2023results about How to "Improve microstructure" patented technology

A method for electrophoretic deposition of ceramic particles as a green body shaped as a dental appliance, the method comprising the steps of (a) forming a suspension of the ceramic particles in a first polar solvent, the ceramic particles constituting at least about 5% of the first suspension by weight; (b) passing a direct electrical current through the first suspension, using a deposition electrode shaped as the dental appliance to form a green body; (c) coating the green body with glass particles; and (d) sintering the resultant coated body for obtaining a glass coated all-ceramic dental appliance.

Self-propagating formation reactions in nanostructured multilayer foils provide rapid bursts of heat at room temperature and therefore can act as local heat sources to melt solder or braze layers and join materials. This reactive joining method provides very localized heating to the components and rapid cooling across the joint. The rapid cooling results in a very fine microstructure of the solder or braze material. The scale of the fine microstructure of the solder or braze material is dependant on cooling rate of the reactive joints which varies with geometries and properties of the foils and components. The microstructure of the solder or braze layer of the joints formed by melting solder in a furnace is much coarser due to the slow cooling rate. Reactive joints with finer solder or braze microstructure show higher shear strength compared with those made by conventional furnace joining with much coarser solder or braze microstructure. It is expected that the reactive joints may also have better fatigue properties compared with conventional furnace joints.

The invention discloses a super-high-performance cement base repairing material and a preparing method thereof. The repairing material is prepared from, by mass, 100 parts of cement, 15-50 parts of admixture, 2-15 parts of nanometer reinforcing agent, 3-10 parts of crack resistance component, 80-220 parts of sand, 10-30 parts of fiber, 2-5 parts of high-performance water reducing agent and 15-35 parts of water. The super-high-performance cement base repairing material has super-high tensile strength, bending resistance and adhesive strength and extremely low shrinkage performance, and has excellent construction performance, high elasticity modulus and super-high durability. The material has effects of repairing, reinforcing, seepage preventing, preventing and the like, and therefore the service life of the repairing material and a structure is prolonged. In addition, the material can be used as a joint material of a structural joint.

Refractory metal products, such as tantalum, can be rejuvenated after metal consumption in selected zones by filling the zones with powder and simultaneously applying focused radiant energy to the powder.

The invention discloses a simulation method of texture evolvement of a heat affected zone in a welding process, relating to a fine texture simulation method of a welding connector and aiming at solving the problems that the quantification of the present fine texture evolvement of a weld joint is mainly based on an experiential or half experiential deterministic model or analysis calculation, and only the texture content is calculated but the state, the size and the distribution of the texture cannot be reflected dynamically. The method comprises the following steps: step 1, calculating the temperature fields of the heat affected zone; step 2, calculating the crystalline grain growth process of crystalline grains at different positions above a beta phase zone according to the distribution of the temperature fields; and step 3, calculating continuous cooling solid state phase change according to the cooling velocity and the beta phase crystalline grain distribution calculation result obtained through the temperature field calculation. The simulation method is used for the fine texture simulation of the welding connector.

The invention discloses a 2:17 type samarium-cobalt sintered magnet material and a preparation method thereof. The 2:17 type samarium-cobalt sintered magnet material comprises the following raw materials in percentage by mass: 10 to 25 percent of samarium, 45 to 55 percent of cobalt, 10 to 20 percent of iron, 3 to 9 percent of copper, 1 to 3 percent of zirconium and 5 to 15 percent of at least one heavy rear earth element. Due to the selection and the proportion of the raw materials and the innovation of the sintering process, a microstructure of the magnet material is optimized, and the aims of reducing the temperature coefficient of a magnet and simultaneously maintaining higher magnetic energy product of the magnet are fulfilled, wherein the magnetic energy product of the prepared magnet is 14 to 25 MGsOe, the residual magnetism temperature coefficient is about -0.005 to -0.03 percent per DEG C, and a lower magnetic flux temperature coefficient is maintained in an environment at the temperature of between -35 and 300 DEG C.

A method for making a current-perpendicular-to the-plane giant magnetoresistance (CPP-GMR) sensor with a Heusler alloy pinned layer on the sensor's Mn-containing antiferromagnetic pinning layer uses two annealing steps. A layer of a crystalline non-Heusler alloy ferromagnetic material, like Co or CoFe, is deposited on the antiferromagnetic pinning layer and a layer of an amorphous X-containing ferromagnetic alloy, like a CoFeBTa layer, is deposited on the Co or CoFe crystalline layer. After a first in-situ annealing of the amorphous X-containing ferromagnetic alloy, the Heusler alloy pinned layer is deposited on the amorphous X-containing ferromagnetic layer and a second high-temperature annealing step is performed to improve the microstructure of the Heusler alloy pinned layer.

The invention provides cement-emulsified asphalt mortar and a preparation method thereof. The cement-emulsified asphalt mortar comprises the following components in part by weight: 110 to 160 parts of emulsified asphalt, 10 to 30 parts of polymer emulsion, 90 to 100 parts of cement, 150 to 250 parts of sand, 0 to 0.5 part of strength modifier, 0 to 10 parts of expanding agent, 0 to 1.0 parts of fiber, 0 to 0.05 part of cellulose, 0.004 to 0.015 part of aluminum powder, 0 to 0.1 part of defoaming agent, 0 to 1.2 parts of air entraining agent and 0 to 25 parts of water. The cement-emulsified asphalt mortar has good low-temperature resistance, and is suitable for the slab tracks of high-speed railways, passenger transport lines and urban high-speed light rails in severe cold areas.

The invention discloses a quasi-continuous laser metal 3D printing method capable of realizing regulation of nickel base alloy crystallographic texture. Laser output is set as a quasi-continuous lasermode, and then a laser metal 3D printing technical window is preliminarily optimized. The temperature field of a molten bath under the preliminarily optimized parameter is calculated by using a finite element heat transfer model; the temperature gradient G and the cooling rate xi of the moving boundary of the molten bath during closing of laser in a single pulse period are extracted, and the growth length L of a single pulse internal columnar dendrite is worked out according to a structure growth theoretical model; the laser parameter is optimized according to the matching rule that the ratioof the scanning speed V to pulse frequency f is 0.5-0.8L, and finally 3D printing forming is conducted according to the optimized parameter, so that a formed part with the consistent crystallographicorientation height is obtained. By regulating the heat source output mode, an effective remelting mechanism for mixed crystal or isometric crystal is introduced in the scanning direction, all columnar dendrite growth is obtained, and the consistency of grain orientation is remarkably improved.

The invention relates to a boron-modified H type steel having good low-temperature impact toughness and the preparing method thereof. The steel is composed of 0.08 to 0.20 by weight percentage of C, 1.00 to 1.60 by weight percentage of Mn, 0.10 to 0.55 by weight percentage of Si, no more than 0.25 by weigh percentage of P, no more than 0.025 by weight percentage of S, 0.015 to 0.035 by weight percentage of Nb, 0.0005 to 0.0012 by weight percentage of B, and the balance Fe and trace impurity. During melting process, the gas content is controlled: no more than 0.004% of N, and no more than 0.0085% of O. According to the invention, the low-temperature impact toughness of Q345 H type steel is greatly improved; compared with Chinese standard, -40 DEG C AKV has a large surplus, the product quality is easy to be guaranteed; the Q345 H type steel can also be applied to regions having more severe condition.

A heat treatment technology for markedly raising comprehensive performance of aluminium alloy is accomplished by the adoption of the following scheme: carrying out a solid solution treatment on the aluminium alloy, taking the aluminium alloy out of a furnace and carrying out water quenching, and carrying out a pre-aging treatment, cold deformation and a secondary aging treatment. Nanometer-level aging precipitation strengthening phase is formed by the pre-aging treatment, and dislocation configuration generated from the subsequent cold deformation can be changed, so as to improve the strength, ductility and toughness of the alloy; during the cold deformation, nanometer-level atomic clusters will precipitate out from solute atoms precipitated during the pre-aging treatment, or ''pinning'' air mass is formed around the dislocation structure, thus further raising the strength of the alloy. The precipitated precipitation strengthening phase is nanometer level, thus raising the ductility and toughness of the alloy and markedly enhancing the strength of the alloy on the basis of guaranteeing good plasticity. The technological process provided by the invention is simple, is convenient to operate, can be adopted to markedly raise comprehensive performance such as the strength and plasticity of the aluminium alloy and improve the corrosion resistant performance and fatigue resistant performance of the aluminium alloy, and is suitable for industrial application.

The present invention provides welder and welding method combining two different kinds of heat source, laser and HF inductor, and adopts real-time temperature monitor and control to overcome the demerits of common laser welding of metal material, which has low energy utilization and is likely to produce air hole. During welding, two kinds of heat source are used to heat the welded part and near part simultaneously. The welder of the present invention has laser welding head as the main body comprising integrated induction heating winding and infrared sensor. Compared with common laser welding, the present invention has greatly raised production efficiency and welding quality and can realize 2D and 3D welding.

Provided is a method for fabricating a metal oxide thin film in which a metal oxide generated by a chemical reaction between a first reactant and a second reactant is deposited on the surface of a substrate as a thin film. The method involves introducing a first reactant containing a metal-organic compound into a reaction chamber including a substrate; and introducing a second reactant containing alcohol. Direct oxidation of a substrate or a deposition surface is suppressed by a reactant gas during the deposition process, as it uses alcohol vapor including no radical oxygen as a reactant gas for the deposition of a thin film. Also, since the thin film is deposited by the thermal decomposition, which is caused by the chemical reaction between the alcohol vapor and a precursor, the deposition rate is fast. Particularly, the deposition rate is also fast when a metal-organic complex with β-diketone ligands is used as a precursor. Further, a thin film with low leakage current can be obtained as the metal oxide thin film fabrication method using a chemical vapor deposition or atomic layer deposition method grows a thin film with fine microstructure.

This invention discloses a Cu alloy contact wire of high strength and high conductivity used in high speed railways and its preparation method, in which, the contact wire is taken Cu as the matrix to be added with Ag: 0-0.15% and Cr: 0.20-0.72%. The preparation method includes: applying a hot-rolling technology to large area Cu alloys and level conticasting technology to produce large length wires or a rod ingot is solutionized then to be rolled, aged and rolled.

The invention discloses an ultrahigh-coercivity sintered neodymium-iron-boron magnet and a preparation method thereof. The ultrahigh-coercivity sintered neodymium-iron-boron magnet comprises a main phase and a crystal boundary adding phase. The main phase comprises low-HA main alloy and high-HA main alloy. The high magnetocrystalline anisotropy field HA main alloy and the low-HA main alloy are used as the main phase, so that the heavy rare earth element diffuses from the high-HA phase to the low-HA phase in the sintering and heat treatment process to initially improve the coercivity; in addition, alloy components and the preparation technology can be controlled at the same time, the content of Nd2Fe14B in the magnet is improved, and it is ensured that the magnet has the high magnetic energy product. The crystal boundary adding phase can further achieve crystalline grain surface magnetic hardening and improve the coercivity, the microscopic structure is optimized, and the coercivity is further improved. The preparation method of the ultrahigh-coercivity sintered neodymium-iron-boron magnet has the advantages of both a traditional dual alloy method and a single alloy crystal boundary adding method, and is easy to operate and suitable for mass production of ultrahigh-coercivity high-residual-magnetism sintered neodymium-iron-boron magnets.

The invention relates to a device for realizing 3D metal printing by virtue of a supporting structure. The device comprises a translation stage capable of moving along the X-axis, the Y-axis and the Z-axis. Heating resistance wires and a thermocouple are arranged on a base plate of the translation stage. The heating resistance wires are used for preheating the base plate, so as to enable metal droplet layers to be tightly overlapped. The thermocouple is used for realizing the measurement and the feedback control of a temperature. An electromagnetic induction heating copper pipe and a cooling water pipe are arranged outside a graphite crucible, metallic raw materials are enabled to be molten to form molten metal, the bottom of the graphite crucible is connected with a metal printing spray nozzle, a protective gas is inputted from a gas inlet pipe at the top of the graphite crucible, and under the pulse pressure, molten metal forms regular metal droplets to drip to the base plate of the translation stage. The 3D metal droplet printing is realized through the cooperation with the movement of the translation stage. A supporting material spray nozzle is adjacent to the metal printing spray nozzle. A uniform mixture of gypsum and photosensitive resin is extruded stably under the constant pressure inputted by the gas inlet pipe so as to print the supporting part of a part. The switching between metal and the supporting material is automatically recognized and controlled by a control system. The 3D metal printing device is reasonable, high in operability, high in degree of automation, high in production efficiency, and suitable for being widely popularized, and ensures the molding quality.

The invention relates to the field of magnetic nano composite materials, and discloses a iron-nickel alloy/nickel ferrite magnetic composite nanofiber and a preparation method thereof. The diameter of the composite nanofiber is 50-300 nm. The preparation method adopts a electrostatic spinning technique and comprises the following steps: using water and ethanol as solvents and polyvinyl pyrrolidone (PVP) as a complex agent, reacting PVP with nickel salts and ferric salts to preparing a precursor solution; electrostatic-spinning to prepare a precursor fiber; drying, carrying out heat treatment in the air atmosphere, and carrying out reduction treatment on the product in the hydrogen atmosphere under appropriate conditions, thereby obtaining the ferronickel/nickel ferrite magnetic composite nanofiber. The method and the route have the advantages of easy control of reaction process, low sintering temperature, simple device and technique, convenient operation, small environmental effect and the like. The method and the technical line are also applicable to preparation of composite nano fiber materials of other magnetic metal or alloy and ferrite.

The invention discloses concrete with common strength and high elastic modulus and a preparation method thereof. The concrete with common strength and high elastic modulus, disclosed by the invention, is prepared from the following components in parts by mass: 100 parts of cement, 30-100 parts of an admixture, 1-10 parts of a nano material, 0.1-2 parts of a viscosity modifier, 200-600 parts of sand, 300-800 parts of crushed stones, 10-60 parts of fibers, 0.5-5 parts of a water reducing agent, 0.1-0.5 part of a powder dispersant and 50-90 parts of water. After the concrete with common strength and high elastic modulus, disclosed by the invention, is subjected to standard curing or natural curing for 28d, the strength grade of the concrete is C40-C50, and the elastic modulus can reach 50GPa or more; and the concrete has excellent working performance and endurance performance.

Disclosed is reactive powder concrete mixed with slag, which is a novel engineering material with super-high intensity and super-high durability, particularly cement-based composite material having super-high property prepared and formed via using all kinds of industrial residue as reactive powder. Corresponding to Portland cement, proportion by weight of all composites of the concrete is: the Portland cement holding 1 part, the slag holding 0.40-0.60 part, silicon powder holding 0.20-0.35 part, quartz flour holding 0.20-0.35 part, river sand holding 1.20-1.60 parts, water holding 0.20-0.28 part and a water reducing agent holding 0.02-0.03 part.

A flux cored aluminium ring for the butt connection between two aluminium or Al-alloy tubers by soldering is composed of the shell made of Al-Si alloy foil and the core made of Al-Si alloy wire and alloy powder. Said Al-Si alloy foil (or wire) contains Al (86.5-97 Wt %), Si (3-13), Sr (0.01-0.3) and La (0.01-0.2). Said alloy powder consists of KalF4-K3AlF6 eutectic and Si powder. Its preparing steps are smelting Al-Si alloy ingot, preparing Al-Si alloy band and wire, preparing their foil and wire, grinding alloy powder, making core wire, and making flux cored ring.

The invention relates to a method for controlling the setting time and early hydration speed of magnesium potassium phosphate cement, and belongs to an early strength quick hardening cement cementing material. A composite retarder can effectively adjust the setting time of magnesium potassium phosphate cement slurry, and the setting time of the magnesium potassium phosphate cement slurry can be effectively controlled in the range of 10 minutes to 6 hours by adjusting the content of chloride and disodium hydrogen phosphate dodecahydrate in the composite retarder, so that the problems of a limited retarding effect, low operability and the like are solved; the composite retarder can change the hydration heat release characteristic of the magnesium potassium phosphate cement, the magnesium potassium phosphate cement slurry doped with the conventional retarder borax has a hydration heat release peak at the initial reaction stage and has a high heat release speed and large heat release amount, and the magnesium potassium phosphate cement doped with the composite retarder has two hydration heat release peaks and has small hydration heat release amount at the initial hydration stage; and the doped composite retarder improves the microstructure and later strength of a hardened magnesium potassium phosphate cement body, so that enough construction operable time can be ensured while the magnesium potassium phosphate cement slurry has early strength and is quickly hardened.

The invention relates to the composite technical field, in particular to a manufacturing method of metal matrix nanocomposites with high toughness. According to the manufacturing method, the size, distribution, interface structure of reinforcement bodies and the metal matrix micro-structure are effectively controlled by the combined composite process of twice ball-milling, discharging plasma in situ reaction sintering and the large strain plastic deformation technology, so that ultra-fine grain metal matrix composites with evenly distributed in situ authigenic nanoparticles and good interface combination are manufactured, and good matching of intensity and toughness is obtained.

This invention discloses a method for adding nm SiN in grain boundary phase to increase NdFeB working temperature and corrosion resistance including: applying casting technology for a main phase alloy to process a NdFeB ingot alloy or applying a foil rapid hardening technology to manufacture NdFeB rapid hardened foils, applying casting technology for grain boundary phase alloy to make ingot alloy or foil technology to foils or rapid extraction band by rapid extraction technology 2 powdering the two alloys, 3 adding nm SiN into the grain boundary phase alloy powder, 4, mixing them and pressing them to formation 5, sintering it in the oven to a sintered magnet.