3results about How to "Increased Diffusion Depth" patented technology

The invention provides a preparation method of a high-performance grain boundary diffusion sintered neodymium iron boron material, and belongs to the technical field of permanent magnet materials. The low-melting-point heavy-rare-earth-free alloy coating is coated and cured on the easy-to-diffuse surface of the neodymium-iron-boron base material magnet, and the heavy-rare-earth alloy coating is coated and cured on the low-melting-point heavy-rare-earth-free alloy coating; and the coated magnet is sequentially subjected to low-temperature pre-diffusion heat treatment, grain boundary diffusion heat treatment and aging treatment, and then the grain boundary diffusion neodymium-iron-boron magnet is obtained. According to the invention, the diffusion efficiency of heavy rare earth elements can be effectively improved, the coercive force of the magnet is improved, and relatively high residual magnetism can be achieved.

The present disclosure relates to a sintered Nd-Fe-B magnet and a method for preparing the sintered Nd-Fe-B magnet, the method comprising the following steps: S1, preparing a sintered Nd-Fe-B magnet substrate; S2, attaching a diffusion source containing RE to the surface of the sintered Nd-Fe-B magnet substrate, and then performing grain boundary diffusion treatment and tempering treatment; RE is Dy and / or Tb; wherein the grain boundary diffusion treatment comprises an initial diffusion heat treatment and N stages of diffusion process segments, N≥1, each stage of the diffusion process segment comprises, in sequence, a high-temperature diffusion heat treatment and a low-temperature diffusion heat treatment; the low-temperature diffusion heat treatment has a temperature of 850-950 ℃ and a time of 6-12 h; the high-temperature diffusion heat treatment has a temperature lower than the sintering temperature and 50-200 ℃ higher than the temperature of the low-temperature diffusion heat treatment, and a time of 2-8 h. The method can promote the diffusion of heavy rare earth elements to the central region of the sintered magnet in the grain boundary diffusion process, and further improve the comprehensive magnetic properties of the sintered Nd-Fe-B magnet.

The application discloses a grain boundary diffusion material, a neodymium-iron-boron magnet material and a preparation method and application thereof. The grain boundary diffusion material comprises a sintered body and a diffusion source. The sintered body comprises the following components: R: 29-32 wt.%, R being a rare earth element; M: 0.1-2 wt.%, M comprising one or more of Cu, Ga and Co; B: 0.9-1.0 wt.%; Fe: 65-70 wt.%, wt.% being the percentage of the mass of each component to the total mass of the sintered body. The diffusion source comprises the following components: Tb: 60-85 wt.%; Ga: 10-30 wt.%; Cu: 5-20 wt.%, wt.% being the percentage of the mass of each component to the total mass of the diffusion source. The grain boundary diffusion material can significantly improve the coercivity of the neodymium-iron-boron magnet material, while maintaining high remanence and high-temperature stability of the magnetic performance.