Evaporation Diffusion and Surface Coating

Evaporation Diffusion

The process of evaporating Dy/Tb on the surface of NdFeB magnets is to place heavy rare earth elements or their compounds and the original sample to be processed in an evaporation furnace, and use high temperature heating to evaporate the heavy rare earth elements at high temperature, and under the induction of foreign rare gases Deposited on the original magnet surface and diffused into the magnet along the grain boundaries.

The vapor deposition diffusion method can be used for the sublimation of the Dy vapor deposition source, the deposition on the NdFeB surface and the diffusion process in the magnet at the same time in the state of high temperature heating. It is more sufficient to reduce the use of heavy rare earth elements and reduce the cost, so as to successfully prepare a NdFeB magnet with high coercivity and low rare earth content.

surface coating

The surface coating method means that the rare earth compound is directly coated on the surface of the original magnet sample, and after drying, it is subjected to high temperature heat treatment and diffusion in a rare gas atmosphere. Using this method can significantly improve the coercive force of the magnet, the advantage is that the process is simple and convenient, and the disadvantage is that it is easy to cause uneven coating and insufficient diffusion.