Rare earth element diffusion treatment method for Nd-Fe-B-based sintered permanent magnetic material

摘要

PROBLEM TO BE SOLVED: To greatly improve the magnetic property of a magnetic material, maintain the uniformity of the magnetic property, reduce the manufacturing process, improve the utilization efficiency of a material, and reduce the cost. A method for diffusing rare earth elements of a permanent magnetic material is provided. In the method, a viscous liquid in which large particles 2 and small particles 3 are mixed is applied to the surface of an Nd-Fe-B-based sintered permanent magnetic material 8 to form a single viscous liquid film 1. By vibrating the viscous liquid film 1 in the vertical direction, the viscous liquid film 1 is vertically separated into a small particle layer and a large particle layer. The small particles 3 are heavy rare earth alloys or heavy rare earth particles, and the large particles 2 are metal particles or metal alloy particles. By low-temperature drying and curing, the small particles 3 of the small particle layer and the large particles 2 of the large particle layer are made into particles having a coating structure, and are changed into a large particle film layer and a small particle film layer having a layered structure, and are subjected to low-temperature diffusion treatment. The crystal grain boundary of the large particle 2 is opened, and the small particle 3 is invaded into the crystal grain boundary by the high temperature diffusion treatment, and then the aging treatment is performed. [Selection diagram] Fig. 1