Nd-Fe-B系焼結磁石の強磁場熱処理と保磁力

摘要: Results of a systematic study concerned with the high-magnetic-field effects on coercivity in processing various series sintered Nd-Fe-B magnets are given. Coercivity enhancement phenomenon was observed several Cu additive after annealing under magnetic fields 10~14 T. A strong correlation suggested between field temperature at which maximum increase and anomaly differential scanning calorimetry experiments. We found linear relation room Hc sample annealed Ta=500℃ Ha for samples different Dy contents, can be expressed as Hc=Hc(0)+ α Ha, Hc(0) being value zero-field-annealed α, factor. Although very small, has positive finite 0 mass% 2 Dy. Significant confirmed content larger than 6 mass%. This suggests higher anisotropy paramagnetic susceptibility Nd-rich intergranular phase containing Also introduced is preliminary results grain boundary diffusion process sinterd surface layer gradient produced by 18 T superconducting magnets.