Title:
Ｒ－Ｔ－Ｂ系焼結磁石の製造方法
Document Type and Number:
Japanese Patent JP7439609
Kind Code:
B2
Abstract:
To provide a method for producing an R-T-B based sintered magnet without requiring an underlay powder in a step of diffusing a heavy rare-earth element or the like in a sintered body from a diffusion source.SOLUTION: There is provided a method for producing an R-T-B based sintered magnet which comprises: a step of preparing an R-T-B-based sintered magnet material (T is Fe or Fe and Co) having an R2Fe14B type compound crystal grains containing a light rare earth element RL as a main rare earth element R, as the main phase; a step of preparing a diffusion source powder formed from a powder of an alloy containing a heavy rare earth element RH; a step of bringing the diffusion source powder into contact with at least the top face and bottom face of a sintered magnet material; a step of mounting the sintered magnet material in a state of being in contact with the diffusion source powder, on a supporting plate; and a step of subjecting the sintered magnet material mounted on a support plate to a heat treatment for heating it at a temperature of 450°C or higher and equal to or lower than the sintering temperature for one hour or more to diffuse the heavy rare earth element RH contained in the diffusion source powder from the surface to the inside of the sintered magnet material, in which at least the top face of the support plate is formed of an Fe-Cr-Al alloy.SELECTED DRAWING: Figure 4
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Inventors:
Naoyuki Okamoto
Application Number:
JP2020055646A
Publication Date:
February 28, 2024
Filing Date:
March 26, 2020
Export Citation:
Assignee:
Proterial Co., Ltd.
International Classes:
B22F1/00; B22F3/00; B22F3/24; C22C28/00; C22C33/02; C22C38/00; C22C38/06; H01F1/057; H01F41/02
Domestic Patent References:
| JP2018026390A | ||||
| JP2012156247A |
Foreign References:
| WO2012099186A1 | ||||
| CN110168680A | ||||
| WO2013061836A1 |
Other References:
丸野 重雄 他,Fe-Cr-Al系電熱材料に形成される高温酸化被膜の走査電顕観察と表面分析,日本金属学会誌,1976年,第40巻、第11号,p.1145-1151,https://doi.org/10.2320/jinstmet1952_40.11_1145
Attorney, Agent or Firm:
Seiji Okuda
Shuichi Kita
Mimichi Kajitani
Shuichi Kita
Mimichi Kajitani
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