Calorimetric study of the crystallization kinetics of Cu{sub 47}Ti{sub 33}Zr{sub 11}Ni{sub 8}Si{sub 1} metallic glass
- FG Physikalische Metallkunde, FB 11 Material- und Geowissenschaften, Technische Universitaet Darmstadt, Petersenstrasse 23, D-64287 Darmstadt (Germany)
- Leibniz-Institut fuer Festkoerper- und Werkstoffforschung Dresden, Helmholtzstrasse 20, D-01069 Dresden (Germany)
- Material and Engineering Physics Program, Ames Laboratory (USDOE), Iowa State University, Ames, Iowa 50014 (United States)
The isochronal and isothermal activation energies for the primary crystallization process of Cu{sub 47}Ti{sub 33}Zr{sub 11}Ni{sub 8}Si{sub 1} metallic glass powders subjected to varying thermal treatments have been evaluated by differential scanning calorimetry and determined using the Kissinger approach and the Johnson-Mehl-Avrami (JMA) analysis, respectively. The values of the differential Avrami exponent are also determined from the isothermal data. Assuming diffusion-controlled growth, it is shown that thermal treatment of the samples in the supercooled liquid region considerably influences the behavior of the nucleation rate during the crystallization process. Microstructural investigations indicate that the thermal treatment is accompanied by precipitation of fine nanocrystals in an amorphous matrix. The values for the activation energies determined by both the Kissinger approach and the JMA analysis are similar for the as-prepared powder, but a significant difference is found for the thermally treated powders. This discrepancy is explained on the basis of the fundamental assumptions made in the models. It will be shown that the Kissinger method fails if the differential Avrami exponent changes significantly during the transformation process.
- OSTI ID:
- 20957763
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 75, Issue 10; Other Information: DOI: 10.1103/PhysRevB.75.104206; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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