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Observations of Accelerated Silicon Carbide Recession by Oxidation at High Water‐Vapor Pressures
Author(s) -
More Karren L.,
Tortorelli Peter F.,
Ferber Mattison K.,
Keiser James R.
Publication year - 2000
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.1151-2916.2000.tb01172.x
Subject(s) - cristobalite , materials science , water vapor , silicon carbide , porosity , carbide , mineralogy , layer (electronics) , composite material , chemical engineering , chemistry , quartz , organic chemistry , engineering
A study of the exposure of SiC at 1200°C and high water‐vapor pressures (1.5 atm) has shown SiC recession rates that exceed what is predicted based on parabolic oxidation at water‐vapor pressures of less than or equal to ∼1 atm. After exposure to these conditions, distinct silica‐scale structures are observed; thick, porous, nonprotective cristobalite scales form above a thin, dense silica layer. The porous cristobalite thickens with exposure time, while the thickness of the underlying dense layer remains constant. These observations suggest a moving‐boundary phenomenon that is controlled by the rapid conversion of dense vitreous silica to a porous, nonprotective crystalline SiO 2 .