Patent application number | Description | Published |
20090252865 | METHOD FOR PRODUCING SINTERED NdFeB MAGNET - The present invention provides a method for producing a sintered NdFeB magnet having high coercivity and capable of being brought into applications without lowering its residual magnetic flux density or maximum energy product and without reprocessing. The method for producing a sintered NdFeB magnet according to the present invention includes applying a substance containing dysprosium (Dy) and/or terbium (Tb) to the surface of the sintered NdFeB magnet forming a base body and then heating the magnet to diffuse Dy and/or Tb through the grain boundary and thereby increase the coercivity of the magnet. This method is characterized in that: (1) the substance containing Dy or Tb to be applied to the surface of the sintered NdFeB magnet is substantially a metal powder; (2) the metal powder is composed of a rare-earth element R and an iron-group transition element T, or composed of R, T and another element X, the element X capable of forming an alloy or intermetallic compound with R and/or T; and (3) the oxygen content of the sintered NdFeB magnet forming the base body is 5000 ppm or lower. The element T may contain nickel (Ni) or cobalt (Co) to produce an anticorrosion effect. | 10-08-2009 |
20100119703 | METHOD FOR MAKING NDFEB SINTERED MAGNET - The objective of the present invention is to provide a method for making a NdFeB sintered magnet, capable of enhancing the effect of increasing the coercive force and preventing the instability of the effects, and in addition, being inexpensive. The method for making a NdFeB sintered magnet according to the present invention has processes of coating a NdFeB sintered magnet with a powder containing Dy and/or Tb, then heating the NdFeB sintered magnet, and thereby diffusing R | 05-13-2010 |
20100266718 | SINTERED MAGNET PRODUCTION SYSTEM - The present invention is aimed at providing a sintered magnet production system that can prevent the influences of a leaking magnetic field in an orienting process. A sintered magnet production system according to the present invention has a filling means | 10-21-2010 |
20100282371 | NDFEB SINTERED MAGNET AND METHOD FOR PRODUCING THE SAME - The present invention is aimed at providing a method for producing an NdFeB sintered magnet having a higher coercivity and higher squareness of the magnetization curve than ever before. A method for producing an NdFeB sintered magnet according to the present invention includes the steps of forming a layer containing Dy and/or Tb on the surface of an NdFeB sintered magnet base material and then performing a grain boundary diffusion process for diffusing Dy and/or Tb from the aforementioned layer through the crystal grain boundaries of the magnet base material into the magnet base material by heating the magnet base material to a temperature equal to or lower than the sintering temperature thereof, and this method is characterized in that a) the content of a rare earth in a metallic state in the magnet base material is equal to or higher than 12.7 at %; b) the aforementioned layer is a powder layer formed by depositing a powder; and c) the powder layer contains Dy and/or Tb in a metallic state by an amount equal to or higher than 50 mass %. | 11-11-2010 |
20110070118 | METHOD FOR MAKING NdFeB SINTERED MAGNET AND MOLD FOR MAKING THE SAME - A mold which is inexpensive and easy to process and does not embrittle. Also provided is a process by which a sintered. NdFeB magnet can be produced using the mold without suffering bending or deformation. At least part (e.g., a bottom plate) of the mold is made of a carbon material. Carbon materials have lower friction with a sinter during sintering than metals. The mold hence enables a sintered NdFeB magnet to be produced without suffering the bending or deformation caused by friction due to sintering shrinkage. Carbon materials are inexpensive and easy to process. The mold does not embrittle even when repeatedly used. Such effects can be significantly produced when a carbon material is used as the bottom plate, on which the load of the sinter is imposed during sintering. | 03-24-2011 |
20120107433 | SINTERED MAGNET PRODUCING APPARATUS - A sintered magnet producing apparatus is provided having a device for fixing a filling container and a lid for the container in the process of orienting alloy powder in the filling container by means of a magnetic field. The sintered magnet producing apparatus includes a filling system for supplying an alloy powder into a filling container and then compacting the alloy powder, a sintering device for sintering the alloy powder, an orienting device having a coil for generating a magnetic field for orienting the alloy powder in the filling and sintering container before the filling process and after the compacting process, and a fixing device for covering the filling container with a lid, and simultaneously, fixing the filling container only during the orienting process. The filling container is prevented from moving due to the magnetic field applied in the orienting process and, simultaneously, the scattering of the alloy powder is prevented. | 05-03-2012 |
20120176211 | SINTERED NdFeB MAGNET AND METHOD FOR MANUFACTURING THE SAME - Disclosed is a sintered NdFeB magnet having high coercivity (H | 07-12-2012 |
20120176212 | METHOD AND SYSTEM FOR PRODUCING SINTERED NdFeB MAGNET, AND SINTERED NdFeB MAGNET PRODUCED BY THE PRODUCTION METHOD - A method and system for producing a slim-shaped sintered NdFeB magnet having a high level of coercive force and high degree of orientation, as well as a sintered NdFeB magnet produced by the aforementioned method or system. A system for producing a slim-shaped sintered NdFeB magnet according to the present invention includes: a filling unit and filling alloy powder; an orienting unit; a sintering furnace; and a conveying unit. The orienting unit is provided with a heating and orienting coil for heating the alloy powder in the molds before and/or after the application of the magnetic field so as to decrease the coercive force of the individual particles of the alloy powder. | 07-12-2012 |
20130040050 | APPLICATOR FOR GRAIN BOUNDARY DIFFUSION PROCESS - An applicator for grain boundary diffusion process that uniformly applies an RH powder without excess or deficiency onto a predetermined surface of a sintered compact with a given thickness and in a given pattern, the applicator being automated and performed on many sintered compacts during the production of a NdFeB system sintered magnet. The applicator includes a work loader and a print head, located above the work loader. The work loader includes: a laterally movable base; a lift being vertically movable with respect to the base; a frame that is attachable to and detachable from the lift; a tray that is attachable to and detachable from the frame; a supporter provided on the upper surface of the tray; and a vertically movable magnetic clamp. The print head includes: a screen having a passage section; and a movable squeegee and a backward scraper that maintains contact with the upper screen surface. | 02-14-2013 |
20130169394 | NdFeB Sintered Magnet and Method for Producing the Same - A method for producing an NdFeB sintered includes forming a layer containing Dy and/or Tb on the surface of an NdFeB sintered magnet base material and then performing a grain boundary diffusion process for diffusing Dy and/or Tb from the aforementioned layer through the crystal grain boundaries of the magnet base material into the magnet base material by heating the magnet base material to a temperature equal to or lower than the sintering temperature thereof. In this method: a) the content of a rare earth in a metallic state in the magnet base material is equal to or higher than 12.7 at %; b) the aforementioned layer is a powder layer formed by depositing a powder; and c) the powder layer contains Dy and/or Tb in a metallic state by an amount equal to or higher than 50 mass %. | 07-04-2013 |
20130189426 | METHOD FOR PRODUCING SINTERED NDFEB MAGNET - A method for producing a sintered NdFeB magnet having high coercivity and capable of being brought into applications without lowering its residual magnetic flux density or maximum energy product and without reprocessing. The method includes applying a substance containing dysprosium (Dy) and/or terbium (Tb) to the surface of the sintered NdFeB magnet forming a base body and then heating the magnet to diffuse Dy and/or Tb through the grain boundary and thereby increase the coercivity of the magnet. This method is characterized in that: (1) the substance containing Dy or Tb to be applied to the surface of the sintered NdFeB magnet is substantially a metal powder; (2) the metal powder is composed of a rare-earth element R and an iron-group transition element T, or composed of R, T and another element X, the element X capable of forming an alloy or intermetallic compound with R and/or T; and (3) the oxygen content of the sintered NdFeB magnet forming the base body is 5000 ppm or lower. The element T may contain nickel (Ni) or cobalt (Co) to produce an anticorrosion effect. | 07-25-2013 |
20130343946 | METHOD AND SYSTEM FOR MANUFACTURING SINTERED RARE-EARTH MAGNET HAVING MAGNETIC ANISOTROPY - A method for manufacturing a sintered rare-earth magnet having a magnetic anisotropy, in which a very active powder having a small grain size can be safely used in a low-oxidized state. A fine powder as a material of the sintered rare-earth magnet having a magnetic anisotropy is loaded into a mold until its density reaches a predetermined level. Then, in a magnetic orientation section, the fine powder is oriented by a pulsed magnetic field. Subsequently, the fine powder is not compressed but immediately sintered in a sintering furnace. A multi-cavity mold for manufacturing a sintered rare-earth magnet having an industrially important shape, such as a plate magnet or an arched plate magnet, may be used. | 12-26-2013 |
20140062631 | NdFeB SYSTEM SINTERED MAGNET - A NdFeB system sintered magnet produced by the grain boundary diffusion method and has a high coercive force and squareness ratio with only a small decrease in the maximum energy product. A NdFeB system sintered magnet having a base material produced by orienting powder of a NdFeB system alloy and sintering the powder, with Dy and/or Tb (the “Dy and/or Tb” is hereinafter called R | 03-06-2014 |
20140062632 | NdFeB SYSTEM SINTERED MAGNET - A NdFeB system sintered magnet produced by the grain boundary diffusion method that has a high coercive force and squareness ratio with only a small decrease in the maximum energy product. The NdFeB system sintered magnet has a base material produced by orienting powder of a NdFeB system alloy and sintering the powder, with Dy and/or Tb (the “Dy and/or Tb” is hereinafter called R | 03-06-2014 |
20140118098 | NDFEB SYSTEM SINTERED MAGNET - A NdFeB system sintered magnet according to the present invention is a NdFeB system sintered magnet having a base material produced by orienting powder of a NdFeB system alloy and sintering the powder, with Dy and/or Tb (the “Dy and/or Tb” is hereinafter called R | 05-01-2014 |
20140308440 | METHOD FOR MAKING NdFeB SINTERED MAGNET - A method for making a NdFeB sintered magnet, capable of enhancing the effect of increasing the coercive force and preventing the instability of the effects, and in addition, being inexpensive is provided. The method for making a NdFeB sintered magnet has processes of coating a NdFeB sintered magnet with a powder containing Dy and/or Tb, then heating the NdFeB sintered magnet, and thereby diffusing R | 10-16-2014 |
20140327503 | NDFEB SYSTEM SINTERED MAGNET AND METHOD FOR PRODUCING THE SAME - Provided is a NdFeB sintered magnet which can be used in the grain boundary diffusion method as a base material in which R | 11-06-2014 |
20150041022 | METHOD FOR PRODUCING NDFEB SYSTEM SINTERED MAGNET - A method for producing a NdFeB system sintered magnet in which a coating material containing a heavy rare-earth element R | 02-12-2015 |
20150059525 | NdFeB SYSTEM SINTERED MAGNET - The NdFeB system sintered magnet according to the present invention is a NdFeB system sintered magnet produced by diffusing Dy and/or Tb which are/is attached to a surface of a base material produced by orienting powder of a NdFeB system alloy in a magnetic field, and sintering the powder of the NdFeB system alloy, into grain boundaries inside the base material by grain boundary diffusion treatment, wherein a squareness ratio is equal to or higher than 95%. The NdFeB system sintered magnet can be produced by producing a base material of the NdFeB system sintered magnet by using a NdFeB system alloy with lamellas of a rare-earth rich phase dispersed substantially uniformly at predetermined spaces, as a starting alloy, and causing the alloy to occlude hydrogen, without performing heating for desorbing the occluded hydrogen thereafter until a sintering process, and applying grain boundary diffusion treatment to the base material. | 03-05-2015 |