Abstract: A high-coercivity neodymium-cerium-iron-boron permanent magnet has at least one of the following features: the area of grain boundary RE-rich phases in the magnet accounts for 4% or more of the area of a whole field of view; the grain boundary RE-rich phases in the magnet are fine and uniformly distributed; and the mean value of ratios of the area of block-shaped grain boundary RE-rich phases located at intersections of three or more main-phase grains to the total area of all the three or more adjacent main-phase grains in the vicinity is less than or equal to 30%. RE-rich phases in the magnet are continuously distributed along grain boundaries, thereby increasing the depth of diffusion of a diffusion source into the magnet, improve the uniformity of distribution of the diffusion source in the, and thus further improving the magnetic performance of the diffusion magnet.

Abstract: A neodymium-iron-boron magnet as well as a preparation method therefor and the use thereof are provided. The magnet contains main-phase grains having an R2(Fe,M)14B structure, and grain boundary phases. The grain boundary phases has two-grain grain boundaries between every two main-phase grains and triangular grain boundaries consisting of gaps among every three or more main-phase grains. M represents Cu, Ga, and/or Al, and R is at least one rare earth element including Nd. By means of regulating the component proportions of elements Cu, Ga, Al, etc, a distribution rule thereof in a magnet, and the grain sizes of grains, a magnet with high Br and Hcj can be obtained.

Abstract: A method for producing a sintered R-iron (Fe)-boron (B) magnet, the method including: (1) producing a sintered magnet R1-Fe—B-M; (2) washing the sintered magnet using an acid solution and deionized water, successively, and drying the sintered magnet to yield a treated magnet; (3) mixing a heavy rare earth element powder RX, an organic solid powder EP and an organic solvent ET to yield a slurry RXE, coating the slurry RXE on the surface of the treated magnet, and drying the treated magnet to yield a treatment unit; and (4) heating, quenching, and then aging the treatment unit.