Evaluation of glass-forming ability for bulk metallic glasses based on characteristic temperatures

Abstract A new criterion ω 2 , defined as T g /(2 T x − T g )− T g / T l (wherein T g is the glass transition temperature, T x the onset crystallization temperature, and T l the liquidus temperature), has been proposed to assess the glass-forming ability (GFA) of bulk metallic glasses (BMGs) based on the classical crystallization theory and the crystallization resistance. The analysis indicates that the factors T g /(2 T x − T g ) and T g / T l could reflect the crystallization resistance and liquid phase stability of metallic glasses, respectively. From the available experimental data in literatures, the new criterion ω 2 has a better correlation with the GFA of metallic glasses than all other existing criteria such as T rg (= T g / T l ), Δ T x (= T x − T g ), γ (= T x /( T g + T l )), Δ T rg (=( T x − T g )/( T l − T g )), α (= T x / T l ), β (= T x / T g + T g / T l ), δ ( =T x / ( T l − T g )), φ ( =T rg (Δ T x /T g ) 0.143 ), γ m (=(2 T x − T g )/ T l ), β (= T x × T g /( T l − T x ) 2 ) and ξ (=Δ T x / T x + T g / T l ). It has also been demonstrated that this ω 2 parameter is a simple and efficient guideline for exploring new BMG formers.