97 results about "Sintering shrinkage" patented technology

The invention discloses a simulation test method for ceramic sintering stress and a method for reducing the ceramic sintering stress. The simulation test method comprises the following steps: 1, measuring the grain size, the relative density and the geometric size before and after sintering; 2, establishing a ceramic geometry by using Abaqus, and constructing a transient heat conduction model; 3, establishing a viscoelastic constitutive equation of sintering shrinkage deformation of the zirconia ceramic, and constructing a sintering shrinkage model; and 4, sequentially coupling the transient heat conduction model and the sintering shrinkage model, and implementing joint simulation of solid-phase sintering simulation to obtain a sintering stress simulation result of the ceramic. The method for reducing the ceramic sintering stress comprises the following steps: 5, establishing a ceramic sintering shrinkage finite element model with grain sizes distributed in proportion, and calculating average sintering stress distribution of the grain size proportion distribution model; and 6, comparing the average sintering stress of the sintering shrinkage models with different grain size proportions, and determining a method for reducing the sintering stress. The ceramic sintering quality and the production efficiency are improved.

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 discloses a low-cost high-polishing titanium alloy plug housing injection molding method, and belongs to the technical field of metal injection molding. The method comprises the following steps: powder preparation, raw material weighing, internal mixing, granulation, injection molding, acid degreasing, thermal degreasing and vacuum sintering, and polishing. Titanium alloy powder used in the method is composite powder formed by adding 0-50 [mu] m non-spherical powder into 0-60 [mu] m spherical powder prepared through a plasma atomization method (PDPA). The cost of the non-spherical titanium powder is far lower than that of spherical titanium powder, and the production cost is relatively reduced by more than 80%; the 0-60 [mu] m spherical powder prepared by the plasma atomization method is high in powder permeability, and sintering densification is facilitated; the sintering shrinkage coefficient of the porous titanium alloy part with the complex shape prepared through vacuum sintering is accurately controlled to be 1.20-1.350, and extra shaping matched equipment is not needed; according to the high-polishing titanium alloy product part manufactured through the method, the density is larger than or equal to 4.45 g / cm < 3 >, the tensile strength is larger than or equal to 950 MPa, the elongation after fracture is larger than or equal to 12%, and the hardness is larger than or equal to 350 (HV).

According to the mullite porous ceramic and the preparation method thereof provided by the invention, solid waste fly ash is used as a raw material, andalusite is introduced as a silicon source regulator, alumina or calcined alumina is used as an aluminum source, and proportioning is carried out according to the chemical composition of near mullite; meanwhile, the structure of the mullite ceramic is regulated and controlled by combining the particle size of the raw material, a compression molding process and segmented sintering preparation. In the process, the preparation of the near-net-size mullite porous ceramic can be effectively realized through particle accumulation and volume expansion accompanied by mullite generation in the sintering process, the sintering shrinkage rate is less than or equal to 1%, the open porosity is more than or equal to 40%, the pore size distribution is unimodal distribution, and the bending strength is gt; and meanwhile, good gas flux is achieved.

The invention discloses in-situ synthesized functional titanium fine stemming for a blast furnace, and belongs to the field of metallurgy. The high-strength and high-toughness refractory material is prepared from the following components in parts by weight: 8-15 parts of first alumina, 8-15 parts of second alumina, 8-15 parts of first silicon carbide, 7-15 parts of kyanite with the particle size of 1-0 mm, 8-15 parts of ferro-silicon nitride, 10-20 parts of second silicon carbide, 3-8 parts of Guangxi mud, 5-15 parts of a titanium-containing raw material, 1-3 parts of a carbon source, 1-3 parts of a catalyst, 1-3 parts of metal silicon powder, 1-7 parts of a nitrogen source and 10 parts of a binding agent. The stemming has the characteristics of simple and convenient process, low production cost, environmental protection and no pollution, the performance of the stemming is stable due to the self-generated TiC, TiN and Ti (C, N) solid solutions, and the stemming shows excellent low-temperature and medium-temperature strength, high volume density, low sintering shrinkage rate and good slag iron corrosion resistance.

The invention discloses an LTCC (Low Temperature Co-Fired Ceramic) material with a controllable shrinkage rate and a preparation method thereof. The material comprises microcrystalline glass A and a glass devitrification material B, wherein the glass devitrification material B is obtained by devitrifying microcrystalline glass C according to a specific temperature system. The glass ceramic A and the glass ceramic C have different softening temperatures. And accurately regulating and controlling the crystallization state of the glass crystallization material B by regulating and controlling the crystallization treatment temperature and / or crystallization treatment time of the microcrystalline glass C. The LTCC substrate prepared from the LTCC material can be co-fired with a silver conductor while ensuring sintering compactness and excellent high-frequency performance, and the sintering shrinkage rate is controllable in the range of 14%-18% on the X / Y axis.

The invention provides porous biological ceramic as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing aluminum oxide slurry with a pore forming agent to obtain mixed slurry; carrying out light curing reaction on the mixed slurry in a layer-by-layer projection manner by adopting DLP 3D printing, and carrying out layer-by-layer printing, accumulation and forming to obtain a ceramic body; according to the preparation method, through the aluminum oxide slurry composite pore-forming agent and the DLP 3D printing technology, it is guaranteed that no through hole exists in the material, high density and mechanical strength are maintained, and the problem that in the prior art, surface performance and mechanical performance are difficult to consider at the same time is solved; a discrete porous structure is constructed on the surface of the high-solid-content aluminum oxide ceramic, so that accurate regulation and control of the surface roughness are realized, surface discrete holes are directly formed, and a complex post-treatment process is omitted; through the sintering process, the overall sintering shrinkage rate is controlled, the forming precision of a complex structure is improved, the large-scale production requirement is met, and the material can be applied to bone tissue engineering scaffolds and tooth restoration materials.

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 belongs to the technical field of precision casting, and discloses light-cured silicon-based ceramic core slurry for investment casting as well as a preparation method and application of the light-cured silicon-based ceramic core slurry. The silicon-based ceramic core slurry is prepared from the following components in parts by weight: 70-85 parts of ceramic powder, 10-25 parts of photosensitive resin, 2-5 parts of a photoinitiator, 1-5 parts of a dispersing agent, 0.2-1.2 parts of an anti-settling agent and 0.01-0.2 part of a light absorber, wherein the total weight of the silicon-based ceramic core slurry is 100 parts; the ceramic powder is prepared from fused quartz powder, aluminum oxide ceramic powder and zirconium silicate ceramic powder according to the weight ratio of (50-90): (5-15): (2-10). The slurry is stable in flowing and settling performance, can be used for additive manufacturing and photocuring integrated forming of a silicon-based ceramic core with high strength, high precision, low sintering shrinkage rate and high porosity, and is of great significance for batch production of complex ceramic cores for the investment casting industry.

The invention provides high-thermal-conductivity aluminum nitride ceramic and a preparation method thereof, and belongs to the technical field of aluminum nitride ceramic. Comprising the following raw materials: aluminum nitride powder, a sintering aid, absolute ethyl alcohol, a dispersing agent and a binder. The specific formula comprises the following raw materials: 100 parts of aluminum nitride powder, 3-5 parts of a sintering aid, 100 parts of absolute ethyl alcohol, 1-2 parts of a dispersant and 2-5 parts of a binder. Preferably, the aluminum nitride ceramic material is prepared from the following raw materials: 100 parts of aluminum nitride powder, 4 parts of a sintering aid, 100 parts of absolute ethyl alcohol, 1.2 parts of a dispersing agent and 3 parts of a binding agent. Through research test and improvement on sintering aids, forming, glue discharging and sintering processes, the heat conductivity of the aluminum nitride ceramic structural part can be effectively improved, the green body is high in strength and small in sintering shrinkage deformation, crystal lattices are further purified, crystal grains are promoted to grow up, the porosity is remarkably reduced by properly prolonging the heat preservation time, and the service life of the aluminum nitride ceramic structural part is prolonged. Therefore, the heat conductivity is improved and can reach more than 200W / (m.K), and batch production can be better carried out.

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 invention discloses a low-shrinkage lithium silicate heat accumulator and a preparation method thereof, the low-shrinkage lithium silicate heat accumulator comprises the following raw materials by weight: 6-14 parts of lithium carbonate with D50 particle size of 3-10 [mu] m; 50-70 parts of silicon oxide, wherein the D50 particle size is 5-30 [mu] m; 8-25 parts of kaolin and calcined kaolin, wherein the D50 particle size is 2-9 [mu] m; 9-17 parts of aluminum oxide, wherein the D50 particle size is 3-10 [mu] m; 4 to 7 parts of a binder; 0.5 to 2 parts of a surfactant; lithium carbonate, kaolin, calcined kaolin, technological silicon oxide and technological aluminum oxide are adopted, heat preservation is conducted for 3-8 h at the temperature of 1320-1400 DEG C, the lithium-containing silicate heat accumulator with the sintering shrinkage smaller than 2% is obtained, the thermal expansion coefficient of the product at the temperature of 30-1000 DEG C is smaller than 1.3 * 10 <-6 > / DEG C, cracking is avoided after thermal shock at the temperature of 700 DEG C, the heat accumulator has the large specific heat capacity, the specific heat at the temperature of 1000 DEG C is 2.28 J / g / K, and the heat accumulator has the good heat preservation performance. And the heat accumulator can be used for the RTO device with higher requirement on heat performance.

The application discloses a curved ceramic heating sheet and a preparation method thereof. The method is aimed at an alumina curved ceramic green sheet with a curvature radius of 10-20 mm and a thickness of 0.3-1.0 mm. The green sheet is prepared from raw materials such as alumina powder, a binder and a solvent in a fixed proportion. The sintering shrinkage is stable at 10%-15%. The process adopts a segmented sintering process of an arc-shaped alumina tooling combined with 'low-temperature pre-sintering and shaping-wolfram-containing slurry circuit printing-intermediate-temperature shaping-high-temperature fusion', including low-temperature gradient pre-sintering for completing the matrix degassing and preliminary shaping, intermediate-temperature slow heat preservation for releasing stress in cooperation with tooling locking curvature, and high-temperature medium-speed heating for realizing multi-layer dense fusion. The application can solve the problems of sintering collapse deformation and circuit falling of the curved thin-wall heating sheet, the product forming yield is more than 90%, the resistance deviation is less than or equal to ±2%, secondary shaping is not needed, the process has strong stability, and is suitable for batch industrialized production of the curved ceramic heating sheet.

The invention belongs to the technical field of refractory materials, and particularly relates to a composite castable for a cement kiln coal injection duct and a preparation method and application of the composite castable for the cement kiln coal injection duct. 15-20% of silicon carbide particles; 8-12% of dispersed alumina micro powder; 4-6% of calcium aluminate cement; the content of SiO2 in the rare earth modified silica fume is greater than or equal to 94%, and the rare earth modified silica fume is doped with 0.5-1.5 wt% of Y2O3; 3% to 5% of ZrO2-TiO2-Al2O3 precursor powder, 2% to 5% of ZrO2-TiO2-Al2O3 0.1%-0.3% of a water reducing agent; 0.05 to 0.1 percent of a retarder; and the balance of water. According to the castable, ZrO2-TiO2-Al2O3 precursor powder is added, in-situ reaction is carried out at the temperature of 1100-1300 DEG C, micro-expansion and sintering shrinkage are dynamically matched, cracking is avoided, thermal stability is remarkably improved through doping of Zr < 4 + >, and once the ZrO2-TiO2-Al2O3 precursor powder is formed, a Zr-doped aluminum titanate crystal phase cannot be decomposed or reversed in a high-temperature environment in follow-up service, and the structural stability can be kept.

The invention relates to the technical field of semiconductors, and provides composite copper powder, a preparation method of the composite copper powder, a semiconductor packaging piece and a preparation method of the semiconductor packaging piece in order to solve the problems of nano-copper oxidation and sintering shrinkage in the prior art. The preparation method of the composite copper powder comprises the following steps: weighing soluble copper salt and a pore-forming agent, dissolving the soluble copper salt and the pore-forming agent in a first alkaline solution, and uniformly mixing the soluble copper salt and the pore-forming agent to obtain a first solution; a reducing agent and a dispersing agent are weighed and dissolved in a second alkaline solution, and a second solution is obtained; quickly mixing the first solution and the second solution under stirring, reacting, cooling to room temperature after the reaction is finished, and carrying out solid-liquid separation to obtain copper particles; the preparation method comprises the following steps: adding copper particles into a solvent, uniformly mixing, adding a coating agent, stirring, carrying out solid-liquid separation, and carrying out vacuum drying to obtain micron copper; and micron copper and nano copper are weighed, the mass ratio of the micron copper to the nano copper is (1-81): 9, the micron copper and the nano copper are mixed, the nano copper is embedded into the concave points of the micron copper, and the composite copper powder is obtained.

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 present invention discloses a photocurable additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage. Its slurry is composed of a photosensitive resin, a dispersant, and ceramic powder. Among them, the photosensitive resin accounts for 35-45 vol% by volume, the ceramic powder accounts for 55-60 vol% by volume, and the dispersant is added according to 1-5% of the mass of the ceramic powder. Moreover, the photosensitive resin contains 0.4-1% of a photoinitiator. The components of the ceramic powder include alumina, cyanite, and silica. The present invention relates to the technical field of additive manufacturing of ceramic materials. For this photocurable additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage, by adding cyanite to the photocurable ceramic slurry, the expansion generated by the decomposition of cyanite at high temperature compensates for the shrinkage of the ceramic core during the sintering stage. Under the combined action of the decomposition expansion of cyanite and the sintering shrinkage of alumina, zero sintering shrinkage of the ceramic core at a sintering temperature of 1600 degrees is achieved. The present invention can prepare complex ceramic cores with a zero sintering shrinkage rate and excellent comprehensive properties.

The invention relates to the technical field of nano materials, and discloses a nano-silver paste material and a preparation method thereof, and the nano-silver paste material comprises composite silver powder, an organic solvent system and a polyvinylpyrrolidone surface modifier. Wherein the composite silver powder is composed of nano silver wires, polygonal nano silver particles and micron-sized flaky silver powder according to a specific mass ratio, the organic solvent system is a gradient volatile solvent, and the polyvinylpyrrolidone surface modifier forms a thin coating layer. By the adoption of the technical scheme, low sintering shrinkage, high sintering compactness, low void ratio, excellent electric and heat conduction performance and high shear strength can be achieved.

The present invention relates to a method for testing the shrinkage rate of secondary sintering of a ceramic core at high temperature, and belongs to the technical field of shrinkage rate testing. The method for testing the shrinkage rate of secondary sintering of a ceramic core at high temperature comprises the following steps: (1) preparing a standard sample of a core; (2) preparing a wax mold sample; (3) preparing a measuring module; (4) preparing a measuring module; (5) measuring the inner cavity size of a casting; (6) calculating the shrinkage rate A of the secondary sintering of a core at high temperature: bringing the above four length dimensions into the following calculation formula: A=T3 / T2-T4 / T1-C. For each of the multiple wax mold samples in the measuring module, the secondary sintering shrinkage rate A is calculated and the average value is obtained as the secondary sintering shrinkage rate of the core under the corresponding casting conditions. Beneficial effects: The principle is simple, the operation is easy, and it does not rely on professional high-precision measuring equipment. It can effectively convert high-temperature measurement into low-temperature measurement, and solves the problem that the high-temperature secondary sintering shrinkage of the core cannot be accurately reflected by simply relying on the thermal expansion coefficient.

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 present invention relates to the field of semiconductor technology. To solve the problems of nano-copper oxidation and sintering shrinkage in the prior art, a composite copper powder, a preparation method thereof, a semiconductor package, and a preparation method thereof are provided. The preparation method of the composite copper powder comprises the following steps: weighing soluble copper salt and a pore-forming agent, dissolving them in a first alkaline solution, and mixing uniformly to obtain a first solution; weighing a reducing agent and a dispersant, dissolving them in a second alkaline solution to obtain a second solution; quickly mixing the first solution and the second solution under stirring and reacting, cooling to room temperature after the reaction ends, performing solid-liquid separation to obtain copper particles; adding the copper particles into a solvent, mixing uniformly, adding a coating agent, and stirring, performing solid-liquid separation and vacuum drying to obtain micron copper; weighing micron copper and nano copper, the mass ratio of micron copper to nano copper being (1 to 81):9, mixing the micron copper and the nano copper, and embedding the nano copper into the concave points of the micron copper to obtain the composite copper powder.

The invention relates to the field of jet bonding forming, and provides high-loading-capacity nickel-based nano ink for jet bonding forming, a preparation method of the high-loading-capacity nickel-based nano ink and part preparation.The preparation method of the ink comprises the steps that a nickel precursor and nickel nano particles are dissolved in a rapid-volatilization solvent, then a dispersing agent is added to regulate and control the rheological property of the ink, and the high-loading-capacity nickel-based nano ink is obtained; finally, uniform and stable ink is formed through stirring and / or ultrasonic treatment. According to the ink, the precursor is added, the stability of the nano particles in a solution is adjusted, the loading capacity of the nano particles of the ink can reach 40-70 wt.%, meanwhile, the formula of the quick-drying solvent and the stable dispersing agent is optimized, and quick curing and stability maintaining after ink jetting are achieved. In the subsequent sintering process, the nickel precursor is heated and self-decomposed into nickel nanoparticles, the nickel nanoparticles are matched with the previously added nickel nanoparticles, so that gradient density distribution is formed between the nanoparticles with different sizes and the base powder to promote sintering, and meanwhile, the nanoparticles with different sizes are filled in gaps of the base powder to improve the sintering performance. And the sintering shrinkage rate is remarkably reduced while material densification is promoted, and finally, high-density and low-shrinkage-rate parts are manufactured.

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.

The invention is applicable to the field of chip manufacturing, and particularly relates to a zirconia ceramic powder tape casting process and a NOx sensor, the zirconia ceramic powder tape casting process comprises the following steps: drying powder: drying 5Y powder in a drying oven; performing ball milling: adding xylene, absolute ethyl alcohol and a fish oil dispersing agent, performing ball milling for 30 minutes, adding 5Y powder into the tank, adding a PVB (Polyvinyl Butyral) adhesive and a butyl benzyl ester plasticizer, and performing ball milling for 16 hours to obtain tape casting slurry; filtering: sealing the tape casting slurry; vacuum defoaming is conducted, specifically, the tape casting slurry is put into a solder paste stirring machine, and the tape casting slurry with the smooth and bubble-free surface is obtained; tape casting: carrying out tape casting to obtain a tape-cast sheet; overlapping: cutting the casting sheet, and putting the casting sheet into an overlapping machine; and sintering. According to the invention, the overlapping property, the obdurability and the sintering shrinkage rate of the zirconium oxide casting lamination are improved, so that the sensitivity, the response speed and the chemical stability of the NOx sensor for the SCR control system after optimization are improved to a certain extent.

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.

A lightweight automobile brake disc (10) and a preparation method therefor. A disc cap (110) of the lightweight automobile brake disc (10) is prepared from a first aluminum-based material with good processibility, and a disc body (120) is prepared from a second aluminum-based material with good wear resistance and heat resistance. By controlling the alloy element content of an aluminum alloy matrix in the first aluminum-based material to be smaller than or equal to the alloy element content of an aluminum alloy matrix in the second aluminum-based material, the sintering shrinking percentages of the two materials during a preparation process, in which a powder metallurgy method is used, are matched.