The invention discloses a low-
boron high-
coercivity neodymium-iron-
boron permanent
magnet and a preparation method thereof, and belongs to the technical field of permanent magnets, the preparation method of the permanent
magnet comprises the following steps: taking Pr, Fe, Cu and Ga as raw materials,
smelting the raw materials through a vacuum melt-
spinning furnace to obtain a Pr65Cu25 melt-
spinning sheet and a Pr65Fe30Ga5 melt-
spinning sheet,
grinding the melt-spinning sheet through a three-head grinder to obtain Pr65Cu25
alloy powder and Pr65Fe30Ga5
alloy powder, and
sintering the Pr65Cu25
alloy powder and the Pr65Fe30Ga5 alloy powder to obtain the low-
boron high-
coercivity neodymium-iron-boron permanent
magnet. Under the protection of
argon or
nitrogen, mixing the two to obtain additive phase powder; the low-boron
neodymium-iron-boron magnet raw materials are adopted to prepare the main phase alloy powder, and the Pr, Fe, A < l >, Cu and Ga raw materials are adopted to prepare the additive phase powder, the additive phase powder is added into the main phase alloy powder, a lubricating agent is added, and mixing,
grinding,
compression molding, isostatic pressing treatment,
sintering and
tempering treatment are conducted to obtain the low-boron neodymium-iron-boron magnet. And the obtained
neodymium iron boron permanent magnet has relatively high coercive force and magnetic performance.