Oxidation Of Silicon Carbide Research Articles

Stabilization of Silicon Carbide Whisker Suspensions: I, Influence of Surface Oxidation in Aqueous Suspensions

The extent of surface oxidation controls the stability of silicon carbide aqueous suspensions. In the present study, x-ray photon spectroscopy (XPS) was used to determine the extent of oxygen on as-received and oxidized silicon carbide whiskers. The isoelectric points at pH 6.0 and pH 4.0 for the as-received and oxidized whiskers, respectively, correlated with the XPS analyses, indicating essentially a silica surface on the oxidized whiskers and both Si-O and Si-C bonds on the surface of the as-received whiskers. Suggestions are made regarding the utility of the oxidation treatment in processing whisker-reinforced ceramics.

High temperature oxidation of silicon carbide based materials

The process of high temperature oxidation of two silicon carbide based materials differing by methods of their production and properties has been studied up to 1500°C in air. The oxidation was performed under the isothermal conditions and at the programmed heat rate of 10° per minute. It was found that the oxidation resistance of the material was the function of the presence of extrinsic metals having close affinity for oxygen. It was also found that under heating up to 1500°C in air phase transitions occurred in the SiC surface layer.

Determination of Free Carbon in Silicon Carbide Powder

Free carbon in a silicon carbide raw material powder was determined by a combustion method. A sample of 0.5g was weighed out into a 3ml-quartz crucible, and the crucible was placed in a graphite-sealed quartz cell. The cell was raised into the induction furnace combustion tube and heated in oxygen flow at 850°C for 10min by controlling the voltage applied to the furnace. The amount of CO2 produced by the combustion of free carbon in silicon carbide was measured with a thermal conduction detector. Heating at 850°C induced oxidation of silicon carbide. Therefore, the amount of free carbon in silicon carbide was calculated by the correction method in ANSI (B74.15). We also used the correction method based on the change of oxygen concentration. For the sample dried at 105°C for 1h, the values obtained by two correction methods did not agree each other. When the samples were heated at 500°C in an argon atmosphere for 1h, the values obtained by the two correction methods agreed well. Free carbon in five commercial silicon carbide powders were determined to be 0.26-0.92wt%, and the precision (relative standard deviation) was 1-11%.

Petrographic and X-ray identification of phases formed by oxidation of silicon carbide

Petrographic and X-ray identification of phases formed by oxidation of silicon carbide

Electrical Characterization of the Oxide-Silicon Carbide Interface by MOS Conductance Technique

ABSTRACTThe electrical properties of the SiO2/SiC interface were studied using the conductance vs voltage (G-V) data for the metal-oxide-SiC (MOS) structure. It was found that the dry oxide contained too mjch charge either at the oxide-SiC interface or within the oxide films to obtain useful data. On the other hand the wet oxide invariably resulted in better capacitance and conductance data. The capacitance-voltage data showed that the SiC surface exhibited accumulation, depletion or inversion when the appropriate gate bias was applied. The conductance-voltage data indicate electronic surface states at the oxide-SiC interface. From this conductance data the interface state density has been estimated.

Petrographic and X-ray identification of phases formed by oxidation of silicon carbide

Petrographic and X-ray identification of phases formed by oxidation of silicon carbide

Oxidation of Silicon Carbide in Oxygen and in Water Vapour at 1500 degrees C.

Oxidation of Silicon Carbide in Oxygen and in Water Vapour at 1500 degrees C.

Metal oxide-semiconductor capacitors on silicon carbide

The purpose of the work discussed in this paper is to determine the feasibility of using Silicon Carbide for making surface field effect devices such as MOSFET's. The device used for making such a determination is the MOS capacitor. This paper discusses briefly the oxidation of Silicon Carbide. The techniques used to make MOS capacitors are outlined, and experimental data are presented which show that it is possible to use Silicon Carbide for constructing surface field effect devices.

Oxidation kinetics of hot-pressed silicon carbide

The oxidation of silicon carbide, hot-pressed with ∼ 4 wt % Al2O3, in 1 atm dry oxygen follows classical parabolic behaviour with an activation energy of 481 kJ mol−1 in the temperature range 1200 to 1400° C. The oxide film consists predominantly of cristobalite and a glassy phase in which additive (Al) and various impurity elements (Fe, Na, K, etc) concentrate. The desorption of CO(g) from the SiC/SiO2 interface appears to be oxidation rate controlling.

Effect of Water Vapor on the Oxidation of Hot‐Pressed Silicon Nitride and Silicon Carbide

Journal of the American Ceramic SocietyVolume 59, Issue 1-2 p. 81-82 Effect of Water Vapor on the Oxidation of Hot-Pressed Silicon Nitride and Silicon Carbide S.C. SINGHAL, S.C. SINGHAL Member, the American Ceramic SocietySearch for more papers by this author S.C. SINGHAL, S.C. SINGHAL Member, the American Ceramic SocietySearch for more papers by this author First published: January 1976 https://doi.org/10.1111/j.1151-2916.1976.tb09398.xCitations: 92 Supported by the Advanced Research Projects Agency, Department of Defense, Under Contract No. DAAG 46–71-C-0162. The writer is with Metallurgy and Metals Processing, Westinghouse Research Laboratories, Pittsburgh, Pennsylvania 15235. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume59, Issue1-2January 1976Pages 81-82 RelatedInformation

The effect of fission fragment irradiation upon the active to passive transition in the oxidation of self-bonded refel silicon carbide at 850–950°C

With increasing oxidant pressures there can be two successive modes of oxidation (active and passive) of silicon carbide and silicon, resulting in the formation of either volatile silicon monoxide, or a protective silica layer. The active corrosion of REFEL silicon carbide, containing ≈ 16% free silicon, has been examined experimentally out-of-reactor at lower temperatures than previously and has been shown to occur at 900 and 950°, but not at ⩽ 875°C. The oxygen pressures for the transition to the passive type of oxidation were not greater than those calculated on the basis of a theoretical model. Irradiation with a fission fragment flux of 1 × 10 11 ff/cm 2 · sec did not affect significantly either the minimum temperature for the onset of active corrosion or the active-passive oxidation transition pressure, at temperatures up to ≈ 950°C.

Anodic oxidation of silicon carbide

Oxide films up to 2500 å thick have been grown on SiC by anodizing p- or n-type crystals in a constant current mode, in a diethylene glycol-KNO 3 solution. Several features of the anodization process are reported here for the first time. Using ellipsometric analysis, the refractive index of the films was measured to be 1.46 at 5460 å. This and other results suggest that silicon dioxide is formed during anodization. Certain discrepancies that make further confirmation necessary are discussed.

The effect of fission fragment irradiation upon the passive oxidation of silicon-bonded silicon carbide by oxygen at 950°C

The effect of fission fragment irradiation on the passive oxidation of a silicon-bonded silicon carbide by oxygen has been examined at 950°C. The fission fragment flux ranged between 6.3 – 12.2 × 10 10 ff/cm 2 · s, and the exposure period varied up to 4768 h. The extent of oxidation was increased slightly by the fission recoil bombardment. The enhancement was more significant during the initial exposure (⩽ 500 h), when it was increased by a factor of between 2.5 – 3.5. Subsequently, the factor became progressively decreased to 1.6 – 1.9 after 4768 h. Comparison between the extents of oxidation of the silicon carbide and free silicon constituents suggest that it was the oxidation of free silicon which was increased, particularly over the initial exposure period. Thereafter, silica film growth on both components was enhanced to comparable extents. The most probable mechanism for the continuing radiation induced attack was that the silica film properties controlling oxidation were influenced by chemical contamination, with fission products and uranium oxide, ejected from the sources with the emerging fission fragments.

The high-temperature oxidation, reduction, and volatilization reactions of silicon and silicon carbide

A thermochemical analysis was made of the oxidation, reduction, and volatilization reactions which occur in the Si-O-C system. One characteristic feature is the high SiO(g) and SiO(g) + CO(g) pressures at the Si(s)-SiO2 and SiC(s)-SiO2(s) interfaces. Active oxidation with weight losses and passive oxidation with weight gains were found on oxidizing Si(s) and SiC(s) in low oxygen pressures above 1000°C. Rapid oxidation was related to the SiO(g) and SiO(g) + C0(g) pressures at the Si(s) or SiC(s)-SiO2(s) interfaces.

The effect of fission-fragment irradiation upon the oxidation of silicon carbide by oxygen at 950 °C

The effect of fission-fragment irradiation on the oxidation of a silicon-bonded silicon carbide by oxygen has been studied at 950 °C. The fission fragment flux was 1.4 × 10 8 ff/ cm 2 sec and the exposure period varied up to 1400 h. The amount of oxidation was increased slightly by the irradiation. The enhancement increased with exposure, such that after 1400 h the oxidation of the irradiated specimens was greater than on the unirradiated controls by a factor between 1.3–1.7. The radiation-induced oxidation probably results from a modification of the oxide film that facilitates ion-transport, although gas-phase radiolysis might also be responsible.

Investigation of the oxidation kinetics of silicon carbide heaters

In the range 1200–1500°C the mechanism of oxidation of industrial heating elements containing 97–99% silicon carbide is approximately identical with, and is controlled in the same way, as the oxidation of pure silicon carbide [1, 2], in the main by oxygen diffusion through a film of SiO2.

High-temperature kinetics of the oxidation and nitridation of pyrolytic silicon carbide in dissociated gases

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHigh-temperature kinetics of the oxidation and nitridation of pyrolytic silicon carbide in dissociated gasesDaniel E. Rosner and H. Donald AllendorfCite this: J. Phys. Chem. 1970, 74, 9, 1829–1839Publication Date (Print):April 1, 1970Publication History Published online1 May 2002Published inissue 1 April 1970https://doi.org/10.1021/j100704a002RIGHTS & PERMISSIONSArticle Views385Altmetric-Citations77LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (2 MB) Get e-Alerts

The wetting of silicon carbide surfaces

Abstract Silicon carbide fibers, 3 mil in diameter, produced by thermal decomposition of dichloromethylsilane on a tungsten substrate, have a relatively smooth surface. This is shown by close agreement of the measured specific surface area, 0.016 m 2 /gm ± 0.02 m 2 /gm with the calculated geometric specific surface area, 0.04 m 2 /gm and is supported by evidence from surface electron micrographs. Electron microprobe analysis of the fibers qualitatively showed the presence of oxygen on the fiber surface, indicating that surface oxidation of silicon carbide takes place quite readily. The critical surface tension of silicon carbide coated graphite coupons, prepared similarly to the fibers was found to be 52 ± 5 dyne/cm. The critical surface tension was not altered by exposure of the coupons to highly oxidizing conditions or to hydrofluoric acid. However, high temperature surface oxidation (air, 500°C) followed by boiling water treatment increased the critical surface tension to greater than 70 dynes/cm. The critical surface tension of a room temperature cured epoxy resin was found to be 45 ± 5 dyne/cm, indicating that an epoxy resin has a lower energy surface than untreated, oxidized, or oxidized-hydrated silicon carbide. Adhesion tension measurements between treated silicon carbide coupons and coupling agents showed that (i) oxidation and oxidation-hydration promote good adhesion of certain coupling agents to the silicon carbide surfaces, (ii) the adsorbed films are retained on the oxidized silicon carbide surfaces under rigid desorption conditions, and (iii) the “bond” between oxidized-hydrated silicon carbide surface and 4,4′-methylenedianiline was improved considerably over the “bond” between oxidized silicon carbide surface and the same compound.

Behavior of nonporous silicon carbide in various gaseous media at high temperatures

1. The oxidation isotherms for monocrystals and polycrystalline specimens of silicon carbide, obtained under identical conditions, are rather close to each other. This indicates that the polycrystalline specimens were monolithic and that their oxidation occurred at the surface. 2. A comparison of the isotherms of silicon carbide oxidation in various media leads to the conclusion that complex processes involving the formation of SiC and its subsequent interaction with silicon carbide occur during the oxidation of SiO3. The phase composition of SiO2 and, consequently, the protective properties of the film depend on the nature of the oxidizing gas.

Temperature and oxygen pressure dependence of silicon carbide oxidation

Temperature and oxygen pressure dependence of silicon carbide oxidation