Improvement of thermal stability in hot-deformed Nd-Fe-B magnets by grain refinement. (15th March 2020)

• Record Type: Journal Article
• Authors: Xia, Xianshuang; Liu, Mei; Zhang, Tieqiao; Wen, Hongyuan; Dong, Qiang; Zhang, Lanting; Zhou, Ligang; Li, Mingqiang
• Is Part Of: Scripta materialia. Number 178(2020)
• Page Start: 129
• Page End: 133
• Publication Date: 2020-03-15
• Subjects: Hot-deformed Nd-Fe-B -- Nd-Fe-Ga-Cu addition -- Thermal stability -- Grain size -- Grain refinement; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2019.11.018
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: The room-temperature coercivity of the hot-deformed magnet increased from 1.21 to 1.86 T and the coercivity at 180 °C increased from 0.33 to 0.70 T by adding 8 wt.% Nd60 Fe15 Ga20 Cu5 alloy powders. The temperature coefficient of coercivity increased from −0.469 to −0.402%/°C and is superior to that of most magnets. The microstructure revealed that the Nd2 Fe14 B grains were isolated by Nd-Ga-Cu-rich intergranular phases. Statistical analysis indicated that the average grain size was reduced by approximately 25%. Both the exchange decoupling between grains and the ultrafine grains were responsible for the improved thermal stability of the magnets without using heavy rare-earth elements. Graphical abstract: Image, graphical abstract