Boundary optimization and coercivity enhancement of high (BH)max Nd-Fe-B magnet by diffusing Pr-Tb-Cu-Al alloys. (September 2017)

• Record Type: Journal Article
• Authors: Lu, Kechao; Bao, Xiaoqian; Tang, Minghui; Chen, Guixian; Mu, Xing; Li, Jiheng; Gao, Xuexu
• Is Part Of: Scripta materialia. Number 138(2017)
• Page Start: 83
• Page End: 87
• Publication Date: 2017-09
• Subjects: Permanent magnet -- Grain boundary diffusion -- Tb-rich shells -- Pr-Tb-Cu-Al alloys -- Coercivity; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2017.05.048
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Commercial N50 Nd-Fe-B magnet was processed by grain boundary diffusing Pr-Tb-Cu-Al alloys. The coercivity increased from original 944.9 kA/m to 1640.6 kA/m, 1741.6 kA/m, 1740.2 kA/m and 1775.4 kA/m by diffusing Tb70 Cu30, Pr52.5 Tb17.5 Cu30, Pr60 Tb20 Al20 and Pr60 Tb10 Cu15 Al15 alloys, respectively. Microstructural analysis confirmed Tb-rich shells on the surfaces of Nd2 Fe14 B grains, contributing to coercivity enhancement of diffused sample. Especially, the partial replacement of Tb by Pr in diffusion sources resulted in higher coercivity by consuming fewer Tb elements, only 0.34–0.53 wt% Tb in the sample by Pr-Tb-Cu-Al, much lower than 1.82 wt% Tb in the sample by Tb-Cu. Graphical abstract: