کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
673335 1459497 2014 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Non-isothermal crystallization kinetics of Zr41.2Ti13.8Cu12.5Ni10Be22.5 amorphous alloy
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
Non-isothermal crystallization kinetics of Zr41.2Ti13.8Cu12.5Ni10Be22.5 amorphous alloy
چکیده انگلیسی


• Some kinetics parameters of Zr41.2Ti13.8Cu12.5Ni10Be22.5 amorphous alloy were calculated.
• The first and third exothermic peaks at the heating rates of 5 K/min and 10 K/min split into two peaks.
• The local Avrami exponents at various heating rates showed different trends under different heating rates.
• The growth dimensionality reduced from 2 to 1 as heating rates increase.
• The heating rate had significant influence on the growth mechanism during annealing.

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”.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Thermochimica Acta - Volume 587, 10 July 2014, Pages 11–17
نویسندگان
, , , , ,