Corrosion kinetics of silicon nitride in dry air containing sodium nitrate vapors

Journal Article · Thu Dec 01 00:00:00 EST 1994 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1994.tb04571.x· OSTI ID:6609285

Sun, T; Pickrell, G R; Brown, Jr, J J ^[1]

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1. Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Center for Advanced Ceramic Materials

The gaseous alkali corrosion kinetics of Si[sub 3]N[sub 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[sub 3]N[sub 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[sub 3]N[sub 4] to SiO[sub 2]. A comparison of the reaction kinetics and mechanism between the oxidation of Si[sub 3]N[sub 4] in pure oxygen and in the alkali-containing atmosphere is present.

• OSTI ID: 6609285
• Journal Information: Journal of the American Ceramic Society; (United States), Vol. 77:12; ISSN 0002-7820
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
SILICON NITRIDES
CORROSION
SODIUM NITRATES
CORROSIVE EFFECTS
ABSORPTION SPECTROSCOPY
GLASS
OXIDATION
REACTION KINETICS
ALKALI METAL COMPOUNDS
CHEMICAL REACTIONS
KINETICS
NITRATES
NITRIDES
NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PNICTIDES
SILICON COMPOUNDS
SODIUM COMPOUNDS
SPECTROSCOPY
360205* - Ceramics
Cermets
& Refractories- Corrosion & Erosion