On the isothermal kinetics analysis of transformations in metastable systems: combined use of isothermal and non-isothermal calorimetry
A procedure to optimize the isothermal calorimetric data of very slow transformation processes of metastable systems is proposed. The method uses an experimental baseline to identify the transitory effects due to the equipment. Moreover, the combined use of isothermal and non-isothermal results is s...
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Published in | Philosophical magazine (Abingdon, England) Vol. 87; no. 27; pp. 4151 - 4167 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Abingdon
Taylor & Francis Group
21.09.2007
Taylor and Francis |
Subjects | |
Online Access | Get full text |
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Summary: | A procedure to optimize the isothermal calorimetric data of very slow transformation processes of metastable systems is proposed. The method uses an experimental baseline to identify the transitory effects due to the equipment. Moreover, the combined use of isothermal and non-isothermal results is shown to be effective in overcoming the intrinsic problems of low signal and signal drift for such processes. The procedure has been applied to the analysis of the nanocrystallization kinetics of the Fe
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Co
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Nb
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B
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alloy at different devitrification stages. Based on microstructural observations, an instantaneous growth approach was assumed and a phenomenological expression of the dependence of the nucleation frequency with both the transformed fraction and the temperature was obtained. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 1478-6435 1478-6443 |
DOI: | 10.1080/14786430701530990 |