Glass Forming Ability, Crystallization, and Viscosity of Rapidly Solidified Amorphous Cо100-xZrx and Cu100-xZrx Alloys

The glass forming ability (GFA) of glassy alloys with Cо-Zr and Cu-Zr as examples is studied, considered, and discussed in relation to their nonisothermal viscous flow and crystallization behavior. The glass forming ability (GFA) and melt fragility number of Angell and its Moynihan interpretation are presented. An FVM interpretation of the melt fragility numbers of Angell and Moynihan is proposed and experimentally proven. It is demonstrated that the exact viscosity measurement of glassy metals allows the determination of FVM parameters describing its temperature dependence. In this way it is possible to calculate the melt fragility number of Angell and to estimate the glass forming ability (GFA) of metallic alloys.