Patents by Inventor David Joseph Mitchell
David Joseph Mitchell 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).
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Patent number: 7449254Abstract: 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: GrantFiled: January 21, 2005Date of Patent: November 11, 2008Assignee: General Electric CompanyInventors: Irene Spitsberg, Christine Govern, Bangalore Aswatha Nagaraj, David Joseph Mitchell
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Patent number: 7434670Abstract: A shroud support method and apparatus for a ceramic component of a gas turbine having: an outer shroud block having a coupling to a casing of the gas turbine; a spring mass damper attached to the outer shroud block and including a spring biased piston extending through said outer shroud block, wherein the spring mass damper applies a load to the ceramic component; and the ceramic component has a forward flange and an aft flange each attachable to the outer shroud block.Type: GrantFiled: August 16, 2006Date of Patent: October 14, 2008Assignee: General Electric CompanyInventors: Randall Richard Good, Kevin Leon Bruce, Gregory Scot Corman, David Joseph Mitchell, Mark Stewart Schroder, Christopher Grace
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Publication number: 20080202877Abstract: A shroud support method and apparatus for a ceramic component of a gas turbine having: an outer shroud block having a coupling to a casing of the gas turbine; a spring mass damper attached to the outer shroud block and including a spring biased piston extending through said outer shroud block, wherein the spring mass damper applies a load to the ceramic component; and the ceramic component has a forward flange and an aft flange each attachable to the outer shroud block.Type: ApplicationFiled: August 16, 2006Publication date: August 28, 2008Applicant: General Electric CompanyInventors: Randall Richard Good, Kevin Leon Bruce, Gregory Scot Corman, David Joseph Mitchell, Mark Stewart Schroder, Christopher Grace
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Patent number: 7326468Abstract: 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: GrantFiled: January 21, 2005Date of Patent: February 5, 2008Assignee: General Electric CompanyInventors: Irene Spitsberg, Christine Govern, Bangalore Aswatha Nagaraj, Brian Thomas Hazel, David Joseph Mitchell
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Patent number: 7117983Abstract: A shroud support apparatus for a ceramic component of a gas turbine having: an outer shroud block having a coupling to a casing of the gas turbine; a spring mass damper attached to the outer shroud block and including a spring biased piston extending through said outer shroud block, wherein the spring mass damper applies a load to the ceramic component; and the ceramic component has a forward flange and an aft flange each attachable to the outer shroud block.Type: GrantFiled: March 5, 2004Date of Patent: October 10, 2006Assignee: General Electric CompanyInventors: Randall Richard Good, Kevin Leon Bruce, Gregory Scot Corman, David Joseph Mitchell, Mark Stewart Schroder, Christopher Grace
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Patent number: 7115327Abstract: 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: GrantFiled: January 21, 2005Date of Patent: October 3, 2006Assignee: General Electric CompanyInventors: Irene Spitsberg, Christine Govern, Bangalore Aswatha Nagaraj, Brian Thomas Hazel, David Joseph Mitchell
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Patent number: 7115326Abstract: 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: GrantFiled: January 21, 2005Date of Patent: October 3, 2006Assignee: General Electric CompanyInventors: Irene Spitsberg, Christine Govern, Bangalore Aswatha Nagaraj, Brian Thomas Hazel, David Joseph Mitchell
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Patent number: 7005200Abstract: A method for manufacturing an article for use in a high-temperature environment, and an article for use in such an environment, are presented. The method comprises providing a substrate; selecting a desired vertical crack density for a protective coating to be deposited on the substrate; providing a powder, wherein the powder has a size range selected to provide a coating having the desired vertical crack density; and applying a thermal-sprayed coating to the substrate, the coating having the desired vertical crack density, wherein the powder is used as a raw material for the coating.Type: GrantFiled: January 14, 2005Date of Patent: February 28, 2006Assignee: General Electric CompanyInventors: Hongyu Wang, David Joseph Mitchell, Yuk-Chiu Lau, Arnold Thomas Henry
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Patent number: 6969555Abstract: A coating for silicon based materials such as those used in high temperature, aqueous environments. An aspect of the invention is directed to an article including a silicon based substrate, a bond coat comprising silicon, and a barrier coat. The barrier coat includes an aluminate such as an alkaline earth metal aluminate or a rare earth aluminate. The barrier coat may be an intermediate coat between the bond coat and a top coat, or it may be the top coat.Type: GrantFiled: October 6, 2003Date of Patent: November 29, 2005Assignee: General Electric CompanyInventors: Peter Joel Meschter, David Joseph Mitchell, Krishan Lal Luthra, Jennifer Su Saak
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Patent number: 6866897Abstract: A method for manufacturing an article for use in a high-temperature environment, and an article for use in such an environment, are presented. The method comprises providing a substrate; selecting a desired vertical crack density for a protective coating to be deposited on the substrate; providing a powder, wherein the powder has a size range selected to provide a coating having the desired vertical crack density; and applying a thermal-sprayed coating to the substrate, the coating having the desired vertical crack density, wherein the powder is used as a raw material for the coating.Type: GrantFiled: September 30, 2002Date of Patent: March 15, 2005Assignee: General Electric CompanyInventors: Hongyu Wang, David Joseph Mitchell, Yuk-Chiu Lau, Arnold Thomas Henry
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Patent number: 6844075Abstract: A coating for a silicon based material such as those used in high temperature environments. An aspect of the invention is directed to an environmental barrier coating including a silicon bond coat, and intermediate coat, and a top coat. The intermediate coat may comprise tantalum aluminate, niobium aluminate, or a mixture of the two. The intermediate coat is resistant to solid-state suburface reactions with the bond coat and the top coat and is substantially inert to reactions with silica at high temperatures.Type: GrantFiled: October 6, 2003Date of Patent: January 18, 2005Assignee: General Electric CompanyInventors: Jennifer Su Saak, Peter Joel Meschter, David Joseph Mitchell, Krishan Lal Luthra
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Patent number: 6740364Abstract: A process for depositing a ceramic coating system for Si-containing materials, particularly those for articles exposed to high temperatures. The process is particularly applicable to depositing a compositionally-graded coating system comprising multiple ceramic layers with differing compositions, including a dense, strain-tolerant, vertically-cracked YSZ-containing ceramic layer deposited on a ceramic layer having a composition that is a mixture of YSZ and either mullite or BSAS. The process entails depositing the YSZ-containing ceramic layer using a plasma spraying technique while maintaining the substrate at a temperature so as not to form horizontal cracks in the coating system, but still maintain the dense vertically-cracked structure of the YSZ-containing ceramic layer for strain tolerance.Type: GrantFiled: May 30, 2002Date of Patent: May 25, 2004Assignee: General Electric CompanyInventors: Yuk-Chiu Lau, Hongyu Wang, David Joseph Mitchell
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Publication number: 20040062954Abstract: A method for manufacturing an article for use in a high-temperature environment, and an article for use in such an environment, are presented. The method comprises providing a substrate; selecting a desired vertical crack density for a protective coating to be deposited on the substrate; providing a powder, wherein the powder has a size range selected to provide a coating having the desired vertical crack density; and applying a thermal-sprayed coating to the substrate, the coating having the desired vertical crack density, wherein the powder is used as a raw material for the coating.Type: ApplicationFiled: September 30, 2002Publication date: April 1, 2004Applicant: General Electric Company-Global Research CenterInventors: Hongyu Wang, David Joseph Mitchell, Yuk-Chiu Lau, Arnold Thomas Henry
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Publication number: 20030224124Abstract: A process for depositing a ceramic coating system for Si-containing materials, particularly those for articles exposed to high temperatures. The process is particularly applicable to depositing a compositionally-graded coating system comprising multiple ceramic layers with differing compositions, including a dense, strain-tolerant, vertically-cracked YSZ-containing ceramic layer deposited on a ceramic layer having a composition that is a mixture of YSZ and either mullite or BSAS. The process entails depositing the YSZ-containing ceramic layer using a plasma spraying technique while maintaining the substrate at a temperature so as not to form horizontal cracks in the coating system, but still maintain the dense vertically-cracked structure of the YSZ-containing ceramic layer for strain tolerance.Type: ApplicationFiled: May 30, 2002Publication date: December 4, 2003Applicant: General Electric CompanyInventors: Yuk-Chiu Lau, Hongyu Wang, David Joseph Mitchell