NANOCRYSTALLIZATION BEHAVIOR OF FESIBCU(NBX) ALLOYS

The crystallization of amorphous Fe73.5Si13.5B9Cu1Nb1X2 (X = Zr, Nb, M o, V) was investigated by combined use of differential scanning calori metry, X-ray diffraction and electron microscopy techniques. The addit ion of refractory elements raises thermal stability of the amorphous a lloys in the order V < Mo < Nb < Zr. The nanocrystallization reaction exhibits a low rate kinetic, as denotes the value close to I of the Av rami index. The volume fraction of the nanophase for the same annealin g conditions decreases in the order V > Mo > Nb > Zr but a maximum val ue of about 65% is found for all cases. Refractory element alloying co ntrols the mean grain size of the Fe,Si nanocrystals, growing up to a value in the range 10-18 nm for the alloys in the sequence V > Mo > Nb > Zr. (C) 1997 Elsevier Science S.A.