Journal ArticleDOI
Influence of water vapour on high-temperature oxidation of Al2O3-MgO-doped hot-pressed silicon nitride
TLDR
In this paper, the influence of water vapour pressure at high temperature (1200°C) on the corrosion of hot-pressed silicon nitride (HPSN) doped with Al 2 O 3 -MgO was evaluated.Abstract:
Silicon nitride is particularly sensitive to high-temperature oxidation. The intensity of oxidation is influenced by the chemical composition of the amorphous phases present at the grain boundaries and consequently by the sintering additives responsible for their formation. The presence of water vapour increases Si 3 N 4 oxidation also in intermediate temperature conditions. In this study the influence of water vapour pressure at high temperature (1200°C) on the corrosion of hot-pressed silicon nitride (HPSN) doped with Al 2 O 3 -MgO was evaluated. The water vapour has a great influence on the devitrification of the amorphous oxide upper layer, due to the formation of crystalline oxides (primarily cristobalite and tridymite). This process increases the oxidation rate, consequently increasing the porosity of the exposed surface. The microstructural evolution of HPSN in the presence of water vapour at 1200°C was analysed by SEM and XRD.read more
Citations
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Journal ArticleDOI
Paralinear Oxidation of Silicon Nitride in a Water Vapor/Oxygen Environment
TL;DR: In this paper, three silicon nitride materials were exposed to dry oxygen flowing at 0.44 cm/s at temperatures between 1200 and 1400 C. Reaction kinetics were measured with a continuously recording microbalance.
Journal ArticleDOI
Effect of Steam Velocity on the Hydrothermal Oxidation/Volatilization of Silicon Nitride
B. Sudhir,Rishi Raj +1 more
TL;DR: In this article, the authors studied the behavior of silicon nitride as a function of vapor velocity in the range of 1-35 cm/s, at atmospheric pressure and ∼100% H2O, using a custom-designed hydrothermal apparatus.
Journal ArticleDOI
Low-Temperature Oxidation of silicon nitride by water in supercritical condition
TL;DR: In this paper, it was shown that the solubility of silica in water seemed to have a great influence on the stability of the oxidation scale, mainly in reaction-bonded silicon nitride samples.
Journal ArticleDOI
The Role of Water Vapour on the Oxidation of two Ln-Si-Al-O-N Glasses (Ln=Y, La)
TL;DR: In this paper, the authors studied the oxidation behavior of LnSiAlON (Ln=Y, La) glasses at different temperatures and under different water vapour pressures.
Book ChapterDOI
Corrosion and Fretting Damage of Non-Oxide Ceramics in Presence of Water Vapour
TL;DR: In this article, it is shown that water vapour contained in a gas at high temperature (> 1000 °C) highly increases the corrosion rate of silicon based non-oxide ceramics, due to devitrification of the amorphous oxide upper layer.
References
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Journal ArticleDOI
Kinetics of Oxidation of Hot‐Pressed Silicon Nitride Containing Magnesia
D. Cubicciotti,K. H. Lau +1 more
TL;DR: In this article, the authors studied the oxidation of NC 132 hot-pressed silicon nitride in dry oxygen at 1521 to 1731 K. The rate of O2 uptake and N2 release, as a function of time, was measured volumetrically.
Journal ArticleDOI
Effect of Water Vapor on the Oxidation of Hot-Pressed Silicon Nitride and Silicon Carbide
Journal ArticleDOI
Oxidation of Si3N4 Alloys: Relation to Phase Equilibria in the System Si3N4-SiO2-MgO
TL;DR: In this article, the authors investigated the oxidation resistance at 1400°C of silicon nitride alloys hot-pressed with magnesia and found that the extent of oxidation, the products of oxidation and the continuity of the oxide scale are all dependent on the initial composition.
Journal ArticleDOI
Oxidation of silicon carbide in a wet atmosphere
TL;DR: In this paper, the effects of water vapour on oxidation of pressureless-sintered silicon carbide containing alumina as a densifying aid were studied in a wet air flow with 10, 20, 30 and 40vol% H2O at 1300° C for 100h.
Book ChapterDOI
Thermodynamic Mechanism for Cation Diffusion Through an Intergranular Phase: Application to Environmental Reactions with Nitrogen Ceramics
TL;DR: In this paper, a mechanistic model for the migration of cations from a continuous intergranular phase in response to environmental reaction at the surface of polyphase silicon nitrides is described.