Oxide evolution in NdDy-Fe-B magnet during aging process

• 作 者: 王景代 冯海波 李安华 李岩峰 朱明刚 李卫
• 机 构: Division of Functional Materials, Central Iron and Steel Research Institute,
• 出 处: Journal of Rare Earths
• 发表日期: 2012年10期
• 关键词: magnet coercivity helpful dissolved sintered substituted aligned metallurgy rema

Sintered NdDy-Fe-B magnets were made from strip cast flakes by powder metallurgy method. For the magnet with 6wt.% Dy substituted Nd, a remarkable coercivity increase of 70% was obtained after aging at 900°C for 2h and a high coercivity of 23.5 kOe was achieved after aging at 520°C for 2h. The average diameter of the oxide particles decreased during the following 900°C aging treatment. Dy and O diffusion from oxide particles to Nd-rich phase during the aging process was observed. The oxide evolution and Dy element diffusion were helpful to the coercivity enhancement.

For the magnet with 6 wt.% Dy substituted Nd, a remarkable coercivity increase of 70% was obtained after aging at 900 ° C for 2h and a high coercivity of 23.5 kOe was achieved after aging at 520 ° C for 2h. The average diameter of the oxide particles decreased during the following 900 ° C aging treatment. Dy and O diffusion from oxide particles to Nd-rich phase during the aging process was observed. The oxide evolution and Dy element diffusion were helpful to the coercivity enhancement.