Ulvac, Inc.

Yoshinori Shingaki

Hiroshi Nagata

Kyuzo Nakamura

Atsushi Nakatsuka

Ryou Yoshiizumi

Takeo Katou

Masami Itou

Ichirou Mukae

Youichi Hirose

Kyoutoshi Miyagi

There is provided an evaporating material of thin plate shape which can be manufactured at a reduced cost and at high productivity, the evaporating material being adapted for use in enhancing the coercive force of neodymium-iron-boron sintered magnet by heat treatment while evaporating Dy in vacuum or in reduced-pressure inert gas atmosphere. The evaporating material of this invention has a core membermade of a fire-resistant metal having a multiplicity of through holes, and is made by melting a rare-earth metal or an alloy thereof so as to get adhered to, and solidified on, the core member. In this case, the above-mentioned adhesion is performed by dipping the core member into a molten bath of the rare-earth metal or an alloy thereof, and pulling it out of the molten bath.

Evaporating material and method of manufacturing the same

The object of the present invention is to improve the productivity of a permanent magnet and to manufacture it at a low cost by effectively coating Dy and Tb on a surface of the magnet of Fe&#x2014;B-rare earth elements having a predetermined configuration. The permanent magnet of the present invention is manufactured by a coating step for coating Dy on the surface of the magnet of Fe&#x2014;B-rare earth elements having a predetermined configuration and a diffusing step for diffusing Dy coated on the surface of the magnet into crystal grain boundary phases of the magnet with being heat treated at a predetermined temperature. In this case, the coating step comprises a first step for heating a process chamber used for carrying out the coating step and generating metallic vapor atmosphere within the process chamber by vaporizing vaporizable metallic material previously arranged within the process chamber, and a second step for introducing into the process chamber the magnet held at a temperature lower than that within the process chamber and then selectively depositing the vaporizable metallic material on a surface of the magnet by an effect of temperature difference between the temperature within the process chamber and that of the magnet by the magnet reaches a predetermined temperature.

Coating method and apparatus, a permanent magnet, and manufacturing method thereof

A permanent magnet is provided which has formed a Dy, Tb film on a surface of an iron-boron-rare earth sintered magnet of a predetermined shape, with diffusion thereof into grain boundary phases, having a higher coercive force. The method of manufacturing a permanent magnet includes a film-forming step of evaporating metal evaporating material containing at least one of Dy and Tb and adhering evaporated metal atoms to a surface of the iron-boron-rare earth sintered magnet, and a diffusing step of performing heat treatment to diffuse metal atoms adhered to the surface into grain boundary phases of the sintered magnet. The metal evaporating material contains at least one of Nd and Pr.

Permanent magnet and method of manufacturing same

There is provided a vacuum evaporating apparatus which is suitable for performing a process in which a metal vapor atmosphere is formed in a processing chamber, the metal atoms in this metal vapor atmosphere are caused to be adhered to the surface of an object to be processed, and the metal atoms adhered to the surface of the object to be processed are diffused into grain boundary phases thereof. The apparatus comprises: a processing furnace (); at least one processing box () disposed inside the processing furnace; and a heating means () provided inside the processing furnace so as to enclose the processing box. An evacuating means is provided which, after housing the processing box inside the processing furnace in a state in which the object to be processed (S) and the metal evaporating material (V) are disposed in the processing box, reduces the processing furnace and the processing box to a predetermined pressure and keep them at that pressure. The heating means is operated in the reduced pressure to evaporate the metal evaporating material while increasing the object to be processed to a predetermined temperature. The evaporated metal atoms are supplied to the surface of the object to be processed.

Vacuum vapor processing apparatus

Crystal fractured surfaces of raw meal powder having more equal crystal orientation relationship in the magnetic field are arranged to be assembled together so that a method of manufacturing a permanent magnet which has an extremely high degree of orientation can be provided. In this invention, raw meal powder (P) is filled into a cavity, the raw meal powder (P) is oriented in the magnetic field while being pressed or urged by pressing means that has a smaller area than the cross-sectional area of the cavity. Semi-finished product thus oriented is compression-molded into a predetermined shape in the magnetic field.

Method of manufacturing permanent magnet

There is provided a method of manufacturing a permanent magnet which has an extremely high coercive force and high magnetic properties is manufactured at high productivity. There are executed: a first step of causing at least one of Dy and Tb to adhere to at least part of a surface of iron-boron-rare-earth based sintered magnet; and a second step of diffusing, through heat-treatment at a predetermined temperature, at least one of Dy and Tb adhered to the surface of the sintered magnet into grain boundary phase of the sintered magnet. As the sintered magnet, there is used one which is manufactured by: mixing each powder of principal phase alloy (constituted primarily by RTB phase, where R is at least one rare earth element primarily including Nd and where T is a transition metal primarily including Fe), and a liquid phase alloy (having a higher content of R than RTB phase and primarily constituted by R-rich phase) in a predetermined mixing ratio; press-forming in magnetic field a mixed powder thus obtained; and sintering a press-formed body in vacuum or inert gas atmosphere.

One object of the present invention is to provide a method for manufacturing a permanent magnet which can effectively improving the magnetizing properties and coercive force with efficiently diffusing Dy into grain boundary phases without deteriorating a surface of sintered magnet of Nd&#x2014;Fe&#x2014;B family and does not require any subsequent working process. Sintered magnet S of Nd&#x2014;Fe&#x2014;B family and Dy are arranged in a processing chamberapart from each other. Then Dy is evaporated by heating the processing chamberunder a reduced pressure condition to evaporate Dy with elevating the temperature of sintered magnet S to a predetermined temperature and to supply and deposit evaporated Dy atoms onto the surface of sintered magnet S. During which the supplying amount of Dy atoms onto the sintered magnet S is controlled so as to diffuse and homogeneously penetrate them into the grain boundary phases of sintered magnet before Dy layer is formed on the surface of sintered magnet.

Permanent magnet and a manufacturing method thereof

There is provided a method of manufacturing a permanent magnet in which Dy and/or Tb adhered to the surface of a sintered magnet containing a lubricant can be efficiently diffused and in which the permanent magnet having high magnetic properties can be manufactured at good productivity. The permanent magnet is manufactured by executing a first step of adhering at least one of Dy and Tb to at least a part of a surface of a sintered magnet made by sintering iron-boron-rare earth based alloy raw meal powder containing a lubricant; and a second step of heat-treating the sintered magnet at a predetermined temperature to thereby disperse at least one of Dy and Tb adhered to the surface of the sintered magnet into grain boundary phase of the sintered magnet. At this time, as the sintered magnet, there is used one manufactured in an average grain size within a range of 4 &#x3bc;m&#x2dc;8 &#x3bc;m.

There is provided a method of manufacturing a permanent magnet having extremely high orientation by arranging such that the crystal fractures of alloy raw meal powder having more equal crystal orientational relationship are combined in magnetic field. In this invention, alloy raw meal powder is filled into a cavity and, while agitating the alloy raw meal powder inside the cavity, is oriented in the magnetic field. This oriented body is then compression molded in the magnetic field into a predetermined shape.

Method of manufacturing oriented body, molded body and sintered body as well as method of manufacturing permanent magnet

By causing at least one of Dy and Tb to be adhered to the surface of an iron-boron-rare earth based sintered magnet of a predetermined shape, and is then to be diffused into grain boundary phase, a permanent magnet can be manufactured at high workability and low cost. An iron-boron-rare earth based sintered magnet is disposed in a processing chamber and is heated to a predetermined temperature. Also, an evaporating material made up of a fluoride containing at least one of Dy and Tb disposed in the same or another processing chamber is evaporated, and the evaporated evaporating material is caused to be adhered to the surface of the sintered magnet. The Dy and/or Tb metal atoms of the adhered evaporating material are diffused into the grain particle phase of the sintered magnet before a thin film made of the evaporated material is formed on the surface of the sintered magnet.

By eliminating the necessity of a prior step for cleaning a sintered magnet before adhering Dy and/or Tb to the surface of the sintered magnet S, the productivity of a permanent magnet having diffused Dy and/or Tb into grain boundary phase is improved. Iron-boron-rare earth based sintered magnet (S) disposed in a processing chamber () is heated to a predetermined temperature. An evaporating material (V) which is made of a hydride containing at least one of Dy and Tb is disposed in the same or in another processing chamber and is evaporated to cause the evaporated evaporating material to the surface of the sintered magnet. Metal atoms of Dy and/or Tb are diffused into grain boundary phase of the sintered magnet.

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Ibaraki, Japan

Yoshinori Shingaki