Abstract:The solidification process of Cu₆₆Ti₃₄ binary alloy was studied by molecular dynamics simulation. The general embedded atomic (GEAM) potential was selected as many-body interaction. The analytical methods, such as pair correction function (PCF) and mean square displacement (MSD), were employed to calculate the glass transition temperature (T_g) and the diffusion behaviors of, atoms at cooling rate of 4×10¹³ K/s. The results show that the glass transition temperature obtained from inflection point of the curve is 600 K, which is the ratio of minimum to maximum of the first peak of PCF for Cu₆₆Ti₃₄ alloy, and is comparable to that of Cu₅₀Ti₅₀ alloy. The maximum of MSD is lower than 1×10⁻² nm² when the temperature is 800 K, showing that the melt is very sticky. However, when the temperature reaches 600 K, the slope of the curve becomes smaller, showing that the melt is frozen dynamically, which shows that the glass transition temperature varies possibly in certain range due to dynamical factor. Simultaneously, the calculated specific heat capacity (c_p) at constant pressure shows that it distributes in secondary order vs temperature. The peak temperature or the glass transition temperature is 892 K, which shows the difference between the glass transition temperatures obtained by dynamics and thermodynamics, respectively.

Key words: Cu₆₆Ti₃₄ alloy; molecular dynamic simulation; glass transition temperature; mean square displacement; thermodynamical analysis