The invention belongs to the field of
rare earth permanent magnetic materials, and particularly provides a sintered Nd-Fe-B permanent
magnet material with an intergranular Nd-rich phase replaced and a preparation method thereof. The sintered Nd-Fe-B permanent
magnet material with the intergranular Nd-rich phase replaced is characterized in that the intergranular Nd-rich phase in the sintered Nd-Fe-B material is replaced by a
grain boundary phase not containing Nd, and the
grain boundary phase has the following characteristics that no
magnetism exists, the
melting point is 500-900 DEG C so that
liquid state sintering can be facilitated, the proportion is 2:14:1, and main phase wettability is good. The
grain boundary phase can be made of Al-Cu (the Cu content range is 5-50at%)
alloy. The preparation method includes the steps that Nd-Fe-B main
alloy ingots with the closely even distribution proportion being 2:14:1 are crushed to be manufactured into
powder particles of 3-5 micrometers, Al-Cu
alloy powder with the
volume fraction being smaller than 5% and the average particle size being smaller than 100nm is added and evenly mixed, and through
magnetic field profiling, isostatic pressing and
sintering densification, products are obtained after heat treatment ultimately. The sintered Nd-Fe-B permanent
magnet material with the intergranular Nd-rich phase replaced and the preparation method thereof have the advantages that conventional
metal Al and Cu are used for replacing the
rare earth element Nd, the cost of raw materials can be greatly lowered, and
rare earth resources are saved. The preparation method is simple to operate and suitable for industrial production.