R-t-b-based permanent magnet, and preparation method therefor and use thereof

Abstract

The invention discloses an R-T-B-based permanent magnet, and preparation method therefor and use thereof. The R-T-B-based permanent magnet comprises a nitrogen content of X ppm which satisfies 500≤X≤1300, the R-T-B-based permanent magnet has an average grain size of D μm which satisfies −2.6lnX+20≤D≤−2.3lnX+19.6; the R-T-B-based permanent magnet comprises a main phase grain and a grain boundary phase; the main phase grain comprise R2Fe14B; the grain boundary phases is distributed between main phase grains; and the grain boundary phase comprises a R—N enriched area having a volume fraction of less than 10% in the grain boundary phase. In the R-T-B-based permanent magnet of the present invention, nitrogen elements are uniformly distributed at the grain boundaries, and no NdN agglomerates are formed or the content thereof is extremely low, thereby increasing the coercive force Hcj of the magnet, reducing the magnetic loss at high-temperature, and improving the corrosion resistance.

Dependencies are inferred from the claim text.