RARE-EARTH CONSTANT MAGNET Russian patent published in 2009 - IPC H01F1/53 

FIELD: metallurgy.

SUBSTANCE: invention relates to powder metallurgy, particularly, to receiving of sintered rare-earth constant magnets on the basis of R-Fe-B. Sintered rare-earth constant magnet of cimpound R¹ _aR² _bT_cA_aF_eO_fM_g, where R¹ - at least one component, selected from rare-earth elements, including Sc and Y, excluding Tb and Dy, R² Tb and/or Dy, T -iron and/or cobalt, A - boron and/or carbon, F - fluorine, O - oxygen, M - at least one elements, selected from Al, Cu, Zn, In, Si, P, S, Ti, V, Cr, Mn, Ni, Ga, Ge, Zr, Nb, Mo, Pd, Ag, Cd, Sn, Sb, Hf, Ta and W. Indexes a-g indicate atomic percentage of corresponding elements in alloy and allows values: 10 ≤ a+b ≤ 15, 3 ≤ d ≤ 15, 0.01 ≤ e ≤ 4, 0.04 ≤ f ≤ 4, 0.01 ≤ g ≤ 11, c - the rest. In body of magnet F and R² are distributed so that its concentration at the average increases from center up to surface. Grain boundaries allows concentration R²/(R¹+R²) more higher, then concentration R²/(R¹⁺R²) in grains of primary phase (R¹,R²)₂T₁₄A tetragonal system, and form structure of space network, which is continuous from surface of magnet up to width at least less than 10 mcm.

EFFECT: sintered magnet allows high coercive force and low magnetization.

6 cl, 2 dwg, 3 tbl, 9 ex