The invention discloses a high-obdurability Nd-Fe-B sintered
magnet reconstructed by the
grain boundary phase and the preparation method thereof. The Nd-Fe-B sintered
magnet comprises the component of NdeFe100-e-f-gBfMg, wherein, e is more than or equal to 6 and less than or equal to 24, f is more than or equal to 5.3 and less than or equal to 6.4, and g is more than or equal to 0.01 and less than or equal to 6, and M is one or more elements of Dy, Tb, Pr, Sm, Ce, Yb, Co, Ni, Mn, Nb, Ta, Zr, Si, Ti, Mo, Ag, Au, Mg, Cu, Al, Zn, Ga, Bi, Sn and In; the preparation method comprises the following steps: main phase
alloy and
grain boundary phase
alloy are respectively prepared into
powder, and then the
powder is intensively mixed; the mixed
powder is pressed into the molded blank in the
magnetic field; and the sintered
magnet is obtained in a high-
vacuum sintering oven. Through the restruction of the
grain boundary phase component, the solution grain boundary phase
alloy with low
smelting point and high strength
ductility is achieved, the obdurability of the grain boundary phase is enhanced on the basis that the magnetic property is guaranteed, thereby the high
ductility of the magnet is enhanced, and the process is simple, the cost is low, and the magnet is suitable for the
mass production, thereby the double-alloy method combined with the grain boundary restruction can be used for preparing the Nd-Fe-B sintered magnet with high obdurability.