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Oxidation of Submicroscopic Fibrous Silicon Carbide
Author(s) -
PULTZ W. W.
Publication year - 1967
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.1151-2916.1967.tb15147.x
Subject(s) - silicon carbide , gravimetric analysis , diffusion , enthalpy , silicon , amorphous silicon , amorphous silica , amorphous solid , chemical engineering , materials science , carbide , chemistry , composite material , metallurgy , crystallography , thermodynamics , crystalline silicon , organic chemistry , physics , engineering
The oxidation rate of silicon carbide fibers of submicroscopic dimensions in static air was investigated by a gravimetric technique at 800°, 900°, and 1000°C. The fibers can be held near 800°C for several hours without significant oxidation, but they rapidly oxidize at 1000°C. A theoretical model for diffusion‐controlled oxidation of the fibers, taking into account a changing reaction interfacial area, was obeyed to more than 60% conversion of the silicon carbide to silica. For the diffusion‐controlled oxidation an enthalpy of activation of 55.8 or 39.8 kcal/mole was calculated depending on whether an amorphous silica sheath was initially present.