134results about How to "Increase green density" patented technology

The invention discloses a process for preparing a metallurgical powder product from titanium hydride powder preparedmade by hydrogenating sponge titanium instead of titanium powder. The process comprises the following steps of: firstly, hydrogenating sponge titanium, crushing and, rating and mixing brittle titanium hydride, and mixing the titanium hydride with an alloy element; and then, carryingout near-net shape pressing to finish dehydrogenation in a vacuum sintering process. In the process of directly forming the titanium hydride powder, because of the secondary crushing of the brittle titanium hydride powder, the pressed green density is higher than that obtainedan occasion when titanium or titanium alloy powder is used, and the titanium is prevented from being oxidized. In the sintering process, the density of a sintering blank can rapidly rise (to be higher than 99 percent) because of the decomposition of the titanium hydride. The method has the characteristics short process flows, high yield and product density, low cost and oxygen content and good performance.

The invention relates to a method for producing powder smelt screw ratchet, which comprises: mixing the materials, compressing molding, sintering, compressing and shaping, to obtain the ratchet. The invention also discloses a relative mould, which is formed by a compressing upper punch, compressing middle mould, compressing lower punch; the upper part of lower punch has the inner screw tooth matched with the outer screw tooth; the upper punch is sliding matched with the middle mould; the middle mould is sliding matched with the lower mould; the compressing core rod has compressing core rod, friction plate, and rotation element; the upper part of compressing core rod has outer screw tooth; the lower end of core rod and the upper end of rotating element have friction plate between them, while their contact surface has lubricant. The invention, via the rotation of core rod, realizes the one-time molding and demoulding of inner screw ratchet, to improve the yield and reduce the cost.

The invention provides silicon nitride ceramic slurry, a preparation method of the silicon nitride ceramic slurry and application of the silicon nitride ceramic slurry to preparation of a silicon nitride cast film. The preparation method comprises the following steps of mixing silicon nitride powder, a sintering aid, a dispersant and a solvent, performing first ball milling, then adding an adhesive and a plasticizer for secondary ball milling, and performing vacuum defoaming to obtain slurry, wherein the mass ratio of the silicon nitride powder, the sintering aid, the dispersant and the solvent is 100 to (5-15) to (49-67) to (2-3.5) to (10-20) to (10-40); and performing tape casting and drying on the slurry to obtain a smooth, uniform, dense, gentle and agreeable Si3N4 biscuit which is benefical to forming processing and sintering in a later period. The silicon nitride ceramic slurry obtained by the method is uniform, is low in viscosity, high in solid content, simple in preparation technology and liable to realize industrialization and is suitable for tape casting.

This invention provides a method of forming a powder compact which can produce a high density compact under a high pressure and at the same time can reduce pressure for ejecting the compact from a die. This method comprises the application step of applying a higher fatty acid lubricant to an inner surface of a heated die, and the compaction step of filling metal powder into the die and compacting the metal powder under such a pressure as to force the higher fatty acid lubricant to be chemically bonded with the metal powder and form a metallic soap coating. Since the metallic soap coating is formed between the die and a compact, friction force between the die and the compact is decreased and ejecting pressure can be remarkably decreased despite of compaction with high pressure. Besides, a high density compact can be obtained owing to the compaction with high pressure.

The invention discloses tape casting slurry for a laminated sheet type electronic component and a preparation method for the tape casting slurry. The tape casting slurry comprises 45 to 55 weight percent of ceramic or ferrite powder, 0.1 to 1.0 weight percent of dispersing agent, 30 to 48 weight percent of solvent, 3 to 8 weight percent of adhesive, 3 to 5 weight percent of plasticizer, 0.1 to 0.5 weight percent of 2-methyl-2,4-pentendiol serving as an addition agent a and 0.1 to 0.5 weight percent of silane coupling agent serving as an addition agent b. The 2-methyl-2,4-pentendiol is added, so that the problems that the viscosity of the slurry is rapidly increased, and the performance of a membrane is rapidly deteriorated because boric is added are solved; the silane coupling agent is added, so that the slurry is low in viscosity and high in dispersing performance, the green density of the membrane is increased, and the ductility is enhanced; and the finally prepared slurry is uniform, stable and suitable for large-scale production.

The invention relates to a preparation method of a compact zirconia ceramic plunger. The preparation method comprises the following steps: fully mixing zirconia ceramic granulated powder with a compound additive; placing the obtained mixture in a die for isostatic pressing; sintering the molded sample into a compact zirconia ceramic plunger blank; and finally grinding the blank into the ceramic plunger with precise size. Compared with the prior art, by utilizing the zirconia plunger material and the preparation method thereof provided by the invention, the compactness, the forming efficiency and the finished product ratio of the ceramic plunger are effectively improved. A high-pressure plunger pump manufactured by the compact zirconia ceramic plunger has the advantages of long service life, wear resistance, corrosion resistance, expanded application range, and shortened time for maintaining and replacing a high-pressure plunger and a sealing bush in the case of shutdown, thus saving engineering operating cost.

A method for preparing a special molybdenum powder relates to a method for preparing the molybdenum powder specially used for the industries of thermal spraying and machining as well as pressing fine apparatuses. The powder is characterized in that the preparing process includes the steps as follows: (1) sintering normal molybdenum powder for increasing the granularity; (2) grading the molybdenum powder, the granularity of which is increased; carrying out spheroidisation on the molybdenum powder with approximate granularity by a plasma device, then cooling and collecting the molybdenum powder; (3) reducing the molybdenum powder after being spheroidized, screening, grading and then obtaining the special molybdenum powder. The molybdenum powder prepared by the method of the invention has the advantages of good fluidity, simple technique, high finished product rate and relates to a technique for preparing the special molybdenum powder used in the fields of thermal spraying and pressing fine apparatuses.

The invention discloses a preparation method of FeSi alloy powder with high direct current superposition characteristics, and belongs to the technical field of alloy powder preparation. The FeSi alloypowder is mainly made of pure iron and metal silicon, and a small amount of manganese and chromium are added. The preparation method comprises the following steps of weighing the ingredients according to a specific proportion, carrying out non-vacuum melting to obtain the alloy melt of required components, and then atomizing to prepare alloy raw powder with an inert gas, obtaining fine powder after the raw powder is collected, screened and graded. According to the preparation method of FeSi alloy powder with high direct-current superposition characteristics, the alloy powder with uniform components and high purity can be obtained, and the powder spherical degree is high; the uniform and compact insulating layer can be easily formed after insulation coating, so that the contact of the alloy matrix is effectively blocked, and the pressed magnetic powder core has good direct-current superposition characteristics.

A magnetic-field thermo-pressing process for preparing the high-performance magnetic material with magnetic anisotropy includes such steps as preparing the ultra-magnetostrictive RE powder or permanent-magnet NdFeB powder or permanent-magnet SmCo powder in vacuum or inertial gas or organic medium, mixing it with adhesive, coupling agent and lubricant, and thermopressing at 80-350 deg.C under 300-900 MPa in a magnetic field (1.5-2.5T).

The present invention concerns a method for producing powder metal parts having a densified surface. The method comprises the steps: - compacting an iron-based powder by high velocity compacting technique to a density above 7.2 g/cm<3> - sintering the parts -subjecting the parts to a surface densifying process.

The invention relates to ceramic rotary target slip casting die and a manufacturing method thereof. The die is characterized by comprising an internal die (1) and an external die (2), wherein the external die (2) is hollow, and the upper part of the external die (2) is provided with an opening; the internal die (1) is T-shaped and is fixedly arranged in the hollow part of the external die (2); the upper edge of the internal die (1) is pressed on that of the external die (2); a cavity (3) is formed between the outer side wall of the internal die (1) and the inner side wall of the outer die (2); the bottom of the external die (2) is provided with a slurry inlet hole path (4) which is communicated with the cavity (3); the internal die (1) is internally provided with an air blowing hole path (5); the outer die (2) is internally provided with a drainage channel (6). The die has the effects that the die material strength is high, so that a mold made of a gypsum material can be replaced by the die, products cast by the die are high in density and uniform in density, the production period is short, and the labor intensity is low.

The invention provides a silicon nitride ceramic ball and a preparation method thereof, and belongs to the technical field of ceramic materials. According to the invention, a vacuum injection-coagulation forming method is adopted, so that the forming of large-size and oversized silicon nitride ceramic balls with high sphericity degree and uniform density can be realized. Microwave drying is adopted, the drying speed is high, and deformation of a green body is small. According to the invention, the cold isostatic pressing treatment is carried out on the degummed ceramic balls, so that the compactness of the sintered ceramic balls is improved. A two-step air pressure sintering process is adopted, so that internal air holes of the ceramic ball can be removed, and the density can be further improved. According to the invention, the surfaces and the core parts of the large-size and oversized silicon nitride ceramic balls prepared by adopting the method of combining injection coagulation forming with cold isostatic pressing forming and two-step air pressure sintering have no obvious difference in properties such as relative density, Vickers hardness and fracture toughness. Homogenization of density and mechanical properties of large-size and oversized silicon nitride ceramic balls can be realized.

This invention offers a kind of composite which can deposit sclerotic stainless steel powder and its warm-pressing method. The composite's components and their mass's percentage content is 0.02-0.07%C, 15.0-17.5%Cr, 3.0-5.0%Ni, 3.0-5.0%Cu, 0-0.6%Mn, 0.15-0.45%Nb, 0-0.1%Mo, and others are Fe and inevitable impurity element. Besides, 0-10% of the whole mass said above of NiC granule and 0.1-0.3% anti-friction material are added. This method uses electrostatic spraying to spray EBS wax powder onto the bore of the die to make the die wall greasing, and the thickness of the paintcoat is between 0.01mm and 0.1mm. The density of the green ware body shaped by warm-pressing is 0.15-0.25g/cm3 higher than the body shaped by cold-pressing, while the intensity increases by 6.2-15%. The characteristics of this invention are high density, low cost, easy operation and that the lamination crack is not easy to happen. So it can largely improve the density and intensity of stainless steel powder composite parts' green ware body. In a word, it can be widely used in the parts production of mechanics, car and chemical industry.

The invention provides a preparation method of a sintered iron powder base soft magnetic composite, and belongs to the technical field of soft magnetic composites. The technological process includes the steps that initially, pretreatment is conducted on water atomized iron powder by means of high-temperature steam treatment, then cementation treatment is conducted by means of a double tapered spraying blender, a binder solution is atomized and evenly sprayed on materials continuously tumbling under the effect of a high-pressure gas, ultrathin pure silica powder and ultrathin iron-phosphorus alloy powder evenly adhere to the surfaces of iron powder particles, and sintered iron base powder is obtained. High-density compact is prepared by high-speed compacting through a warm mold with the mold wall lubricated, then fast sintering densification at low temperature is conducted, and finally an iron-silicon-phosphorus soft magnetic composite is obtained. The sintered iron powder base soft magnetic composite has the advantages of high magnetic permeability, low eddy-current loss and high strength, and is suitable for high-frequency application.

A process for the preparation of a niobium compound of formula (I):

D_αNb_βE_γO_3-δ  (I)

• • wherein
  • D is an alkali metal (e.g. Li, Na, K, Rb, Cs and/or Fr), alkaline earth metal (such as Ba, Ca, Mg and/or Sr), La and/or Bi and may be present as a mixture of two or more metals;
  • E is Ta, Sb and/or Fe and may be present as a mixture of two or more metals;
  • α is a positive number
  • β is a positive number
  • γ is zero or a positive number
  • δ is a number 0≦δ≦0.5;
  • and wherein the formula (I) has the perovskite or tungsten bronze structure;
  • comprising spray pyrolising a solution, for example an aqueous solution, comprising metal (D) ions, Nb ions and if present, metal (E) ions.

A method for improving an iron powder forming property belongs to the technical field of powder metallurgy forming. Pressed blank density can be increased by using good lubricating performance of sulfide. Iron powder and ferrous sulfide powder are mixed in a ball mill and annealed in a hydrogen furnace after being mixed evenly, and the ferrous sulfide is distributed on the surface of the iron powder evenly. In a pressing process, the ferrous sulfide has a lubricating effect, friction condition among powder particles is improved, the forming property is improved, and a blank with the density as 7.2g/cm<3>-7.6g/cm<3> can be obtained. The method has the advantages that the iron powder forming property is good, the blank with higher density can be obtained under low pressing pressure, loss of a grinding tool is reduced, simultaneously sulfur does not affect the performance of iron-based parts, and the process is simple and suitable for industrialized production.

The invention discloses a preparation method of a silicon carbide ceramic pot using graphene to enhance heat conductivity. The preparation method comprises the following steps of according to scientific and reasonable component proportional ratio, compounding silicon carbide micropowder, boron carbide micropowder, liquid phenolic resin, and graphene component; performing ball milling, granulating, isostatic pressing forming, non-pressure sintering and the like, so as to obtain the silicon carbide ceramic pot. The silicon carbide ceramic pot has the advantages that the density of a prepared blank is large, the uniformity is good, the strength is high, and the sintering can be performed through simple drying; by adopting the non-pressure sintering, the energy consumption is decreased. The preparation method has the advantages that the method is simple, the industrial control is convenient, the raw material cost is low and the obtaining is easy, and the non-toxic and non-harmful ceramic pot which can be in direct contact with food can be prepared; the heat conductivity is higher, the boiling time of foods is accelerated, and the energy-saving effect is realized.

The invention discloses a method utilizing powder metallurgy friction reducing materials to manufacture gears. Surface layer materials including graphite, molybdenum, titanium, copper, cerium dioxide,zinc stearate, tin and iron are uniformly mixed by a ratio. Base body materials including nickel, molybdenum, titanium, graphite, a lubricating agent, a sintering aid and iron powder are uniformly mixed after being previously dispersed. Then, the surface layer materials and the base body materials which are mixed together are sequentially put in the same mould, and a green is pressed at 60-120DEGC under the pressure of 500-600Mpa. Low-temperature pre-sintering and high-temperature sintering are carried out under the protection of hydrogen and argon. Then, oil immersion is carried out, and afinished product is finally obtained. The finished product comprises a surface layer and a base body layer, the base body layer is high in density, high in strength and high in hardness, has high carrying capability and is used for carrying, the surface layer is a porous layer and provides a lubricating function, and at the same time, TiC particles produced on the surface layer ensure the strengthand hardness of the surface layer.

The invention discloses a method for recycling cadmium from metallurgical cadmium-contained dust and a device for recycling cadmium from a cadmium-ammonia solution. The metallurgical cadmium-containeddust is subject to ammoniacal circular leaching, when the lead/cadmium molar ratio in the solution is smaller than 0.01, the circular leaching process is ended; after leaching is finished, liquid solution separation is carried out, and the cadmium-ammonia solution is obtained; the proper amount of vulcanizing agent is added to enable impurity ions in the cadmium-ammonia solution to be subject tovulcanization precipitation separation. After impurity removal, liquid is placed in an ultrasonic enhancing electric strengthening replacement cadmium extraction key device to be subject to efficientcadmium extraction, and high-grade sponge cadmium and zinc-ammonia solution can be obtained. The sponge cadmium can be directly used for briquetting distillation or fusion casting-electrolytic refining to obtain high-purity cadmium. The zinc- ammonia solution can be directly turned into an electric zinc system to produce electric zinc.

The invention relates to 99%-above alumina granulating powder and a preparation method thereof. The 99%-above alumina granulating powder comprises the following components in parts by weight: 100-200 parts of high-aluminum alumina balls, 50-150 parts of a calcined material CT-3000SG, 1-5 parts of a binder, 0.1-1 part of a dispersant, 0.1-1 part of a demolding agent, 0.1-1 part of yttria, 0.1-1 part of magnesia and 50-150 parts of deionized water. The preparation method comprises the following steps: carrying out ball milling, sieving after pulp is obtained, stirring, and processing with magnets; carrying out centrifugal spraying granulation; removing coarse and fine particles from granulated powder by virtue of a sieve, then removing iron and impurities, and finally homogenizing. The granulating powder is low in water content and high in apparent density; after blank molding, a green body is high in density, good in stability and tenacity and excellent in post-machining performance and does not easily collapse from corners; the preparation method is simple in process and low in cost and has good application prospect.

The invention provides a cast film slurry of an ultrathin lamination flaky inductor and a manufacturing method for a cast film of the ultrathin lamination flaky inductor. The cast film slurry comprises ceramic or ferrite powder, dihydric alcohol or polyhydric alcohols, a silane coupling agent, a dispersing agent, a plasticizer, binders and a solvent. By adding hexylene glycol, the hexylene glycol and a boron-containing sintering aid are subject to complexing reaction, so the problems of rapidly increased slurry viscosity and rapidly deteriorated diaphragm performance caused by addition of boron are solved; combining between the power and the binder as well as between the binders can be enhanced by adding the silane coupling agent, so the slurry viscosity is reduced, the dispersion is excellent, the diaphragm green-pressing density is increased, ductility is enhanced, and a diaphragm thinning effect is more obvious.

The invention relates to a preparing method for a TiC matrix steel base steel bond hard alloy. The preparing method includes the following steps that titanium carbide powder and matrix steel matrix powder are weighed according to the proportion, alloy powder is put into a ball grinding machine to be mixed and smashed, added absolute ethyl alcohol is a process control agent, and the wet mixed powder is put into a vacuum drying box to be dried after ball grinding and is used for standby use after drying; an organic monomer and an initiator are added into a solvent to prepare pre-mixed liquid; an additive improving slurry fluidity and dispersity is added; a catalyst and a pH modifier are added and are evenly stirred, and slurry is obtained; and the slurry is injected into an injection and coagulation die, vacuum suction or vibration gas removing is conducted, after the slurry is cured to be formed, a blank is put into the vacuum drying box to be dried, the dried blank is subjected to integrated degumming and sintering in a vacuum sintering furnace, and the steel bond hard alloy is prepared. The preparing method has the beneficial effects that the technology is simple, the cost is relatively low, and parts large in size and complex in shape are easy to prepare on the basis that the macro performance of the steel bond hard alloy is ensured.