46results about How to "Improve sintering driving force" patented technology

The invention discloses a crystalline silicon solar cell front silver paste and a preparation method thereof. The front silver paste comprises the following components in percentage by weight: 85-90%of silver powder, 5-10% of an organic carrier, 5-10% of an organic carrier, 1.5-5% of composite glass powder, and 0.05-1% of a silver paste additive. The silver powder in different particle size distribution is cooperatively used, the slurry is good in ink permeability, and the silver powder particles in the grid line are more uniformly and tightly filled, so that the sintering density of the gridline is facilitated, the resistance of the grid lines is reduced, and the photoelectric conversion efficiency is improved. The preparation process of the glass powder is simple, the control is facilitated; the glass powder with different components is compounded and used, so that a series of particles are uniform, the softening temperature is low, and the composite glass powder has good wettability to the silver powder and the silicon substrate, a front silver paste prepared from the composite glass powder is sintered on the front surface of the cell, the silver electrode and the silicon havegood ohmic contact and welding performance, and the adhesion strength of the electrode is high.

The invention relates to a low temperature sintering boride-based ceramic material and a preparation method thereof. The invention solves the problem of over high sintering temperature and pressure and low sintered density of the boride-based ceramic material in the prior art. The boride-based ceramic material is prepared by boride powders, carborundum powders and additives which are the mixture powders of alumina and yttria. The method is as follows: first, the boride powders, the carborundum powders and additives are mixed; second, the mixture is put in absolute ethyl alcohol for ultrasonic cleaning and dispersion, ball mill mixing and drying; and third, the mixture is cooled after hot-press sintering. The prepared low-temperature boride-based ceramic material after sintering at the condition of 1800 DEG C to 1850 DEG C and 30 Mpa are uniform and compact in structure, small in grain size and strong in mechanical property simultaneously, the relative density is above 96 percent and the intensity and toughness are respectively reach 786MPa and 7.12 MPam<1 / 2>. The method is simple and practical in technology, low in cost and easy for popularization.

The invention discloses a preparation method of a nuclear reactor core neutron absorbing material terbium titanate pellet. The preparation method of the terbium titanate pellet consists of ball milling, cold isostatic pressing and sintering, also the preparation technology is simplified, the economic cost is low, the needed equipment is simple, and the obtained terbium titanate pellet has uniform structure and superior performance.

The invention discloses water-based nano-silver electrically-conductive printing ink capable of sintering at a room temperature as well as preparation and application thereof. The preparation method comprises the following steps: mixing a reducing agent, a short-chain molecular dispersant and deionized water to obtain a reducing liquid; mixing silver salt and deionized water to form a reaction liquid; adding the reducing liquid into the reaction liquid dropwise and performing reaction after dropwise adding; centrifuging and cleaning to prepare nano-silver particles dispersed by the short-chainmolecular dispersant; mixing a functional aid and deionized water to prepare a composite aqueous solution of the functional aid; and mixing the nano-silver particles dispersed by the obtained short-chain molecular dispersant and the composite aqueous solution and performing ultrasonic dispersion in ice water bath. The electrically-conductive printing ink contains the electrically-conductive filler nano-silver particles, the deionized water and the composite aqueous solution of the functional aid, the viscosity is 8 to 15 cP, the surface tension is 25 to 35 mN / m, and the electrically-conductive printing ink can be sintered at a room temperature; and the electrically-conductive printing ink has low organic matter content and is environment-friendly.

The invention discloses a method for preparing a tungsten slab by low-temperature sintering. The method comprises the following steps: (1) mixed tungsten powder is prepared; (2) the mixed tungsten powder is pressed to a slab by a cold isostatic pressing mode; and (3) under hydrogen atmosphere, the slab is heated and sintered, and is naturally cooled to obtain the tungsten slab. The method uniformly mixes the tungsten powder with three particle size ranges in proportion; on the one hand, excellent filling capacity is realized, higher pressing blank density is obtained, and higher sintering density is obtained; and on the other hand, quick actuation of densification process at a lower temperature is guaranteed, and the highest sintering temperature and insulation time are reduced; and in addition, through controlling the slab sintering temperature and time, the phenomenon of difficult elimination of a core hole of the sintered slab caused by the surface dentification speed of the sintered slab far faster than the core dentification speed due to excessive fast heating speed or shorter insulation time in medium-low-temperature phase can be prevented, and each part of the slab has better structure uniformity and higher density.

The invention relates to a preparation method of boron carbide granulation powder for pressureless sintering. The invention aims to solve the problems that the density of existing pressureless sintering boron carbide is difficult to be higher than 90% and the mechanical property of the existing pressureless sintering boron carbide is poor. According to the invention, two dispersants respectively directed at nanometer boron carbide and micron boron carbide are used to prepare uniformly and stably dispersed nanometer boron carbide slurry and micron boron carbide slurry respectively. In a spray granulation process, the nanometer boron carbide slurry and the micron boron carbide slurry are instantly mixed in an atomizing disc rotating at a high speed, and then moisture in a high-temperature spray granulation tower is rapidly evaporated, so dry granulation powder is obtained, and the phenomenon of agglomeration is prevented. The method is applied to the field of preparation of boron carbide ceramic.

The invention belongs to the technical field of ceramic materials, and discloses super-multielement high-entropy ceramic as well as a preparation method and application thereof. The molecular formula of the high-entropy ceramic is (HfxZryTazNbaMobWcVdTieCrf)B2, wherein 0<x<1, 0<y<1, 0<z<1, 0<a<1, 0<b<1, 0<c<1, 0<d<1, 0<e<1, 0<f<1, and x+y+z+a+b+c+d+e+f=1; The preparation method comprises the following steps: adding HfO2, ZrO2, Ta2O5, Nb2O5, MoO3, WO3, V2O5, TiO2, Cr2O3 and amorphous boron powder into an organic solvent, mixing, drying, preparing the obtained mixed powder into a green body, and keeping the temperature at 1,400-1,600 DEG C under a vacuum condition to obtain ceramic powder; introducing a protective atmosphere into ceramic powder at 1,000-1,400 DEG C by spark plasma sintering, pressurizing to 10-100 MPa, performing calcining at 1,800-2,200 DEG C, and obtaining the product. The relative density of the super-multielement high-entropy ceramic is greater than 95%, the hardness is 32-45 GPa, and the room-temperature strength is 1,000-1,500 MPa.

The invention belongs to the technical field of ceramic materials, and discloses hafnium-niobium-based ternary solid solution boride conductive ceramic and a preparation method and application thereof, the molecular formula of the conductive ceramic is (HfaNbbMic) B2, a is more than or equal to 0.1 and less than or equal to 0.9, bis more than 0 and less than 0.9,c is more than 0 and less than 0.9 and a+b+c=1, and Me is Zr, Ta or Ti. The conductive ceramic is prepared by the following steps of adding HfO2, Nb, Me oxide, B4C and carbon powder into a solvent, carrying out ball milling and mixing to obtain mixed powder, carrying out die pressing to obtain a green body, putting the green body into a graphite crucible, heating to 1400-1600 DEG C, carrying out heat preservation, and carrying out vacuum heat treatment to obtain (HfaNbbMec)B2 hafnium-niobium-based ternary solid solution boride powder, heating the boride powder to 1000-1400 DEG C by adopting spark plasma sintering, introducing a protective atmosphere, heating to 1900-2100 DEG C, and calcining at the pressure of 10-100 MPa.

The invention relates to rapid sintering equipment for dynamically loading coupling alternating current. The rapid sintering equipment comprises the following components including a furnace frame, a dynamic loading system,a sintering control system and an alternating current control system; a furnace body is arranged in the furnace frame, and a closed pressure maintaining cabin is formed in the furnace body; the dynamic loading system comprises a dynamic loading generation part and a dynamic loading control part, and the dynamic loading generation part is arranged in the pressure maintaining cabin and used for heating a sintering material; the dynamic loading control part is arranged outside the pressure maintaining cabin, the output end of the dynamic loading control part is connected with the dynamic loading generation part, and the dynamic loading control part is used for outputting coupled total dynamic loading to the dynamic loading generation part; the sintering control system isarranged outside the pressure maintaining cabin, and the output end of the sintering control system is connected with the input end of the dynamic loading control part; and the alternating current control system is arranged outside the pressure maintaining cabin, the input end of the alternating current control system is connected with the output end of the sintering control system, and the output end of the alternating current control system is connected with the dynamic loading generation part. The equipment can remarkably improve the sintering driving force, inhibit grain growth, improve the density of a sintered body and improve the material performance.

The invention relates to an additive for magnesium aluminate spinel sintering and an application method.The main constituents of the additive are scandium salt, ammonia water and water.The application method of the additive comprises the following steps of 1, dissolving the scandium salt into the water; 2, adding magnesium aluminate spinel powder to a solution obtained in step 1; 3, adding the ammonia water to adjust pH of water-based slurry obtained in step 2 to be 9-11; 4, then conducting drying for 24 hours or longer in a drying oven at the temperature of 120 DEG C, and then conducting calcination for 1-6 hours at the temperature of 600-800 DEG C; 5, after compression molding conducted on the calcinated powder is completed, controlling the sintering temperature to be 1400-1600 DEG C, and controlling sintering time to be 1-6 hours.By means of the additive for magnesium aluminate spinel sintering, the sintering temperature can be lowered, sintering time can be shortened, sintering compactness can be improved, and a uniform microstructure can be formed easily.

The invention belongs to the field of high-entropy ceramic materials, and specifically discloses a method for preparing perovskite-type composite oxide high-entropy ceramics by hot-pressing sintering. The A site of the perovskite-type composite oxide high-entropy ceramics is occupied by Sr, and the B The bit is composed of Zr, Sn, Ti, Hf elements and any element in Nb, Ta, Mn, Tb in nearly equimolar ratio. The present invention adopts hot pressing sintering technology to prepare Sr(Zr 0.2 sn 0.2 Ti 0.2 f 0.2 m 0.2 )O 3 (M=Nb, Ta, Mn, Tb) composite oxide high-entropy ceramic material, the prepared ceramic material grains are submicron order, compact structure, simple preparation process and short cycle.

The invention discloses a method for preparing high-purity ultrafine zirconium boride powder by grinding aid-assisted sand milling. Acetic acid, boric acid and sorbitol are mixed together, stirred and dissolved at a constant temperature to obtain a clear solution; the clear solution is cooled to room temperature, Drop in zirconium n-propoxide at a constant speed to prepare zirconium boride precursor sol; seal the zirconium boride precursor sol to make it fully gel to obtain zirconium boride precursor gel; gel the zirconium boride precursor The glue is dried and ground into powder, and then calcined in the debinding furnace to obtain inorganic dry powder; the inorganic dry powder and grinding aid are made into a suspension, and then poured into a sand mill for sand grinding to obtain superfine Inorganic dry powder slurry: dry the ultrafine inorganic dry powder slurry, and then put it into a high-temperature tube furnace for high-temperature calcination to obtain high-purity ultrafine zirconium boride powder. The zirconium boride powder prepared by the invention has higher purity, finer particle size and good microscopic appearance, and can enhance the mechanical properties and sintering driving force of the sintered body in the subsequent molding process.

The invention discloses a large-scale preparation of HfO 2 ‑ThO 2 The method for ultra-high temperature oxide composite phase ceramics comprises the following steps: HfO 2 Powder, ThO 2 powder and sintering additives are mixed to obtain mixed powder, granulated to obtain powder, and the powder is molded to obtain a composite ceramic green body, and then sintered in an oxidizing atmosphere to obtain HfO 2 ‑ThO 2 Ultra-high temperature composite phase ceramics; the compression molding adopts secondary pressure holding; the invention provides a kind of HfO under normal pressure for the first time 2 ‑ThO 2 A method for sintering and densifying ultra-high temperature oxide multi-phase ceramics. The inventors found that in the presence of sintering aids, the green body obtained by using the second pressure during the pressing process can be sintered in an oxidizing atmosphere to obtain a dense HfO 2 ‑ThO 2 Ultra-high temperature oxide composite ceramics. The preparation method of the present invention can realize low-cost and large-scale production because the sintering is carried out under normal pressure without special equipment.

The invention discloses a high-performance powder metallurgy pressed and sintered semi-high-speed steel and a preparation method thereof. The invention uses carbonyl iron powder and carbide powder as raw materials, and realizes the preparation of high-performance powder metallurgy semi-high-speed steel through processes such as ball milling, cold pressing, thermal degreasing and vacuum sintering. The prepared semi-high-speed steel has uniform chemical composition, fine grains, and overall dispersed distribution of carbides, which avoids the problems of composition segregation and coarse carbides in the traditional casting method, and significantly improves the strength and toughness of the material. The invention has the advantages of simple technological process, low production cost, easy control of components and the like. Compared with the semi-high-speed steel prepared by melting and casting, the provided semi-high-speed steel has significantly improved bending strength and impact toughness under the same density.

The invention discloses a method for preparing a tungsten slab by low-temperature sintering. The method includes: first, preparing mixed tungsten powder; second, pressing the mixed tungsten powder into a slab by cold isostatic pressing; third, in a hydrogen atmosphere, The slab is heated and sintered, and the tungsten slab is obtained after natural cooling. The present invention mixes the tungsten powders of three particle size ranges uniformly in proportion, on the one hand, it achieves good filling property, obtains a higher compact density and then obtains a higher sintered density; In addition, by controlling the temperature and time of slab sintering, it can be avoided that the surface densification speed of the sintered blank is much faster than that of the core due to the excessively fast heating speed or the short holding time in the medium and low temperature stage. Therefore, it will cause the phenomenon that the pores in the core of the sintered slab are difficult to eliminate, and ensure that each part of the slab has good organizational uniformity and high density.

The invention discloses a method for preparing a nano-particle toughened high-toughness SiC part, which relates to a preparation method for a high-toughness SiC part. The invention mainly solves the problem that in the existing process of toughening silicon carbide ceramics with silicon carbide nano particles, the nano particles are easy to agglomerate and combine, and uniform dispersion cannot be achieved. Preparation method: 1. powder pretreatment; 2. micron powder dispersion; 3. primary granulation; 4. nanometer encapsulation; 5. secondary granulation; The invention is used for the preparation of nano particle toughened SiC parts with high toughness.

The invention discloses a method for preparing high-performance powder metallurgy titanium and titanium alloy by solid-phase deoxidation, which belongs to the field of powder metallurgy titanium. The present invention proposes to TiCl 2 As titanium powder oxygen scavenger, TiCl 2 Mix evenly with titanium powder, form and sinter to obtain high-performance titanium products. During sintering, TiCl 2 Oxidation-reduction reaction with titanium powder and oxide film on the surface to generate TiCl x o y The titanium matrix is ​​removed in a gaseous state without producing solid phase impurity particles, avoiding the introduction of the second phase to hinder sintering, and TiCl x o y It is beneficial to break the oxide film on the powder surface, thereby improving the sintering activity of titanium powder, promoting densification and sintering, so as to obtain low-oxygen and high-density titanium products, and has excellent comprehensive mechanical properties. The invention provides a new idea for deoxidizing powder metallurgy titanium and titanium alloys, and is conducive to promoting the industrialization development of low-cost powder metallurgy titanium and titanium alloys.

The invention discloses a preparation method of a nuclear reactor core neutron absorbing material terbium titanate pellet. The preparation method of the terbium titanate pellet consists of ball milling, cold isostatic pressing and sintering, also the preparation technology is simplified, the economic cost is low, the needed equipment is simple, and the obtained terbium titanate pellet has uniform structure and superior performance.