Other

United States of America As Represented by the Administrator of Nasa

General Electric Company

The United States of America As Represented by the Administrator of the

Kang Neung Lee

Hongyu Wang

Nathan S Jacobson

Krishan Lal Luthra

Peter Joel Meschter

William Patrick Allen

James L Smialek

Harry Edwin Eaton, Jr

Elizabeth J Opila

Robert A Miller

Bangalore Aswatha Nagaraj

Irene T Spitsberg

Narottam P Bansal

Deborah L Waters

Nanottam P Bansal

Slurry EBC systems and method for fabricating slurry EBC systems for protecting component substrates and extending the longevity of such components are disclosed. The slurry EBC systems include a bond coat having a temperature capability of up to 1482&#xb0; C. (2700&#xb0; F.). Example bond coats include a mullite-based bond coat and a rare earth disilicate-based bond coat.

Environmental barrier coatings for improved temperature capabilities and longevity

A multilayer article comprises a substrate comprising a ceramic or a silicon-containing metal alloy. The ceramic is a Si-containing ceramic or an oxide ceramic with or without silicon. An outer layer overlies the substrate and at least one intermediate layer is located between the outer layer and the substrate. An optional bond layer is disposed between the at least one intermediate layer and the substrate. The at least one intermediate layer may comprise an optional chemical barrier layer adjacent the outer layer, a mullite-containing layer and an optional chemical barrier layer adjacent to the bond layer or substrate. The outer layer comprises a compound having a low coefficient of thermal expansion selected from one of the following systems: rare earth (RE) silicates; at least one of hafnia and hafnia-containing composite oxides; zirconia-containing composite oxides and combinations thereof.

Multilayer article characterized by low coefficient of thermal expansion outer layer

A multilayer article includes a substrate that includes at least one of a ceramic compound and a Si-containing metal alloy. An outer layer includes stabilized zirconia. Intermediate layers are located between the outer layer and the substrate and include a mullite-containing layer and a chemical barrier layer. The mullite-containing layer includes 1) mullite or 2) mullite and an alkaline earth metal aluminosilicate. The chemical barrier layer is located between the mullite-containing layer and the outer layer. The chemical barrier layer includes at least one of mullite, hafnia, hafnium silicate and rare earth silicate (e.g., at least one of RE SiO and RE Si O where RE is Sc or Yb). The multilayer article is characterized by the combination of the chemical barrier layer and by its lack of a layer consisting essentially of barium strontium aluminosilicate between the mullite-containing layer and the chemical barrier layer. Such a barium strontium aluminosilicate layer may undesirably lead to the formation of a low melting glass or unnecessarily increase the layer thickness with concomitant reduced durability of the multilayer article. In particular, the chemical barrier layer may include at least one of hafnia, hafnium silicate and rare earth silicate.

Multilayer article having stabilized zirconia outer layer and chemical barrier layer

An article includes a silicon-containing substrate and a modified mullite coating. The modified mullite coating comprises mullite and a modifier component that reduces cracks in the modified mullite coating. The article can further comprise a thermal barrier coating applied to the modified mullite coating. The modified mullite coating functions as a bond coating between the external environmental/thermal barrier coating and the silicon-containing substrate. In a method of forming an article, a silicon-containing substrate is formed and a modified mullite coating is applied. The modified mullite coating comprises mullite and a modifier component that reduces cracks in the modified mullite coating.

Coated article and method of making

A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a barium-strontium alumino silicate.

Silicon based substrate with environmental/ thermal barrier layer

Silicon based substrate with environmental/thermal barrier layer

A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a yttrium silicate.

Silicon based substrate with yttrium silicate environmental/thermal barrier layer

A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a calcium alumino silicate.

Silicon based substrate with calcium aluminosilicate environmental/thermal barrier layer

Silicon based substrate with calcium aluminosilicate/thermal barrier layer

A silicon-base ceramic substrate is provided with a mullite chemical barrier/thermal barrier coating uniformly bonded to a surface. The coating is substantially free of amorphous mullite.

Plasma sprayed mullite coatings on silicon-base ceramics

A silicon-base ceramic substrate is provided with a mullite coating by flame-spraying heated crystalline mullite powders onto a substrate that is preheated to a temperature in excess of 800.degree. C. The mullite immediately crystallizes as it solidifies.

Growing community of inventors

Westlake, OH, United States of America

Kang Neung Lee