Ramesh S Subramanian

US Patent:

6365281, Apr 2, 2002

Filed:

Sep 24, 1999

Appl. No.:

09/405498

Inventors:

Ramesh Subramanian - Oviedo FL
Stephen M. Sabol - Orlando FL
John G. Goedjen - Oviedo FL
Kelly M. Sloan - Bethesda MD
Steven J. Vance - Orlando FL

Assignee:

Siemens Westinghouse Power Corporation - Orlando FL

International Classification:

B32B 1504

US Classification:

428472, 428469, 428632, 428633, 416241 B

Abstract:

A turbine component, such as a turbine blade having a metal substrate ( ) is coated with a metal MCrAlY alloy layer ( ) and then a thermal barrier layer ( ) selected from LaAlO , NdAlO , La Hf O , Dy Al O , HO Al O , ErAlO , GdAlO , Yb Ti O , LaYbO , Gd Hf O or Y Al O.

US Patent:

6387539, May 14, 2002

Filed:

Jun 18, 2001

Appl. No.:

09/884601

Inventors:

Ramesh Subramanian - Oviedo FL

Assignee:

Siemens Westinghouse Power Corporation - Orlando FL

International Classification:

B32B 1504

US Classification:

428633, 428623, 428469, 428678, 428680, 428697, 428699, 427453, 427454, 427585, 427567, 416241 B, 416241 R

Abstract:

A device ( ) comprising a substrate ( ) having a deposited ceramic thermal barrier coating characterized by a microstructure having gaps ( ) where the thermal barrier coating comprises a first thermal barrier layer ( ), and a second thermal barrier layer ( ) with a pyrochlore crystal structure having a chemical formula of A B O , where A is selected from the group of elements consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and mixtures thereof, where B is selected from the group of elements consisting of Zr, Hf, Ti and mixtures thereof, where n and m are the valence of A and B respectively, and for -0. 5x0. 5, and excluding the following combinations for x=0, y=0: A=La and B=Zr; A=La and B=Hf; A=Gd and B=Hf; and A=Yb and B=Ti.

US Patent:

6444259, Sep 3, 2002

Filed:

Jan 30, 2001

Appl. No.:

09/774550

Inventors:

Ramesh Subramanian - Oviedo FL
Gregg P. Wagner - Apopka FL
Brij B. Seth - Maitland FL

Assignee:

Siemens Westinghouse Power Corporation - Orlando FL

International Classification:

B05D 102

US Classification:

427191, 427192, 427203, 427205, 427421

Abstract:

A process ( ) for applying a thermal barrier coating ( ) to a turbine component ( ) including the step ( ) of depositing a bond coating layer ( ) by, directing solid particles using a cold spray process. The layer of bond coating material may have different depths ( ) in different areas of the component ( ), and it may have different compositions ( ) across its depth. The precise control afforded by the cold spray material deposition step allows the surface of the bond coating material layer to be formed with a predetermined surface roughness or with a plurality of micro-ridges ( ) in order to optimize its bond to the overlying ceramic insulating layer ( ).

US Patent:

6602053, Aug 5, 2003

Filed:

Aug 2, 2001

Appl. No.:

09/921084

Inventors:

Ramesh Subramanian - Oviedo FL
Mercedes Keyser - Cocoa Beach FL

Assignee:

Siemens Westinghouse Power Corporation - Orlando FL

International Classification:

F01D 518

US Classification:

416 97R, 416241 R, 416241 B

Abstract:

A method of forming a cooling feature ( ) on a surface ( ) of a substrate ( ) to protect the substrate from a high temperature environment. The cooling feature is formed by first depositing a layer of a masking material ( ) such as epoxy resin on the surface of the substrate. A pattern of voids ( ) is then cut into the masking material by a laser engraving process which exposes portions of the substrate surface. A plurality of supports ( ) are then formed by electroplating a support material onto the exposed portions of the substrate surface. A layer of material is then electroplated onto the supports and over the masking material to form a skin that interconnects the supports. Finally, the remaining portions of the masking material are removed to form a plurality of cooling channels ( ) defined by the supports, skin and substrate surface. An additional layer of material ( ) may be deposited onto a top surface ( ) of the cooling feature to provide additional thermal and/or mechanical protection.

US Patent:

6677064, Jan 13, 2004

Filed:

May 29, 2002

Appl. No.:

10/157569

Inventors:

Ramesh Subramanian - Oviedo FL

Assignee:

Siemens Westinghouse Power Corporation - Orlando FL

International Classification:

B32B 1504

US Classification:

428702, 428469, 428472, 428701, 428697, 428699, 428937, 416241 B

Abstract:

A multiphase ceramic thermal barrier coating is provided. The coating is adapted for use in high temperature applications in excess of about 1200Â C. , for coating superalloy components of a combustion turbine engine. The coating comprises a ceramic single or two oxide base layer disposed on the substrate surface; and a ceramic oxide reaction product material disposed on the base layer, the reaction product comprising the reaction product of the base layer with a ceramic single or two oxide overlay layer.

US Patent:

6703137, Mar 9, 2004

Filed:

Aug 2, 2001

Appl. No.:

09/921206

Inventors:

Ramesh Subramanian - Oviedo FL

Assignee:

Siemens Westinghouse Power Corporation - Orlando FL

International Classification:

B32B 1504

US Classification:

428469, 4283044, 4283122, 4283166, 428699, 428701, 428702, 416241 B

Abstract:

A thermal barrier coating ( ) having a less dense bottom layer ( ) and a more dense top layer ( ) with a plurality of segmentation gaps ( ) formed in the top layer to provide thermal strain relief. The top layer may be at least 95% of the theoretical density in order to minimize the densification effect during long term operation, and the bottom layer may be no more than 95% of the theoretical density in order to optimize the thermal insulation and strain tolerance properties of the coating. The gaps are formed by a laser engraving process controlled to limit the size of the surface opening to no more than 50 microns in order to limit the aerodynamic impact of the gaps for combustion turbine applications. The laser engraving process is also controlled to form a generally U-shaped bottom geometry ( ) in the gaps in order to minimize the stress concentration effect.

US Patent:

6716539, Apr 6, 2004

Filed:

Sep 24, 2001

Appl. No.:

09/962734

Inventors:

Ramesh Subramanian - Oviedo FL

Assignee:

Siemens Westinghouse Power Corporation - Orlando FL

International Classification:

B21D 3900

US Classification:

428621, 428622, 428623, 428632, 428141, 428148, 42725528, 4272557, 427269, 4272499, 416241 B

Abstract:

A multi-layer thermal barrier coating ( ) having a porous first layer of ceramic insulating material ( ) and a second relatively dense layer of ceramic insulating material ( ) having a plurality generally vertical gaps ( ) formed therein. The porous conventional as-deposited APS microstructure of the first layer provides thermal and chemical protection for the substrate, while the gaps of the columnar-grained second layer provide thermal shock resistance for the coating. An air plasma spray process may be used to deposit both the first and the second layers of material, as well as any underlying bond coat layer. The gaps of the columnar-grained second layer do not extend into the first layer. The pores ( ) of the first layer function as crack-arrestors for cracks initiating at the gaps of the second layer.

US Patent:

6756082, Jun 29, 2004

Filed:

Aug 17, 2000

Appl. No.:

09/640073

Inventors:

Ramesh Subramanian - Oviedo FL
Brij B. Seth - Maitland FL

Assignee:

Siemens Westinghouse Power Corporation - Orlando FL

International Classification:

B05D 136

US Classification:

427454, 4272481, 4272557, 4273722, 4274193, 4274197, 4274432

Abstract:

A device ( ) is made, having a ceramic thermal barrier coating layer ( ) characterized by a microstructure having gaps ( ) with a sintering inhibiting material ( ) disposed on the columns ( ) within the gaps ( ). The sintering resistant material ( ) is stable over the range of operating temperatures of the device ( ), is not soluble with the underlying ceramic layer ( ) and is applied by a process that is not an electron beam physical vapor deposition process.