钕铁硼永磁合金的晶粒相互作用和矫顽力

钕铁硼永磁合金的矫顽力由单个晶粒的矫顽力和晶粒之间的相互作用决定。晶粒的矫顽力及其相互作用与晶粒取向有关。按照不同的矫顽力机制，晶粒的矫顽力及其角度关系有不同的表达式。晶粒相互作用可分为长程静磁相互作用和近邻晶粒的交换耦合相互作用。烧结磁体的交换作用影响很小，静磁相互作用影响较大，使晶粒混乱取向磁体的矫矫顽力大于晶粒理想取向磁体的矫顽力。综合考虑单个晶粒的矫顽力和不同取向晶粒之间的相互作用的影响。

INTERACTIONS BETWEEN THE GRAINS AND COERCIVITY FOR NdFeB PERMANENT ALLOYS

The coercivity of NdFeB permanent alloys is determined by the coercivity of individual grains and the interactions between the grains. The coercivity of individual grains and the intergrain interaction are related to the grain alignment. There are different expressions on the coercivity and its angular dependence according to the difFerent coercivity mechanisms. The intergrain interactions can be classified as the long-range magnetostatic interaction and the exchange-coupling interaction of neighboring grains. For sintered magnet. the long-range magnetostatic interaction is stronger than the exchange-coupling interaction and it makes the coercivity of the misaligned magnet larger than that of the ideally aligned magnet. Taking account of the effects of coercivity of individual grains and the intergrain interactions, the starting field theory is in good agreement with the experimental result for the coercivity of sintered NdFeB magnets.