Process for producing, through strip casting, raw alloy for nanocomposite type permanent magnet

摘要

To make a raw alloy, consisting mostly of amorphous structure, highly productively and at a reduced cost for a nanocomposite magnet, a molten alloy represented by Fe_100-x-y-zR_xQ_yM_z (where R is at least one element selected from Pr, Nd, Dy and Tb; Q is B and/or C; M is at least one element selected from Co, Al, Si, Ti, V, Cr, Mn, Ni, Cu, Ga, Zr, Nb, Mo, Ag, Pt, Au and Pb; and 1 at %≦x6 at %, 15 at %≦y≦30 at % and 0 at %≦z≦7 at %) is prepared. This molten alloy is rapidly cooled by a strip casting process in which the alloy is fed onto a chill roller, rotating at a peripheral velocity of 3 m/s to less than 20 m/s, at a feeding rate per unit contact width of 0.2 kg/min/cm to 5.2 kg/min/cm. In this manner, an alloy including at least 60 volume percent of amorphous phase can be obtained.