A
samarium and
cobalt sintered permanent
magnet material comprises, in weight percent, 25-27%wt of
samarium, 49-51%wt of
cobalt, 5-6.5%wt of
copper, 3-3.5%wt of
zirconium and 15-18%wt of iron. A preparation method includes the steps:
smelting;
casting an
ingot; absorbing
hydrogen for the cast
ingot; making
powder; performing orientation forming and
sintering. In the
smelting process, the thickness of a
casting mould cavity is decreased, cooling water is filled into the wall of the mould cavity, cooling of the cast
ingot is accelerated,
element composition segregation is decreased, the production process is stabilized, a
dendrite crystal is restrained by adding a
zirconium element,
hydrogen absorbing is performed for the cast ingot in the
smelting process, production steps are saved, and
energy consumption is reduced. In the subsequent milling process, the cast ingot absorbed
hydrogen is crystallized into particles, the particles fracture along
crystal boundaries in the milling process of
airflow, the integrality of
crystal particles is ensured, the
anisotropy of the crystal particles is improved,
magnetic powder particles are obtained,
particle size distribution is concentrated with the range of 3.5-4.5 micrometers, the
sintering temperature needed by the
magnetic powder particle of each point of a blank is the same in the later
sintering process, the sizes of the sintered crystal particles are the same and uniform, and the performances, particularly, such as residual
magnetism Br, maximum
magnetic energy product (BH) max and
critical magnetic field Hk of a sintered permanent
magnet are improved.