42 results about "Sintering shrinkage" patented technology

The invention discloses an injection molding aluminum alloy feed and a preparation process thereof, the feed is composed of aluminum alloy powder and a compound binder, and the aluminum alloy powder is composed of Si, Fe, Cu, Mn, Mg, Zn, Cr, Ti, Co and Al; according to the technical scheme, aiming at the technical problems that a brittle phase is easy to form due to high magnesium and silicon content of the 6013 aluminum alloy, the interface bonding force is poor, the sintering shrinkage is difficult to control and the like due to a stable surface oxide film, and through collaborative optimization of a formula and a process, the high-magnesium-silicon-content high-magnesium-silicon-content high-brittleness aluminum alloy is obtained; the feeding and finished product performance is obviously improved; and the prepared aluminum alloy part has the advantages of high sintering density, high hardness, high tensile strength, high elongation and the like, and can meet the manufacturing requirements of high-end fields such as aerospace and traffic transportation on complex precision parts.

The invention provides silver powder and a preparation method thereof, and belongs to the technical field of metal powder preparation. According to the method, the silver powder microstructure control agent and the small-particle silver powder oriented growth inducer are used in a combined mode, the pH value, the temperature and the adding mode of the reaction solution are cooperatively controlled, and the large-flake silver powder with the small-particle thick-flake silver powder growing in an oriented arrangement mode is obtained. An oxidizing agent solution and a reducing agent solution are added into a base solution at the same time, sodium citrate in the base solution controls generation of small-particle thick-sheet-shaped silver powder, an alkaline inducer can promote oriented growth of silver powder particles while adjusting the pH of the solution, then target silver powder is prepared, and on the other hand, in an alkaline reaction system, the prepared silver powder is high in sedimentation rate and high in stability. The solid-liquid separation effect is good, and the waste liquid treatment cost is low. Compared with dendritic or traditional single flaky silver powder, the flaky silver powder prepared through the method has the advantages that the sintering shrinkage rate of powder slurry is low, the contact effect between silver powder particles is better, the sintering activity and conductivity are good, and the market application prospect is good.

The invention provides a production size control method for a hard alloy roll collar blank and an intelligent production system, and belongs to the technical field of powder metallurgy. The method aims to solve the problems of low finished product qualification rate and high cost caused by uncontrollable sintering shrinkage of the hard alloy roll collar in the prior art. According to the technical scheme, the method comprises the steps that a set of linear shrinkage coefficients of a hard alloy roll collar pressed blank are designed in advance based on the target finished product size, and the target size of the pressed blank is calculated according to the set of linear shrinkage coefficients and the target finished product size; then, according to the calculated target size, wax-doped powder serving as a raw material is subjected to compression molding, and a compressed blank is obtained; and finally, the pressed blank is transferred into a low-pressure sintering furnace for dewaxing and sintering treatment. According to the method, the quantifiable linear shrinkage coefficient is introduced, empirical estimation is converted into accurate calculation, operation is simplified, the accuracy and consistency of the size of a finished product are remarkably improved, and the rejection rate and the production cost are reduced.

The application relates to a preparation method of a low-density zirconium diboride-silicon carbide foam ceramic material and belongs to the technical field of foam ceramic preparation. The application aims at solving the problems of forming difficulty and sintering shrinkage of the zirconium diboride-silicon carbide foam ceramic. The preparation method is simple. The silicon carbide template prepared by impregnating a ceramic impregnation solution under vacuum conditions is dried and sintered in subsequent steps, and finally, the low-density zirconium diboride-silicon carbide foam ceramic is obtained. The low-density zirconium diboride-silicon carbide foam ceramic material prepared by the application has the characteristics of uniform structure, nanometer-level grains and excellent mechanical properties, and has a good application prospect in the high-temperature heat insulation field.

The invention provides a ceramic pump part and a preparation method thereof. The ceramic pump part is prepared from the following raw materials: silicon carbide particles, carbon black, epoxy resin emulsion, a curing agent, cellulose ether, an inorganic silicon solution and silicon particles. The silicon carbide particles with four-stage particle sizes (500-841 [mu] m, 212-500 [mu] m, 180-250 [mu] m and 109-154 [mu] m) and a specific mass ratio are adopted, so that the solid-phase bulk density is remarkably improved, low-viscosity mold filling is maintained while high solid content is ensured, drying and sintering shrinkage and stress concentration are reduced from the source, and cracking and deformation of large-size or non-uniform-wall-thickness parts are remarkably reduced.

This invention discloses a method for simulating and testing ceramic sintering stress and a method for reducing ceramic sintering stress. The simulation and testing method includes: 1. Measuring the grain size, relative density, and geometric dimensions before and after sintering; 2. Using Abaqus to establish the ceramic geometry and construct a transient heat conduction model; 3. Establishing the viscoelastic constitutive equation for the sintering shrinkage deformation of zirconia ceramics and constructing a sintering shrinkage model; 4. Sequentially coupling the transient heat conduction model and the sintering shrinkage model to perform joint simulation of solid-state sintering, obtaining the simulation results of ceramic sintering stress. The method for reducing ceramic sintering stress includes: 5. Establishing a finite element model of ceramic sintering shrinkage with proportionally distributed grain sizes and calculating the average sintering stress distribution of the grain size proportional distribution model; 6. Comparing the average sintering stress of sintering shrinkage models with different grain size proportions to determine the method for reducing sintering stress. This invention improves ceramic sintering quality and production efficiency.

The application discloses a kind of based on numerical simulation's silicon nitride sintering process parameter optimization method, including the following steps: to photo-curing 3D printing silicon nitride ceramic is successively implemented and sintered experiment is debound, micro characterization is carried out to the ceramic after sintering, and second characterization result is obtained;Establish the viscoelastic constitutive equation of silicon nitride ceramic sintering shrinkage deformation, based on the viscoelastic constitutive equation in Abaqus Sintering finite element model is constructed, to obtain the simulation result of transient temperature field and the simulation result of sintering shrinkage deformation;Second characterization result is corrected to finite element model, and verified finite element model is obtained;According to verified finite element model, the original sintering process curve is optimized, and the sintering process curve with the lowest cost and the greatest influence on sintering stress reduction is selected as the optimal sintering process, to realize the optimization of sintering process.The sintering process parameter optimization method not only reduces the cost, but also shortens the experimental period, and the production efficiency is high.

The application provides silver powder and a preparation method thereof, and belongs to the technical field of metal powder preparation. The application obtains large flaky silver powder by using silver powder micro-morphology control agent and small particle silver powder directional growth inducer in combination, and by synergistically controlling solution pH, temperature and adding mode of the reaction, so that the small particle thick flaky silver powder is directionally arranged and grown. The oxidizing agent and reducing agent solution are simultaneously added into the base solution, the sodium citrate in the base solution controls the generation of the small particle thick flaky silver powder, and the alkaline inducer adjusts the solution pH while promoting the directional growth of the silver powder particles, thereby obtaining the target silver powder. On the other hand, in the alkaline reaction system, the prepared silver powder has a fast settling rate, a good solid-liquid separation effect and a low waste liquid treatment cost. Compared with the dendritic or traditional single flaky silver powder, the flaky silver powder prepared by the application has a low sintering shrinkage rate of the powder slurry, a better contact effect between the silver powder particles, a good sintering activity and conductivity, and a good market application prospect.

The invention provides a diamond grinding tool based on silicon carbide wafer processing and a preparation method and application, the diamond grinding tool comprises a grinding pellet piece and a grinding disc, the grinding pellet piece is provided with Ni powder, a metal binding agent, a ceramic binding agent, a pore forming agent and a wetting agent, diamond abrasive particles and the metal-ceramic binding agent are adopted as raw materials and are mixed with Ni, a certain amount of pore forming agent is added, and the mixture is stirred to be uniform; the preparation method comprises the following steps: sintering for 20 minutes at high temperature and high pressure in a high-temperature mold, removing pressure after sintering, cooling to 810 DEG C, preserving heat for 10 minutes, then cooling to 550 DEG C, and preserving heat for 10 minutes, so that sintering shrinkage can be effectively prevented; compared with a conventional metal-ceramic bond diamond grinding tool, the multi-nickel metal-ceramic bond diamond grinding tool has the advantages that the material removal rate is increased by 18.3%, the overall level of the grinding process and technology can be improved, the quality of a processed product is improved, the preparation period is short, the product cost can be greatly reduced, and the economic benefit is high.

This invention relates to the field of electronic materials technology, specifically disclosing a titanium nitride ceramic electronic paste, its preparation method, and a ceramic electrode. The titanium nitride ceramic electronic paste is prepared from the following components by mass percentage: 50%–80% titanium nitride powder, 10%–50% organic components, 0.5%–5% solid binder phase, and 0–5% additives. This invention uses titanium nitride powder as the functional phase. The physicochemical properties of titanium nitride are similar to those of the ceramic substrate. It is bonded to the ceramic substrate via high-temperature sintering, resulting in sintering shrinkage behavior that is more closely similar to that of the ceramic substrate. This reduces the difficulty of sintering and matching with the ceramic substrate, effectively reducing stress and defects during co-firing, and improving bonding strength and process stability. The paste provided by this invention also has comprehensive advantages such as low cost, excellent dispersibility, good stability, high temperature resistance, and corrosion resistance, and has broad application prospects in the high-end electronics field.

This invention relates to a powder metallurgy forming method for a high-strength guardrail bolt with an anti-loosening structure, comprising: filling a mold with metal-based powder, the mold including a bolt head forming cavity, a lower contact surface forming cavity, a square neck forming cavity, and a screw forming cavity; forming a first annular powder region and a second annular powder region radially within the lower contact surface forming cavity; pressing the metal-based powder to give the first annular powder region a first compaction density and the second annular powder region a lower second compaction density, forming a green blank; pre-sintering and high-temperature sintering the green blank to give the axial sintering shrinkage of the second annular powder region a higher amount than that of the first annular powder region, thereby forming an inclined wedge-shaped anti-loosening surface on the lower contact surface; shaping the sintered blank while retaining the wedge-shaped anti-loosening surface to obtain the guardrail bolt. This invention eliminates the need for external anti-loosening components, improves the anti-slip and anti-vibration loosening capabilities of the connection pair, and balances forming accuracy and large-scale manufacturing requirements.

The application provides a high-thermal-conductivity heating element and a preparation method thereof. The high-thermal-conductivity heating element is prepared from first black silicon carbide powder, second black silicon carbide powder, flaky graphite, polyvinyl alcohol aqueous solution and a small amount of high-thermal-conductivity MgO sintering aid. The particle sizes of the first black silicon carbide powder and the second black silicon carbide powder are different, and the particle size ratio of the first black silicon carbide powder and the second black silicon carbide powder satisfies the Horsfield filling relationship. The application uses two silicon carbide powder raw materials with different particle size distributions, so that the D50 index satisfies the Horsfield filling relationship, the small-particle-size silicon carbide powder can be filled in the gaps formed by the particle accumulation of the large-particle-size silicon carbide powder, the forming density of the pressed silicon carbide heating sheet blank is improved, the requirement for realizing the densification of the heating sheet through the shrinkage of the later high-temperature sintering is reduced, the sintering temperature is reduced, and the loss of the flaky graphite in the sintering process is avoided.

The invention provides a hollow turbine blade design method. Firstly, a ceramic simulation part is designed based on the size of a mold core of the hollow turbine blade, then the ceramic simulation part is pressed and sintered, the shrinkage rate of the ceramic simulation part during sintering is obtained, and finally a ceramic mold core mold and an appearance mold of the hollow turbine blade are designed based on the shrinkage rate. According to the hollow turbine blade design method disclosed by the invention, the shrinkage rate of the ceramic simulation piece with the similar size during sintering is firstly obtained, and then the ceramic core mold and the appearance mold of the hollow turbine blade are designed according to the shrinkage rate of the ceramic simulation piece during sintering, so that the core sintering shrinkage size of the hollow turbine blade can be effectively controlled; and the size and the flow of the inner cavity of the turbine blade can be ensured, so that the design and the manufacturing of the high-precision hollow turbine blade are realized.

The application discloses a preparation method of spherical nano-barium titanate coated nickel powder and belongs to the technical field of MLCC internal electrode materials. The method comprises the following steps: dispersing nano-nickel powder in water and performing ultrasonic treatment; adding titanium tetrachloride into the water, and then adding a nickel powder dispersion liquid; then adding a barium source, adjusting the pH to alkaline by using lye, stirring and reacting at 60-80 DEG C under normal pressure and in an air atmosphere, and separating and drying to obtain the product. The barium source is barium hydroxide, barium chloride or barium acetate. The application uses cheap titanium tetrachloride as a titanium source to synthesize the barium titanate coated nickel powder with a core-shell structure in an aqueous solution in one step, and the reaction condition is mild, and no organic solvent and inert atmosphere protection are needed, so that the process is simple and the cost is low. The obtained product has a continuous and dense coating layer, the oxidation starting temperature is above 385 DEG C, the volume shrinkage rate at 1200 DEG C is less than or equal to 9.1%, the oxidation resistance and sintering shrinkage matching property of the nickel powder are significantly improved, and the product is suitable for MLCC internal electrode materials.

The invention relates to an ink-jet 3D printing magnesium oxide ceramic powder material and a magnesium oxide ceramic material.The powder material comprises 50-90 parts of dead burned MgO, 10-30 parts of phosphate, 2-7 parts of a precision improving component, 1-10 parts of a sintering aid and 1-10 parts of a sintering shrinkage-reducing flexibilizer. Firstly, an ink-jet 3D printing technology is adopted for preparing a magnesium oxide ceramic green body of a complex structure; and sintering in a high-temperature muffle furnace to obtain the compact high-strength magnesium oxide ceramic. The powder material disclosed by the invention can realize ink-jet 3D printing, has the characteristics of high precision and high degree of freedom, can be used for preparing any ceramic green body in a complex shape, and provides a new way for preparing complex ceramics.

This invention relates to the field of electronic materials technology, specifically disclosing a titanium diboride ceramic electrode slurry, its preparation method, and a ceramic electrode. The titanium diboride ceramic electrode slurry is characterized by being prepared from the following components by mass percentage: 40%–89% titanium diboride powder, 10%–50% organic system, 1%–5% solid binder phase, and 0–5% additives. This invention uses titanium diboride powder as the functional phase. The physicochemical properties of titanium diboride are similar to those of the ceramic substrate. By bonding it to the ceramic substrate through high-temperature sintering, the sintering shrinkage behavior is more compatible, effectively reducing stress and defects during co-firing, and improving bonding strength and process stability.

The invention discloses an AI-based closed-loop glue discharging sintering control system and production equipment, and relates to the technical field of multilayer ceramic capacitor manufacturing processes, the control system comprises an AI decision module, and a data acquisition module, a feature extraction module and an execution mechanism module which are electrically connected with the AI decision module, the control system uses online crystal phase analysis data for sintering control, establishes a process parameter-product performance end-to-end mapping model, realizes automatic monitoring and prediction of the shrinkage rate of the ceramic material by adopting a sintering shrinkage rate compensation model, and automatically adopts a strategy for compensation when the deviation between the real-time shrinkage rate and the predicted shrinkage rate is too large, so that the quality of the product is ensured. The sintering quality can be improved, so that the product quality is improved.

This invention provides a method for preparing gradient HA / ZrO2 bioceramics and the bioceramics themselves, relating to the field of ceramic material preparation technology. The method includes: conducting sintering experiments with different solid contents and different combinations of HA and ZrO2 component ratios to obtain sintering shrinkage data and establishing a sintering shrinkage control model; determining the component ratio of each layer of the ceramic gradient structure according to biomechanical requirements; performing reverse design of the gradient structure based on the component ratio of each layer of the ceramic gradient structure using the sintering shrinkage control model to obtain the required solid content for each layer of the ceramic gradient structure; and preparing HA / ZrO2 composite ceramic slurries with different solid contents according to the required solid content for each layer of the ceramic gradient structure to prepare gradient HA / ZrO2 bioceramics. This invention enables the ZrO2-rich layer and the HA-rich layer to achieve equal shrinkage during co-sintering, fundamentally eliminating interlayer stress and preventing cracking and warping.

The invention discloses a method for reducing anisotropy of a neodymium-iron-boron permanent magnet in the sintering shrinkage process, and belongs to the technical field of rare earth permanent magnet material preparation. The method comprises the following steps: smelting a main phase alloy which hardly contains a rare earth-rich phase; carrying out rapid hardening, hydrogen decrepitation and air jet pulverization to obtain main phase powder with D50 of 3.5-5.0 [mu] m; a rare earth-rich phase thin film layer with the thickness of 100-150 nm is formed on the surface of the powder through magnetron sputtering or steam deposition, and the thin film layer comprises at least one of the R element, Al, Cu, Ga, Zr and Nb; carrying out compression molding under a magnetic field of 1.5-2.0 T; and then carrying out multi-section vacuum sintering and tempering treatment. According to the method, rare earth-rich phases on the surfaces of main phase particles are uniformly distributed, neodymium-rich phase accumulation in the orientation direction is avoided, the shrinkage anisotropy is smaller than or equal to 5%, the yield of the radiation ring is larger than or equal to 96%, and the problem of cracking caused by uneven distribution of the rare earth-rich phases in a traditional process is effectively solved.

Alumina-lanthanum hexaluminate special heat-insulating refractory material and preparation method and application thereof relate to the field of heat-insulating refractory materials for high-temperature kiln lining.The present application uses tabular corundum fine powder, active alumina micro powder, lanthanum oxide micro powder and lanthanum aluminate micro powder with suitable particle size as raw materials, selects hydratable alumina as a binder, adds water to obtain a slurry by stirring; microspherical foam prepared by using animal protein foaming agent is added into the slurry as a pore-forming template, and the slurry is stirred, cast, maintained, demolded, dried and high-temperature sintered to obtain the alumina-lanthanum hexaluminate special heat-insulating refractory material. Compared with the existing porous heat-insulating materials, the alumina-lanthanum hexaluminate special heat-insulating refractory material has the advantages of high strength and low thermal conductivity, can be directly used as the working lining of high-temperature kiln, has obvious advantages of integration of structure and heat-insulating function, has high load softening temperature and low re-sintering shrinkage, and has a use temperature of up to 1800 DEG C. Compared with the existing alumina porous materials, the service life is increased by 3-5 times.

The application belongs to the technical field of refractory materials, and particularly relates to a composite castable for a coal injection pipe of a cement kiln, a preparation method and application, which comprises the following components in percentage by weight: zircon mullite aggregate: 45-55%; silicon carbide particles: 15-20%; dispersible alumina micropowder: 8-12%; calcium aluminate cement: 4-6%; rare earth modified silica ash: 3-5%, the SiO2 content of the rare earth modified silica ash is greater than or equal to 94%, and 0.5-1.5 wt% of Y2O3 is doped; ZrO2-TiO2-Al2O3 precursor powder: 3-5%; water reducing agent: 0.1-0.3%; retarder: 0.05-0.1%; and the balance is water. 4+ The castable of the application adds ZrO2-TiO2-Al2O3 precursor powder, in-situ reacts at 1100-1300 DEG C, dynamically matches micro-expansion and sintering shrinkage, avoids cracking, Zr doping significantly improves thermal stability, once formed, the Zr-doped aluminum titanate crystal phase does not decompose or reverse in a high-temperature environment in subsequent service, and can maintain structural stability.

The invention discloses a laminated inductor and an inductor preparation method, and relates to the field of inductors. The inductor comprises a functional layer, the functional layer comprises a membrane, the membrane comprises a material sheet, a filling layer and an inner electrode, the inner electrode comprises a first conductive slurry layer and a second conductive slurry layer which are sequentially stacked, and the second conductive slurry layer is located on the face, back to the material sheet, of the first conductive slurry layer. The thickness of the first conductive slurry layer is 4-9 times that of the second conductive slurry layer, and the viscosity of the second conductive slurry layer is larger than that of the first conductive slurry layer. According to the invention, the weak bonding position of the inner electrode and the magnet is further printed with the second conductive slurry layer with optimized viscosity, and the glass powder is used for bonding the inner electrode and the magnet in a sintering molten state to enhance the bonding force, thereby effectively avoiding layering and cracking under the actions of lamination, cutting and subsequent sintering shrinkage. And the resistance value of the inductor is reduced.

The invention discloses a preparation method of a multi-pole magnetic ring, and belongs to the technical field of powder metallurgy process preparation, the process comprises the steps of powder preparation, forming, splicing, isostatic pressing and sintering, a radial orientation or diagonal orientation forming method is adopted in the forming process, and low-melting-point powder is laid at two or more positions of the edge of a splicing face in the splicing process; a conventional two-pole parallel orientation forming press is adopted, and a radial orientation or diagonal orientation forming method is utilized, so that the orientation degree of the material is greatly improved, and the magnetic performance of the material is improved; by laying the low-melting-point powder on the edge of the splicing face and adopting the pre-sintering process, the problem that the splicing face cracks or cracks are generated due to the fact that the sintering shrinkage directions of green bodies with different orientations are inconsistent is solved, the whole ring with the multi-pole orientation is sintered, the mechanical performance of the magnetic ring is improved, and the use performance is improved.

The application discloses a construction waste sintered brick for heat preservation and a preparation method thereof, and relates to the technical field of sintered bricks. The modified fly ash is wrapped by aerogel, so that the fine coal gangue and construction waste can be embedded in the surface mesopore of the modified flyash, and then the sintered brick is prepared from the starch, the modified fly ash and the sludge. In the sintering process, the aerogel is carbonized to form a fixed structure, the sintering shrinkage deformation of the fly ash is inhibited, the starch forms carbon microspheres, and the carbon aerogel is connected. Then, the brick body is wetted by a sodium hydroxide solution, and the second sintering is carried out, so that the solid network support structure is formed in the brick body, the mechanical properties and the heat preservation performance of the sintered brick are improved, the internal pores of the sintered brick are regulated, and the high water absorption of the sintered brick is prevented.

The application provides an alumina multilayer ceramic substrate and a preparation method thereof, and relates to the field of ceramic substrate preparation, and comprises the following preparation steps: (1) preparing raw materials according to a proportioning ratio; (2) ball milling the raw materials; (3) mixing the material prepared in the step (2) with water, and then spray drying to prepare a powder material; (4) ball milling the powder material prepared in the step (3) with a binder and a solvent for 3-7 hours, and then cold isostatic pressing; (5) drying the semi-finished product prepared in the step (4), and then pressing by a dry pressing method, and then stacking, laminating, cutting and drilling to prepare a green ceramic substrate. The application can improve the stability of a sintering process, shorten sintering time, and reduce sintering shrinkage. During sintering, the green ceramic substrate can rotate to be uniformly heated and sintered in a sintering box, and the green ceramic substrate placing disc can be automatically slid out by adjusting the angle between a movable plate and a butt joint material groove.

The embodiment of the utility model discloses a burning bearing jig for a complex structural part. The burning bearing jig comprises a jig body, a fixing groove formed in the longitudinal direction of the jig body, positioning grooves formed in the two sides of the fixing groove at intervals, a receding groove formed in the center of the bottom of the fixing groove, and the front-back distance between the positioning grooves is 3 mm. According to the sintering jig for the complex structural part, the contact face between a product and the sintering jig in the sintering process can be reduced, friction between the product and the sintering jig can be reduced, the deformation amount of the product in the sintering shrinkage process is reduced to the minimum, product deformation caused by sintering is greatly reduced, the production cost is effectively reduced, and the production efficiency of the product is improved.

The utility model discloses a ferrite magnetic core sintering device, which relates to the field of industrial part processing, and comprises a device main body, a forming groove is arranged in the device main body, a cover plate is arranged at the top of the forming groove, the cover plate is clamped with the forming groove, a clamping block is arranged in the device main body in a sliding manner, and the clamping block is clamped with the forming groove. The side, close to the forming groove, of the clamping block is provided with an ejection block matched with the forming groove, and the end, away from the interior of the forming groove, of the clamping block is provided with an extrusion air bag. The device is communicated with an external air source through the connector, air pressure in the forming groove is regulated and controlled in real time through the connecting valve, and the material sintering shrinkage amount is compensated in cooperation with elastic deformation of the extrusion air bag.

The invention discloses a profiling die and a profiling method for sintered neodymium iron boron, and belongs to the field of magnetic material preparation. The working surfaces of the upper pressure head and the lower pressure head of the mold are concave spherical surfaces, the front and rear working surfaces of the pressure heads are convex cylindrical surfaces, and the front and rear surfaces of a mold cavity are designed by adopting concave cylindrical surfaces with the same radian and matched with each other; the pressing method comprises the steps that neodymium iron boron magnetic powder is pre-pressed to the set density, orientation pressing is conducted under the conditions of a 1.52.0 T magnetic field and the pressure of 610 MPa, an arc-shaped pressed blank with the surface parallel to the direction of the magnetic field is obtained, and after the blank is sintered and shrunk, the cuboid magnet with the regular geometrical shape and the remarkably-reduced edge magnetic declination angle is finally formed. The easy magnetization axis of the magnetic powder is highly consistent with the direction of an external magnetic field, the magnetic declination angle is effectively reduced, and the material utilization rate is increased to 98% or above from traditional about 94%.

The present application relates to the technical field of capacitor manufacturing, and discloses a kind of MLCC electrode nickel paste sintering shrinkage and BaTiO3 ceramic medium matching regulation and control method, comprising the following steps: S1: the conductive ceramic shrinkage inhibitor powder, dispersing agent and organic carrier are ball milled to obtain pre-dispersion, the conductive ceramic is selected from at least one of titanium nitride, titanium carbide, calcium copper titanate, lanthanum titanate or lanthanum strontium manganese oxide;S2: nickel powder is heat treated in H2 / N2 mixed atmosphere to obtain surface-activated nickel powder;S3: pre-dispersion, surface-activated nickel powder, dispersing agent, organic carrier and additives are mixed to form paste;S4: grinding dispersion to fineness≤5 μm.The present application replaces insulating oxide with conductive ceramic, combines nickel powder activation and contains heat preservation platform's step temperature rise, constructs conductive rigid skeleton, realizes shrinkage matching, gives consideration to electrode conductivity and interface bonding force, solves the problem that shrinkage matching and conductive performance are difficult to give consideration to.

The utility model discloses a graphite boat device for sintering a hard alloy large plate and an assembly structure. The graphite boat device comprises a graphite boat body, a supporting block, a supporting ball and a bonding solid, the graphite boat body further comprises side wall exhaust holes, supporting block clamping grooves, an annular arc groove and upper and lower end stacking clamping grooves. The supporting balls are placed on the periphery of the supporting block, and a pressed blank is placed on the same plane formed by the top ends of the supporting balls and the top end of the supporting block. When the pressed blank is sintered and shrunk, the supporting ball can be driven to roll freely, and the shrinkage resistance on the periphery of the pressed blank is almost zero; the supporting block in the middle plays a role in supporting and stabilizing the pressed blank and prevents the pressed blank from sliding; a communicating space is formed among the supporting balls, the supporting blocks and the side wall exhaust holes, so that the uniformity and the stability of the carbon atmosphere around the pressed blank are ensured; the periphery of the pressed blank is mainly subjected to heat transfer and heating in a heat radiation heat transfer mode, and it is guaranteed that the pressed blank is evenly heated. Therefore, the sintering deformation of the hard alloy large plate can be effectively reduced.