(1. School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China 2. CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China)
Abstract:Anisotropic Nd-Fe-B magnets were prepared by hot deformation process. Nano-particles with high melting point, such as WC, BN and ZrO2 were mixed with the Nd-Fe-B melt-spun ribbons before hot pressing process. The effects of different additions on the magnetic properties and microstructures of the hot-deformed magnets were investigated. The results show that the variation in the remanence is not obvious after adding micro additions. Oxide?nano-particles significantly decrease the coercivity of the hot-deformed magnets, while coercivity of the magnets with carbide addition is enhanced. The optimum magnetic properties are obtained at hot-deformed magnet with WC addition. The remanence thermal stability of the magnet is improved, while the coercivity temperature coefficient is hardly affected after adding WC particles. The reversible magnetization of the magnet shows no obvious peak value after adding WC nanoparticles, indicating that the addition of WC nanoparticles inhibits the growth of coarse crystal regions in the hot-deformed magnet and makes the microstructure of the magnet more uniform. At the same time, a new Fe2W phase forms at the WC-aggregated region.
郑晓芬,陈仁杰,雷 芳,李 东,闫阿儒. 高熔点纳米颗粒添加对热变形Nd-Fe-B磁体性能与微观结构的影响[J]. , 2018, 28(06): 42-46.
ZHENG Xiao-fen,,CHEN Ren-jie,LEI Fang,LI Dong,YAN A-ru. Impact of nano-particles with high-melting point on magnetic properties and microstructures of hot-deformed Nd-Fe-B magnet. , 2018, 28(06): 42-46.
参考文献:[1] Brown D, Ma Baomin, Chen Zhongmin. Developments in the processing and properties of NdFeb-type permanent magnets [J]. Journal of Magnetism and Magnetic Materials, 2002, 248(3): 432.[2] Tang Xin, Chen Renjie, Yin Wenzong, Wang Jinzhi, Tang Xu, Lee Don, Yan Aru. Enhanced texture in die-upset nanocomposite magnets by Nd-Cu grain boundary diffusion [J]. Applied Physics Letter, 2013, 102(7): 072409.[3] Tang Xin, Chen Renjie, Yin Wenzong, Wang Jinzhi, Tang Xu, Lee Don, Yan Aru. Mechanism of texture enhancement in nanocomposite magnets during process of die upsetting coupled with Nd-Cu grain boundary diffusion [J]. J. Alloy. Compd., 2015, 623: 386.[4] Lai Bin, Li Yanfeng, Wang Huijie, Li Anhua, Zhu Minggang, Li Wei. Quasi-periodic layer structure of die-upset NdFeB magnets [J]. J. Rare Earths, 2013, 31(7): 679.[5] 剧锦云. 稀土对热变形钕铁硼磁体性能及矫顽力机制的影响研究[D].山西:中北大学, 2015.[6] Volkov V V, Zhu Y. Magnetic structure and microstructure of die-upset hard magnets RE13.75Fe80.25B6 (RE = Nd, Pr): A possible origin of high coercivity [J]. J. Appl. Phys., 1999, 85: 3254.[7] Liu Z W, Huang H Y, Gao X X, Yu H Y, Zhong X C, Zhu J, Zeng D C. Microstructure and property evolution of isotropic and anisotropic NdFeB magnets fabricated from nanocrystalline ribbons by spark plasma sintering and hot deformation [J]. J. Phys. D-Appl. Phys., 2011.44(2): 025003.[8] Lee R W, Brewer E G, Schaffel N A. PROCESSING OF NEODYMIUM-IRON-BORON MELT-SPUN RIBBONS TO FULLY DENSE MAGNETS[J]. IEEE Trans. Magn., 1985,21(5): 1958.[9] Ju Jinyun, Tang Xu, Chen Renjie, Yan Aru, Jin Chaoxiang, Yin Wenzong, Wang Zexuan, Lee Don, Zhang Zhimin. The study of magnetic properties, coercivity mechanism and bending strength of hot-deformed RE-Fe-B magnets[J]. J. Magn. Magn. Mater., 2015,386: 31.[10] Mishra R K, Brewer E G, Lee R W. GRAIN-GROWTH AND ALIGNMENT IN HOT DEFORMED ND-FE-B MAGNETS[J]. J. Appl. Phys., 1988,63: 3528.[11] Li L, Graham C D. THE ORIGIN OF CRYSTALLOGRAPHIC TEXTURE PRODUCED DURING HOT DEFORMATION IN RAPIDLY-QUENCHED NDFEB PERMANENT-MAGNETS[J]. IEEE Trans. Magn., 1992,28(5): 2130.[12] McGuiness P J, Drazic G, Kobe S, Brown D N, Ma B M. Magnetic properties and micro structures of Nd-Dy-Fe-Co-B-Ga hot-deformed magnets, IEEE Trans. Magn., 2004, 40(4): 2892.[13] Li Ying, Kim Y B, Yoon T S, Suhr D S, Kim T K, Kim C O. Coercivity enhancement by Zn addition in hot deformed NdFeB magnets [J]. J. Magn. Magn. Mater., 2002, 242: 1369.[14] Ma Yilong, Chen Dengming, Zhou Anruo, Sun J C, Cao P J. Enhanced alignment and magnetic properties of die-upset nano-crystal Nd2Fe14B magnets with Nb addition [J]. Physica B, 2012, 407(23): 4562.[15] Wu Y Q, Ping D H, Xiong X Y, K. Hono. Magnetic properties and microstructures of alpha-Fe/Nd2Fe14B nanocomposite microalloyed with Zr [J]. J. Appl. Phys., 2002, 91(10): 8174.[16] 周寿增, 董清飞. 超强永磁体一稀土铁系永磁材料. 北京:冶金工业出版社[M],2013:53-55.[17] Zheng Xiaofen, Li Ming, Chen Renjie,Lei Fang, Jin Chaoxiang, Wang Zexuan, Ju Jinyun, Yin Wenzong, Lee Don, Yan Aru. Coercivity enhancement by inhibiting the formation of coarse grains region in hot-deformed Nd-Fe-B magnets with WC nano-particles addition [J]. Scr. Mater., 2017,132: 49.[18] Kneller E.F., Hawig R. THE EXCHANGE-SPRING MAGNET - A NEW MATERIAL PRINCIPLE FOR PERMANENT-MAGNETS[J]. IEEE Trans. Magn., 1991, 27(4): 3588-3600.[19] Feutrill E.H., McCormick P.G., Street R. Magnetization behaviour in exchange-coupled Sm2Fe14Ga3C2/alpha-Fe[J]. J. Phys. D-Appl. Phys., 1996, 29(9): 2320-2326.[20] Chen Renjiie, Guo Shuai, Wang Jinzhi, Lee Don, Yan Aru. Magnetic properties and magnetization behaviors of melt-spun PrCo6.6Ti0.4Bx (x=0-0.35) ribbons[J]. J. Appl. Phys., 2011, 109(7): 07A747.[21] Wang Jinzhi, Chen Renjie, Rong Chuanbing, Liu Zhuang, Zhang Hongwei, Shen Baogen, Yan Aru. The magnetization behavior and magnetic viscosity of Sm (Co, Fe, Cu, Zr)Z ribbons with different temperature dependence of coercivity[J]. J. Appl. Phys., 2010, 107(9): 09A707.