A new criterion for evaluating the glass-forming ability of bulk glass forming alloys

Based on the classical theory of nucleation and growth, we propose a dimensionless criterion, β, expressed by TxTg/(Tl − Tx)2, with Tg, the glass transition temperature, Tx, the onset of crystallization temperature and Tl, the liquidus temperature for evaluating the glass-forming ability (GFA) of bulk metallic glasses (BMGs). A survey of the readily available experimental data associated with the thermal analysis of various BMGs show that the new criterion, β, is statistically better than other currently used criteria, such as γ (=Tx/(Tl + Tg)) and Trg (=Tg/Tl), and also better than newly proposed criteria, such as δ (=Tx/(Tl − Tg)) and φ (=Trg((Tx − Tg)/Tg)0.143) in reflecting the GFA. It is also demonstrated that the β criterion can be used as a guideline for exploring new bulk metallic glass formers in a wide range of BMGs.