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Corrosion Kinetics of Silicon Nitride in Dry Air Containing Sodium Nitrate Vapors
Author(s) -
Sun Tawei,
Pickrell Gary R.,
Brown Jesse J.
Publication year - 1994
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.1151-2916.1994.tb04571.x
Subject(s) - alkali metal , dissolution , kinetics , corrosion , chemistry , inorganic chemistry , activation energy , silicon nitride , nitrogen , sodium , nitride , oxygen , chemical kinetics , silicon , materials science , organic chemistry , physics , layer (electronics) , quantum mechanics
The gaseous alkali corrosion kinetics of Si 3 N 4 were systematically investigated from 950° to 1100°C in dry air containing 0.98 vol% sodium nitrate vapors. The linear reaction rates observed at all temperatures indicate that the alkali corrosion of Si 3 N 4 is interface‐controlled with an activation energy of 199 kJ/mol. The overall reaction involves a complex absorption–dissolution–oxidation process and the rate‐controlling step appears to be the interfacial oxidation of Si 3 N 4 to SiO 2 . A comparison of the reaction kinetics and mechanism between the oxidation of Si 3 N 4 in pure oxygen and in the alkali‐containing atmosphere is presented.