Details

Autor(en) / Beteiligte

• Akiya, Takahiro
• Kato, Hiroaki
• Une, Yasuhiro
• Sagawa, Masato

Titel

Effects of Annealing on the Coercivity in Sintered Nd-Fe-B Magnets

Ist Teil von

• Journal of the Japan Institute of Metals and Materials, 2012, Vol.76(1), pp.36-42

Ort / Verlag

The Japan Institute of Metals and Materials

Erscheinungsjahr

2012

Link zum Volltext

Quelle

EZB-FREE-00999 freely available EZB journals

Beschreibungen/Notizen

• In order to understand the coercivity enhancement mechanism by annealing in sintered Nd-Fe-B magnets, we performed systematic annealing experiments. It was found that an addition of 0.13% of Cu not only enhance the coercivity but also ease the required cooling condition after annealing to obtain high coercivity. Using single successive annealing technique, we observed a 0.3 MA/m jump in coercivity at annealing temperature Ta=640℃ for Cu-free Nd-Fe-B magnets and at Ta=440-460℃ for Cu containing ones. We also observed sharp reduction of 0.15 MA/m in coercivity for Cu doped sintered Nd-Fe-B magnets at Ta=600℃. Furthermore, we confirmed a reversible behavior of coercivity at the annealing temperature range which is lower than the optimal annealing temperature. This implies that some kinds of reversible structural natures depending on the temperature are closely related to the coercivity of sintered Nd-Fe-B magnets.