OPTIMUM DESCRIPTION FOR THE GRAIN ALIGNMENT IN PERMANENT MAGNETIC-MATERIALS

Two types of Gaussian function for describing the grain alignment in N dFeB permanent magnetic materials are introduced and compared in this paper. The results show that when the degree of grain alignment is fav orable, the theoretical results based on the ''theta-type'' Gaussian f unction are in agreement with those based on the ''tan theta-type'' Ga ussian function in the variation tendency of the distribution coeffici ents and the distribution curves. When the degree of grain alignment i s not good, the two descriptions have a large difference from each oth er. The theoretical results based on the ''tan theta-type'' Gaussian f unction are in good agreement with the experiments in the grain alignm ent dependence of the coercivity. However, the obtained results based on the ''theta-type'' Gaussian function are not in agreement with the experiments. The ''tan theta-type'' Gaussian function can be used to d escribe the grain alignment of various degrees and is consistent with the common Gaussian function taking x as a variable. So it is an optim um function for describing the grain alignment.