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Kinetics and Mechanisms for Nitridation of Floating Aluminum Powder
Author(s) -
Chang Anjae,
Rhee ShiWoo,
Baik Sunggi
Publication year - 1995
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1995.tb08357.x
Subject(s) - activation energy , nitride , kinetics , atmospheric temperature range , nitrogen , rate equation , aluminium , chemical kinetics , ammonia , chemistry , reaction rate , reaction rate constant , reaction mechanism , materials science , analytical chemistry (journal) , inorganic chemistry , thermodynamics , catalysis , organic chemistry , layer (electronics) , physics , quantum mechanics
Aluminum powder entrained by ammonia‐containing nitrogen gas was reacted at various temperatures and time to form aluminum nitride powder. The kinetics of nitride formation were determined by a quantitative X‐ray analysis and compared with those determined by a nitrogen analysis of the product. The conversion to aluminum nitride increased with the reaction time following a sigmoidal rate law. The reaction time for full conversion decreased as the temperature increased in the range 1050°–1300°C. The reaction rate constant at a given temperature was evaluated using the Avrami equation. The activation energy for the reaction was 1054 ± 91 kJ/mol in the temperature range of 1050°–1200°C, and decreased to 322 ± 70 kJ/mol above 1200°C. Comparative analysis of powders formed below and above 1200°C suggested strongly that the rate‐controlling step changed from chemical reaction to mass transport above 1200°C.