High-coercivity hot-deformed Nd–Fe–B permanent magnets processed by Nd–Cu eutectic diffusion under expansion constraint
Scripta Materialia 81 (2014) 48–51
Scripta Materialia 81 (2014) 48–51
T. Akiya ( NIMS )
J. Liu, K. Hono ( NIMS, Tsukuba Univ. )
H. Sepehri-Amin, T. Ohkubo ( NIMS )
K. Hioki, A. Hattori ( Daido Steel Co. Ltd )
Abstract
The application of expansion constraint during the grain-boundary diffusion process using Nd70Cu30 eutectic alloy minimizes the remanence loss for the coercivity enhancement by optimizing the volume fraction of the Nd(Cu)-rich non-ferromagnetic intergranular layer.
The diffusion-processed sample exhibits l0Hc 2 T, l0Mr = 1.36 T and (BH)max = 358 kJ m3 at room temperature.
Because of the low-temperature coefficient of coercivity, the magnet showed (BH)max 191 kJ m3 at 200 C, which is superior to that of Dy-containing high-coercivity sintered magnets.
Available online
7 March 2014
Acknowledgement
This work was supported by Japan Science and Technology Agency, CREST.
