Abstract
Si3N4 substrates coated with chemically-vapor-deposited, crystalline mullite (3Al2O3·2SiO2) were subjected to a corrosive environment containing Na2SO4 and O2 at 1000°C for 100 h. The composition and microstructure of the as-deposited and corroded specimens were examined and compared. The coating appeared to be effective in preserving and therefore protecting the surface microstructure of the underlying Si3N3 substrates. However, a small degree of Na penetration through mullite grain boundaries was observed to a coating depth of ∼1 μm.
Original language | English |
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Pages (from-to) | 2489-2492 |
Number of pages | 4 |
Journal | Journal of the American Ceramic Society |
Volume | 79 |
Issue number | 9 |
DOIs | |
State | Published - Sep 1996 |