Production of Sintered Nd-Fe-B Magnets with a Maximum Energy Density of 53 MGOe

摘要

New sintered Nd-Fe-B near net-shape magnets with a high remanent polarization of 1.47 T, a coercivity H_cJ of 9.6 kA/cm (12 kOe) and a maximum energy density of 420 kJ/m~3 (53 MGOe) can be manufactured by rubber isostatic presisng. The optimization of the remanent polarization by an improved alignment process of the powder particles results in a decrease of the coercivity by 0.4 kA/cm per 1 percent DELTAfphi for alignment coefficients f_phi in the range 96 to 98 percent. For alignment coefficients between 98 to 99 percent the decrease of the coercivity even increase to about -1 kA/cm per percent 1 DELTAfphi.