Thermodynamic characteristics of Ti-based glass-forming alloys

Based on thermodynamic characteristics of the stable metallic liquid at melting temperature and the supercooled liquid, the present work calculated the mixing enthalpy ΔHmix, the mixing entropy ΔSmix and the Gibbs free energy difference between the supercooled liquid and the resulting crystalline phases ΔG of typical Ti-based amorphous alloys. The results show that for the case of larger ΔSmix, moderate ΔHmix for the stable liquid and smaller ΔG for the supercooled liquid, Ti-based alloys tend to achieve high glass-forming ability (GFA). A new parameter, β, defined as (Tg − Tk)/(Tl − Tg), has been introduced to evaluate the GFA of Ti-based bulk amorphous alloys (wherein Tg, Tl, and Tk represent the glass transition temperature, the liquidus temperature, and the Kauzmann temperature, respectively). Experimental data imply that the larger the β, the better the GFA for Ti-based amorphous alloys.