Journal ArticleDOI
Mass Spectrometric Identification of Si–O–H(g) Species from the Reaction of Silica with Water Vapor at Atmospheric Pressure
Reads0
Chats0
TLDR
In this article, a high pressure sampling mass spectrometer was used to detect the volatile species formed from SiO2 at temperatures between 1200C and 1400C in a flowing water vapor/oxygen gas mixture at 1 bar total pressure.Abstract:
A high-pressure sampling mass spectrometer was used to detect the volatile species formed from SiO2 at temperatures between 1200C and 1400C in a flowing water vapor/oxygen gas mixture at 1 bar total pressure. The primary vapor species identified was Si(OH)4. The fragment ion Si(OH)3+,' was observed in quantities 3 to 5 times larger than the parent ion Si(OH)4+. The Si(OH)3+ intensity was found to have a small temperature dependence and to increase with the water vapor partial pressure as expected. In addition, SiO(OH)+ believed to be a fragment of SiO(OH)2, was observed. These mass spectral results were compared to the behavior of silicon halides.read more
Citations
More filters
Journal ArticleDOI
Solid Oxide Electrolysis Cells: Microstructure and Degradation of the Ni/Yttria-Stabilized Zirconia Electrode
TL;DR: In this article, the degradation of solid oxide fuel cells during long-term galvanostatic electrolysis testing was analyzed by impedance spectroscopy and the degradation was found mainly to be caused by increasing polarization resistance associated with the hydrogen electrode.
Journal ArticleDOI
SiC Recession Caused by SiO2 Scale Volatility under Combustion Conditions: I, Experimental Results and Empirical Model
TL;DR: In this article, a high-pressure burner rig was developed to evaluate the response of chemical-vapor-deposited SiC material during exposure to simulated gas turbine combustor conditions.
Journal ArticleDOI
Response of ytterbium disilicate-silicon environmental barrier coatings to thermal cycling in water vapor
Bradley T. Richards,Kelly A. Young,Foucault de Francqueville,Stephen Sehr,Matthew R. Begley,Haydn N. G. Wadley +5 more
TL;DR: In this article, a bi-layer environmental barrier coating (EBC) was designed to reduce the susceptibility of SiC composites to hot water vapor erosion is reported, which consisted of a silicon bond coat and a pore-free ytterbium disilicate (YbDS) topcoat.
Journal ArticleDOI
Accelerated oxidation of SiC CMC's by water vapor and protection via environmental barrier coating approach
Harry E. Eaton,Gary D. Linsey +1 more
TL;DR: In this article, an approach has been proposed to prevent accelerated oxidation by limiting oxidant access to the surface of the silica former, which is shown to exhibit paralinear behavior and result in unacceptable recession of the surface.
Journal ArticleDOI
Plasma spray deposition of tri-layer environmental barrier coatings
TL;DR: In this paper, an air plasma spray process has been used to deposit tri-layer environmental barrier coatings consisting of a silicon bond coat, a mullite inter-diffusion barrier, and a Yb 2 SiO 5 top coat on SiC substrates.
References
More filters
Journal ArticleDOI
Paralinear Oxidation of CVD SiC in Water Vapor
TL;DR: In this article, the long-term degradation rate of CVD SiC is determined by the volatility of the silica scale, which is observed as the water vapor oxidized the SiC and simultaneously volatilized the scale.
Journal ArticleDOI
The effect of H2O gas on volatilities of planet-forming major elements: I. Experimental determination of thermodynamic properties of Ca-, Al-, and Si-hydroxide gas molecules and its application to the solar nebula
TL;DR: In this paper, the vapor pressures of Ca, Al, Al(OH)3, and Si, Mg, and Fe were determined, and were used to derive the heats of formation and entropies of these species under the currently postulated physical conditions in the primordial solar nebula.
Journal ArticleDOI
Thermochemistry of gaseous SiO(OH), SiO(OH)2, and SiO2
D. L. Hildenbrand,K. H. Lau +1 more
TL;DR: In this paper, the gaseous species SiO(OH) and SiO (OH)2 were detected as products of the reaction of SiO2(l) and H2O(g) near 2000 K, using effusion-beam mass spectrometry.
Journal ArticleDOI
Reactions of silicon-based ceramics in mixed oxidation chlorination environments
TL;DR: The reaction of silicon-based ceramics with 2 percent Cl2/Ar and 1 percent Cl 2/1 percent to 20 percent O 2/Ar at 950 C was studied with thermogravimetric analysis and high-pressure mass spectrometry as discussed by the authors.