Back to results
US 9,945,036 B2Granted
Hot corrosion-resistant coatings and components protected therewith
AssigneeGeneral Electric Company
InventorsPeter Joel Meschter, Raymond Grant Rowe
Life of this patent
Estimating the term…
Abstract
A coating system on a superalloy or silicon-containing substrate of an article exposed to high temperatures. The coating system includes a coating layer that overlies the substrate and is susceptible to hot corrosion promoted by molten salt impurities. A corrosion barrier coating overlies the coating layer and contains at least one rare-earth oxide-containing compound that reacts with the molten salt impurities to form a dense, protective byproduct barrier layer.
Claims19
A coating system on a substrate of an article, the coating system comprising:
- at least one coating layer overlying the substrate, the coating layer having a composition that is susceptible to hot corrosion promoted by molten salt impurities;
- and
- a corrosion barrier coating overlying the coating layer and wherein the corrosion barrier coating contains at least one rare-earth oxide-containing compound that reacts with the molten salt impurities to form a dense, protective byproduct barrier layer on the surface of the corrosion barrier coating, the at least one rare-earth oxide-containing compound being present in the corrosion barrier coating in an amount of at least 15 weight percent of the corrosion barrier coating
- wherein the rare-earth oxide-containing compound is comprised of a rare earth zirconate (RE2Zr2O7), a rare earth hafnate (RE2Hf2O7) or a mixture thereof
- wherein RE in the RE2Zr2O7 is selected from the group consisting of Sc, Ce, Pr, Pm, Sm, Eu, Tb, Ho, Er, Tm, Yb, Lu and combinations thereof and
- wherein RE in the RE2Hf2O7 is selected from the group consisting of Sc, Ce, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu and combinations thereof;
- wherein the substrate comprises a silicon-containing material selected from the group consisting of metal silicide alloys, metal matrix composites reinforced with any one or more of silicon carbide, silicon nitride, a silicide and/or silicon, composites having a matrix of silicon carbide, silicon nitride, a silicide and/or silicon, and composites with a silicon carbide, silicon nitride, silicide and/or silicon matrix reinforced with silicon carbide, silicon nitride, a silicide and/or silicon.
4 more elements
A coating system on a substrate of an article, the coating system comprising:
- at least one coating layer overlying the substrate, the coating layer having a composition that is susceptible to hot corrosion promoted by molten salt impurities;
- and
- a corrosion barrier coating overlying the coating layer and wherein the corrosion barrier coating contains at least one rare-earth oxide-containing compound that reacts with the molten salt impurities to form a dense, protective byproduct barrier layer on the surface of the corrosion barrier coating, the at least one rare-earth oxide-containing compound being present in the corrosion barrier coating in an amount of at least 15 weight percent of the corrosion barrier coating
- wherein the rare-earth oxide-containing compound is comprised of a rare earth zirconate (RE2Zr2O7), a rare earth hafnate (RE2Hf2O7) or a mixture thereof
- wherein RE in the RE2Zr2O7 is selected from the group consisting of Sc, Ce, Pr, Pm, Sm, Eu, Tb, Ho, Er, Tm, Yb, Lu and combinations thereof and
- wherein RE in the RE2Hf2O7 is selected from the group consisting of Sc, Ce, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu and combinations thereof;
- wherein the coating layer is an environmental barrier layer comprising silicates, alkaline-earth metal aluminosilicates and/or rare-earth metal silicates.
4 more elements
A coating system on a substrate of an article, the coating system comprising:
- at least one coating layer overlying the substrate, the coating layer having a composition that is susceptible to hot corrosion promoted by molten salt impurities;
- and
- a corrosion barrier coating overlying the coating layer and wherein the corrosion barrier coating contains at least one rare-earth oxide-containing compound that reacts with the molten salt impurities to form a dense, protective byproduct barrier layer on the surface of the corrosion barrier coating, the at least one rare-earth oxide-containing compound being present in the corrosion barrier coating in an amount of at least 15 weight percent of the corrosion barrier coating
- wherein the rare-earth oxide-containing compound is comprised of a rare earth zirconate (RE2Zr2O7), a rare earth hafnate (RE2Hf2O7) or a mixture thereof
- wherein RE in the RE2Zr2O7 is selected from the group consisting of Sc, Ce, Pr, Pm, Sm, Eu, Tb, Ho, Er, Tm, Yb, Lu and combinations thereof and
- wherein RE in the RE2Hf2O7 is selected from the group consisting of Sc, Ce, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu and combinations thereof;
- wherein the corrosion barrier coating further comprises rare-earth monosilicates (RE2SiO5) and/or rare-earth disilicates (RE2Si2O7) wherein RE in the RE2 SiO5 is selected from the group consisting of Sc, Ce, Pr, Pm, Sm, Eu, Tb, Ho, Er, Tm, Yb, Lu and combinations thereof and
- wherein RE in the RE2 Si2O7 is selected from the group consisting of Sc, Ce, Pr, Pm, Sm, Eu, Tb, Ho, Er, Tm, Yb Lu and combinations thereof.
5 more elements
A coating system on a substrate of an article, the coating system comprising:
- at least one coating layer overlying the substrate, the coating layer having a composition that is susceptible to hot corrosion promoted by molten salt impurities;
- and
- a corrosion barrier coating overlying the coating layer and wherein the corrosion barrier coating contains at least one rare-earth oxide-containing compound that reacts with the molten salt impurities to form a dense, protective byproduct barrier layer on the surface of the corrosion barrier coating, the at least one rare-earth oxide-containing compound being present in the corrosion barrier coating in an amount of at least 15 weight percent of the corrosion barrier coating
- wherein the rare-earth oxide-containing compound is comprised of a rare earth zirconate (RE2Zr2O7), a rare earth hafnate (RE2Hf2O7) or a mixture thereof
- wherein RE in the RE2Zr2O7 is selected from the group consisting of Sc, Ce, Pr, Pm, Sm, Eu, Tb, Ho, Er, Tm, Yb, Lu and combinations thereof and
- wherein RE in the RE2Hf2O7 is selected from the group consisting of Sc, Ce, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu and combinations thereof;
- wherein the coating system further comprises a byproduct barrier layer on the surface of the corrosion barrier coating, the byproduct barrier layer defining an outermost surface layer of the coating system, and
- wherein the byproduct barrier layer comprises any one or more of REVO4, RE2V2O7 and Na—RE-Si—O compounds wherein RE in each of REVO4, RE2V2O7 and Na—RE-Si—O compounds is selected from the group consisting of Sc, Ce, Pr, Pm, Sm, Eu, Tb, Ho, Er, Tm, Yb, Lu and combinations thereof.
5 more elements
A gas turbine engine component comprising:
- a substrate comprising a superalloy or silicon-containing material;
- at least one bondcoat on the substrate;
- a barrier layer overlying the bondcoat, the barrier layer having a composition that is susceptible to hot corrosion promoted by molten salt impurities;
- a corrosion barrier coating overlying the barrier layer and having at least 15 weight percent of at least one rare-earth oxide-containing compound that reacts with the molten salt impurities, wherein the at least one rare-earth oxide-containing compound is selected from the group consisting of rare-earth zirconates (RE2Zr2O7) and rare-earth hafniates (RE2Hf2O7) and mixtures thereof,
- wherein RE in the RE2Zr2O7 is selected from the group consisting of Sc, Ce, Pr, Pm, Sm, Eu, Tb, Ho, Er, Tm, Yb, Lu and combinations thereof and wherein RE in the RE2Hf2O7 is selected from the group consisting of Sc, Ce, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu and combinations thereof;
- and
- a dense and continuous protective byproduct barrier layer on the surface of the corrosion barrier coating and formed by the at least one rare-earth oxide-containing compound reacting with the molten salt impurities, the byproduct barrier layer defining an outermost surface layer of the component;
- wherein the byproduct barrier coating comprises any one or more of REVO4, RE2V2O7 and Na—RE-Si—O compounds wherein RE in each of REVO4, RE2V2O7 and Na—RE-Si—O compounds is selected from the group consisting of Sc, Ce, Pr, Pm, Sm, Eu, Tb, Ho, Er, Tm, Yb, Lu and combinations thereof.
5 more elements
Dependencies are inferred from the claim text.