On the effect of the number of components on glass-forming ability of alloys from the liquid state: Application to the new generation of multicomponent bulk glasses

The aim of this work is to demonstrate that an increase of the number of components in a liquid glass forming alloy may contribute to inhibit intermetallic nucleation thus enhancing glass-forming ability. The approach is based on an analysis of the distribution of concentration fluctuations in undercooled multicomponent liquid alloys. It is demonstrated that fluctuations in the undercooled liquid can help intermetallic nucleation in a certain range of temperature and concentration. Addition of one component lowers the probability of creating a nucleant fluctuation by a factor of ten. Furthermore such a stochastic approach shows that, provided the wettability of the embryo on heterophase nucleants remains moderate, heterogeneous nucleation can even be suppressed in the highly undercooled domain of the multicomponent liquid. The possibility of obtaining multicomponent bulk metallic glasses with low cooling rates from high purity liquid alloys, which however contain a significant amount of heterophase nucleants, can be explained by the proposed approach.