Large-size neodymium iron boron diffusion magnet and preparation method thereof

The invention discloses a large-size neodymium iron boron diffusion magnet and a preparation method thereof. The preparation method comprises: firstly, forming a heavy rare earth metal layer on the surface of metal foil, and obtaining modified metal foil; then combining N pieces of neodymium-iron-boron magnets to be diffused and sintered with N-1 pieces of modified metal foils to obtain a combined body; and finally, carrying out heat treatment on the combined body to obtain the large-size neodymium iron boron diffusion magnet. The preparation method is simple in process, high in flexibility and low in energy consumption, and diffusion and bonding processes are simultaneously realized in a one-time heat treatment process. The thickness of the metal foil is small, the heavy rare earth participates in diffusion in the form of a metal simple substance, the diffusion effect is better, the performance of the diffused and bonded magnet is higher, and the application prospect is achieved. 本发明公开了一种大尺寸钕铁硼扩散磁体及其制备方法，该制备