Twin-Roll Strip Casting of Iron-Base Amorphous Alloys

Abstract

In this study, three Fe-base amorphous alloys with quite different critical cooling rates were subjected to twin-roll strip casting to see the possibility of fabricating amorphous sheet by the same process. Continuous cooling transformation (CCT) diagrams of the alloys were calculated using the heterogeneous nucleation theory coupled with thermal data obtained during cooling to evaluate their critical cooling rates and glass forming abilities (GFAs). It shows that the GFAs calculated by CCT diagram are in agreement with the experimental results, while the well known empirical thermal parameters do not agree with the experimental results. Optimum twin-roll strip casting conditions have been determined based on the calculated critical cooling rates and the simulated thermal behavior of the sheet during twin-roll strip casting.