한국주조공학회

The interrelationship between new parameter σ and maximum diameter Dmax is elaborated and discussed in comparison with four other glass forming ability (GFA) parameters, i.e. (1) super-cooled liquid region ΔTx (=Tx − Tg), (2) reduced glass transition temperature Trg (=Tg/Tl), (3) K parameter K (=[Tx − Tg]/[Tl − Tx]), and (4) gamma parameter γ (= [Tx]/[Tl + Tg]) in Ca-based bulk metallic glass (BMG) systems. The σ parameter, defined as ΔT* × P', has a far better correlation with Dmax than the GFA parameters suggested so far, clearly indicating that the liquid phase stability and atomic size mismatch dominantly affect the GFA of Ca-based BMGs. Thus, it can be understood that the GFA of BMGs can be properly described by considering structural aspects for glass formation as well as thermodynamic and kinetic aspects for glass formation.

Ca-based alloy, Bulk metallic glass, Glass-forming ability, σ parameter .