| 摘要 |
PURPOSE:To enable effective fine grinding and to acquire good oxidation resistance by containing R2Fe14B and specifying average grain diameter, apparent density, orientation degree and magnetic characteristic. CONSTITUTION:A casting piece of fine and uniform structure is manufactured, which is comprised of R (R is at least one kind of rare earth elements including Y) of 12 to 16 atomic %, B of 4 to 8 atomic %, O3 of 5000ppm or less and a remaining part of Fe (Fe is partially displaced with one or two kinds of Ni) and inevitable impurities and contains a main phase of R2Fe14B of 90% or more. After the casting piece is hydrogen occluded, fine powder 7 which is obtained by finely grinding alloy powder stabilized by de-H2 treatment is orientated by a pulse coil 6 to realize average grain diameter of 10mum or less, apparent density of 7.45g/cm<3> or more and orientation degree of 85% or more. Thereafter, it is molded and sintered to acquire a total of (BH)max value and iHc value of 59 or more and angularity {(Br<2>/4)/(BH)max} of 1.01 to 1.045. |
