Crystallization kinetics study of melt-spun Zr66.7Ni33.3 amorphous alloy by electrical resistivity measurements
Résumé
In this paper, the electronic transport properties of as-spun Zr66.7Ni33.3 alloys were studied in detail by a combination of
electrical resistivity and absolute thermoelectric power measurements over a temperature range from 25 up to 400 C.
Moreover, the isochronal and isothermal crystallization kinetics of Zr66.7Ni33.3 glassy alloy has been investigated based on
the electrical resistivity measurements. The comparative study of the crystallization kinetics of these binary amorphous
alloys was carried out, for the first time to our knowledge, using an accurate method for electrical resistivity measurements.
In the isochronal heating process, the apparent activation energy for crystallization was determined to be, respectively,
371.4 kJ mol-1 and 382.2 kJ mol-1, by means of Kissinger and Ozawa methods. The Johnson–Mehl–Avrami model was
used to describe the isothermal transformation kinetics, and the local Avrami exponent has been determined in the range
from 2.97 to 3.23 with an average value of 3.1, implying a mainly diffusion-controlled three-dimensional growth with an
increasing nucleation rate. Based on an Arrhenius relationship, the local activation energy was analyzed, which yields an
average value Ex = 376.2 kJ mol-1.