Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
  • C04B41/009—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone characterised by the material treated
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
  • C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
  • C04B41/52—Multiple coating or impregnating multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
  • C04B41/80—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only ceramics
  • C04B41/81—Coating or impregnation
  • C04B41/89—Coating or impregnation for obtaining at least two superposed coatings having different compositions
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
  • C23C28/04—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material
  • C23C28/042—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material including a refractory ceramic layer, e.g. refractory metal oxides, ZrO2, rare earth oxides
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/12—All metal or with adjacent metals
  • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
  • Y10T428/1266—O, S, or organic compound in metal component
  • Y10T428/12667—Oxide of transition metal or Al
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31652—Of asbestos
  • Y10T428/31667—Next to addition polymer from unsaturated monomers, or aldehyde or ketone condensation product
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31678—Of metal

Definitions

• Embodiments described herein generally relate to environmental barrier coatings (EBCs) providing CMAS mitigation capability for use with ceramic substrate components.
• EBCs environmental barrier coatings
• Ceramic matrix composites are a class of materials that consist of a reinforcing material surrounded by a ceramic matrix phase. Such materials, along with certain monolithic ceramics (i.e. ceramic materials without a reinforcing material), are currently being used for higher temperature applications. Using these ceramic materials can decrease the weight, yet maintain the strength and durability, of turbine components. Furthermore, since these materials have higher temperature capability than metals, significant cooling air savings can be realized that increase the efficiency of a turbine engine. Therefore, such materials are currently being considered for many gas turbine components used in higher temperature sections of gas turbine engines, such as airfoils (e.g. turbines, and vanes), combustors, shrouds and other like components that would benefit from the lighter-weight and higher temperature capability these materials can offer.
• airfoils e.g. turbines, and vanes
• combustors e.g. turbines, and vanes
• CMC and monolithic ceramic components can be coated with EBCs to protect them from the harsh environment of high temperature engine sections.
• EBCs can provide a dense, hermetic seal against the corrosive gases in the hot combustion environment.
• silicon-based (nonoxide) CMCs and monolithic ceramics undergo oxidation to form a protective silicon oxide scale.
• the silicon oxide reacts rapidly with high temperature steam, such as found in gas turbine engines, to form volatile silicon species.
• This oxidation/volatilization process can result in significant material loss, or recession, over the lifetime of an engine component. This recession also occurs in CMC and monolithic ceramic components comprising aluminum oxide, as aluminum oxide reacts with high temperature steam to form volatile aluminum species as well.
• EBCs used for CMC and monolithic ceramic components consist of a three-layer coating system generally including a bond coat layer, at least one transition layer applied to the bond coat layer, and an optional outer layer applied to the transition layer.
• a silica layer may be present between the bond coat layer and the adjacent transition layer. Together these layers can provide environmental protection for the CMC or monolithic ceramic component.
• the bond coat layer may comprise silicon and may generally have a thickness of from about 0.5 mils to about 6 mils.
• the bond coat layer serves as an oxidation barrier to prevent oxidation of the substrate.
• the silica layer may be applied to the bond coat layer, or alternately, may be formed naturally or intentionally on the bond coat layer.
• the transition layer may typically comprise mullite, barium strontium aluminosilicate (BSAS), a rare earth disilicate, and various combinations thereof, while the optional outer layer may comprise BSAS, a rare earth monosilicate, and combinations thereof. There may be from 1 to 3 transition layers present, each layer having a thickness of from about 0.1 mils to about 6 mils, and the optional outer layer may have a thickness of from about 0.1 mils to about 40 mils.
• Each of the transition and outer layers can have differing porosity. At a porosity of about 10% or less, a hermetic seal to the hot gases in the combustion environment can form. From about 10% to about 40% porosity, the layer can display mechanical integrity, but hot gases can penetrate through the coating layer damaging the underlying EBC. While it is necessary for at least one of the transition layer or outer layer to be hermetic, it can be beneficial to have some layers of higher porosity range to mitigate mechanical stress induced by any thermal expansion mismatch between the coating materials and the substrate.
• CMAS calcium magnesium aluminosilicate
• Embodiments herein generally relate to environmental barrier coatings having CMAS mitigation capability for silicon-containing components, the barrier coating comprising: a bond coat layer comprising aluminide-alumina TGO; and an outer layer selected from the group consisting of AeA12O19, AeHfO3, AeZrO3, ZnA12O4, MgA12O4, Ln4A12O9, Lna4Ga2O9, Ln3A15O12, Ln3Ga5O12, Ga2O3, HfO2, and LnPO4.
• Embodiments herein also generally relate to environmental barrier coatings having CMAS mitigation capability for silicon-containing components, the barrier coating comprising: a bond coat layer comprising aluminide-alumina TGO; a transition layer comprising AeA12O19; and an outer layer comprising AeA14O7.
• Embodiments herein also generally relate to environmental barrier coatings having CMAS mitigation capability for silicon-containing components, the barrier coating comprising: a bond coat layer comprising aluminide-alumina TGO; a transition layer comprising BSAS; and an outer layer selected from the group consisting of ZnA12O4, MgA12O4, Ln2Si2O7, HfO2, LnPO4, and Ln2SiO5.
• Embodiments herein also generally relate to environmental barrier coatings having CMAS mitigation capability for silicon-containing CMC components, the barrier coating comprising: a bond coat comprising aluminide-alumina TGO; a transition layer comprising HfO2 or YPO4; and an outer layer selected from the group consisting of AeA12O19, AeHfO3, AeZrO3, ZnA12O4, MgA12O4, Ln4A12O9, Lna4Ga2O9, Ln3A15O12, Ln3Ga5O12, Ln2Si2O7, Ln2SiO5 and Ga2O3.
• FIG. 1 is a schematic cross sectional view of one embodiment of an environmental barrier coating providing CMAS mitigation in accordance with the description herein. DETAILED DESCRIPTION OF THE INVENTION
• Embodiments described herein generally relate to EBCs providing CMAS mitigation capability for ceramic substrate components.
• CMCs refers to silicon-containing, or oxide- oxide, matrix and reinforcing materials.
• silicon-containing CMCs acceptable for use herein can include, but should not be limited to, materials having a matrix and reinforcing fibers comprising non-oxide silicon-based materials such as silicon carbide, silicon nitride, silicon oxycarbides, silicon oxynitrides, and mixtures thereof.
• CMCs with silicon carbide matrix and silicon carbide fiber; silicon nitride matrix and silicon carbide fiber; and silicon carbide/silicon nitride matrix mixture and silicon carbide fiber.
• CMCs can have a matrix and reinforcing fibers comprised of oxide ceramics. These oxide- oxide composites are described below.
• the "oxide-oxide CMCs" may be comprised of a matrix and reinforcing fibers comprising oxide-based materials such as aluminum oxide (AI2O3), silicon dioxide (SiO 2 ), aluminosilicates, and mixtures thereof.
• oxide-based materials such as aluminum oxide (AI2O3), silicon dioxide (SiO 2 ), aluminosilicates, and mixtures thereof.
• Aluminosilicates can include crystalline materials such as mullite (3AI2O3 2SiO 2 ), as well as glassy aluminosilicates.
• monolithic ceramics refers to materials comprising only silicon carbide, only silicon nitride, only alumina, or only mullite.
• CMCs and monolithic ceramics are collectively referred to as “ceramics.”
• barrier coating(s) refers to environmental barrier coatings (EBCs).
• EBCs environmental barrier coatings
• the barrier coatings herein may be suitable for use on ceramic substrate components 10 found in high temperature environments, such as those present in gas turbine engines.
• Substrate component or simply “component” refers to a component made from “ceramics,” as defined herein.
• EBC 12 may comprise an optional bond coat layer 14, an optional silica layer 15, optionally at least one transition layer 16, and an outer layer 18, as shown generally in FIG. 1.
• the bond coat layer 14 may comprise silicon, suicide, aluminide, or aluminide with a thermally grown aluminide oxide scale (henceforth "aluminide-alumina TGO").
• suicide may include, but is not limited to, niobium disilicide, molybdenum disilicide, rare earth (Ln) suicides, nobel metal suicides, chromium suicide (e.g. CrSi 3 ), niobium suicide (e.g. NbSi 2 , NbSi 3 ), molybdenum suicide (e.g. MoSi 2 , MoSi 3 ), tantalum suicide (e.g.
• TaSi 2 , TaSi 3 titanium suicide (e.g. TiSi 2 , TiSi 3 ), tungsten suicide (e.g. WSi 2 , WsSi 3 ), zirconium suicide (e.g. ZrSi 2 ), hafnium suicide (e.g. HfSi 2 ),
• Ln refers to the rare earth elements of scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), and mixtures thereof, while “Lna” refers to the rare earth elements of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), and mixtures thereof.
• rare earth suicides may include scandium suicide (e.g. ScSi 2 , Sc 5 Si 3 , Sc 3 Si 5 , ScSi, Sc 3 Si 4 ), yttrium suicide (e.g. YSi 2 , Y 5 Si 3 , Y 3 Si 5 , YSi, Y 3 Si 4 ), lanthanum suicide (e.g. LaSi 2 , La 5 Si 3 , La 3 Si 5 , LaSi, La 3 Si 4 ), cerium suicide (e.g. CeSi 2 , Ce 5 Si 3 , Ce 3 Si 5 , CeSi, Ce 3 Si 4 ), praseodymium suicide (e.g.
• scandium suicide e.g. ScSi 2 , Sc 5 Si 3 , Sc 3 Si 5 , ScSi, Sc 3 Si 4
• yttrium suicide e.g. YSi 2 , Y 5 Si 3 , Y 3 Si 5 , YSi, Y 3 Si 4
• aluminides may include, but should not be limited to, ruthenium aluminide, platinum aluminide, nickel aluminide, titanium aluminide, or mixtures thereof.
• the bond coat layer 14 may comprise any of a silicon bond coat layer, a silicide bond coat layer, or an aluminide - alumina TGO bond coat layer, each of which is described herein below.
• silicon-containing component includes silicon-containing CMCs, monolithic silicon carbide ceramics and monolithic silicon nitride ceramics.
• a silicon-containing component may have a silicon bond coat layer 14.
• the EBC may comprise one of the following architectures: a silicon bond coat layer 14, an optional silica layer 15, and a Ln 4 Al 2 Og outer layer 18; a silicon bond coat layer 14, an optional silica layer 15, and a Lna 4 Ga 2 0g outer layer 18; a silicon bond coat layer 14, an optional silica layer 15, a HfO 2 transition layer 16, and a Ln 4 Al 2 Og outer layer 18; a silicon bond coat layer 14, an optional silica layer 15, a HfO 2 transition layer 16, and a Ln 4 Ga 2 Og outer layer 18; a silicon bond coat layer 14, an optional silica layer 15, a LnPO 4 transition layer 16, and a Ln 2 SiO 5 outer layer 18; a silicon bond coat layer 14, an optional silica layer 15, a LnPO 4 transition layer 16, and a Ln 2 Si 2 O 7 outer layer 18; a silicon bond coat layer 14, an optional silica layer 15, a LnPO 4
• mullite/BSAS mixture refers to a mixture comprising from about 1% to about 99% mullite and from about 1% to about 99% BSAS.
• a silicon-containing component may comprise a suicide bond coat layer 14.
• the EBC may comprise any of the previously listed architectures with the exception that the silicon bond coat layer is replaced with a suicide bond coat layer.
• the EBC may comprise on of the following architectures: a suicide bond coat layer 14, an optional silica layer 15, a Ln 2 Si 2 O 7 first transition layer 16, a BSAS second transition layer 16, and a ZnAl 2 O 4 outer layer 18; a suicide bond coat layer 14, an optional silica layer 15, a Ln 2 Si 2 O 7 transition layer 16, and a Ln 4 Ga 2 Og outer layer 18; a suicide bond coat layer 14, an optional silica layer 15, a Ln 2 Si 2 O 7 transition layer 16, and a Ln 3 GaSOi 2 outer layer 18.
• a silicon-containing component may comprise an aluminide-alumina TGO bond coat layer 14.
• the EBC does not need a silica layer and may comprise one of the following architectures: an aluminide- alumina TGO bond coat layer 14 and a AeAl 2 Oig outer layer 18; an aluminide- alumina TGO bond coat layer 14 and an HfO 2 outer layer; an aluminide-alumina TGO bond coat layer 14 and a LnPO 4 outer layer; an aluminide-alumina TGO bond coat layer 14, AeAl 2 Oig transition layer 16, and a AeAl 4 O 7 outer layer 18; an aluminide- alumina TGO bond coat layer 14 and a AeHfO 3 outer layer 18; an aluminide-alumina TGO bond coat layer 14 and a AeZrO 3 outer layer 18; an aluminide-alumina TGO bond coat layer 14 and a Z
• oxide component includes oxide-oxide CMCs, monolithic alumina ceramics, and monolithic mullite ceramics.
• EBC layers can provide CMAS mitigation capability to high temperature ceramic components such as those present in gas turbine engines such as combustor components, turbine blades, shrouds, nozzles, heat shields, and vanes, which are exposed to temperatures of about 300OF (1649 0 C) during routine engine operations.
• any bond coat layer 14, silica layer 15, transition layer 16, and outer layer 18 present may be made using conventional methods known to those skilled in the art. More particularly, and regardless of the particular architecture of the EBC having CMAS mitigation capability, the substrate component can be coated using conventional methods known to those skilled in the art, including, but not limited to, plasma spraying, high velocity plasma spraying, low pressure plasma spraying, solution plasma spraying, suspension plasma spraying, chemical vapor deposition (CVD), electron beam physical vapor deposition (EBPVD), sol-gel, sputtering, slurry processes such as dipping, spraying, tape-casting, rolling, and painting, and combinations of these methods. Once coated, the substrate component may be dried and sintered using either conventional methods, or unconventional methods such as microwave sintering, laser sintering or infrared sintering.
• the inclusion of the present CMAS mitigation compositions can help prevent the EBC from degradation due to reaction with CMAS in high temperature engine environments. More particularly, these CMAS mitigation compositions can help prevent or slow the reaction of CMAS with the barrier coating that can form secondary phases that rapidly volatilize in steam. Additionally, the present CMAS mitigation compositions can help prevent or slow the penetration of CMAS through the barrier coating along the grain boundaries into a nonoxide, silicon-based substrate. Reaction of CMAS with substrates such as silicon nitrate and silicon carbide evolve nitrogen-containing and carbonaceous gases, respectively. Pressure from this gas evolution can result in blister formation within the EBC coating. These blisters can easily rupture and destroy the hermetic seal against water vapor provided by the EBC in the first instance.
• the presence of the CMAS mitigation compositions described herein can help prevent or slow the attack of molten silicates on the EBC, thereby allowing the EBC to perform its function of sealing the ceramic component from corrosive attack in high temperature steam.
• the CMAS mitigation compositions can help prevent recession of the ceramic component, and also any layers of the EBC that may be susceptible to steam recession if CMAS reacts with it, to form steam-volatile secondary phases. Dimensional changes of ceramic components due to steam recession can limit the life and/or functionality of the component in turbine engine applications.
• the CMAS mitigation compositions are important to allow the barrier coating to perform its functions; thereby allowing the ceramic component to function properly and for its intended time span.
• any transition layers present can provide moderate to strong barriers to high temperature steam penetration. This can help reduce the occurrence of a reaction between the layers of the barrier coating. Multiple transition layers can be included to further help reduce the occurrence of interlayer reactions, which can arise after long-term thermal exposure of the barrier coating.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Structural Engineering (AREA)
• Inorganic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Turbine Rotor Nozzle Sealing (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=41559479

Family Applications (1)

Country Status (5)

Cited By (2)

Families Citing this family (24)

Citations (6)

Family Cites Families (30)

• 2008
  • 2008-12-19 US US12/340,126 patent/US8273470B2/en active Active
• 2009
  • 2009-12-14 WO PCT/US2009/067852 patent/WO2010071768A1/en not_active Ceased
  • 2009-12-14 JP JP2011542301A patent/JP5671476B2/ja active Active
  • 2009-12-14 CA CA2746450A patent/CA2746450C/en active Active
  • 2009-12-14 EP EP20090793400 patent/EP2379776B1/en active Active

Patent Citations (6)

Also Published As

Similar Documents

Legal Events