Patents by Inventor Ngunjoh Lawrence Ndamka
Ngunjoh Lawrence Ndamka 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: 11976013Abstract: An article may include a substrate including a ceramic matrix composite (CMC); a composite coating layer including a first coating material that includes a rare-earth disilicate and a second coating material that includes at least one of a rare-earth monosilicate, a CMAS-resistant material, or a high-temperature dislocating material, where the second coating material forms a substantially continuous phase in the composite coating layer.Type: GrantFiled: September 21, 2018Date of Patent: May 7, 2024Assignees: Rolls-Royce Corporation, Rolls-Royce plcInventors: Stephanie Gong, Ngunjoh Lawrence Ndamka, Matthew R. Gold, Li Li, Taylor K. Blair, Sunny Chang, Ann Bolcavage
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Patent number: 11952317Abstract: An example article includes a substrate and a barrier coating on the substrate. The barrier coating includes a matrix including a rare-earth disilicate extending from an inner interface facing the substrate to an outer surface opposite the inner interface. The barrier coating includes a graded volumetric distribution of rare-earth oxide rich (REO-rich) phase regions in the matrix along a direction from the inner interface to the outer surface. The graded volumetric distribution defines a first volumetric density of the REO-rich phase regions at a first region of the matrix adjacent the outer surface. The graded volumetric distribution defines a second volumetric density of the REO-rich phase regions at a second region of the matrix adjacent the inner surface. The second volumetric density is different from the first volumetric density. An example technique includes forming the barrier coating on the substrate of a component.Type: GrantFiled: October 18, 2019Date of Patent: April 9, 2024Assignees: Rolls-Royce Corporation, Rolls-Royce plcInventors: Ngunjoh Lawrence Ndamka, Li Li, Stephanie Gong, Ann Bolcavage, Taylor K. Blair, Robert Golden
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Patent number: 11827986Abstract: In some examples, an article may include a substrate and a coating system on the substrate. The coating system may include a layer comprising a plurality of voids, wherein respective voids of the plurality of voids define respective void volumes; and a nucleating agent within at least some of the respective void volumes of the layer, wherein the nucleating agent is configured to induce crystallization of the molten CMAS. The coating system may include an environmental barrier coating, thermal barrier coating, and/or abradable coating.Type: GrantFiled: March 15, 2019Date of Patent: November 28, 2023Assignees: Rolls-Royce Corporation, Rolls-Royce North American Technologies, Inc., Rolls-Royce plcInventors: Sean E. Landwehr, Ngunjoh Lawrence Ndamka, Matthew R. Gold, Michael Cybulsky, Li Li, Robert Golden
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Patent number: 11655543Abstract: A method includes predicting a composition of calcium-magnesium-aluminum-silicate (CMAS) to be encountered by a high temperature mechanical system during use of the high temperature mechanical system. The method further includes selecting a composition of a CMAS-resistant barrier coating layer based at least in part on the predicted composition of CMAS. The CMAS-resistant barrier coating layer includes a base composition and at least one secondary oxide selected based on the predicted composition of CMAS. The at least one secondary oxide includes at least one of an oxide of a divalent element, an oxide of a trivalent element, or an oxide of a tetravalent element. The CMAS-resistant barrier coating layer comprises greater than 0 mol. % and less than about 7 mol. % of the at least one secondary oxide.Type: GrantFiled: August 8, 2018Date of Patent: May 23, 2023Assignees: ROLLS-ROYCE CORPORATION, ROLLS-ROYCE PLC, ROLLS-ROYCE NORTH AMERICAN TECHNOLOGIES, INC.Inventors: Ngunjoh Lawrence Ndamka, Li Li, Ann Bolcavage, Bruce Edward Varney, Sean E. Landwehr
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Publication number: 20230002288Abstract: In some examples, an article for a high-temperature mechanical system including a substrate and a doped calcia-magnesia-alumina-silicate resistant (doped CMAS-resistant) layer on the substrate. The doped CMAS-resistant layer is a thermal barrier coating or an environmental barrier coating and includes a calcia dopant.Type: ApplicationFiled: September 6, 2022Publication date: January 5, 2023Inventors: Ngunjoh Lawrence Ndamka, Ann Bolcavage
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Patent number: 10871078Abstract: An article for use in a high-temperature environment that includes a substrate including a superalloy material, a ceramic, or a ceramic matrix composite, and an abradable coating on the substrate, the abradable coating including a rare earth silicate and a dislocator phase, the dislocator phase forms one or more distinct phase regions in the abradable coating and comprises at least one of hafnium diboride (HfB2), zirconium diboride (ZrB2), tantalum nitride (TaN or Ta2N), tantalum carbide (Ta2C), titanium diboride (TiB2), zirconium carbide (ZrC), hafnium carbide (HfC), tantalum diboride (TaB2), hafnium nitride (HfN), or niobium carbide (NbC).Type: GrantFiled: September 19, 2018Date of Patent: December 22, 2020Assignees: Rolls-Royce Corporation, Rolls-Royce plcInventors: Ngunjoh Lawrence Ndamka, Li Li, Stephanie Gong, Sunny Chang, Ann Bolcavage, Taylor K. Blair
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Patent number: 10851656Abstract: An article includes a substrate, a bond coat on the substrate, and a multilayer environmental barrier coating (EBC) on the bond coat. The multilayer EBC includes a first EBC layer defining a first thickness and a second EBC layer defining a second thickness. The first EBC layer includes a first rare earth disilicate and a first concentration of a sintering aid that includes alumina. The second EBC layer includes a second rare earth disilicate and a second concentration of the sintering aid that includes alumina, less than the first concentration of the sintering aid.Type: GrantFiled: September 25, 2018Date of Patent: December 1, 2020Assignees: Rolls-Royce Corporation, Rolls-Royce PLCInventors: Stephanie Gong, Taylor K. Blair, Ngunjoh Lawrence Ndamka, Li Li, Sunny Chang, Ann Bolcavage
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Publication number: 20200123071Abstract: An example article includes a substrate and a barrier coating on the substrate. The barrier coating includes a matrix including a rare-earth disilicate extending from an inner interface facing the substrate to an outer surface opposite the inner interface. The barrier coating includes a graded volumetric distribution of rare-earth oxide rich (REO-rich) phase regions in the matrix along a direction from the inner interface to the outer surface. The graded volumetric distribution defines a first volumetric density of the REO-rich phase regions at a first region of the matrix adjacent the outer surface. The graded volumetric distribution defines a second volumetric density of the REO-rich phase regions at a second region of the matrix adjacent the inner surface. The second volumetric density is different from the first volumetric density. An example technique includes forming the barrier coating on the substrate of a component.Type: ApplicationFiled: October 18, 2019Publication date: April 23, 2020Inventors: Ngunjoh Lawrence Ndamka, Li Li, Stephanie Gong, Ann Bolcavage, Taylor K. Blair, Robert Golden
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Publication number: 20190284673Abstract: In some examples, an article may include a substrate and a coating system on the substrate. The coating system may include a layer comprising a plurality of voids, wherein respective voids of the plurality of voids define respective void volumes; and a nucleating agent within at least some of the respective void volumes of the layer, wherein the nucleating agent is configured to induce crystallization of the molten CMAS. The coating system may include an environmental barrier coating, thermal barrier coating, and/or abradable coating.Type: ApplicationFiled: March 15, 2019Publication date: September 19, 2019Inventors: Sean E. Landwehr, Ngunjoh Lawrence Ndamka, Matthew R. Gold, Michael Cybulsky, Li Li, Robert Golden
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Publication number: 20190093497Abstract: An article for use in a high-temperature environment that includes a substrate including a superalloy material, a ceramic, or a ceramic matrix composite, and an abradable coating on the substrate, the abradable coating including a rare earth silicate and a dislocator phase, the dislocator phase forms one or more distinct phase regions in the abradable coating and comprises at least one of hafnium diboride (HfB2), zirconium diboride (ZrB2), tantalum nitride (TaN or Ta2N), tantalum carbide (Ta2C) titanium diboride (TiB2), zirconium carbide (ZrC), hafnium carbide (HfC), tantalum diboride (TaB2), hafnium nitride (HfN), or niobium carbide (NbC).Type: ApplicationFiled: September 19, 2018Publication date: March 28, 2019Inventors: Ngunjoh Lawrence Ndamka, Li Li, Stephanie Gong, Sunny Chang, Ann Bolcavage, Taylor K. Blair
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Publication number: 20190093498Abstract: An article includes a substrate, a bond coat on the substrate, and a multilayer environmental barrier coating (EBC) on the bond coat. The multilayer EBC includes a first EBC layer defining a first thickness and a second EBC layer defining a second thickness. The first EBC layer includes a first rare earth disilicate and a first concentration of a sintering aid that includes alumina. The second EBC layer includes a second rare earth disilicate and a second concentration of the sintering aid that includes alumina, less than the first concentration of the sintering aid.Type: ApplicationFiled: September 25, 2018Publication date: March 28, 2019Inventors: Stephanie Gong, Taylor K. Blair, Ngunjoh Lawrence Ndamka, Li Li, Sunny Chang, Ann Bolcavage
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Publication number: 20190092701Abstract: An article may include a substrate including a ceramic matrix composite (CMC); a composite coating layer including a first coating material that includes a rare-earth disilicate and a second coating material that includes at least one of a rare-earth monosilicate, a CMAS-resistant material, or a high-temperature dislocating material, where the second coating material forms a substantially continuous phase in the composite coating layer.Type: ApplicationFiled: September 21, 2018Publication date: March 28, 2019Inventors: Stephanie Gong, Ngunjoh Lawrence Ndamka, Matthew R. Gold, Li Li, Taylor K. Blair, Sunny Chang, Ann Bolcavage
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Publication number: 20190048475Abstract: A method includes predicting a composition of calcium-magnesium-aluminum-silicate (CMAS) to be encountered by a high temperature mechanical system during use of the high temperature mechanical system. The method further includes selecting a composition of a CMAS-resistant barrier coating layer based at least in part on the predicted composition of CMAS. The CMAS-resistant barrier coating layer includes a base composition and at least one secondary oxide selected based on the predicted composition of CMAS. The at least one secondary oxide includes at least one of an oxide of a divalent element, an oxide of a trivalent element, or an oxide of a tetravalent element. The CMAS-resistant barrier coating layer comprises greater than 0 mol. % and less than about 7 mol. % of the at least one secondary oxide.Type: ApplicationFiled: August 8, 2018Publication date: February 14, 2019Inventors: Ngunjoh Lawrence Ndamka, Li Li, Ann Bolcavage, Bruce Edward Varney, Sean E. Landwehr
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Publication number: 20180282851Abstract: In some examples, an article for a high-temperature mechanical system including a substrate and a doped calcia-magnesia-alumina-silicate resistant (doped CMAS-resistant) layer on the substrate. The doped CMAS-resistant layer is a thermal barrier coating or an environmental barrier coating and includes a calcia dopant.Type: ApplicationFiled: April 2, 2018Publication date: October 4, 2018Inventors: Ngunjoh Lawrence Ndamka, Ann Bolcavage