✦ LIBER ✦
High-temperature oxidation-protection CVD coatings for structural ceramics: Oxidation behaviour of CVD-coated reaction-bonded silicon nitride
✍ Scribed by J Desmaison; N Roels; P Belair
- Publisher
- Elsevier Science
- Year
- 1989
- Tongue
- English
- Weight
- 688 KB
- Volume
- 120-121
- Category
- Article
- ISSN
- 0921-5093
No coin nor oath required. For personal study only.
✦ Synopsis
Chemical vapour deposition of Si3N 4 by
pyrolysis (1200-1275°C) of tetramethylsilane-ammonia-hydrogen mixtures (N:Si = 10) was used to protect reaction-bonded silicon nitride substrates against internal oxidation at 1000-1350 °C. The results reveal the existence of a critical thickness (6 gm) of the coatings and the poorer protectiveness of amorphous deposited coatings compared with crystallized coatings. Under the optimum deposition conditions, better protection was achieved than by the use of more conventional surface modification treatments such as high-temperature flash pre-oxidation.