Effectiveness of diffusion barrier coatings for Mo-Re embedded in C/SiC and C/C

Cover of: Effectiveness of diffusion barrier coatings for Mo-Re embedded in C/SiC and C/C |

Published by National Aeronautics and Space Administration, Langley Research Center, Available from NASA Center for AeroSpace Information (CASI) in Hampton, Va, Hanover, MD .

Written in English

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Subjects:

  • Protective coatings.,
  • Carbon-carbon composites.,
  • Rhenium.,
  • Fabrication.,
  • Refractory metals.,
  • Powder metallurgy.,
  • Silicon carbides.,
  • Molybdenum carbides.,
  • Diffusion.

Edition Notes

Book details

StatementDavid E. Glass ... [et al.].
Series[NASA technical memorandum] -- NASA/TM-2001-211264., NASA technical memorandum -- 211264.
ContributionsGlass, David E., Langley Research Center.
The Physical Object
FormatMicroform
Pagination1 v.
ID Numbers
Open LibraryOL17720225M

Download Effectiveness of diffusion barrier coatings for Mo-Re embedded in C/SiC and C/C

Effectiveness of Diffusion Barrier Coatings For Mo-Re Embedded in C/SiC and C/C David E. Glass, NASA Langley Research Center, Hampton, VA Ravi N.

Shenoy, Lockheed Martin Engineering & Sciences, Hampton, VA Zengmei Wang, Chromealloy Gas Turbine Corporation, Orangeburg, NY and. Request PDF | Effectiveness of Diffusion Barrier Coatings for Mo-Re Embedded in C/SiC and C/C | Advanced high-temperature cooling applications may often require the elevated-temperature capability.

The results showed that a layer of brittle Mo-carbide formed on the substrates of both the uncoated MoRe and the uncoated MoRe, subsequent to the C/C or the PyC/SiC processing. Both the RE and the MoSi2(Ge) coatings were effective in preventing not only the diffusion of C into the Mo-Re substrate, but also the formation of the Mo-carbides.

Both the RE and the MoSi 2 (Ge) coatings were effective in preventing not only the diffusion of C into the Mo-Re substrate, but also the formation of the Mo-carbides. However, Mo-silicide layers formed on the Mo-Re substrates as a result of the chemical interaction with both the RE and the MoSi 2 (Ge) coatings.

Get this from a library. Effectiveness of diffusion barrier coatings for Mo-Re embedded in C/SiC and C/C. [David E Glass; Langley Research Center.;]. Materials Science and Engineering, A () - Investigation of diffusion barrier coatings on SiC monofilaments for use in titanium-based composites K.

Bilba, J. Manaud, Y. Le Petitcorps and J. Quenisset Laboratoire de ('hirnie du Solide, Universit(de Bordeaux I, ('ours de la Libdration, Talence (France) Abstract The development of. A CVD coating of SiC applied to a strand of fibers can suppress gas diffusion through the fiber surface. The effectiveness of these barriers is reported in terms of the rate of flaw growth, the extent of chemical decomposition and gas diffusion, and the loss of fiber strength.

Effectiveness of Diffusion Barrier Coatings for Mo-Re Embedded in C/SiC and C/C David E. Glass, Ravi N. Shenoy, Zeng-mei Wang, Michael C. Halbig Materials Science. Besides, the TEC mismatch between the Me/Me x C interlayers and the diamond coatings still exists and serious. Compared with the mentioned metallic carbides, silicon carbide (SiC) has an intermediate TEC and hardness ( × 10 −6 K −1, ∼30 GPa) between diamond and WC-Co, thus is one of the most appropriate interlayer candidates.

A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. The nature and effect of silica coatings which develop on Nicalon™ ceramic fiber surfaces upon exposure to O 2 He gas mixtures at °C was investigated.

Heat treated samples were analyzed for their chemical composition and bonding of the elements present both on the surface and in the bulk of the fiber.

Nc-TiC/a-C/SiC nanocomposite coatings consisting of nanocrystalline (nc) TiC embedded in an amorphous (a) matrix of C/SiC were deposited by magnetron sputtering with rates as high as 16 μm/h. These coatings have a contact resistance comparable with Ag at high loads (~ N) and a resistivity of μΩcm.

Fabrication of cost-effective, nano-grained net-shaped components has brought considerable interest to Department of Defense, National Aeronautics and Space Administration, and Department of Energy.

The objective of this paper is to demonstrate the versatility of electron beam-physical vapor deposition (EB-PVD) technology in engineering new nanostructured. Copper diffusion barrier films having low dielectric constants are suitable for a variety of copper/inter-metal dielectric integration schemes.

Copper diffusion barrier films in accordance with the invention are composed of one or more layers of silicon carbide, at least one of the silicon carbide layers having a composition of at least 40% carbon (C), for example, between.

A multilayer sliding bearing includes a rigid metal backing (12) having a metal bearing liner (14) attached thereto. The metal bearing liner includes a metal bearing liner layer (16) which is attached to the bearing surface of the metal backing layer and at least one metal overplate layer deposited over an outer surface of the metal bearing liner layer.

Search result for c-barrie-re-flavy: Paris-Barri res, Souvenir de 30 ANS(), Effectiveness of Diffusion Barrier Coatings for Mo-Re Embedded in C/Sic and C/C(), Une Soeur de Charit Dans Le Monde(), Effectiveness of Diffusion Barrier Coatings for Mo-Re Embedded in C/Sic and C/C().

The matrix consists of silicon carbide (SiC) and elemental silicon (Si). The reinforcement fiber is carbon (C). Silicon carbide provides the hardness required for wear resistance while the carbon fibers provide the fracture toughness.

The strain at fracture of such C/SiC composites ranges from to %, which is quite high for ceramics. Silicon carbide (SiC) ceramic is considered to be a promising coating material because of its good physical and chemical compatibility with C/C composites and the formation of continuous protective oxide scale (SiO 2) by high‐temperature oxidation reactions.

Nevertheless, the volatilization of glass layer and active oxidation of SiC will. Environmental barrier coatings (EBCs) are needed to protect SiC structures exposed to high temperatures in water vapor-rich environments. Recent studies of a tri-layer EBC system consisting of a silicon layer attached to the SiC, a mullite diffusion barrier and a low-steam volatility ytterbium silicate topcoat have shown some promise for use at temperatures up to °C.

The comparison shown in Fig. 3 visually demonstrates that the Zr-based TFMG acted as an effective diffusion barrier layer even after long-term high-temperature annealing, while the Ni layer did.

A titanium nitride (TiN) coating using microwaves can be accomplished in air, and satisfies the required conditions of an on-demand TiN coating process.

However, the coating mechanism using microwaves is not completely clear. In this study, to understand the detailed mechanism of microwave titanium nitridation in air, the quantity of nitrogen and oxygen in reacted TiN powder. SiC is considered the main diffusion barrier against the release of FPs.

The SiC layer, that is, in a TRISO-coated particle has primarily two functions; 1) the pressure vessel providing structural support, and 2) the main barrier for the retention of metallic FPs. Ternary TiSiN materials have been shown to be effective barriers to Cu diffusion and reaction, rivaling Ta-based materials.

CVD of ternary barriers using TDEAT, NH3, and SiH4 proceeds at temperatures of °C, producing sidewall coverage of > 80% in a aspect ratio hole. It is also found that a SiO2 layer, which was formed during annealing, may serve as an effective barrier to reduce or prevent Ag out diffusion through the SiC coating layer.}, doi = {/t}, journal = {Journal of Nuclear Materials}, issn = {}, number = C, volume =place = {United States}, year = {Thu May The nitrides generated play the roles as element diffusion barriers, and together with the surface alumina they provide a long-term effective anti-oxidant protection to the steel substrate.

The coatings on N substrate were not deteriorated and the substrate was protected well, being exposed to °C for hours.

Additionally, SiC y, SiN x C y, and SiC y O z are applied as diffusion barriers in combination with low dielectric constant (κ) material replacements to SiO 2. 11–13 Similarly, SiN x and SiN x C y are used as capping layers and etch stops for copper interconnects either individually or, more recently, in combination with selective cobalt.

The results suggest little migration of buried Ag in the bulk, and an out-diffusion of the implanted Ag in the near-surface region of single crystal SiC.

It is also found that a SiO2 layer, which was formed during annealing, may serve as an effective barrier to reduce or prevent Ag out diffusion through the SiC coating layer. Find link is a tool written by Edward Betts. searching for Diffusion barrier 41 found (50 total) alternate case: diffusion barrier Vestibular membrane ( words) exact match in snippet view article find links to article function of the spiral organ of Corti.

It primarily functions as a diffusion barrier, allowing nutrients to travel from the perilymph to the endolymph. 1 Influence of infiltration temperature on the microstructure and oxidation behavior of SiC–ZrC ceramic coating on C/C composites prepared by reactive melt infiltration Z.J.

Donga, b, S. Liub, X.K. Lia,b,฀, A. Westwoodc, G.M. Yuanb, Z.W. Cuib, Y. Congb a The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and. The crystalline structure of the coating/substrate as measured by glancing-angle XRD is shown in Fig. 2 for a 1 μm-thick adhered coating grown using oxygen.

Cobalt is known to undergo a phase transformation from hexagonal (ε-Co, stable below °C) to face-centered cubic (α-Co, stable from to °C), although both phases may a result of the close match in.

Figures 2 (a)–(c) show SEM micrographs of the AuGe/Ni couples that had reacted at °C for one, four and eight hours, respectively.

Since the AuGe alloy is a liquid phase at °C 6, these AuGe/Ni couples were liquid/solid couples prior to being quenched at the end of the presented in Fig. 2 (a), large bright grains and two gray layers were found.

The microstructure evolution of two coatings, Hf 7 B 23 Si 22 C 6 N 40 and Hf 6 B 21 Si 19 C 4 N 47, annealed to °C in air is investigated to understand their high oxidation resistance.

The. The thermal stability of the film as a diffusion barrier was investigated in the temperature range of to °C. The diffusion barrier integrity of the film and its thermal stability were investigated via substrate junction leakage current and contact resistance measurements done on test structures fabricated using a complete and Successful bonding of three-dimensional C f /SiC to a niobium alloy has been reported using a Ti–Cu bi-foil interlayer by a two-stage joining process: at °C for 30 min under 6 MPa (solid state diffusion bonding) and at °C for 8– min under – MPa (transient liquid phase diffusion bonding) [Xiong J.H.

et al., ]. A superalloy, or high-performance alloy, is an alloy with the ability to operate at a high fraction of its melting point. Several key characteristics of a superalloy are excellent mechanical strength, resistance to thermal creep deformation, good surface stability, and resistance to corrosion or oxidation.

The crystal structure is typically face-centered cubic (FCC) austenitic. Environmental/thermal barrier coating system with silica diffusion barrier layer While the nonmetallic substrate can be a monolithic ceramic such as a silicon carbide or a silicon nitride, more typically the nonmetallic substrate such as when a component is made from SiC/SiC material comprising a silicon carbide fiber embedded in a.

response time diffusion barrier/geometry dependent, demonstrated to C – low-cost NOX demonstrated to C; commercialization partner on board – resistive mixed potential sensors for NOX, NH4, H2S, hydrocarbons with potential for lower cost and easier to produce Alumina (Al2O3) Zirconia (ZrO2) Zirconia (ZrO2) Cavity Zirconia (ZrO2) Cavity.

Therefore, a number of diffusion barrier coatings were applied to the Pt:SiC junctions in an attempt to improve stability and lower drift in this promising new class of : Process Integration Engineer.

Thermal barrier coatings (TBCs) provide effective thermal barrier to the components of gas turbine engines by allowing higher operating temperatures and reduced cooling requirements.

Plasma spraying, electron-beam physical vapor deposition, and solution precursor plasma spray techniques are generally used to apply the TBCs on the metallic. Bearing liner 14 may also include a thin barrier layer or film 22 (i.e., about 1 to 2 μm thick) of either nickel or copper or other materials effective as a diffusion barrier and/or an adhesion promotion or bonding layer between the constituent materials of bearing liner layer 16 and the overplate layer 24 described below.

To avoid reactions between the boron filament and metals during high-temperature fabrication of the composites, the surface of the fiber is coated by CVD with a thick diffusion barrier of B 4 C.

The B 4 C coating also increases the tensile strength by about 10 percent and improves composite properties.The size of 50, 70, in diameter and in height.

The holes were prepared by DRIE method. TaN and Ta was sputtered for copper diffusion barrier. Via specimen were filled by DC, pulse and pulse-reverse current electroplating methods.

The effects of additives and current types on copper deposits were investigated.carbon and silicon carbide side lining materials and ramming pastes, concretes, and mortars for their installation; refractory barrier-layer bricks and dry barrier mixtures.

Heat insulation materials are described in the following sequence: the purpose of the material and its basic properties, and the grades of materials.

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