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

Abstract

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.

Description

technical field [0001] The invention belongs to the field of rare earth permanent magnet materials, and in particular relates to a preparation method of a large-size NdFeB diffusion magnet, and also relates to a large-size NdFeB diffusion magnet obtained by diffusing the preparation method. Background technique [0002] Sintered NdFeB magnets are the strongest magnetic materials so far, and are widely used in aerospace, automotive industry, electronic appliances, medical equipment, energy-saving motors, new energy, wind power and other fields. They are currently the fastest growing and most promising market Good permanent magnet material. Sintered NdFeB magnets have outstanding advantages such as high magnetic energy product, high coercive force, high energy density, high cost performance and good mechanical properties, and have played an important role in the high-tech field. After more than 30 years of research and development, with reasonable alloy composition and mature...

AI Technical Summary

Problems solved by technology

[0011] This technology effectively overcomes the problems existing in the previous diffusion technology, but there are still deficiencies, mainly including: ①Comparison of the thickness of rare earth alloy thin strips prepared by stripping method thicker (between 30 and 100 μm), since rare earth alloy thin strips are non-magnetic substances, thicker alloy thin strips will reduce the overall magnetic properties of the magnet; ② in thicker rare earth alloy thin strips, in order to ensure the final magnet The coercive force requires a certain percentage of rare earths. In order to ensure the percentage of rare earths, more rare earth elements need to be added. Otherwise, the percentage of rare earth elements is too low, and the improvement of the coercive force of the final magnet is very limited; ③The alloy used is M-Cu alloy, and M is Pr, Nd or Dy. After alloying, the chemical activity of rare earth elements decreases, the diffusion power is insufficient, and the diffusion effect is limited

Images