Layer system with double MCrAlX metallic layer

Patent metadata

Field	Value
Publication number	US-9556748-B2
Application number	US-201114344208-A
Country	US
Kind code	B2
Filing date	Sep 12, 2011
Priority date	Sep 12, 2011
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

Known protective coatings with a high Cr-content and silicon as an additive have brittle phases which become additionally brittle under the influence of carbon during use. The protective coating herein has a double metallic layer that only contains tantalum on the outside contents of the layers.

First claim

The invention claimed is:

1. A layer system, for a component of a gas turbine, the system at least comprising:
a substrate, the substrate being nickel-based or cobalt-based;
a protective layer comprising an at least two-layered metallic layer comprised of at least a first bottom layer toward the substrate and a second top layer on the first bottom layer and away from the substrate; and
optionally a ceramic thermal barrier coating applied to the second top layer;
wherein:
the first bottom layer comprises an MCrAlX alloy, M being at least one of the elements selected from the group consisting of iron, cobalt, and nickel, and the alloy of the first bottom layer comprises no tantalum (Ta), silicon (Si), iron (Fe), and rhenium (Re);
the alloy of the first bottom layer contains at least the following elements (amounts in % by weight):
22%-26% cobalt (Co);
12%-16% chromium (Cr);
10%-12% aluminum (Al);
0.2%-0.6% of X which is at least one of the elements from the group consisting of scandium (Sc), and the rare earth elements, including yttrium (Y); and
a remainder of nickel;
the second top layer comprises an MCrAlX alloy, M being at least one of the elements selected from the group consisting of iron, cobalt, and nickel, such that a cobalt (Co) content in the alloy of the second top layer is at least 1% by weight and a chromium (Cr) content in the alloy of the second top layer is at least 1% by weight;
the alloy of the second top layer further comprises at least 1% by weight aluminum (Al), is nickel-based, and optionally includes iron (Fe);
X in the alloy of the second top layer is optional and is at least one of the elements from the group consisting of scandium (Sc), rhenium (Re) and the rare earth elements, including yttrium (Y);
the alloys of the first bottom layer and the second top layer do not contain:
at least one of zirconium (Zr),
titanium (Ti),
gallium (Ga), and
germanium (Ge); and
a proportion of tantalum (Ta) in the alloy of the second top layer is between 4% by weight and 7.0% by weight.

2. The layer system as claimed in claim 1 , wherein the content of tantalum (Ta) in the alloy of the second top layer is between 5% by weight and 6.8% by weight.

3. A layer system, for a component of a gas turbine, the system at least comprising:
a substrate, the substrate being nickel-based or cobalt-based;
a protective layer comprising an at least two-layered metallic layer comprised of at least a first bottom layer toward the substrate and a second top layer on the bottom layer and away from the substrate; and
optionally a ceramic thermal barrier coating which is applied to the second top layer;
wherein:
the first bottom layer comprises an MCrAlX alloy, M being at least one of the elements selected from the group consisting of iron, cobalt, and nickel, and the alloy of the first bottom layer comprises no tantalum (Ta), silicon (Si), iron (Fe), and rhenium (Re);
the alloy of the first bottom layer contains at least the following elements (amounts in % by weight):
22%-26% cobalt (Co);
12%-16% chromium (Cr);
10%-12% aluminum (Al);
0.2%-0.6% of X which is at least one of the elements from the group consisting of scandium (Sc), and the rare earth elements, including yttrium (Y); and
a remainder of nickel;
the second top layer comprises an MCrAlX alloy, M being at least one of the elements selected from the group consisting of iron, cobalt, and nickel, such that a cobalt (Co) content in the alloy of the second top layer is at least 1% by weight and a chromium (Cr) content in the alloy of the second top layer is at least 1% by weight;
the alloy of the second top layer further comprises at least 1% by weight aluminum (Al), is nickel-based, and optionally includes iron (Fe);
X in the alloy of the second top layer is optional and is at least one of the elements from the group consisting of scandium (Sc), rhenium (Re) and the rare earth elements, including yttrium (Y);
the alloys of the first bottom layer and the second top layer do not contain:
at least one of zirconium (Zr),
titanium (Ti),
gallium (Ga), and
germanium (Ge); and
a content of tantalum (Ta) in the alloy of the second top layer is between 3.5% by weight and 5.5% by weight.

4. A layer system, for a component of a gas turbine, the system at least comprising:
a substrate, the substrate being nickel-based or cobalt-based;
a protective layer comprising an at least two-layered metallic layer comprised of at least a first bottom layer toward the substrate and a second top layer on the bottom layer and away from the substrate; and
optionally a ceramic thermal barrier coating which is applied to the second top layer;
wherein:
the first bottom layer comprises an MCrAlX alloy, M being at least one of the elements selected from the group consisting of iron, cobalt, and nickel, and the alloy of the first bottom layer comprises no tantalum (Ta), silicon (Si), iron (Fe), and rhenium (Re);
the alloy of the first bottom layer contains at least the following elements (amounts in % by weight):
22%-26% cobalt (Co);
12%-16% chromium (Cr);
10%-12% aluminum (Al);
0.2%-0.6% of X which is at least one of the elements from the group consisting of scandium (Sc), and the rare earth elements, including yttrium (Y); and
a remainder of nickel;
the second top layer comprises an MCrAlX alloy, M being at least one of the elements selected from the group consisting of iron, cobalt, and nickel, such that a cobalt (Co) content in the alloy of the second top layer is at least 1% by weight and a chromium (Cr) content in the alloy of the second top layer is at least 1% by weight;
the alloy of the second top layer is nickel-based, and further includes either tantalum (Ta) and/or iron (Fe) or includes the γ phase and the γ′ phase and optionally the β phase;
X in the alloy of the second top layer is optional and is at least one of the elements from the group consisting of scandium (Sc), rhenium (Re) and the rare earth elements, including yttrium (Y);
the alloys of the first bottom layer and the second top layer do not contain:
at least one of zirconium (Zr),
titanium (Ti),
gallium (Ga), and
germanium (Ge); and
a content of aluminum (Al) in the alloy of the second top layer is between 10.5% by weight and 12% by weight.

5. A layer system, for a component of a gas turbine, the system at least comprising:
a substrate, the substrate being nickel-based or cobalt-based;
a protective layer comprising an at least two-layered metallic layer comprised of at least a first bottom layer toward the substrate and a second top layer on the bottom layer and away from the substrate; and
optionally a ceramic thermal barrier coating which is applied to the second top layer;
wherein:
the first bottom layer comprises an MCrAlX alloy, M being at least one of the elements selected from the group consisting of iron, cobalt, and nickel, and the alloy of the first bottom layer comprises no tantalum (Ta), silicon (Si), iron (Fe), and rhenium (Re);
the alloy of the first bottom layer contains at least the following elements (amounts in % by weight):
22%-26% cobalt (Co);
12%-16% chromium (Cr);
10%-12% aluminum (Al);
0.2%-0.6% of X which is at least one of the elements from the group consisting of scandium (Sc), and the rare earth elements, including yttrium (Y); and
a remainder of nickel;
the second top layer comprises an MCrAlX alloy, M being at least one of the elements selected from the group consisting of iron, cobalt, and nickel, such that a cobalt (Co) content in the alloy of the second top layer is at least 1% by weight and a chromium (Cr) content in the alloy of the second top layer is at least 1% by weight;
the alloy of the second top layer further comprises at least 1% by weight aluminum (Al), and is nickel-based;
X in the al

Assignees

• Bostanjoglo Georg
• Kaiser Axel
• Stamm Werner
• Steinbach Jan
• Thomaidis Dimitrios
• Siemens Ag

Inventors

• Bostanjoglo Georg
• Kaiser Axel
• Stamm Werner
• Steinbach Jan
• Thomaidis Dimitrios

Classifications

• C23C28/321

  with at least one metal alloy layer · CPC title

• C22C19/05

  with chromium · CPC title

• B32B2250/03

  3 layers · CPC title

• F01D25/005 Primary

  Selecting particular materials · CPC title

• B32B33/00

  Layered products characterised by particular properties or particular surface features, e.g. particular surface coatings; Layered products designed for particular purposes not covered by another single class · CPC title