[ Papers ]

Journal of the Korean Society of Manufacturing Technology Engineers - Vol. 30, No. 2, pp.119-126

ISSN: 2508-5107 (Online)

Print publication date 15 Apr 2021

Received 09 Feb 2021 Revised 18 Feb 2021 Accepted 25 Feb 2021

DOI: https://doi.org/10.7735/ksmte.2021.30.2.119

열처리 온도에 따른 NdFeB계 자석의 탈자 및 분별 연구

김병준^a ; 박익근^b ; 김용성^b^{, *}

Study on the Demagnetization and Classification of NdFeB Magnets According to Different Heat Treatment Temperatures

Byeong Jun Kim^a ; Ik Keun Park^b ; Young Sung Kim^b^{, *}

aGraduate School of NIDE Fusing Technology, Seoul National University of Science & Technology
bSeoul Tech NDT Research Center, Seoul National University of Science & Technology

Correspondence to: ^*Tel.: +82-2-970-6804 E-mail address: youngsk@seoultech.ac.kr (Young Sung Kim).

Abstract

In this study, demagnetization heat treatment conditions were studied for recycling and reuse of waste NdFeB magnets. The specimens used four different Nd magnets of N, H, UH and AH grades. To investigate the heat treatment conditions of a Nd magnet, a thermal flow computational simulation was performed to determine the exact temperature change of the magnet specimen according to the heat treatment time change at an ambient temperature inside a heat treatment furnace. It was determined that the content of elements existing inside the magnet, such as expensive heavy rare earths Dy and Tb, could be predicted by examining the rate of decrease in magnetic flux density at each heat treatment temperature.

Keywords:

Recycling, Demagnetization, Classification, NdFeB, Magnet, Heat treatment

Acknowledgments

이 논문은 2020년도 에너지기술개발사업 과제번호 20205210100070의 연구비지원으로 수행되었습니다.

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Byeong Jun Kim

Master Candidate in the Graduate School of NIDE Fusing Technology, Seoul National University of Science and Technology.His research interest is Material and Nano-Micro Technology.

E-mail: kbj1020@naver.com

Ik Keun Park

Professor in the Department of Mechanical & Automotive Engineering, Seoul National University of Science and Technology.His Research interest is Nondestructive Evaluation.

E-mail: ikpark@seoultech.ac.kr

Young Sung Kim

Professor in the NDT Research Center, Seoul National University of Science and Technology.His research interest in Material and Nano-Micro Technology.

E-mail: youngsk@seoultech.ac.kr