Effects of Nd-rich phase on the improved properties and recoil loops for hot deformed Nd-Fe-B magnets. (15th August 2016)

• Record Type: Journal Article
• Authors: Hou, Y.H.; Wang, Y.L.; Huang, Y.L.; Wang, Y.; Li, S.; Ma, S.C.; Liu, Z.W.; Zeng, D.C.; Zhao, L.Z.; Zhong, Z.C.
• Is Part Of: Acta materialia. Volume 115(2016)
• Page Start: 385
• Page End: 391
• Publication Date: 2016-08-15
• Subjects: Hot deformed Nd-Fe-B magnet -- Recoil loops -- Nd-rich phase -- Magnetic properties; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2016.06.015
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: Nd-rich phase plays a critical role in wetting grain boundary and facilitating texture formation for hot deformed (HD) Nd-Fe-B magnets. In this study, a non-uniform distribution of Nd-rich phase with dimension up to a few micrometers was observed in nanocrystalline HD magnets. The aggregation of the Nd-rich phase is confirmed to result from the low density precursor prepared by spark plasma sintering (SPS). The large local demagnetizing fields induced by Nd-rich phase aggregation led to the open recoil loops and reduced coercivity. Upon reducing recoil loop openness by eliminating Nd-rich phase aggregation, the coercivity of the HD magnet was significantly improved from 226 kA/m to 995 kA/m, and a high maximum energy product of 293 kJ/m 3 was obtained. The dependences of microstructure and coercivity on the recoil loop characteristics suggest an essential approach for improving the magnetic properties of nanocrystalline HD Nd-Fe-B magnets. Graphical abstract: