Study on Key Techniques for Producing High Performance NdFeB Sintered Permanent Magnets

摘要

High energy products (BH)_(max) of 365 and 310 kJ·m~(-3) with intrinsic coercivity _iH_c of 1640 kA·m~(-1) of NdFeB sintered magnets were produced. Some new techniques were applied, such as thin NdFeB ingot technique, narrow particle distribution on jet mill, low oxygen content control and high aligned magnetic field press. It is necessary to produce thin NdFeB ingot with fine flake crystal, narrow particle distribution, the average size of NdFeB powders less than 4.0μm, uniform microstructure, high oriented Nd_2Fe_(14)B small grains, and finally high performance NdFeB sintered magnets were prepared.