摘要:
A process for producing R-T-B-based rare earth magnet powder having excellent coercive force and high remanent flux density. A process for producing R-T-B-based rare earth magnet powder by HDDR treatment, in which a raw material alloy for the R-T-B-based rare earth magnet powder includes R (wherein R represents at least one rare earth element including Y), T (wherein T represents Fe, or Fe and Co) and B (wherein B represents boron), and has a composition including R in an amount of between 12.0 atom % and 17.0 atom %, and B in an amount of between 4.5 atom % and 7.5 atom %; the HDDR treatment includes a DR step including a preliminary evacuation step and a complete evacuation step; and a rate of pressure reduction caused by evacuation in the preliminary evacuation step is not less than 1 kPa/min and not more than 30 kPa/min.
摘要:
The present invention provides a powder for a magnet which can form a rare earth magnet having excellent magnetic characteristics and which has excellent moldability, a method for producing the powder for a magnet, a powder compact, and a rare earth-iron-boron-based alloy material.Magnetic particles constituting a powder for a magnet each include a structure in which a particle of a phase 3 of a hydrogen compound of a rare earth element is dispersed in a phase 2 of an iron-containing material. Since the phase 2 of the iron-containing material is uniformly present in each of the magnetic particles 1, the powder has excellent moldability and easily increases the density of a powder compact 4. The powder for a magnet can be produced by heat-treating a powder of a rare earth-iron-boron-based alloy (R—Fe—B-based alloy) in a hydrogen atmosphere at a temperature equal to or higher than the disproportionation temperature of the R—Fe—B-based alloy to separate the powder into the rare earth element and the iron-containing material and to produce the hydrogen compound of the rare earth element. The powder compact 4 is produced by compacting the powder for a magnet. The powder compact 4 is heat-treated in a vacuum to produce a R—Fe—B-based alloy material 5, and the R—Fe—B-based alloy 5 is magnetized to produce a R—Fe—B-based alloy magnet 6.
摘要:
Provided is a method of manufacturing an alloy for an R-T-B-based rare earth sintered magnet, with which an R-T-B-based magnet having high coercive force can be obtained even when the B concentration is low and the Dy concentration is zero or extremely low.This method includes: a casting step of manufacturing a cast alloy by casting a molten alloy, a hydrogenating step of absorbing hydrogen in the cast alloy; and a dehydrogenating step of removing hydrogen from the cast alloy absorbing hydrogen in an inert gas atmosphere at a temperature lower than 550° C., wherein the molten alloy consists of B, a rare earth element R, a transition metal T essentially containing Fe, a metal element M, and unavoidable impurities, in which the R content is 13 at % to 15.5 at %, the B content is 5.0 at % to 6.0 at %, the M content is 0.1 at % to 2.4 at %, the T content is a balance, a ratio of a Dy content to the total content of the rare earth element is 0 at % to 65 at %, and the molten alloy satisfies the below formula (1). 0.32≦B/TRE≦0.40 (1).
摘要翻译:提供一种制造用于R-T-B系稀土烧结磁体的合金的方法,即使当B浓度低,Dy浓度为零或极低时,也可以获得具有高矫顽力的R-T-B系磁体。 该方法包括:通过铸造熔融合金制造铸造合金的铸造步骤,在铸造合金中吸氢的氢化步骤; 以及在低于550℃的温度下在惰性气体气氛中从铸造合金中除去氢的脱氢步骤,其中熔融合金由B组成,稀土元素R,基本上含有Fe的过渡金属T, 金属元素M和不可避免的杂质,其中R含量为13原子%至15.5原子%,B含量为5.0原子%至6.0原子%,M含量为0.1原子%至2.4原子%,T含量 是余量,Dy含量与稀土元素的总含量的比例为0at%〜65at%,熔融合金满足下式(1)。 0.32≦̸ B / TRE≦̸ 0.40(1)。
摘要:
A method of preparing R—Fe—B-based rare earth magnetic powder for a bonded magnet and magnetic powder prepared thereby, and a method of manufacturing a bonded magnet using magnetic powder and a bonded magnet manufactured thereby. Further, a method of preparing R—Fe—B-based rare earth magnetic powder having improved magnetic properties including grinding rare earth sintered magnet products as a raw material, performing a hydrogenation process where a ground product is charged into a furnace, and the furnace is then filled with hydrogen and a temperature of the furnace is increased, performing a disproportionation process where the temperature of the furnace is further increased in the same hydrogen atmosphere above, performing a desorption process where hydrogen is exhausted from an inside of the furnace, and performing a recombination process where hydrogen in the inside of the furnace is exhausted, and magnetic powder prepared thereby, and a method of manufacturing a bonded magnet.
摘要:
A method and a device for recovering hydrogen pulverized powder of a raw-material alloy for rare-earth magnets capable of lowering a possibility that hydrogen pulverized powder after hydrogen was pulverized remains in a recovery chamber and capable of enhancing magnetic properties by reducing an amount of oxygen of an obtained rare-earth magnet, a processing container 50 is carried into a recovery chamber 40 from a processing chamber through a carry-in port after inert gas was introduced into the recovery chamber 40 by inert gas introducing means 12, the raw-material alloy for rare-earth magnets in the processing container 50 is discharged into the recovery chamber 40 after the pressure in the recovery chamber 40 was reduced by evacuating means 33 and thereafter, inert gas is introduced into the recovery chamber 40 by inert gas introducing means 12, and the raw-material alloy for rare-earth magnets is recovered into the recovery container 50 from an discharge port 40a after a pressure in the recovery chamber 40 was set to a predetermined pressure by inert gas.
摘要:
A method for producing a NdFeB system sintered magnet. The method includes: a hydrogen pulverization process, in which coarse powder of a NdFeB system alloy is prepared by coarsely pulverizing a lump of NdFeB system alloy by making this lump occlude hydrogen; a fine pulverization process, in which fine powder is prepared by performing fine pulverization for further pulverizing the coarse powder; a filling process, in which the fine powder is put into a filling container; an orienting process, in which the fine powder in the filling container is oriented; and a sintering process, in which the fine powder after the orienting process is sintered as held in the filling container. The processes from hydrogen pulverization through orienting are performed with neither dehydrogenation heating nor evacuation each for desorbing hydrogen occluded in the hydrogen pulverization process. The processes from hydrogen pulverization through sintering are performed in an oxygen-free atmosphere.
摘要:
The invention relates to a method for producing a magnetic material, said magnetic material consisting of a starting material that comprises a rare earth metal (SE) and at least one transition metal. The method has the following steps: —hydrogenating the starting material, —disproportioning the starting material, —desorption, and —recombination. A magnetic field is applied during at least one step such that a textured magnetic material is obtained and the formation of a texture is promoted in the magnetic material.
摘要:
An object of the present invention is to enhance a coercive force of magnetic particles by promoting formation of a continuous R-rich grain boundary phase in a crystal grain boundary of a magnetic phase of the particles, and to thereby obtain R-T-B-based rare earth magnet particles further having a high residual magnetic flux density. The present invention relates to production of R-T-B-based rare earth magnet particles capable of exhibiting a high coercive force even when a content of Al therein is reduced, and a high residual magnetic flux density, in which formation of an R-rich grain boundary phase therein can be promoted by heat-treating Al-containing R-T-B-based rare earth magnet particles obtained by HDDR treatment in vacuum or in an Ar atmosphere at a temperature of not lower than 670° C. and not higher than 820° C. for a period of not less than 30 min and not more than 300 min.
摘要:
A method of making a permanent magnet includes a step of providing an alloy powder comprising at least one rare earth element. The alloy powder is shaped and then exposed to microwave radiation or a pulsed electric current to form a sintered magnet.
摘要:
R-T-B-based rare earth magnet particles are produced by an HDDR treatment which comprises a first stage HD step of heating particles of a raw material alloy having a composition of R, B and Co in an inert atmosphere or in a vacuum atmosphere and then replacing the atmosphere with a hydrogen-containing gas atmosphere in which the raw material alloy particles are held in the same temperature range and a second stage HD step of heating a material obtained in the first stage HD step in which the material is held in the hydrogen-containing gas atmosphere.