Patents by Inventor Bangalore A. Nagaraj

Bangalore A. Nagaraj has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20060222884
    Abstract: An article comprising a turbine component other than an airfoil having a metal substrate and a ceramic corrosion resistant coating overlaying the metal substrate. This coating has a thickness up to about 5 mils (127 microns) and comprises a ceramic metal oxide selected from the group consisting of zirconia, hafnia and mixtures thereof. This coating can be formed by a method comprising the following steps: (a) providing a turbine component other than an airfoil comprising the metal substrate; (b) providing a gel-forming solution comprising a ceramic metal oxide precursor; (c) heating the gel-forming solution to a first preselected temperature for a first preselected time to form a gel; (d) depositing the gel on the metal substrate; and (e) firing the gel at a second preselected temperature above the first preselected temperature to form the ceramic corrosion resistant coating comprising the ceramic metal oxide.
    Type: Application
    Filed: March 31, 2005
    Publication date: October 5, 2006
    Inventors: Bangalore Nagaraj, Brian Hazel, Jeffrey Pfaendtner
  • Publication number: 20060199032
    Abstract: A protected article includes a substrate having a surface, and a protective system overlying and contacting a first portion of the surface of the substrate. The protective system has a nickel-base superalloy bond coat, an aluminide layer overlying and contacting the bond coat, and a dense vertically microcracked ceramic thermal barrier coating overlying and contacting the aluminide layer.
    Type: Application
    Filed: March 7, 2005
    Publication date: September 7, 2006
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Bangalore Nagaraj, D. Patrick, Thomas Tomlinson, David Parry
  • Publication number: 20060166018
    Abstract: An article comprising a substrate formed of a silicon-comprising material, such as an article exposed to the hostile thermal environment of a gas turbine engine. The article further comprises an environmental barrier layer, e.g., an alkaline earth metal aluminosilicate, and a physical barrier layer overlying the environmental barrier layer. The physical barrier layer comprises zirconia or hafnia stabilized with an oxide of a metal selected from the group consisting of magnesium, calcium, scandium, yttrium, and lanthanide metals; and a low CTE oxide selected from the group consisting of niobia and tantala; and mixtures thereof. A method for preparing an environmental barrier coating system on a substrate formed of a silicon-comprising material is also disclosed.
    Type: Application
    Filed: January 21, 2005
    Publication date: July 27, 2006
    Inventors: Irene Spitsberg, Christine Govern, Bangalore Nagaraj, David Mitchell
  • Publication number: 20060165893
    Abstract: A thermal barrier coating for an underlying metal substrate of articles that operate at, or are exposed to, high temperatures, as well as being exposed to environmental contaminant compositions. This coating comprises an optional inner layer nearest to the underlying metal substrate comprising a non-alumina ceramic thermal barrier coating material in an amount up to 100%, and an outer layer having an exposed surface and comprising at least about 50% of a non-alumina ceramic thermal barrier coating material and alumina in an amount up to about 50% and sufficient to protect the thermal barrier coating at least partially against environmental contaminants that become deposited on the exposed surface. This coating can be used to provide a thermally protected article having a metal substrate and optionally a bond coat layer adjacent to and overlaying the metal substrate.
    Type: Application
    Filed: December 22, 2005
    Publication date: July 27, 2006
    Inventors: Bangalore Nagaraj, Brett Boutwell, Robert Baur
  • Publication number: 20060166015
    Abstract: An article comprising a substrate formed of a silicon-comprising material, such as an article exposed to the hostile thermal environment of a gas turbine engine. The article further comprises an environmental barrier layer, e.g., an alkaline earth metal aluminosilicate, and a top coat comprising zirconia or hafnia stabilized with up to about 10 mole % of an oxide of a metal selected from the group consisting of magnesium, calcium, scandium, yttrium, and lanthanide metals, and mixtures thereof. The article further comprises a transition layer between the environmental barrier layer and the top coat, the transition layer comprising zirconia or hafnia stabilized with up to about 10 mole % of an oxide of a metal selected from the group consisting of magnesium, calcium, scandium, yttrium, and lanthanide metals; and a low CTE oxide selected from the group consisting of niobia and tantala; and mixtures thereof.
    Type: Application
    Filed: January 21, 2005
    Publication date: July 27, 2006
    Inventors: Irene Spitsberg, Christine Govern, Bangalore Nagaraj, Brian Hazel, David Mitchell
  • Publication number: 20060166016
    Abstract: An article comprising a substrate formed of a silicon-comprising material, such as an article exposed to the hostile thermal environment of a gas turbine engine. The article further comprises an environmental barrier layer, e.g., an alkaline earth metal aluminosilicate, and a top coat comprising hafnia stabilized with from about 0.5 mole % to about 10 mole % of an oxide of a metal selected from the group consisting of magnesium, calcium, scandium, yttrium, and lanthanide metals, and mixtures thereof. The article optionally comprises a transition layer between the environmental barrier layer and the top coat. A method for preparing a thermal/environmental barrier coating on a substrate formed of a silicon-comprising material is also disclosed.
    Type: Application
    Filed: January 21, 2005
    Publication date: July 27, 2006
    Inventors: Irene Spitsberg, Christine Govern, Bangalore Nagaraj, Brian Hazel, David Mitchell
  • Publication number: 20060166017
    Abstract: An article comprising a substrate formed of a silicon-comprising material, such as an article exposed to the hostile thermal environment of a gas turbine engine. The article further comprises an environmental barrier layer, e.g., an alkaline earth metal aluminosilicate, and a top coat comprising zirconia or hafnia stabilized with an oxide of a metal selected from the group consisting of magnesium, calcium, scandium, yttrium, and lanthanide metals, and mixtures thereof. The article further comprises a transition layer between the environmental barrier layer and the top coat, the transition layer comprising zirconia or hafnia stabilized with an oxide of a metal selected from the group consisting of magnesium, calcium, scandium, yttrium, and lanthanide metals; and a low CTE oxide selected from the group consisting of niobia and tantala; and mixtures thereof. A method for preparing a thermal/environmental barrier coating system on a substrate formed of a silicon-comprising material is also disclosed.
    Type: Application
    Filed: January 21, 2005
    Publication date: July 27, 2006
    Inventors: Irene Spitsberg, Christine Govern, Bangalore Nagaraj, Brian Hazel, David Mitchell
  • Publication number: 20060121295
    Abstract: In accordance with an embodiment of the invention, a thermal barrier coating (TBC) for inclusion in a thermal barrier coating/environmental barrier coating system (TBC/EBC system) for use on a silicon containing material substrate is provided. The TBC comprises a compound having a primary constituent portion and a stabilizer portion stabilizing said primary constituent. The primary constituent portion of the TBC comprises hafnia present in an amount of at least about 5 mol % of the primary constituent. The stabilizer portion of said thermal barrier coating comprises at least one metal oxide comprised of cations with a +2 or +3 valence present in the amount of about 10 to about 40 mol % of the thermal barrier coating.
    Type: Application
    Filed: December 6, 2004
    Publication date: June 8, 2006
    Inventors: Brett Boutwell, Irene Spitsberg, Christine Govern, Bangalore Nagaraj, Brian Hazel
  • Publication number: 20060121293
    Abstract: In accordance with an embodiment of the invention, an article is provided. The article comprises a substrate comprised of silicon containing material, an environmental barrier coating (EBC) overlying the substrate and a thermal barrier coating (TBC) on the environmental barrier coating. The thermal barrier coating comprising a compound having a rhombohedral phase.
    Type: Application
    Filed: December 6, 2004
    Publication date: June 8, 2006
    Inventors: Brett Boutwell, Irene Spitsberg, Christine Govern, Bangalore Nagaraj, Brian Hazel, Ramgopal Darolia, Curtis Johnson, Yan Gao, Mark Gorman
  • Publication number: 20060115661
    Abstract: According to an embodiment of the invention, an article of manufacture for use in a gas turbine engine is disclosed. The article comprises a part having a surface covered with a ceramic thermal barrier coating. The thermal barrier coating has an outer surface covered with a sacrificial phosphate coating, wherein the sacrificial phosphate coating reacts with contaminant compositions to prevent contaminant infiltration into the thermal barrier coating.
    Type: Application
    Filed: December 1, 2004
    Publication date: June 1, 2006
    Inventors: Brian Hazel, Mark Gorman, Bangalore Nagaraj
  • Publication number: 20060115659
    Abstract: According to an embodiment of the invention, disclosed is a composite comprising a porous thermal barrier coating on a metallic part and an impermeable barrier coating adjacent to the outer surface of the thermal barrier coating. The impermeable barrier coating is dense and non-porous and comprises a rare earth silicate, the impermeable barrier coating thereby preventing infiltration of the contaminant composition into the thermal barrier coating.
    Type: Application
    Filed: December 1, 2004
    Publication date: June 1, 2006
    Inventors: Brian Hazel, Irene Spitsberg, Christine Govern, Bangalore Nagaraj
  • Publication number: 20060093849
    Abstract: A method for applying a chromium containing coating to an underlying metal substrate where the metal substrate has an overlaying platinum-containing layer, as well as a corrosion resistant coated article thereof. A chromium-containing layer is deposited on the platinum-containing layer with an aluminide diffusion layer being deposited on the chromium-containing layer, the aluminide diffusion layer having an inner diffusion layer adjacent the chromium-containing layer and an outer additive layer adjacent to the inner diffusion layer. The chromium-containing layer is deposited by a deposition technique that permits chromium in the chromium-containing layer to more readily diffuse into a subsequently deposited aluminde diffusion coating layer. The chromium-containing and aluminide diffusion layers are then treated to cause chromium from the chromium-containing layer to diffuse into the outer additive layer in an amount of at least about 8%. The resulting coated article is resistant to corrosion.
    Type: Application
    Filed: November 2, 2004
    Publication date: May 4, 2006
    Inventors: Andrew Farmer, Bangalore Nagaraj, Roger Wustman, Theodore Grossman, John Reiss
  • Publication number: 20060057406
    Abstract: Thermal barrier coating (TBC) and a method of depositing a TBC having a modulated columnar microstructure that exhibits increased impact resistance. The TBC is deposited to have a columnar microstructure in which columns extend from a substrate surface. The columns having inner regions contacting the surface, outer regions near an outermost surface of the TBC, and interior regions therebetween. The inner regions of the columns are substantially normal to the substrate surface and at least one of the interior and outer regions of the columns are nonaligned with its respective inner regions, so that the columns of the columnar microstructure are continuous but modulated between the inner and outer regions to reduce tensile stresses within the columns resulting from particle impact.
    Type: Application
    Filed: September 14, 2004
    Publication date: March 16, 2006
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Ramgopal Darolia, Brett Boutwell, Brian Hazel, Bangalore Nagaraj, Joseph Rigney, Roger Wustman
  • Publication number: 20060057416
    Abstract: A surface of an article is protected by coating the surface with a silicon-containing coating by preparing a coating mixture of silicon, a halide activator, and an oxide powder, positioning the surface of the article in gaseous communication with the coating mixture, and heating the surface of the article and the coating mixture to a coating temperature of from about 1150° F. to about 1500° F. The article is preferably a component of a gas turbine engine made of a nickel-base superalloy.
    Type: Application
    Filed: April 19, 2005
    Publication date: March 16, 2006
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Nrinpendra Das, Bangalore Nagaraj, Matthew Saylor, Jackie King
  • Patent number: 7003959
    Abstract: A high temperature splash plate for use in the combustor of a gas turbine engine that also is a specular optical reflector. A thin layer of a high temperature reflector is applied to the surface of the splash plate of the component that forms a boundary for hot combustion gases. The component typically includes a thermal barrier coating overlying the high temperature metallic component that permits the component to operate at elevated temperatures. The thermal barrier coating must be polished in order to provide a surface that can suitably reflect the radiation into the gas flow path. A thin layer of the high temperature reflector then is applied over the polished thermal barrier coating by a process that can adequately adhere the reflector to the polished surface without increasing the roughness of the surface. The surface reflects radiation in the direction of the turbine back into the hot gas flow path. The reflected radiation is not focused onto any other hardware component.
    Type: Grant
    Filed: December 31, 2002
    Date of Patent: February 28, 2006
    Assignee: General Electric Company
    Inventors: John F. Ackermann, Paul V. Arszman, Bangalore A. Nagaraj, Craig D. Young, Nicole Justis
  • Publication number: 20050191516
    Abstract: A method applying a thermal barrier coating to a metal substrate, or for repairing a thermal barrier coating previously applied by physical vapor deposition to an underlying aluminide diffusion coating that overlays the metal substrate. The aluminide diffusion coating is treated to make it more receptive to adherence of a plasma spray-applied overlay alloy bond coat layer. An overlay alloy bond coat material is then plasma sprayed on the treated aluminide diffusion coating to form an overlay alloy bond coat layer. A ceramic thermal barrier coating material is plasma sprayed on the overlay alloy bond coat layer to form the thermal barrier coating. In the repair embodiment of this method, the physical vapor deposition-applied thermal barrier coating is initially removed from the underlying aluminide diffusion coating.
    Type: Application
    Filed: April 25, 2005
    Publication date: September 1, 2005
    Inventors: Bangalore Nagaraj, Eva Lanman, Deborah Schorr, Thomas Tomlinson, Raymond Heidorn, David Kastrup, Craig Young
  • Publication number: 20050178126
    Abstract: A turbine engine combustor member, for example a deflector including an inner surface at a combustor interior and an outer surface away from such interior includes a body of a high temperature alloy having properties combining resistance to hot corrosion and oxidation to avoid coating the outer surface. In one embodiment, the inner surface includes an environmental resistant coating comprising a ceramic-base thermal barrier coating. In some forms such coating includes an inner coating including Al under the ceramic-base coating. In another embodiment, the member includes air cooling passages and is substantially uncoated. Provision of such a member enables complete combustor assembly including a plurality of members and then coating all inner surfaces concurrently rather than individually before assembly.
    Type: Application
    Filed: February 12, 2004
    Publication date: August 18, 2005
    Inventors: Craig Young, Bangalore Nagaraj, Dane Elliott-Lewis, Joshua Miller, Kevin O'Hara
  • Patent number: 6925811
    Abstract: A high temperature gas turbine component for use in the gas flow path that also is a specular optical reflector. A thin layer of a high temperature reflector is applied to the flow path surface of the component, that is, the surface of the component that forms a boundary for hot combustion gases. The component typically includes a thermal barrier coating overlying the high temperature metallic component that permits the component to operate at elevated temperatures. The thermal barrier coating must be polished in order to provide a surface that can suitably reflect the radiation into the gas flow path. A thin layer of the high temperature reflector then is applied over the polished thermal barrier coating by a process that can adequately adhere the reflector to the polished surface without increasing the roughness of the surface. The high temperature reflector can be applied to any surface aft of the compressor, such as on a combustor wall. The surface reflects radiation back into the hot gas flow path.
    Type: Grant
    Filed: December 31, 2002
    Date of Patent: August 9, 2005
    Assignee: General Electric Company
    Inventors: Nicole Justis, John F. Ackermann, Paul V. Arszman, Bangalore A. Nagaraj, Craig D. Young
  • Patent number: 6926496
    Abstract: A high temperature gas turbine component for use in the gas flow path that also is a specular optical reflector. A thin layer of a high temperature reflector is applied to the gas flow path of the component, that is, the surface of the component that forms a boundary for hot combustion gases. The component typically includes a thermal barrier coating overlying the high temperature metallic component that permits the component to operate at elevated temperatures. The thermal barrier coating must be polished in order to provide a surface that can suitably reflect the radiation into the gas flow path. A thin layer of the high temperature reflector the is applied over the polished thermal barrier coating by a process that can adequately adhere the reflector to the polished surface without increasing the roughness of the surface. The high temperature reflector can be applied to any surface aft of the compressor, such as on a turbine nozzle. The surface reflects radiation back into the hot gas flow path.
    Type: Grant
    Filed: December 31, 2002
    Date of Patent: August 9, 2005
    Assignee: General Electric Company
    Inventors: John F. Ackermann, Paul V. Arszman, Bangalore A. Nagaraj
  • Publication number: 20050170200
    Abstract: A TBC system suitable for protecting the surface of a substrate subjected to a hostile thermal environment. The TBC system comprises a bond coat on the substrate surface, an alumina scale on the bond coat, and a multilayer TBC comprising a thermal-sprayed first ceramic layer on the alumina scale and a thermal-sprayed second ceramic layer overlying the first ceramic layer. The first ceramic layer consists essentially of partially stabilized zirconia so as to comprise the tetragonal and cubic phases of zirconia. The second ceramic layer consists essentially of fully stabilized zirconia so as to consist essentially of the cubic phase of zirconia. The second ceramic layer is also characterized by having vertical microcracks that extend through the thickness thereof. The second ceramic layer is thicker and more erosion resistant than the first ceramic layer.
    Type: Application
    Filed: February 3, 2004
    Publication date: August 4, 2005
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Bangalore Nagaraj, Ramgopal Darolia