Dependence of GFA and thermal stability of the Cu50Zr50 alloy on temperature-functioned different liquid states

• Alterations of the liquid structural state of Cu50Zr50 alloy are observed by both resistivity and DTA measurement.
• Crystallization and thermal-stability of Cu50Zr50 MGs are greatly affected by temperature functioned different melt states.
• GFA of Cu50Zr50 MGs can achieve Ф3 mm using cone-shape copper mould injection casting, by over-heating the melt to 1693 K.

Liquid polyamorphism and transitions between different states have triggered great interest, concerning which the present paper aimed to investigate the correlations of the glass formation ability (GFA) and glassy thermal stability of Cu50Zr50 alloy with its original liquid states. As structurally sensitive, the resistivity (ρ) change pattern of liquid Cu50Zr50 was explored as temperature (T) elevated, hereby two obvious turns of ρ-T slope were observed, and corresponding to the first turn an endothermic peak appeared on DTA curve, which suggest alterations of its liquid structural state. Based on the results, by preparing Cu50Zr50 metallic glasses with different quenching temperature (Tq), experiments were carried out to find out the above mentioned correlations. It is verified by resistivity and DSC methods that there are two crystallization stages for the melt-spun glassy ribbons with Tq below the first turn, while there is only one crystallization stage for cases above the first turn. More significantly, although characteristic parameters of the glassy ribbons change indistinctively with Tq below the first turn, all they change obviously with Tq elevated above the first turn, i.e. Tg, Tx move to higher degree, and Trg, ΔTx and γ become larger. The former trend indicates a better thermal stability of glassy Cu50Zr50, and the latter trend signifies an enhanced GFA of the melt. By the copper mould cast method, it is intriguingly proved that GFA of Cu50Zr50 can rise to Ф3, when its melt prepared with temperature above the second turn.