Short-Range Order and Micromechanisms Controlling Nanocrystallization of Iron-Cobalt Based Metallic Glasses

Abstract

Transition from amorphous to nanocrystalline state has been investigated from the viewpoint of rate theory in Fe–Co–Zr–B metallic glass by evaluation of changes of electrical resistivity using a novel method of continuous distribution analysis and by transmission electron microscopy and X-ray diffraction. Ordering process inside α-FeCo nanograins has been observed. The mechanism controlling nanocrystallization is the same throughout the entire reaction. Before the nanocrystallization is over, a new microprocess becomes active. The units active in initial and final stages of transformation may differ in local chemical ordering. The results allow to infer on the character of the original amorphous structure for which we propose two types of internally correlated and chemically ordered regions with different Zr content.