Dongming Z Zhu

US Patent:

7001859, Feb 21, 2006

Filed:

Aug 27, 2004

Appl. No.:

10/928496

Inventors:

Dongming Zhu - Westlake OH, US
Robert A. Miller - Brecksville OH, US

Assignee:

Ohio Aerospace Institute - Cleveland OH
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration - Washington DC

International Classification:

C04B 35/48

US Classification:

501102, 501103, 252 62

Abstract:

A thermal barrier coating composition is provided. The composition has a base oxide, a primary stabilizer, and at least two additional cationic oxide dopants. Preferably, a pair of group A and group B defect cluster-promoting oxides is used in conjunction with the base and primary stabilizer oxides. The new thermal barrier coating is found to have significantly lower thermal conductivity and better sintering resistance. In preferred embodiments, the base oxide is selected from zirconia and hafnia. The group A and group B cluster-promoting oxide dopants preferably are selected such that the group A dopant has a smaller cationic radius than the primary stabilizer oxide, and so that the primary stabilizer oxide has a small cationic radius than that of the group B dopant.

US Patent:

7186466, Mar 6, 2007

Filed:

Nov 17, 2005

Appl. No.:

11/282859

Inventors:

Dongming Zhu - Westlake OH, US
Robert A. Miller - Brecksville OH, US

Assignee:

Ohio Aerospace Institute - Cleveland OH
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration - Washington DC

International Classification:

B32B 15/01

US Classification:

428632, 428633, 428701, 428702, 428699, 416241 B

Abstract:

A thermal barrier coating composition is provided. The composition has a base oxide, a primary stabilizer, and at least two additional cationic oxide dopants. Preferably, a pair of group A and group B defect cluster-promoting oxides is used in conjunction with the base and primary stabilizer oxides. The new thermal barrier coating is found to have significantly lower thermal conductivity and better sintering resistance. In preferred embodiments, the base oxide is selected from zirconia and hafnia. The group A and group B cluster-promoting oxide dopants preferably are selected such that the group A dopant has a smaller cationic radius than the primary stabilizer oxide, and so that the primary stabilizer oxide has a small cationic radius than that of the group B dopant.

US Patent:

7700508, Apr 20, 2010

Filed:

Aug 28, 2006

Appl. No.:

11/510574

Inventors:

Dongming Zhu - Westlake OH, US
Robert A. Miller - Brecksville OH, US

Assignee:

The United States of Americas as represented by the Secretary of the Army - Washington DC

International Classification:

C04B 35/48

US Classification:

501103, 501126, 501152, 501127

Abstract:

A composition for thermal barrier coatings exhibiting improved thermal conductivity and toughness is provided. The composition is comprised of a base majority oxide, a first dopant oxide, at least one small rare earth oxide, at least one large rare earth oxide and at least one toughening oxide. Compared to traditional thermal barrier coatings, a composition of the present invention provides approximately twice the toughness one-third to one-half the thermal conductivity.

US Patent:

7740960, Jun 22, 2010

Filed:

Aug 28, 2006

Appl. No.:

11/510573

Inventors:

Dongming Zhu - Westlake OH, US
Robert A. Miller - Brecksville OH, US

Assignee:

The United States of America as represented by the Secretary of the Army - Washington DC

International Classification:

B32B 9/00
F16L 59/00

US Classification:

428699, 428689, 428697, 4289088, 416241 R, 416241 B

Abstract:

A multilayered coating system consisting of a multicomponent zirconia-base or hafnia-base oxide top layer, an interlayer comprised of a plurality of sublayers and a bond coat layer is provided. The multilayered coating system of the present invention, with an interlayer comprised of a plurality of sublayers, provides a protective coating solution for silicon-base ceramic components exposed to very high temperatures and/or high gas flow velocity water vapor combustion environments. The plurality of sublayers affords for a multitude of interfaces that aid in phonon scattering within the coating system and thereby reduces its thermal conductivity. Furthermore, the plurality of interlayer sublayers afford a strain tolerant buffer between the top layer and substrate and thereby accommodate the thermal expansion mismatch between the oxide top layer (coefficient of thermal expansion (CTE) up to 8-10×10m/m-C) and the silicon-base ceramic substrate (CTE≈4-5×10m/m-C).

US Patent:

6812176, Nov 2, 2004

Filed:

Jul 12, 2001

Appl. No.:

09/904084

Inventors:

Dongming Zhu - Westlake OH
Robert A. Miller - Brecksville OH

Assignee:

Ohio Aerospace Institute - Cleveland OH
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration - Washington DC

International Classification:

C04B 3548

US Classification:

501102, 501103

Abstract:

A thermal barrier coating composition comprising a base oxide, a primary stabilizer oxide, and at least one dopant oxide is disclosed. Preferably, a pair of group A and group B defect cluster-promoting oxides is used in conjunction with the base and primary stabilizer oxides. The new thermal barrier coating is found to have significantly lower thermal conductivity and better sintering resistance. The base oxide is selected from the group consisting of zirconia and hafnia and combinations thereof. The primary stabilizing oxide is selected from the group consisting of yttria, dysprosia, erbia and combinations thereof. The dopant or group A and group B cluster-promoting oxide dopants are selected from the group consisting of rare earth metal oxides, transitional metal oxides, alkaline earth metal oxides and combinations thereof. The dopant or dopants preferably have ionic radii different from those of the primary stabilizer and/or the base oxides.