174 results about "Decrepitation" patented technology

The invention discloses a method for recycling sintered neodymium-iron-boron waste materials. The method is characterized by including the following steps that the neodymium-iron-boron waste materials are classified and collected according to performance trade marks; the classified and collected waste materials and abrasive materials are mixed and then placed in a vibration polisher machine, and a cleaning agent is added for vibration finishing cleaning; the waste materials obtained after vibration finishing cleaning are ultrasonically cleaned and dried for standby; according to the standard identical to the performance trade marks of the waste materials obtained through the steps, alloy cast slices are prepared through batching, smelting and casting; the cleaned waste materials and the prepared alloy cast slices with the same trade marks are mixed, and hydrogen decrepitation processing is conducted on the mixture; the materials obtained after hydrogen decrepitation processing are ground into powder, pressed, formed, and sintered into a neodymium-iron-boron magnet. According to the method, no harmful matter is generated in the production process, the production process is environmentally friendly and free of pollution, resources can be effectively saved, the recovery rate is high, cost is reduced, and procedures are simple, easy and convenient to implement and feasible.

The invention provides a rare earth sintered magnet and a manufacturing method thereof. The magnetic property residual magnetism Br of the magnet is between 12.8 and 13.3 kGs, the intrinsic coercivity Hcj is more than or equal to 30 kOe, and the content of oxygen in the magnet is between 500 and 900 ppm. The rare earth sintered magnet is prepared by the manufacturing process that: a smelting procedure is a vacuum quick-setting process, and the thickness of produced sheet alloys is between 0.1 and 0.5mm; a hydrogen decrepitation process is used for production in an intermediate crushing procedure; a jet mill is used for production in a micro powder manufacturing procedure, and the average particle size of micro powder is between 3.0 and 4.5 mu m; a compression procedure is used for compression molding under the environment of anaerobic inert gas; and a sintering procedure is used for sintering and aging by means of a vacuum sintering furnace.

The invention discloses a manufacturing method of high-mechanical-strength sintered neodymium iron boron permanent magnets, which includes: firstly, utilizing rare-earth elements, iron, titanium, cobalt and boron iron alloy as raw materials and weighing the raw materials; secondly, mixing the weighed raw materials and disposing the same in a vacuum melting induction furnace, and preparing quick-hardened tablets by means of quick hardening process; thirdly, saturating the quick-hardened tablets to absorb hydrogen at the room temperature and dehydrogenating the same to prepare hydrogen decrepitation powder, then preparing magnetic powder by the hydrogen decrepitation powder through jet mill process; fourthly, molding the magnetic powder in an oriented manner, pressing to form magnets, disposing the magnets into a vacuum sintering furnace to be sintered in a vacuum environment, and performing tempering heat treatment to obtain blanks; and fifthly, machining the blanks, cleaning and removing oil, scouring to obtain high-mechanical-strength sintered neodymium iron boron permanent magnets with bending resistance strength not lower than 500MPa and impact toughness not lower than 7.5KJ / m2. By the manufacturing method, processing difficulty of the sintered neodymium iron boron permanent magnets is reduced greatly, application range of the sintered neodymium iron boron permanent magnets is broadened and economic potential thereof is high.

The invention discloses a method for preparing a heavy rare earth hydride nano-particle doped sintered NdFeB permanent magnet, which belongs to the technical field of magnetic materials. The prior preThe invention discloses a method for preparing a heavy rare earth hydride nano-particle doped sintered NdFeB permanent magnet, which belongs to the technical field of magnetic materials. The prior preparation method improves the coercive force and the temperature stability of magnets by adding heavy rare earth elements, namely terbium or dysprosium into master alloy, but the method can cause the rparation method improves the coercive force and the temperature stability of magnets by adding heavy rare earth elements, namely terbium or dysprosium into master alloy, but the method can cause the residual magnetism of the magnets, the reduction of magnetic energy product and the increase of manufacturing cost. The method adopts heavy rare earth terbium hydride and dysprosium hydride nano-powderesidual magnetism of the magnets, the reduction of magnetic energy product and the increase of manufacturing cost. The method adopts heavy rare earth terbium hydride and dysprosium hydride nano-powder doping technology to prepare the sintered NdFeB permanent magnet with high coercive force and excellent magnetic property. The method comprises the following steps: preparing NdFeB powder by a rapidldoping technology to prepare the sintered NdFeB permanent magnet with high coercive force and excellent magnetic property. The method comprises the following steps: preparing NdFeB powder by a rapidly solidified flake process and a hydrogen decrepitation process; preparing the terbium hydride or the dysprosium hydride nano-powder by physical vapor deposition technology; mixing the two powders, any solidified flake process and a hydrogen decrepitation process; preparing the terbium hydride or the dysprosium hydride nano-powder by physical vapor deposition technology; mixing the two powders, and performing magnetic field orientation and press forming; and performing dehydrogenation treatment, sintering and heat treatment on a green compact at different temperatures, and obtaining the sinterd performing magnetic field orientation and press forming; and performing dehydrogenation treatment, sintering and heat treatment on a green compact at different temperatures, and obtaining the sintered magnet. The coercive force of the magnet prepared by the method is higher than that of the prior sintered magnet with the same ingredients; and compared with the sintered magnet with the equivalented magnet. The coercive force of the magnet prepared by the method is higher than that of the prior sintered magnet with the same ingredients; and compared with the sintered magnet with the equivalent coercive force, the proportion of the terbium and dysprosium needed by the magnet prepared by the method is remarkably reduced.coercive force, the proportion of the terbium and dysprosium needed by the magnet prepared by the method is remarkably reduced.

The invention provides a method for preparing a radiation oriental magnetic ring and a radiation multipolar magnetic ring. The method comprises the following steps of: melting and casting raw material of alloy in a vacuum furnace; carrying out coarse / hydrogen decrepitation on the ingots in the inert atmosphere; adding matters into the powder subject to coarse / hydrogen decrepitation to mix; carrying out micro crushing on the alloy coarse powder by an airflow mill in the nitrogen atmosphere; annealing the alloy powder in the inert gas, vacuum or reduction atmospheres; adding carbonyl iron powder and at least one type of alicyclic hydrocarbon into the annealed alloy powder to mix; carrying out preorientation operation on the mixing powder; enabling the mixing powder to form a circular former in the magnetic field; carrying out integral grinding treatment on the inner wall of the circular former; and sintering the circular former in the vacuum or inert gas atmosphere. The invention has the advantages of effectively decreasing the oriental field required in forming, enhancing the oriental degree of the magnetic rings and improving the property of the magnetic rings.

The invention discloses a manufacturing method for a neodymium iron boron lanthanon permanent magnet device with a composite plated film. The manufacturing method includes the steps that an alloy is firstly smelted, and the alloy in a molten state is cast on a rotary copper roller with water cooling to form alloy sheets through cooling; hydrogen decrepitation is then performed, material is mixed after the hydrogen decrepitation, airflow grinding is performed after material mixing, the material is mixed through a mixing machine under the protection of nitrogen and then conveyed to a magnetic field orientation pressing machine protected by nitrogen to be formed, the formed material is encapsuled in a protection box and then taken out to be subjected to isostatic pressing, and then the pressed material is conveyed to sintering equipment for sintering to manufacture a neodymium iron boron lanthanon permanent magnet in a timeliness mode; the neodymium iron boron lanthanon permanent magnet is machined to obtain the neodymium iron boron lanthanon permanent magnet device, then the neodymium iron boron lanthanon permanent magnet device is plated with films, the plated films comprise the first magnetron sputtering plated layer with the thickness of 0.02 micrometer-5 micrometers, the second magnetron sputtering and ion plating mixed plated layer with the thickness of 1 micrometer-10 micrometers and the third magnetron sputtering plated layer with the thickness of 0.1 micrometer-5 micrometers. The composite plated films are adopted in the surface treatment process of the lanthanon permanent magnet device, not only corrosion resistance but also magnetic performance of the lanthanon permanent magnet device are improved.

The invention discloses a manufacturing method for high-performance NdFeB rare earth permanent magnet devices. The high-performance NdFeB rare earth permanent magnet devices are made of R-Fe-Co-B-M rapid-hardening alloy, microcrystal HR-Fe alloy fibers and TmGn compound micro-powder. The manufacturing method comprises the steps of manufacturing the R-Fe-Co-B-M rapid-hardening alloy, manufacturing the microcrystal HR-Fe alloy fibers, performing hydrogen decrepitation on the alloy, performing mixing before pulverization, performing pulverization in a grinding mode through air flow, performing mixing after pulverization, forming a magnetic field, performing sintering and performing aging. In this way, a sintered NdFeB permanent magnet is manufactured, and machining and surface treatment are performed on the sintered NdFeB permanent magnet to manufacture various rare earth permanent magnet devices.

The invention discloses a recycling technique for galvanized sintered NdFeB wastes. The recycling technique comprises the following steps: performing multi-level breaking, hydrogen decrepitation, screening and airflow grinding on the sintered NdFeB wastes with a galvanized layer in turn, thereby acquiring the fine grains with few impurities and particle size being 3-5 microns; uniformly mixing the prepared auxiliary alloy with the fine grains made from the galvanized wastes at a certain ratio, wherein the auxiliary alloy can be the alloy powder containing one or more of praseodymium neodymium, holmium iron, gadolinium iron and dysprosium iron, and the proportion of the auxiliary alloy is 10-50%; performing the processes of forming, sintering, and the like, on the magnetic powder, thereby acquiring the required magnet. According to the recycling technique, the galvanized sintered NdFeB wastes are directly utilized to prepare the NdFeB products, and the rare earth separation is no longer performed, so that the environmental pollution is reduced and the manufacturing cost is lowered. According to the recycling technique, the galvanized sintered NdFeB wastes are subjected to multi-level breaking and hydrogen decrepitation and then screening and impurity-cleaning, so that the galvanized coating tablets and impurities in the electroplated wastes are extremely removed, and the basis for manufacturing the products at different grades is established.

The present invention relates to a low-weight loss neodymium-iron-boron magnet and a preparation method thereof. The low-weight loss neodymium-iron-boron magnet mainly consists of the following components in percentage by mass: 27%-32.5% of Nd, 1%-1.2% of B, 2%-3% of Co, 0.15%-2.75% of alloy element M1, 0.05%-1.1% of alloy element M2, 0.7%-1.3% of rare-earth elements (excluding rare-earth element Nd), and the balance Fe. The preparation method comprises the following steps: preparing raw materials according to components of the neodymium-iron-boron magnet and mass percentages of the components; performing smelting and casting to obtain a throwing band; performing hydrogen decrepitation and jet milling to form a powder material; pressing and shaping the powder material; performing high temperature sintering and surface treatment to obtain the low-weight loss neodymium-iron-boron magnet. According to the low-weight loss neodymium-iron-boron magnet and the preparation method thereof provided by the present invention, corrosion resistance of the magnet is improved, and moreover, the protective layer formed by the metal coating and the organic coating is applied to the surface of the magnet, thereby effectively alleviating the problem of corrosion weight loss of the neodymium-iron-boron magnet.