Ramesh 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:

6443211, Sep 3, 2002

Filed:

Aug 31, 1999

Appl. No.:

09/386520

Inventors:

Martin R. Myers - Columbus IN
Michael J. Warwick - Columbus IN
Yongching Chen - Columbus IN
Ramesh Subramanian - Oviedo FL
Srinath Viswanathan - Knoxville TN
Karren More - Knoxville TN
Quingyou Han - Beijing, CN

Assignee:

Cummins Inc. - Columbus IN
UT-Battelle, LLC - Oak Ridge TN

International Classification:

B22D 1900

US Classification:

164100, 164310

Abstract:

A method for forming light-weight composite metal castings incorporating metallurgically bonded inserts for a variety of applications. Castings formed by the invention have a particular utility as components of an internal combustion engine. A casting method includes the step of coating the insert with a first layer which is followed by coating a second layer and concluded by a casting step under conditions including sufficient temperature to cause the second coated layer to be sacrificed by dissolving into the cast metal material while leaving at least a portion of the first layer as a diffusion barrier between the insert and the cast material. The molten casting material is treated and handled to keep the hydrogen content below 0. 15 and preferably below 0. 10 parts per million.

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:

6484790, Nov 26, 2002

Filed:

Aug 31, 1999

Appl. No.:

09/386519

Inventors:

Martin R. Myers - Columbus IN
Michael J. Warwick - Columbus IN
Yongching Chen - Columbus IN
Ramesh Subramanian - Oviedo FL
Srinath Viswanathan - Knoxville TN
Karren More - Knoxville TN
Quingyou Han - Beijing, CN

Assignee:

Cummins Inc. - Columbus IN
UT-Battelle, LLC - Oak Ridge TN

International Classification:

B22D 1900

US Classification:

164100, 164310

Abstract:

A method for forming light-weight composite metal castings incorporating metallurgically bonded inserts for a variety of applications. Castings formed by the invention have particular utility as components of an internal combustion engine. A casting method includes the step of coating the insert with a first layer under conditions including sufficient temperature to cause a portion of the layer to be sacrificed by dissolving into the cast metal material while leaving at least a portion of the first layer as a diffusion barrier between the insert and the cast material. The molten casting material is treated and handled to keep the hydrogen content below 0. 15 and preferably below 0. 10 parts per million. The casting step takes place under a protective gas environment of dry air, argon or nitrogen with a moisture content of less than 3 parts per million.

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.