The technology and mechanism of coercivity promotion of Ce-rich dual-main-phase sintered magnets

The diffusion treatment of suspension liquid of Dy, Tb and TbF3 coated onto Ce-rich dual-main-phase Nd-Fe-B/(Nd, Ce)-Fe-B sintered magnets was carried out. The magnetic properties, microstructure and temperature characteristics of three kinds of diffusion magnets were studied. The optimum diffusion temperature of Dy, Tb and TbF3 was obtained by adjusting the heat treatment process. The most significant aspect of improving magnetic properties is that the coercivity achieves the optimal effect with the remanence lossless slightly. Amount of increase of Hcj after diffusion is: Tb > Dy > TbF3; Proposing the diffusion process mainly consists of three aspects firstly, and respective diffusion coefficients.