424results about How to "Improve remanence" patented technology

In a rotating machine comprising a rotor including a rotor core and a plurality of permanent magnet segments, and a stator including a stator core and windings, the permanent magnet segment is obtained by disposing a powder comprising an R² oxide, R³ fluoride or R⁴ oxyfluoride on a sintered magnet body of R¹—Fe—B composition, wherein R¹ to R⁴ are rare earth elements, and heat treating the powder-covered magnet body. The permanent magnet segment of a cross-sectional shape which is tapered from the center toward opposed ends has a higher coercive force at the ends than at the center.

A rare earth permanent magnet is prepared from a sintered magnet body of a R¹—Fe—B composition wherein R¹ is a rare earth element inclusive of Y and Sc, by forming a plurality of slits in a surface of the magnet body, disposing a powder on the magnet body surface, the powder comprising an oxide of R², a fluoride of R³, or an oxyfluoride of R⁴ wherein each of R², R³, and R⁴ is a rare earth element, and heat treating the magnet body and the powder below the sintering temperature in vacuum or in an inert gas.

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 discloses a sintered neodymium-iron-boron magnet, comprising the following components in percent by weight: 29.5%-32.5% of R, 62.85%-67.54% of Fe, 0.96%-1.15% of B and 2.0%-3.5% of TM, wherein R consists of Nd, Pr and Gd or consists of Nd, Pr and Ho; B represents boron, Fe represents iron, and Tm is one or more in Al, Nb, Cu, Co, Ga and Zr. In addition, the invention also discloses a preparation method of the sintered neodymium-iron-boron magnet, and the sintered neodymium-iron-boron magnet is prepared by adopting a quick-curing piece technology and a forming and pre-pressing process. The invention has the advantages that the largest magnetic energy product and intrinsic coercive force of the sintered neodymium-iron-boron magnet can be furthest improved, and the produced sintered neodymium-iron-boron magnet has high residual magnetism and high coercive force and is lower in cost.

The invention relates to a composition containing an aqueous dispersion of colloidal particles of at least one mineral filler, and fibres. The invention also relates to a process for treating the skin, especially wrinkled skin, via the application of the described composition to the skin.

The invention discloses a nano toughening NdFeB magnetic material and a preparation method of the nano toughening NdFeB magnetic material. The main mechanism is that a nano composite crystal boundary phase is formed on an NdFeB main phase crystal boundary, an H-grade rare earth permanent magnetic material with high coercive force M is prepared without doping any heavy rare earth, and then, a SH-grade rare earth permanent magnetic material is prepared by adding a little heavy rare earth. The nano material is prepared by a plasma arc method, has a grain size of 5-80nm and mainly contains metallic elements, such as Al, Cu, Cr, Co, Fe, Zn and the like, and all kinds of rare earth elements. A NdFeB main phase having a rare earth content of Pr-Nd is prepared by a SC-HD process; after smelting and hydrogen breaking, the product grain size is milled to be about 3.5 microns by an air-current mill, and in the argon protection atmosphere, a nano additive is added in a manner of jetting composite, so the nano additive is uniformly attached to the NdFeB main phase. In the sintering process, the nano powder and the main phase form the crystal boundary, the coercive force of NdFeB is greatly increased, and since the product has uniform crystal components, the machining property is also elevated well, the NdFeB magnetic material can be applied to the wider field. At the same time, the technical process is simple, low-cost and suitable for the batch production.

The invention discloses a method for preparing a sintered samarium-cobalt magnet. The method comprises the following steps of: preparing a first samarium-cobalt alloy and a second samarium-cobalt alloy; performing primary crushing on the first samarium-cobalt alloy and the second samarium-cobalt alloy; mixing first samarium-cobalt alloy primarily crushed magnetic powder and second samarium-cobalt alloy primarily crushed magnetic powder, and performing fine crushing, so that primarily crushed mixed magnetic powder is refined, and components are homogenized; and performing magnetic field orientation forming, cold isostatic pressing, sintering, solid solution treatment and ageing treatment on samarium-cobalt magnetic powder obtained by fine crushing in sequence. The method has the advantages that the first samarium-cobalt alloy has high remanence component characteristic, the second samarium-cobalt alloy has high coercivity component characteristic, the sintered samarium-cobalt magnets with various magnetic properties can be obtained by adjusting the mixing ratio of the first samarium-cobalt alloy primarily crushed magnetic powder to the second samarium-cobalt alloy primarily crushed magnetic powder, and the process is stable and low in cost.

The invention relates to an NdFeB (neodymium-iron-boron) magnet, in particular to a method for preparing the NdFeB magnet by waste materials, and belongs to the technical field of magnetic materials. The preparing method of the NdFeB magnet comprises the following steps that firstly, NdFeB magnet waste materials are cleaned and are dried through being blown, the NdFeB magnet waste materials are crushed into particles being 10 to 15mm by a crushing machine, rare earth metal is added into the particles, then, hydrogen crushing treatment is carried out to obtain crushed powder, and next, antioxidants are added for airflow grinding to obtain fine powder with the average particle diameter being 3.0 to 4.0 mu. m; next, lubricating agents are added, orientation is carried out under the protection atmosphere of nitrogen gas, in addition, pressing forming is carried out, and finally, NdFeB magnet finished products are obtained through discharging plasma sintering, secondary tempering heat treatment and surface treatment. The method has the advantages that waste materials are used as major raw materials, the simple and feasible preparing method is adopted, the recovery and utilization rate of the waste materials is effectively improved, in addition, Tb, Dy, Nd and Ce are added and compounded in the preparing process, and the obtained NdFeB magnet has better coercive force, residual magnetism and magnetic energy product.

The high stability and high magnetism quenched R-Fe-B base permanent magnetic alloy powder has the basic expression of RxFe100-x-y-z-vMzCovBy, where R is light RE element(s) Nd, Pr and La, and M is element(s) of Nb, Zr, Ti, etc; and consists of main R2Fe14B phase and small amount of superfine auxiliary Fe-alpha-M-beta phase. Adding Nb and other transition elements to form small amount of superfine auxiliary Fe-alpha-M-beta phase during fast solidification can inhibit over nucleation and growth of Nd2Fe14B crystal grain, improve the performance of the quenched material, fine the Nd2Fe14B crystal grain and raise the temperature stability and antioxidant process of the material. In addition, the permanent magnetic alloy powder has obviously raised intrinsic coercive force, high saturated magnetization, high residual magnetism and other advantages.

The invention discloses a method for manufacturing cerium-rich anisotropy nano-crystalline rare-earth permanent magnets. The method includes (1), proportioning materials according to a chemical formula of (Ce<x>, RE<1-x>)Fe<100-a-b-c>BTM<c>; (2), melting the materials to obtain alloy ingots; (3), crushing the alloy ingots, and then rapidly quenching melt to obtain rapidly quenched magnetic powder; (4), carrying out hot-pressing on the rapidly quenched magnetic powder for 1-10 minutes at the temperatures ranging from 500 DEG C to 800 DEG C under the pressures ranging from 100MPa to 300MPa, and then enabling the rapidly quenched powder to thermally deform for 3-10 minutes at the temperatures ranging from 600 DEG C to 900 DEG C under the pressures ranging from 50MPa to 200MPa. The invention further provides a method for manufacturing the cerium-rich anisotropy nano-crystalline rare-earth permanent magnets according to chemical formulas of (Ce<x>, RE<1-x>)Fe<100-a-b-c>BTM<c> and NdFe<100-a-b-c>BTM<c>. The methods have the advantages that processes can be simplified, the cost can be reduced, and the obtained cerium-rich anisotropy nano-crystalline rare-earth permanent magnets are excellent in magnetic performance.