The invention belongs to the technical field of
rare earth permanent
magnet materials, and relates to a high-
corrosion-resistance multi-hard-magnetic-principal-phase Ce permanent
magnet and a preparation method thereof. The permanent
magnet is prepared through a process that
hydrogen absorption and
oxygen control are achieved through
powder and
dehydrogenation is achieved through pre-
sintering. The
rare earth element with the maximum
mass percentage content in the final magnet is Ce. The
chemical formula of the permanent magnet is shown, according to the
mass percentage, as (Ce,Re)aFe100-a-b-cBbTMc. The permanent magnet is prepared from multiple hard magnetic principle phases including (Pr,La,Ce,Nd)-Fe-B, (Nd,Pr)-Fe-B and (Dy,Ho,Gd,Er)-Fe-B which are different in particle size and
magnetocrystalline anisotropy constant k. The chemical formulas of the principle phase are (RL1-x,Cex)a1Fe100-a1-b1-c1Bb1TMc1, (NdyPr1-y)a2Fe100-a2-b2-c2Bb2TMc2 and [RHz, (Nd,Pr)1-z]a3FE100-a3-b3-c3Bb3TMc3 respectively, wherein x is larger than 0.25 and smaller than or equal to 1.0, y is larger than or equal to 1 and smaller than or equal to 1.0, z is larger than 1 and smaller than or equal to 1.0, a is larger than or equal to 27 and smaller than or equal to 31, b is larger than or equal to 0.8 and smaller than or equal to 1.5, c is larger than or equal to 0.5 and smaller than or equal to 2, the value range of a is the same as those of a1, a2 and a3, the value range of b is the same as those of b1, b2 and b3, and the value range of c is the same as those of c1, c2 and c3. Re is selected from
rare earth elements. RL contains light rare earth elements. RH contains heavy rare earth elements. TM is one or more of Ga, Co, Cu, Nb and Al. The permanent magnet has the advantages of being high in
corrosion resistance and small in weight-loss ratio, and the preparation technology is suitable for
engineering large-scale production.