion crystal lattice of light-burned magnesite is destroyed, and the influence of the illusion of mother salt is eliminated, so that the ball pressing material is more compact and stable, which is of great significance to the production of high-purity magnesite. Meanwhile, during ball pressing, when the balling pressure excitation is larger than 300 MPa, part of pseudocrystals are damaged, sintering is promoted, the closed porosity is obviously reduced, high-purity magnesia can be obtained, and the balling rate and the volume density of balls can be greatly improved by adopting the secondary ball pressing process.

The present application relates to the field of composite ceramics, and aims to provide a new B4C-cBN composite ceramic with good mechanical properties and thermal conductivity, and a preparation method thereof, which comprises the following steps: S100, mixing boron carbide 5-9 parts, cubic boron nitride 1-5 parts and sintering additives to obtain a mixture; S200, obtaining the B4C-cBN composite ceramic through a sintering process; the sintering temperature is 1400-1550 DEG C; the sintering pressure is 4.9-5.5 GPa; and the sintering time is 1-3 h. The reason why aluminum and cobalt are selected as sintering additives is that the melting point of aluminum is low, and a liquid phase formed in the sintering process can effectively fill the pores through capillary action, thereby promoting the sintering process. Aluminum reacts with cubic boron nitride to form aluminum nitride, which can inhibit the conversion of cubic boron nitride into hexagonal boron nitride. Cobalt has oxygen affinity and can play a purifying role of "deoxidation and degassing", thereby reducing pores, improving density and improving the sintering performance of the composite ceramic. The optimal raw material ratio and sintering parameters are determined, so that the mechanical properties and thermal conductivity of the composite ceramic are both excellent.

The invention belongs to the field of electronic materials, and relates to glass-coated gold powder and a preparation method and application of gold conductor paste. The glass-coated gold powder comprises gold powder and a coating layer located on the surface of the gold powder. The coating layer is prepared from PbO-Bi2O3-SiO2-CuO glass, and the coating layer is prepared from The preparation method comprises the following steps: mixing, stirring and heating TEOS and metal salt in a solvent to obtain sol; uniformly mixing the pretreated gold powder with the sol, and sequentially carrying out evaporation concentration and drying to obtain gel-coated gold powder; preparing a reaction mixture containing the gel-coated gold powder and water at the same time, performing heat treatment, and performing post-treatment to obtain the glass-coated gold powder; the conductive paste is used for preparing the conductive paste for electronic packaging. The glass-coated gold powder prepared by the preparation method disclosed by the invention is high in adhesive force with a substrate and good in sintering shrinkage matching property.

This aluminum powder mixture is obtained by mixing a starting material powder, which is composed of pure aluminum or an aluminum alloy, with 5% by mass to 30% by mass of an aluminum alloy powder that has a lower melting point than the pure aluminum or the aluminum alloy. The aluminum alloy powder is composed of an aluminum alloy which has a composition that contains 5% by mass to 20% by mass of at least one of Si and Cu, and 0.2% by mass to 2.0% by mass of Mg, with a balance of aluminum and unavoidable impurities. Consequently, sintering among the aluminum powders is accelerated and it is possible to obtain an aluminum sintered body that has a higher density and a high electrical conductivity as well as obtaining a high thermal conductivity.

The invention relates to the technical field of investment casting, in particular to a low-thermochemical-activity ceramic core for investment casting and a preparation method of the low-thermochemical-activity ceramic core. The ceramic core comprises the following chemical components in percentage by weight: 70-90 wt% of fused quartz glass powder, 3-15 wt% of a thermal chemical reaction inhibitor and 7-15 wt% of a combined mineralizer. According to the low-thermochemical-activity ceramic core and the preparation method thereof, the thermochemical reaction inhibitor and the combined mineralizer are added, so that the high-temperature thermochemical stability and the mechanical property of the ceramic core are remarkably improved, and the problem of shell liquid reaction of a high-temperature alloy casting can be effectively solved; and the strict requirements of directional / single-crystal high-temperature alloy investment casting are met, the quality and the qualified rate of castings are improved, and reliable technical support is provided for production of high-temperature alloy directional / single-crystal castings of aero-engines.