Abstract:The crystallization process of Zr₅₅Al₁₀Ni₅Cu₃₀ bulk amorphous alloy in the supercooled liquid region was investigated by differential scanning calorimetry in the mode of continuous heating and isothermal annealing. The parameters including glass transition temperature, onset crystallization temperature, and supercooled liquid region associated with the thermal stability of this alloy were measured. It is found that, in the case of continuous heating, both the onset and peak crystallization temperatures exhibit a strong dependence of the heating rate. And this relationship can be fitted by first order exponential decay equation. In addition, the isothermal kinetics was studied by Johnson-Mehl-Avrami (JMA) equation, and the Avrami exponents were calculated to be in the range of 2.0-5.0. On the basis of the Avrami exponents, it can be concluded that the crystallization process is mainly dominated by three-dimensional nucleation and growth.

Key words: bulk amorphous alloy; supercooled liquid; crystallization; JMA equation; kinetics