Anomalous grain growth in nanocrystalline Fe73.5Cu1Nb3Si13.5B9 alloys

The grain growth of the FeSi phase during the crystallization process of the amorphous Fe73.5Cu1Nb3Si13.5B9 alloy was studied using transmission electron microscopy and x-ray diffractometry. An anomalous grain growth behavior of the FeSi phase in the samples annealed in temperature range from 743 to 823 K for one hour was observed, i.e. the grain size of the FeSi phase slightly decreases. when the annealing temperature increases from 743 K to 823 K. The mechanism of the anomalous grain growth may be due to the different nucleation and volume diffusion rates in the samples annealed at low and high temperatures. (C) 1997 Acta Metallurgica Inc.