| 摘要 |
PURPOSE:To manufacture a permanent magnet material having superior magnetic characteristics at a low cost by blending the oxide of a rare earth element with iron powder and pure boron powder, ferroboron powder or boron oxide so as to obtain a specified composition and by subjecting the mixture to reduction with Ca and diffusion under specified conditions and to specified processing and treatment. CONSTITUTION:The oxide of at least one kind of rare earth element is blended with iron powder and at least one among pure boron powder, ferroboron powder, boron oxide and boride so as to obtain a composition consisting essentially of, by atom, 12-20% R (R is at least one among Nd, Pr, Dy, Ho and Tb combined optionally with at least one among la, Ce, Sm, Gd, Er, Eu, Tm, Yb and Y), 4-20% B, 0.05-3.0% boride and 65-81% Fe. The powdery mixture is subjected to reduction with Ca and diffusion by heat to 900-1,200 deg.C in an inert gaseous atmosphere and the resulting reaction product is put in water and slurrified. This slurry is treated with water and the treated starting material is pulverized, pressed, sintered and aged to obtain an Fe-B-R type permanent magnet material having a tetragonal phase as the principal phase. |
