Patent ID: 6494968
Filing Date: 2002-12-17
Classification: B22F,B82Y,C22C,H01F

Abstract:
Lamellar rare earth-iron-boron-based magnet alloy particles having a composition represented by the formula:RxFe(100âˆ’xâˆ’yâˆ’zâˆ’w)CoyMzBw wherein R is at least one rare earth element selected from the group consisting of Nd, Pr, Dy, Tb and Ce, M is at least one element selected from the group consisting of Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W, Mn, Cu, Ga, Ag and Si, x is 5 to 9, y is 1.0 to 9.0, z is 0.1 to 5, w is 2 to 7, (x+w) is not less than 9, and (y+z) is more than 5,said particles having an intrinsic coercive force (iHc) of not less than 3.5 kOe, a residual magnetic flux density (Br) of not less than 9.5 kG, and a maximum energy product ((BH)max) of not less than 13 MGOe, and having an average major axial diameter of 60 to 500 &mgr;m, an average minor axial diameter of 50 to 460 &mgr;m, an average axis ratio (major axial diameter/minor axial diameter) of 1.1 to 10 and an average aspect ratio (major axial diameter/thickness) of 3 to 100.