Kinetics of Mg6Ni nanocrystallization in amorphous Mg83Ni17
| Autor: | Tony Spassov, St. Todorova, Valeri Petkov |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Amorphous metal
Materials science Kinetics Nucleation Thermodynamics Crystal growth Condensed Matter Physics Nanocrystalline material Electronic Optical and Magnetic Materials Amorphous solid law.invention Condensed Matter::Materials Science Crystallography law Phase (matter) Materials Chemistry Ceramics and Composites Crystallization |
| Zdroj: | Journal of Non-Crystalline Solids. 355:1-5 |
| ISSN: | 0022-3093 |
| DOI: | 10.1016/j.jnoncrysol.2008.09.038 |
| Popis: | A comprehensive crystallization kinetics study was carried out in order to understand the mechanism of formation of a Mg-rich nanocrystalline Mg6Ni phase in a metallic glass with similar overall composition, Mg83Ni17. Adequate description of the transformation kinetics was obtained by the JMKA equation with an integer Avrami exponent n = 4, associated with nucleation and three-dimensional linear growth crystallization mechanism. To study the nanocrystals growth mechanism separately a controlled heat treatment of the amorphous alloy was applied and thus a three-dimensional growth with a constant rate was obtained (n = 3) for the pre-annealed alloys. For all transformation curves the dependence of n on the degree of transformation α, n(α), was analyzed and the regions with constant n were defined. The correct separation of the processes of nucleation and crystal growth allowed reliable values for the activation energies of both nucleation and growth processes to be determined. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect