A comparative study of NdY-Fe-B magnet and NdCe-Fe-B magnet

Low cost and high abundance rare earth elements Y and Ce have attracted tremendous interests of the industrial and scientific societies for fabricating the highly cost-performance efficient rare earth permanent magnets. However, the effect of separate replacement of Nd by Y or Ce on the performances of NdFeB-type magnet under the same atomic ratio and preparation conditions is still unclear. In this work, we systematically investigated the magnetic properties, thermal stabilities and service performances of (Nd0.8Y0.2)(13.80) FebalAl0.24Cu0.1B6.04 (atomic fraction, denoted as 20Y) and (Nd0.8Ce0.2)(13.80)FebalAl0.24Cu0.1B6.04 (atomic fraction, denoted as 20Ce) magnets. The results demonstrate that the mu M-0(r), mu H-0(c) and (BH)(max) of 20Y magnet are respectively 1.325 T, 1.173 T and 343.467 kJ/m(3), which are comprehensively higher than those of 20Ce magnet ( mu M-0(r) = 1.310 T, mu H-0(c) = 0.948 T, (BH)(max) = 321.105 kJ/m(3)). Moreover, the 20Y magnet has higher thermal stability compared with 20Cemagnet which is favorable for the magnetic performances at elevated temperatures. The investigation of microstructure and elemental distribution indicates that the excellent magnetic performances of NdY-Fe-B magnet can be attributed not only to the preferable intrinsic properties 4 pi M-s, H-a and T-c of Y2Fe14B, but also to the in-situ coreeshell structure of the 2:14:1 matrix phase grainwith Y-rich core and Nd-rich shell, along with the thicker grain boundary layer between the adjacent matrix phase grains in NdY-Fe-B magnet. Furthermore, the 20Y magnet exhibits better mechanical property and higher corrosion resistance than 20Ce magnet, which are helpful for prolonging the service life of the magnet in practical application. (c) 2021 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.

Automated summary

This study systematically investigated the effect of substituting Nd with Y or Ce on the properties of NdFeB-type magnets. The results showed that the replacement with Y significantly improved the magnetic properties, thermal stability, and corrosion resistance of the magnets, leading to a longer service life.