Diffusion barrier coatings, and related articles and processes
AssigneeGeneral Electric Company
InventorsJi-Cheng Zhao, Melvin Robert Jackson
Life of this patent
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Abstract
A barrier coating is disclosed, containing about 15 atom % to about 95 atom % chromium; and about 5 atom % to about 60 atom % of at least one of rhenium, tungsten, and ruthenium. Nickel, cobalt, iron, and aluminum may also be present. The barrier coating can be disposed between a metal substrate (e.g., a superalloy) and an oxidation-resistant coating, preventing the substantial diffusion of various elements at elevated service temperatures. A ceramic overcoat (e.g., based on zirconia) can be applied over the oxidation-resistant coating. Related methods for applying protective coatings to metal substrates are also described.
Claims54
A diffusion barrier coating, comprising:
- (a) about 15 atom % to about 85 atom % chromium;
- and
- (b) about 15 atom % to about 60 atom % rhenium.
An article for use in a high-temperature, oxidative environment, comprising:
- (i) a metal-based substrate, comprising aluminum and other alloy elements;
- (ii) a diffusion barrier layer overlying the substrate, said layer comprising
- (A) about 15 atom % to about 95 atom % chromium;
- and
- (B) about 5 atom % to about 60 atom % of at least one element selected from the group consisting of rhenium, tungsten, ruthenium, and combinations thereof;
- and
- (iii) an oxidation-resistant coning over the diffusion barrier layer.
A turbine engine component for use in a high-temperature, oxidative environment, comprising:
- (I) a superalloy substrate, comprising a nickel or nickel-cobalt alloy;
- (II) a diffusion barrier layer overlying the substrate, said layer comprising
- (a) about 15 atom % to about 95 atom % chromium;
- (b) about 5 atom % to about 60 atom % of at least one element selected from the group consisting of rhenium, tungsten, ruthenium, and combinations thereof;
- (c) about 1 atom % to about 35 atom % of at least one element selected from the group consisting of nickel, cobalt, iron, and combinations thereof;
- and
- (d) about 1 atom % to about 35 atom % aluminum,
- wherein, for the maximum level of chromium present the sum off (a), (b), (c), and (d) is no greater than 100%;
- (III) an oxidation-resistant coating over the diffusion barrier layer, comprising a material selected from the group consisting of aluminide materials, MCrAI(X) materials, and nickel-chromium materials,
- where M is an element selected from the group consisting of Ni, Co, Fe, and combinations thereof, and X is an element selected from the group consisting of Y, Ta, Si, Hf, Ti, Zr, B, C, and combinations thereof;
- and
- (IV) a zirconia-based thermal barrier coating over the oxidation-resistant coating.
A diffusion barrier coating, comprising:
- (a) about 15 atom % to about 90 atom % chromium;
- and
- (b) about 10 atom % to about 60 stein % tungsten.
A barrier coating material, comprising:
- (a) about 15 atom % to about 95 atom % chromium;
- (b) about 10 atom % to about 60 atom % ruthenium;
- and
- (c) about 1 atom % to about 15 atom % aluminum;
- wherein, for the maximum level of chromium present the sum of (a), (b), and (c) is no greater than 100%.
A diffusion barrier coating having a thickness in the range of about 1 micron to about 50 microns, and consisting essentially of:
- (a) about 40 atom % to about 95 atom % chromium;
- and
- (b) about 5 atom % to about 60 atom % of at least one element selected from the group consisting of rhenium, tungsten, ruthenium, and combinations thereof.
A diffusion barrier coating, consisting essentially of
- (a) about 15 atom % to about 95 atom % chromium;
- (b) at least one element selected from the group consisting of rhenium, tungsten, ruthenium, and combinations thereof;
- wherein for each element which may be present:
- the level of rhenium is from about 15 atom % to about 60 atom %;
- the level of tungsten is from about 10 atom % to about 60 atom %;
- and
- the level of ruthenium is from about 5 atom % to about 60 atom %;
- and
- (c) about 1 atom % to about 35 atom % of at least one element selected from the group consisting of nickel, cobalt, iron, and combinations thereof,
- wherein, for the maximum level of chromium present, the sum of(a), (b), and (c) is no greater than 100%.
A barrier coating material, consisting essentially of
- (a) about 15 atom % to about 95 atom % chromium;
- (b) at lest one element selected from the group consisting of rhenium, tungsten, ruthenium, and combinations thereof;
- wherein for each element which may be present:
- the level of rhenium is from about 15 atom % to about 60 atom %;
- the level of tungsten is from about 10 atom % to about 60 atom %;
- and
- the level of ruthenium is from about 5 atom % to about 60 atom %;
- (c) about 1 atom % to about 35 atom % of at least one element selected from the group consisting of nickel, cobalt, iron, and combinations thereof;
- and
- (d) about 0.1 atom % to about 5 atom % of at least one element selected from the group consisting of zirconium, titanium, hafnium, silicon, boron, carbon, tantalum, molybdenum, and yttrium,
- wherein, for the maximum level of chromium present, the sum of(a), (b), (c), and (d) is no greater than 100%.
A method for preventing the substantial migration of aluminum from an aluminum-rich, oxidation-resistant coating into an underlying metal-based substrate in a high-temperature, oxidative environment, comprising the step of disposing a diffusion barrier layer between the substrate and the coating, wherein the diffusion barrier layer comprises:
- (a)about 15 atom % to about 95 atom % chromium;
- and
- (b)about 5 atom % to about 60 atom % of at least one element selected from the group consisting of rhenium, tungsten, ruthenium, and combinations thereof.
A method for providing a protective coating system over the surface of a superalloy substrate, comprising the following steps:
- (i)applying a diffusion barrier layer overlying the substrate, said layer comprising
- (A) about 15 atom % to about 95 atom % chromium;
- and
- (B) about 5 atom % to about 60 atom % of at least one element selected from the group consisting of rhenium, tungsten, ruthenium, and combinations thereof;
- (ii)applying an oxidation-resistant coating over the diffusion barrier layer;
- and then (iii)applying a zirconia-based thermal barrier coating over the oxidation-resistant coating.
Dependencies are inferred from the claim text.