Abstract
The ribbons of amorphous Zr61Al7.5Cu 17.5Ni10Si4 alloy were studied by means of differential scanning calorimetry (DSC), X-ray diffractometry (XRD), high-temperature optical microscope and transmission electron microscopy (TEM). The activation energy for such the crystallization of the amorphous phase was about 360 and 370 kJ mole-1 calculated by Kissinger and Avrami plots, respectively. Kinetics for the crystallization was analyzed by means of Johnson-Mehl-Avrami equation and discussed regarding to the value of Avrami exponent. The average value of the Avrami exponent n was measured about 2.43 at the range from 698 to 713 K. In addition, the cube of crystal size as a function of isothermally annealing time presents a linear relationship for the Zr61Al7.5Cu17.5Ni10Si4 alloy. When the Zr61Al7.5Cu17.5Ni 10Si4 alloy was isothermally annealed at 698 K, a Zr 2Cu crystal with an average size of 105 nm was first observed at the early stage (30% crystallization) of crystallization. In addition, both nano-crystals of ordered fee ZrCu (∼100 nm) and ordered fcc Zr 3Al (∼30 nm) were observed to precipitate from the amorphous matrix upon the middle stage (50% crystallization) of crystallization.
Original language | English |
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Pages (from-to) | 227-233 |
Number of pages | 7 |
Journal | Materials Chemistry and Physics |
Volume | 88 |
Issue number | 1 |
DOIs | |
State | Published - 15 Nov 2004 |
Keywords
- Amorphous alloy
- Crystallization behavior
- Thermal properties
- Zirconium-based alloy