Magnetic alignment improvement of Nd–Fe–B sintered magnets by a new axial pulse pressing method

A new axial pressing method using a pulsed magnetizing field was studied to improve the remanence of Nd-Fe-B sintered magnets. In the pulsed axial die pressing (PADP) process the tapping density of powders and green density of compacts were optimized to increase magnetic alignment and remanence. As a result, it was found that axial pressing under a pulsed magnetizing field was very effective in increasing the degree of magnetic alignment of powders, yielding remanences even higher than those obtained by transverse die pressing. A remanence and energy product of 14.3 kG and 51 MGOe were easily obtained by the PADP process from a 30.6R-68.4TM- 1B (in wt%) sintered magnet.