Dinesh K Gupta

US Patent:

6383570, May 7, 2002

Filed:

Dec 21, 2000

Appl. No.:

09/745781

Inventors:

Sudhangshu Bose - Manchester CT
Dinesh K. Gupta - South Windsor CT
Jeanine T. Marcin - Marlborough CT
Nicholas E. Ulion - Marlborough CT

Assignee:

United Technologies Corporation - Hartford CT

International Classification:

C23C 2800

US Classification:

427405, 427454, 427456, 427142, 427258, 427287, 2988971

Abstract:

A thermal barrier coating system for a superalloy substrate is disclosed. The superalloy is preferably of the type that is capable of forming an adherent alumina layer. A bond coat is applied to a local area of the substrate, so that a portion of the substrate remains exposed. The localized area is defined to be the area(s) at which a TBC typically fails first, e. g. , the leading and trailing edges of an airfoil, or other area. An alumina layer is formed on the remaining portion of the substrate, and also on the bond coat. A ceramic layer is then applied on the alumina layer. Even if the ceramic material is removed, the localized bond coat remains, and reduces the rate at which the underlying substrate oxidizes. A coated article is also disclosed, as is a system that utilizes a conventional superalloy and aluminide coating with the localized bond coat.

US Patent:

7575039, Aug 18, 2009

Filed:

Oct 15, 2003

Appl. No.:

10/685631

Inventors:

James T. Beals - West Hartford CT, US
Joshua Persky - Manchester CT, US
Dilip M. Shah - Glastonbury CT, US
Venkat Seetharaman - Rocky Hill CT, US
Sudhangshu Bose - Manchester CT, US
Jacob Snyder - Southington CT, US
Keith Santeler - Middletown CT, US
Carl Verner - Windsor CT, US
Stephen D. Murray - Marlborough CT, US
John Marcin - Marlborough CT, US
Dinesh Gupta - South Windsor CT, US
Daniel A. Bales - Avon CT, US
Daniel Francis Paulonis - Higganum CT, US
Glenn Cotnoir - Thompson CT, US
John Wiedemer - Glastonbury CT, US

Assignee:

United Technologies Corporation - Hartford CT

International Classification:

B22C 9/10

US Classification:

164369

Abstract:

A refractory metal core for use in a casting system has a coating for providing oxidation resistance during shell fire and protection against reaction/dissolution during casting. In a first embodiment, the coating includes at least one oxide and a silicon containing material. In a second embodiment, the coating includes an oxide selected from the group of calcia, magnesia, alumina, zirconia, chromia, yttria, silica, hafnia, and mixtures thereof. In a third embodiment, the coating includes a nitride selected from the group of silicon nitride, sialon, titanium nitride, and mixtures thereof. Other coating embodiments are described in the disclosure.

US Patent:

20010012568, Aug 9, 2001

Filed:

Dec 21, 2000

Appl. No.:

09/746466

Inventors:

Sudhangshu Bose - Manchester CT, US
Dinesh Gupta - South Windsor CT, US
Jeanine Marcin - Marlborough CT, US
Nicholas Ulion - Marlborough CT, US

Assignee:

United Technologies Corporation

International Classification:

B32B015/00
B05D001/36

US Classification:

428/615000, 427/404000, 428/686000

Abstract:

A thermal barrier coating system for a superalloy substrate is disclosed. The superalloy is preferably of the type that is capable of forming an adherent alumina layer. A bond coat is applied to a local area of the substrate, so that a portion of the substrate remains exposed. The localized area is defined to be the area(s) at which a TBC typically fails first, e.g., the leading and trailing edges of an airfoil, or other area. An alumina layer is formed on the remaining portion of the substrate, and also on the bond coat. A ceramic layer is then applied on the alumina layer. Even if the ceramic material is removed, the localized bond coat remains, and reduces the rate at which the underlying substrate oxidizes. A coated article is also disclosed, as is a system that utilizes a conventional superalloy and aluminide coating with the localized bond coat.

US Patent:

48973157, Jan 30, 1990

Filed:

Sep 3, 1986

Appl. No.:

6/903831

Inventors:

Dinesh K. Gupta - Vernon CT

Assignee:

United Technologies Corporation - Hartford CT

International Classification:

B22F 300

US Classification:

428552

Abstract:

A protective coating system for superalloys is described. The coating is an yttrium enriched aluminide, and can be formed by aluminizing an MCrAlY coated superalloy, wherein during the aluminizing process, aluminum diffuses completely through the MCrAlY coating and into the substrate. The coating system exhibits desirable oxidation resistance and resistance to thermal fatigue cracking.

US Patent:

59217510, Jul 13, 1999

Filed:

Dec 19, 1995

Appl. No.:

8/575116

Inventors:

Melvin Freling - West Hartford CT
Dinesh K. Gupta - South Windsor CT

Assignee:

United Technologies Corporation - Hartford CT

International Classification:

F04D 2944

US Classification:

415200

Abstract:

In a gas turbine engine, a method and apparatus for containing molten materials and ignited titanium and titanium alloys within the confines of the turbine engine environment. The method includes the step of first applying a bond coating to the inner surface of the outer compressor casing. The bond coating is then plasma oversprayed with a non-reactive, thermally insulative ceramic top coating. The apparatus includes a substrate having a bond coating and a ceramic top coating, surrounding at least a portion of the gas turbine engine, for containing turbine engine fires within the turbine engine environment. Preferably, the bond coating is a Ni--Co--Cr--Al--Y alloy, and the top coat is stabilized zirconia.

US Patent:

50007823, Mar 19, 1991

Filed:

Mar 3, 1989

Appl. No.:

7/318296

Inventors:

Walter E. Olson - Vernon CT
Dinesh K. Gupta - Vernon CT
Michael S. Milaniak - Middlefield CT

Assignee:

United Technologies Corporation - Hartford CT

International Classification:

B22F 100

US Classification:

75253

Abstract:

Methods are described for forming an yttrium enriched aluminide coating on the surface of a nickel or cobalt base superalloy article. In one preferred embodiment, a pack mixture for forming the coating consists essentially of, by weight percent, 5-35 of an Al-Y-Si alloy, 1-20 CoI. sub. 2, balance Y. sub. 2 O. sub. 3.

US Patent:

46158650, Oct 7, 1986

Filed:

Jul 12, 1983

Appl. No.:

6/512945

Inventors:

David S. Duvall - Cobalt CT
Dinesh K. Gupta - Vernon CT

Assignee:

United Technologies Corporation - Hartford CT

International Classification:

B32B 1501
B32B 1520
C22C 1903
C22C 3000

US Classification:

420588

Abstract:

Improved coating compositions are described for the protection of superalloys at elevated temperatures. The coatings of the NiCrAlY or NiCoCrAlY type are significantly improved by the use of higher levels of yttrium.

US Patent:

52779360, Jan 11, 1994

Filed:

Nov 19, 1987

Appl. No.:

7/122868

Inventors:

Walter E. Olson - Vernon CT
Dinesh K. Gupta - Vernon CT

Assignee:

United Technologies Corporation - Hartford CT

International Classification:

B05D 100

US Classification:

427453

Abstract:

The oxidation resistance of MCrAlY-type overlay coatings is improved by incorporating small discrete oxide particles into the coating. The particles are preferably yttrium oxide, and the coating is applied by simultaneously plasma spraying MCrAlY-type powder particles and oxide particles onto a substrate in a nonoxidizing atmosphere. Improvements in resistance to rumpling has also been observed in coatings applied according to this invention.