Preparation of ultrafine Sm2Fe17N3 magnetic powders without ball milling

Jing Wang; Wei Cai; Jingwu Zheng; Junhui Zhu; Xinqi Zhang; Haibo Chen; Liang Qiao; Yao Ying; Wangchang Li; Jing Yu; Juan Li; Yuebin Su; Shenglei Che

Journal of Materials Research and Technology (Nov 2023)

Preparation of ultrafine Sm2Fe17N3 magnetic powders without ball milling

Jing Wang,
Wei Cai,
Jingwu Zheng,
Junhui Zhu,
Xinqi Zhang,
Haibo Chen,
Liang Qiao,
Yao Ying,
Wangchang Li,
Jing Yu,
Juan Li,
Yuebin Su,
Shenglei Che

Affiliations

Jing Wang: Research Center of Magnetic and Electronic Materials, College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, 310014, China
Wei Cai: Research Center of Magnetic and Electronic Materials, College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, 310014, China
Jingwu Zheng: Research Center of Magnetic and Electronic Materials, College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, 310014, China; Corresponding author.
Junhui Zhu: Research Center of Magnetic and Electronic Materials, College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, 310014, China
Xinqi Zhang: Research Center of Magnetic and Electronic Materials, College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, 310014, China
Haibo Chen: Research Center of Magnetic and Electronic Materials, College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, 310014, China
Liang Qiao: Research Center of Magnetic and Electronic Materials, College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, 310014, China
Yao Ying: Research Center of Magnetic and Electronic Materials, College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, 310014, China
Wangchang Li: Research Center of Magnetic and Electronic Materials, College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, 310014, China
Jing Yu: Research Center of Magnetic and Electronic Materials, College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, 310014, China
Juan Li: Research Center of Magnetic and Electronic Materials, College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, 310014, China
Yuebin Su: Zhejiang Haoxiang Mining Co. LTD, Lishui, 323900, China
Shenglei Che: Research Center of Magnetic and Electronic Materials, College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, 310014, China

Journal volume & issue: Vol. 27
pp. 6688 – 6695

Abstract

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Ultrafine Sm2Fe17N3 powders obtained via ball or airflow milling usually exhibit defects and localized demagnetization owing to their irregular morphologies. Therefore, this study employs the ultrasonic spray pyrolysis–reduction diffusion method in conjunction with CaO coating to control the precursor size of the oxides and obtain a size-controllable nearly spherical micronano-sized pure-phase Sm2Fe17N3 magnetic powder. The investigation involved testing and analyzing the microstructure, phase composition, and magnetic properties of the magnetic powder. The results indicate that the influence of hydrogen reduction after calcium oxide coating is crucial for achieving morphology control, and the amount of calcium oxide coating can regulate the size and morphology of the powder; excessive coating can hinder the subsequent calcium reduction and nitriding processes. By using 40 wt% Ca(NO3)2 to coat the composite oxide obtained via ultrasonic spray pyrolysis and by adjusting the reduction diffusion time, further particle refinement can be achieved, ultimately resulting in a nearly spherical strontium iron nitride magnetic powder with a D50 of 0.52 μm. The coercivity of this magnetic powder reaches 9.13 kOe, and the maximum energy product is 27.83 MGOe. This study provides new methods and avenues to address the issues of magnetic powder sintering growth and improve magnetic performance. It also lays the foundation for the further enhancement of the performance of Sm2Fe17N3 magnets.

Published in Journal of Materials Research and Technology

ISSN: 2238-7854 (Print); 2214-0697 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Mining engineering. Metallurgy
Website: https://www.journals.elsevier.com/journal-of-materials-research-and-technology/

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