Sintered neodymium-iron-boron magnet with low boundary phase potential difference and preparation method of sintered neodymium-iron-boron magnet

The invention relates to the technical field of rare earth permanent magnets, in particular to a sintered neodymium-iron-boron magnet with a low boundary phase potential difference and a preparation method of the sintered neodymium-iron-boron magnet. The sintered neodymium-iron-boron magnet with the low boundary phase potential difference is prepared from the following raw materials in percentage by weight: 28%-33% of Nd, 1.1%-1.2% of B, 62%-67% of Fe, 0.6%-0.8% of Gd, 0.6%-0.8% of Dy, 0.1%-0.15% of Co, 0.05%-0.1% of Cu, 0.03%-0.06% of Ga and the balance of unremovable impurities. The preparation method of the sintered neodymium-iron-boron magnet with the low boundary phase potential difference comprises the steps of (1) raw material preparation and pretreatment, (2) smelting, (3) hydrogen explosion powder preparation, (4) molding orientation, (5) sintering, (6) zinc plating and (7) film plating. The sintered neodymium-iron-boron magnet with the low boundary phase potential difference and the preparation meth