60results about How to "Not prone to segregation" patented technology

The invention relates to an auxiliary material for casting and moulding, in particular to a formula of alcohol group dry powder mold paint for sand mold casting. The dry powder mold paint comprises surface modifier, suspending agent, binder and refractory powder, wherein the surface modifier is 0.6-4.2wt% of refractory powder, the suspending agent is 4.0-8.0wt% of refractory powder and the binderis 4.0-6.2wt% of refractory powder. The alcohol group nanometer composite and surface modified dry powder mold paint of the invention adopts nanometer layered clay and nano-SiO2 to form composite suspending agent so that the controllability of operation technological parameters of the alcohol group dry powder mold paint is good and the process performance and operating performance of the obtainedpulp-type paint can both meet the demand of the casting factory.

The new process for preparing TiB2 and TiC double-phase mixed hybridization reinforced magnesium alloy base composite material is characterized by that it adopts Al-Ti-B-C system reaction prefabricated block and makes it produce chemical synthesis reaction under the condition of vacuum or inert gas protection to prepare (TiB2+TiC)/Al intermediate phase carrier, then adds the intermediate phase carrier into molten magnesium alloy to make dissolution and diffusion, and fully stirs them to make said intermediate phase carrier be uniformly distributed in molten magnesium alloy to obtain the invented product in which the TiB2 is formed into block form and the TiC is formed into ball form, so that the comprehensive performance of said composite can be obviously raised.

The invention discloses a method of copper and iron alloy materials for novel motor rotors, and belongs to the technical field of nonferrous metal material manufacturing. The method mainly comprises the steps of (1) burdening, (2) vacuum induction smelting, (3) mechanical centrifugal atomization, (4) discharge plasma sintering and (5) aging. Cu and Fe raw materials with higher purity are selected,fed silver is excellent in electric conductivity, and meanwhile, iron, silicon and copper are lower in solid solubility, so that the influence on electricity and heat conductivity of copper rods is lower, the solid solubility cannot be changed along with the temperature change, and alloys formed by Cu and Fe achieve higher electric conductivity; and through the mechanical centrifugal atomizationmode, Cu-Fe alloys are atomized as drops, and the drops are quickly condensed through low-temperature and high-purity argon, so that the cooling speed of the alloy drops can be accelerated, the macroscopic segregation of the alloys is overcome, and the electromagnetic shielding performance of the alloys is further improved.

The invention discloses a medium-strength nitric acid corrosion-resistant titanium alloy. The titanium alloy is composed of the following components of, in percentage by mass, 5.0-7.0% of Ta, 0.7-1.5%of Al, 0.2-2% of Zr, 0.6-1.5% of Mo, 0.2-2% of Nb, and the balance Ti and inevitable impurities. The tensile strength of the annealed titanium alloy subjected to annealing treatment is 670-750 MPa, the yield strength of the annealed titanium alloy is 520-650 MPa, and the corrosion rate of the annealed titanium alloy in a boiling nitric acid solution with the concentration of 6 mol/L is not higherthan 0.08 mm/a. According to the medium-strength nitric acid corrosion-resistant titanium alloy, through adjusting the content of each element in the titanium alloy, the medium-strength nitric acid corrosion-resistant titanium alloy has excellent tensile strength, yield strength, corrosion resistance and impact toughness, also has excellent cold and hot processing properties, can be prepared intovarious processed products, and is suitable for manufacturing related equipment in the fields of nuclear industry and chemical industry.

The invention discloses an ecological dustproof type seawater sea-sand anti-corrosion marine concrete and a preparation method thereof. The concrete comprises the following raw materials: cement, silica fume, coal ash beads, blast furnace slag powder, corroding ion inhibitors, sea sand, steel fibers, a water reducing agent and seawater. The preparation method comprises the following steps: mixingcement, silica fume, coal ash beads, blast furnace slag powder, corroding ion inhibitors and steel fibers and then uniformly stirring with a stirrer; adding sea sand and continuing to uniformly stir;adding seawater and the water reducing agent; mechanically stirring till uniformly stirring, thereby acquiring a concrete slurry; pouring and then removing a mold and maintaining for 48h at 80 DEG C under the condition of humidity of 95%, thereby acquiring the marine concrete. The concrete disclosed by the invention has the advantages of high curing rate of chloride ions, excellent working performances, high durability, lower cost, locally acquired raw materials, short construction period and suitability for popularization and application.

The invention discloses a preparation method of an N-doped polysilicon ingot, which comprises the following steps that: the mixture of polysilicon material, silicon nitride nano powder with the grain size of 1 to 100nm and electrically active dopant is put into a quartz crucible and is loaded into a furnace; a furnace chamber is vacuumized and heated to 1420 to 1550DEG C, the temperature is insulated until the mixture is fully melted, to obtain molten silicon mixture; and then the molten silicon mixture is solidified to obtain the polysilicon ingot, wherein the electrically active dopant is any one type of B, P or Ga and the added amount makes the concentration of the electrically active dopant in the polysilicon ingot be 0.02 to 2ppm, and the added amount of the silicon nitride nano powder makes the nitrogen concentration in the polysilicon ingot be 0.0002 to 1ppm. The preparation method of N-doped polysilicon can dope nitrogen with existing equipment, and has the advantages of uniform nitrogen doping, high concentration of doped nitrogen, simple and easily controllable process and low cost. In addition, the invention also discloses a preparation method of an N-doped mono-crystalline ingot.

The invention discloses a preparation method of epoxy resin coated ceramic powder, which comprises the following steps: ceramic powder, an epoxy resin and an acetone solvent are proportionally added into a reaction kettle, the sealed reaction kettle is heated and mechanically stirred, and the acetone is directly volatilized and recovered in the thermal insulation process; in the cooling process, the epoxy resin crystal is coated on the surface of the ceramic powder; and the powder is taken out of the reaction kettle, naturally dried, ground and screened to obtain the final epoxy resin coated ceramic powder material. The method is beneficial to enhancing the strength of the initial blank, lowers the adhesive content, has the advantages of favorable coating effect, simple technique and low facility request, and can not pollute the environment.

The invention discloses a preparation method of an N-doped polysilicon ingot. The preparation method comprises the following steps of: putting polysilicon and silicon nitride nanopowder with the grain size of 1 to 100nm in a quartz crucible and charging, vacuumizing a furnace room and heating to 1420 to 1550 DEG C, and preserving the temperature till mixture is fused completely; gradually reducing the cooling speed in 1 to 10 DEG C/min in a furnace till reaching 1350 to 1420 DEG C; then naturally cooling the temperature in the furnace room to the room temperature; taking the silicon ingot out and crushing into small pieces to obtain master alloy silicon blocks; putting mixture of the master alloy silicon blocks, the polysilicon material and electrical activity dopants in the quartz crucible, vacuumizing the furnace room and heating to 1420 to 1550 DEG C to obtain a fused silicon material mixture; and enabling the fused silicon material mixture to solidify to obtain the polysilicon ingot. According to the preparation method of the N-doped polysilicon, the invention can carry out N-doping by adopting conventional devices and has even N-doping, high N-doping concentration, simple entire process and low cost. In addition, the invention also discloses a preparation method of an N-doped monocrystalline silicon ingot.

The present invention relates to a magnesium alloy base composite material, and is characterized by that it is a reinforced composite material obtained by making TiB2 granules be dispersed and uniformly distributed in the magnesium alloy base body. Its preparation includes the following processes: preparing reaction prefabricated block, preparing intermediate phase carrier containing reinforcement granules, dissolving and diffusing the intermediate phase carrier in magnesium alloy base body and dispersing and distributing the reinforcement granules in the magnesium alloy base body. Said composite material has good comprehensive performance, so that it has extensive application range.

The invention relates to the technical field of road engineering, in particular to an asphalt mixture and a preparation method thereof. The preparation method comprises the following steps: preparingmaterials and performing hot melting, wherein the step of preparing the materials comprises a substep of preparing asphalt, rubber, water-soluble silicate, ceramsite, perlite, slag and river sand; thestep of performing hot melting comprises the substeps of performing hot melting for the first time, performing hot melting for the second time, performing hot melting for the third time and performing hot melting for the fourth time; the substep of performing hot melting for the first time further comprises the substeps of adding asphalt into a preheated hot melting tank, heating at 150-160 DEG Cfor 20-30 min, and then heating to 170-185 DEG C; the substep of performing hot melting for the second time further comprises the substeps of adding the water-soluble silicate and the ceramsite to the hot-melt asphalt, and performing hot stirring together; the substep of performing hot melting for the third time further comprises the substeps of adding the rubber into a mixture obtained after hotmelting for the second time, heating and stirring; the substep of performing hot melting for the fourth time further comprises the substeps of adding the perlite, the slag and the river sand into a mixture obtained after hot melting for the third time, and performing hot stirring. By the preparation method, the performance of the asphalt mixture can be improved, and the prepared asphalt mixture has improved cracking resistance after being paved.

The invention relates to a preparation method of a copper-tin alloy oil-containing bearing. The preparation method includes the following steps that S1, copper powder is firstly oxidized and then reduced to obtain porous copper powder, the porous copper powder is mixed with tin powder, then the product is heated for 5-8 min under the temperature of 450 DEG C-650 DEG C, and first copper-tin alloy powder with the tin content being 3wt%-5wt% is obtained; S2, the first copper-tin alloy powder is mixed with second copper-tin alloy powder with the tin content being 12 wt%-14 wt% to obtain mixed powder with the tin content being 9.5 wt%-10.5 wt%; and S3, the mixed powder is sintered for 15-25 min under the temperature of 680 DEG C-720 DEG C after being pressed into green bodies. The made oil-containing bearing is not prone to generating unfilled corners, and has high porosity.

The invention discloses a composite powder material for making a high-performance abrasion resistant exhaust valve seat, and its application, and belongs to the technical field of making of exhaust valve seats. The composite powder material comprises, by mass, 8-12% of Mo, 4-8% of Ni, 0.5-2.5% of Cr, 1-3% of V, 0-2.5% of Cu, 0.5-2.0% of C, 1% or less of impurities, and the balance Fe. A making method of the exhaust valve seat comprises the following steps: 1, powder preparation: preparing iron-based pre-alloy powder with the granularity of 100 meshes through a pre-alloy diffusion process; 2, compacting: adding graphite having an amount accounting for 0.5-2.0% of the mass of the composite powder material and zinc stearate having an amount accounting for 0.5-1.0% of the mass of the composite powder material, and compacting under a pressure of 600-800Mpa; and 3, sintering: sintering in ammonia decomposition atmosphere for 0.5-1h to make the high-performance abrasion resistant exhaust valve seat. The method has the advantages of simple flow and high technical content, and the made exhaust valve seat has the advantages of unlikely segregation and good abrasion resistance, and is suitable for the automobile industry.

The invention provides a bi-metal composite high-vanadium high-speed steel roller sleeve for hot rolling. The composite high-speed steel roller sleeve comprises an outer layer and an inner layer. Theouter layer is a high-vanadium high-speed steel wear-resisting layer, and comprises, by mass percentage, 1.8%-2.8% of C, 0.2%-1.0% of Si, 0.3%-0.8% of Mn, 4%-10% of V, 4%-8% of Cr, 3%-6% of Mo, 1.0%-4.0% of Nb, 2.0%-5.0% of Co, smaller than or equal to 1.0% of W, smaller than or equal to 0.03% of S, smaller than or equal to 0.04% of P and the balance Fe and inevitable impurities. According to thebi-metal composite high-vanadium high-speed steel roller sleeve for hot rolling, the alloy component of the roller sleeve is optimized, the organization structure of the roller sleeve is improved, andtherefore the performance such as the strength of the roller sleeve is improved. In addition, the problems that in the existing process of centrifugal casting of high-speed steel roller sleeves, segregation is prone to existing, and an integral roller is not prone to being subjected to thermal treatment can be effectively solved.

The invention relates to concrete, and specifically relates to C35 low-gel-material self-compacting water-tolerant concrete and a preparation method of the water-tolerant concrete. The scheme of the invention is that the C35 low-gel-material self-compacting water-tolerant concrete comprises the following raw materials, by mass: 180-300 kg/m3 of cement, 30-80 kg/m3 of coal ash, 220-640 kg/m3 of fine river sand, 300-600 kg/m3 of machine-made sand, 600-1100 kg/m3 of cobblestone with a diameter of 5-25 mm, 2-10 kg/m3 of a polycarboxylic acid water reducer, 0.01-0.03 kg/m3 of a thickening agent, 4-8 kg/m3 of an early strength agent, and 2-10 kg/m3 of a water-tolerant agent. The C35 low-gel-material self-compacting water-tolerant concrete provided in the invention is less in use amount of materials, has better fluidity, early strength, and water-tolerant property, and plays an important part in accelerating popularization of application of C35 self-compacting concrete.

The invention discloses a method for extracting vanadium efficiently from vanadium slag by controlling the particle diameter of additive. A sodium salt roasting vanadium extraction technology is adopted in the method, and when the additive is added in the vanadium slag, the particle diameter of the additive is determined through the following steps of (1) calculating the ratio between the particle number of the vanadium slag and the particle number of the additive based on the stacking density of the vanadium, the stacking density of the additive and the dosage of the additive to obtain an ideal particle diameter of the additive, and (2) taking the particle diameter of the vanadium slag, an original particle diameter of the additive, the ideal particle diameter of the additive and a final particle diameter of the additive as boundary points to obtain the ranges of the three sections of the particle diameters of the additive, taking the particle diameter of the additive as a variable, carrying out comparison on sodium salt roasting leaching based on a single factor analysis method, and taking the particle diameter range with the optimal result as the final particle diameter of the additive. The method for extracting the vanadium efficiently from the vanadium slag by controlling the particle diameter of the additive can reduce the caking phenomenon of the additive, materials are mixed more evenly, and the utilization efficiency of the additive and the roasting conversion rate of the vanadium slag are improved.

The invention discloses high-performance concrete and a preparation method thereof. The high-performance concrete comprises the following raw materials in parts by weight: 100 to 110 parts of machine-made sand, 130 to 140 parts of macadam, 30 to 45 parts of sea sand, 30 to 45 parts of seawater, 25 to 35 parts of Portland cement, 30 to 32 parts of silica fume, 25 to 30 parts of polypropylene fibers, 20 to 28 parts of steel slag powder, 20 to 25 parts of a shrinkage compensation agent, 20 to 22 parts of polystyrene foam particles, 16 to 20 parts of silica sand particles, 15 to 20 parts of steelfibers, 15 to 18 parts of desulfurized gypsum, 15 to 18 parts of red mud particles, 15 to 18 parts of mineral slag powder, 12 to 16 parts of fly ash, 10 to 15 parts of nano dolomite particles, 10 to 15 parts of phosphorus slag powder, 8 to 10 parts of aluminate cement, 8 to 10 parts of reef powder, 8 to 10 parts of ceramic particles, 8 to 10 parts of sodium alginate, 5 to 8 parts of calcium formate, 5 to 7 parts of calcium nitrite, 4 to 5 parts of pyridine-3-formic acid, 2 to 5 parts of a polycarboxylate water-reducer, 2 to 3 parts of white carbon black, 1 to 1.5 parts of sodium silicate, 0.8to 1.2 parts of caustic soda, 1 to 2 parts of crystalline wax, 1 to 1.5 parts of polyvinyl alcohol, 0.5 to 1 part of diethylene glycol monobutyl ether, 0.3 to 0.7 part of a defoaming agent and 0.2 to0.5 part of azodicarbonamide. The high-performance concrete disclosed by the invention is high in stability, good in durability, excellent in segregation resistance and filling property and stable inconcrete quality. The manufacturing method is simple in process, low in energy consumption, low in investment cost and high in production efficiency.

The invention relates to a preparation method of copper-tin local alloy powder for an oil-containing bearing. The method includes the following steps that S1, oxidation is carried out on copper powderto obtain copper oxide powder, and then reduction treatment is carried out on the copper oxide powder to obtain porous copper powder; S2, the porous copper powder is mixed with tin powder to obtain the mixed powder with the tin content of 9.5-10.5%, and the mixed powder is heated at the temperature of 450-650 DEG C for 5-8 minutes; S3, the heated mixed powder is crushed, and then 0.2-0.4% of paraffin powder is added into the crushed mixed powder. The copper-tin local alloy powder uniform in tin distribution can be obtained, and meanwhile, the prepared oil-containing bearing has high porosity.

The invention discloses a low-Gd-content Mg-Gd alloy and a preparation and heat treatment method thereof. The Mg-Gd alloy with the low Gd content is prepared from the following chemical components in percentage by mass: 2-5% of Gd, 2-5% of Li, 1-3% of Y, 1-2% of Nd, 0.2-0.6% of Zr and the balance of magnesium and inevitable impurities. The preparation method comprises the following steps of S1, preparing materials according to the proportion of the Mg-Gd alloy with the low Gd content; and S2, under the protection of SF6+CO2 gas, melting the alloy material in a resistance furnace and then refining for 2-4 minutes, then standing for 25-30 minutes in the resistance furnace and then casting into a metal mold to obtain a casting. The heat treatment method comprises the steps that the casting is put into a crucible, the crucible is put into a muffle furnace, the temperature is increased to 480-500 DEG C, then heat preservation treatment is conducted, and the heat preservation time is 2-4 hours; and after heat preservation is completed, the crucible is taken out and immediately quenched in water, and heat treatment is completed. The Li in the solid solution state is used for promoting the formation of an MgGd phase under the condition of low alloy content, and the content of Gd in the Mg-Gd alloy is reduced.

The invention discloses a centrifugal model test device and method for researching an underground diaphragm wall construction environment effect. The device comprises a model box, model soil, a model tunnel, an underground diaphragm wall construction simulation system and an environment effect measurement system. The test device can be used for researching the influence effect of underground diaphragm wall construction on mechanical behaviors of surrounding stratums and near shallow buried pipelines or shield tunnels and the internal mechanism of the underground diaphragm wall construction. The sodium chloride solution is adopted to simulate the slurry adopted in the grooving construction process of the underground diaphragm wall, the method has the advantages that materials are easy to obtain, low in price, environmentally friendly, convenient to control heavily, safe, harmless and the like, and the problem of high corrosivity when a zinc chloride solution is used is effectively avoided; by regulating and controlling the liquid level of the sodium chloride solution to exceed the height of the surface of the model soil or to be flush with the surface of the model soil, the initial ground stress acting on the groove position of the underground diaphragm wall before excavation of the underground diaphragm wall can be conveniently and accurately represented or the soil pressure unloading effect in the grooving construction process of the underground diaphragm wall can be simulated.

The invention discloses a 1000MPa-grade nitric acid corrosion resistant titanium alloy. The alloy comprises the following components of, by mass, 4%-6% of Ta, 4%-6% of V, 7%-9% of Cr, not larger than 1.5% of Al and the balance Ti and inevitable impurities, wherein the tensile strength of the titanium alloy subjected to solution aging treatment is not less than 1000 MPa, the yield strength is not less than 900 MPa, and the corrosion rate in a boiling nitric acid solution with the concentration of 6 mol/L is not higher than 0.1 mm/a. The novel titanium alloy designed by optimizing the beta stable element and the proportion thereof is simple in composition, not prone to segregation, uniform and stable in structure, excellent in cold and hot workability and easy to prepare; compared with an existing titanium alloy, the nitric acid corrosion resistance is improved, meanwhile, the tensile strength and the yield strength are greatly improved; and the alloy is applied to nuclear power and chemical engineering equipment and has a good application prospect.

The invention discloses a method for preparing a high-magnetic-property powder silicon steel sheet, and belongs to the field of powder metallurgy. According to the method, electrolytic iron powder, pure silicon powder and ferrophosphorus alloy powder are evenly mixed according to Fe-(3-4) wt.% Si -(0.05-0.3) wt.% P, a thick plate blank is formed through isostatic cool pressing, multi-pass hot rolling is carried out after metallurgical bonding of the thick plate blank is achieved through sintering, cold rolling is carried out for 2-4 times, and finally heat treatment is carried out to obtain the silicon steel sheet with excellent performance. Compared with low-silicon steel, a small amount of P element is added into the silicon steel, so that the resistivity can be effectively improved, andthe iron loss is greatly reduced; compared with high-silicon steel, the Si content is greatly reduced, the iron loss can be slightly increased by slightly increasing the P content, meanwhile, the saturation magnetization intensity is improved, and the formability and the subsequent hot working performance of a powder system are obviously improved; in addition, the P element is added, activated sintering can be promoted, the sintering temperature is remarkably reduced, and the plate blank brittleness is reduced; and the method has the advantages of simple steps, high preparation efficiency, high product precision, no pollution and inclusion, excellent magnetic performance and the like.