High orientation Nd-Fe-B sintered magnets prepared by wet pressing method.

• The orientation of the magnet is significantly increased by the wet pressing method with special double-layer mold. • The liquid solvents lubricate the powders well and are almost eliminated at the end of the pressing process. • The remanent magnetization of the magnet shows a significant increase with negligible coercivity change. • The density of magnet is greatly increased and approaches the limit one. • The compressive strength of the magnet is greatly improved compared with that of the traditional pressing method. Fine magnetic powder particles are usually utilized to prepare high coercivity Nd-Fe-B magnets. However, it is more difficult to obtain high orientation degree due to the larger friction between finer powder particles during magnetic-aligned compaction process, which greatly affects the performance of final magnets. In this work, a special wet pressing method is adopted to reduce the friction between the powder particles. The degree of alignment of the magnet is obviously increased and the microstructure is optimized. The remanent magnetization of the magnet shows a significant increase with negligible coercivity change, while the compressive strength is improved compared with that of the traditional method. [ABSTRACT FROM AUTHOR]