A new glass-forming ability criterion for bulk metallic glasses Original Research Article

A new indicator of glass-forming ability (GFA) for bulk metallic glasses (BMGs) is proposed based on crystallization processes during cooling and reheating of the supercooled liquid. The interrelationship between this new parameter and the critical cooling rate or critical section thickness is elaborated and discussed in comparison with two other representatives, i.e. reduced glass transition temperature Trg (=Tg/Tl, where Tg and Tl are the glass transition temperature and liquidus temperature, respectively) and supercooled liquid range ΔTxg (=Tx−Tg, where Tx is the onset crystallization temperature and Tg the glass transition temperature). Our results have shown that ΔTxg alone cannot infer relative GFA for BMGs while the new parameter γ, defined as Tx/(Tg+Tl), has a much better interrelationship with GFA than Trg. An approximation of the critical cooling rate and critical section thickness for glass formation in bulk metallic glasses is also formulated and evaluated.