| 摘要 |
PURPOSE:To enhance the corrosion resistance by providing a protective layer, containing a corrosion resistant phase principally comprising a specified element, on the surface of an R-T-B based sintered green magnet. CONSTITUTION:A green magnet containing R (at least one kind of rare earth element including Y), T (Fe, or Fe and Co), and B and having main phase of substantially tetragonal system is provided, on the surface thereof, with a protective layer containing a corrosion resistant phase principally comprising T and M (at least one element selected from group IV, Va and VIa elements) or R, T and M. M is at least one element selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and E wherein M/(R+T+M) is in the range of 0.1-10wt.% and R/(R+T+M) is 10wt.% or less in the corrosion resistant phase. This method produces an R-T-B based sintered magnet excellent in corrosion resistance and magnetic characteristics at low cost. |
