Non-isothermal crystallization kinetics of Zr41.2Ti13.8Cu12.5Ni10Be22.5 amorphous alloy

The thermodynamics and kinetics of Zr41.2Ti13.8Cu12.5Ni10Be22.5 amorphous alloy under non-isothermal condition were evaluated using differential scanning calorimetry (DSC). The first and third exothermic events at the heating rates of 5 K/min and 10 K/min split into two peaks. The local Avrami exponents at various heating rates calculated by the Kolmogorov-Johnson-Mehl-Avrami equations showed different trends. The grain growth was controlled by atom diffusion at all heating rates. But their growth dimensionality reduced from 2 to 1 as heating rates increase at the beginning of crystallization process. The result exhibited that the heating rate had a great influence on growth mechanism, the crystallization peaks of Zr41.2Ti13.8Cu12.5Ni10Be22.5 amorphous alloy separated into two single-step processes for the change of growth dimensionality. Two fragility indexes evaluated by Angell and DA equations were 44 and 42.5, respectively, implying that the as-cast Zr41.2Ti13.8Cu12.5Ni10Be22.5 amorphous alloy should be considered as intermediate glasses. (C) 2014 Elsevier B.V. All rights reserved.