3种相分布模型中纳米复合永磁体矫顽力与晶粒尺寸的关系

GRAIN SIZE DEPENDENCE OF COERCIVITY OF NANOCOMPOSITE PERMANENT MAGNETS IN THREE PHASE-DISTRIBUTION MODELS

建立了3种物理模型,研究了纳米复合永磁材料中晶粒尺寸、两相分布及体积分数与矫顽力间的变化关系.计算结果表明:不同的两相分布导致晶粒接触界面分数变化,从而引起晶间交换耦合作用的涨落;相分布影响纳米复合永磁体矫顽力的大小,但没有改变其随晶粒尺寸变化的关系;设计理想的相分布并且适当控制晶粒尺寸,是实现纳米复合永磁材料高矫顽力的可能途径.

Based on three simple physical models, the dependences of coercivity of nanocomposite permanent magnet on the grain size, phase distribution and volume fraction of phase were analyzed. The obtained results show that the different phase distributions lead to the variation of grain-interface fraction, resulting in random fluctuation of the intergrain exchange-coupling. Phase distribution influences the values of coercivity of nanocomposites, but does not change its variation tendency with changing hard phase grain size. High coercivity can be probably obtained by designing an ideal phase distribution and controlling the grain sizes.