A new parameter to evaluate the glass-forming ability of bulk metallic glasses

Based on the consideration of the liquid phase stability, the resistance to crystallization and the glass transition enthalpy, a new criterion Q, defined as ((Tg + Tx)/Tl)·(ΔE/ΔH), where the Tg, Tx, Tl, ΔE and ΔH are the glass transition temperature, the onset crystallization temperature, the liquidus temperature, the crystalline enthalpy and the fusion enthalpy, respectively, has been proposed for evaluating the glass-forming ability of bulk metallic glasses. The new criterion Q exhibits better correlation with the maximum cross section thickness (Dm) for glass formation compared with γ (=Tx/(Tl + Tg)), Trg (=Tg/Tl) and ΔTx (=Tx − Tg) respectively. The available data from literatures and experiments have confirmed the effectiveness of the newly developed criterion.

Research highlights▶ Develop a new criterion, i.e., Q=((Tg+Tx)/Tl)·(ΔE/ΔH). ▶ The reliability and benefits of the new criterion have been demonstrated in a wide range of BMG alloys. ▶ It corresponds well with the critical diameter of BMGs investigated up to now.