INVESTIGATION OF THE CRYSTALLIZATION PROCESS OF NANOCRYSTALLINE FE-SI-B ALLOYS BY SAXS

The evolution of the size distribution during the crystallization proc ess of amorphous Fe(77.5-x)Si(15.5)B(7)M(x) alloys was investigated by SAXS. Partial substitutions of the minor elements M = Nb, W, and Cu c hange tremendously the crystallization process. In alloys containing b oth M = Cu and Nb or W nanoscaled Fe3Si precipitates with radii of typ ically 5 nm are formed. In alloys containing only Cu or Nb the crystal lites have radii larger than 30 nm. In alloys containing Cu a third ty pe of precipitate Ess formed beside Fe3Si and Fe-boride phases, with g rain radii of about 1 nm, which were found to be Independent of the an nealing temperature.