Layer system having a two-ply metal layer
AssigneeSiemens Aktiengesellschaft
InventorsGeorg Bostanjoglo, Axel Kaiser, Werner Stamm, Jan Steinbach, Dimitrios Thomaidis
Life of this patent
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Abstract
Known protective layers having high Cr content and additional silicon form brittle phases, which additionally become brittle under the effect of carbon during use. The protective layer according to the invention comprises a two-part metal layer, which contains tantalum on the outside.
Claims44
A layer system (1)
- at least comprising:
- a substrate (4),
- an at least two-layered metallic layer (7, 10)
- consisting of at least a first bottom layer (7) and
- a second top layer (10) on the bottom layer (7),
- wherein the bottom layer (7)
- comprises an MCrAlX alloy
- without tantalum (Ta) and without silicon (Si) and without iron (Fe),
- in particular contains at least the following elements,
- very particularly consists thereof:
- (amounts in % by weight):
- 24%-26% cobalt (Co),
- in particular 25%,
- 12%-14% chromium (Cr),
- in particular 13%,
- 10%-12% aluminum (Al),
- in particular 11%,
- 0.2%-0.5%,
- very particularly 0.3%,
- nickel,
- in particular remainder nickel,
- wherein the second layer (10) comprises an MCrAlX alloy, either with tantalum (Ta) and/or iron (Fe)
- or with the γ and the γ′ phase and optionally the β phase, where X is in each case optional and is at least one of the elements from the group comprising scandium (Sc), rhenium (Re) and the rare earth elements,
- in particular yttrium (Y),
- very particularly only yttrium (Y).
The layer system as claimed in one or more of the preceding claims,
- in which the proportion of tantalum (Ta) in the alloy of the top layer (10) is at least 2.0% by weight,
- in particular is between 3.0% by weight and 6.0% by weight.
The layer system as claimed in one or more of the preceding claims,
- in which the content of cobalt (Co) in the alloy of the top layer (10) is at least 1% by weight.
The layer system as claimed in one or more of the preceding claims,
- in which the alloy of the top layer (10) comprises at least 1% by weight chromium (Cr).
The layer system as claimed in one or more of the preceding claims,
- which in the alloy of the bottom layer (7) comprises no rhenium (Re).
The layer system as claimed in one or more of the preceding claims,
- in which the content of aluminum (Al) in the alloy of the top layer (10) is between 5% by weight-15% by weight, in particular is between 8% by weight-12% by weight.
The layer system as claimed in one or more of the preceding claims,
- which in the alloy of the top layer (10) comprises no rhenium (Re).
The layer system as claimed in one or more of the preceding claims,
- in which the following holds true for the alloys of the metallic layers (7, 10):
- not containing zirconium (Zr) and/or
- not containing titanium (Ti) and/or
- not containing gallium (Ga) and/or
- not containing germanium (Ge).
The layer system as claimed in one or more of the preceding claims,
- in which the alloy of the bottom layer (7) and/or of the top layer (10) contains no silicon (Si).
The layer system as claimed in one or more of the preceding claims,
- in which the respective alloy of the layers (7, 10) comprises no hafnium (Hf).
The layer system as claimed in one or more of the preceding claims,
- in which the alloy of the top layer (10) is nickel-based.
The layer system as claimed in one or more of the preceding claims,
- in which the alloy of the bottom layer (7) is nickel-based.
The layer system as claimed in one or more of the preceding claims,
- in which the top layer (10) comprises the γ phase, the γ′ phase and optionally the β phase,
- in particular also comprises the β phase.
The layer system as claimed in one or more of the preceding claims,
- in which the alloy of the top layer (10) comprises at least 1% by weight aluminum (Al).
The layer system as claimed in one or more of the preceding claims,
- in which the alloy of the top layer (10) comprises at least 0.1% by weight,
- in particular comprises between 0.1% by weight and 0.7% by weight,
- very particularly comprises 0.3% by weight, yttrium (Y).
The layer system as claimed in one or more of the preceding claims,
- in which the content of cobalt (Co) in the alloy of the top layer (10) is between 15% by weight and 30% by weight,
- in particular is between 18% by weight and 27% by weight,
- very particularly is between 21% by weight and 24% by weight.
The layer system as claimed in one or more of the preceding claims,
- in which the content of chromium (Cr) in the alloy of the top layer (10) is between 12% by weight-22% by weight,
- in particular is between 15% by weight-19% by weight.
The layer system as claimed in one or more of the preceding claims,
- which in the top layer (10) contains the β phase,
- in particular at least 5% by volume.
The layer system as claimed in one or more of the preceding claims,
- in which the top layer (10) comprises an alloy consisting of nickel (Ni), cobalt (Co), aluminum (Al), chromium (Cr), tantalum (Ta) and optionally yttrium (Y),
- in particular consists thereof.
The layer system as claimed in one or more of the preceding claims,
- in which the top layer (10) comprises an alloy consisting of nickel (Ni), cobalt (Co), aluminum (Al), chromium (Cr), tantalum (Ta) and yttrium (Y),
- in particular consists thereof.
The layer system as claimed in one or more of the preceding claims,
- in which the top layer (10) comprises an alloy consisting of nickel (Ni), cobalt (Co), aluminum (Al), chromium (Cr), tantalum (Ta), iron (Fe) and optionally yttrium (Y),
- in particular consists thereof.
The layer system as claimed in one or more of the preceding claims,
- in which the top layer (10) comprises an alloy consisting of nickel (Ni), cobalt (Co), aluminum (Al), chromium (Cr), tantalum (Ta), iron (Fe) and yttrium (Y),
- in particular consists thereof.
The layer system as claimed in one or more of the preceding claims,
- in which the content of chromium (Cr) in the alloy of the top layer (10) is between 12% by weight-16% by weight,
- in particular is 14.4% by weight.
The layer system as claimed in one or more of the preceding claims,
- in which the proportion of aluminum (Al) in the alloy of the top layer (10) is between 7% by weight and 8% by weight,
- in particular is 7.75% by weight.
The layer system as claimed in one or more of the preceding claims,
- in which the proportion of rhenium (Re) in the alloy of the top layer (10) is between 0.1% by weight and 2% by weight.
The layer system as claimed in one or more of the preceding claims,
- in which the content of tantalum (Ta) in the alloy of the top layer (10) is between 5% by weight and 6.8% by weight.
The layer system as claimed in one or more of the preceding claims,
- in which the alloy of the metallic layers (7, 10) contains no platinum (Pt).
The layer system as claimed in one or more of the preceding claims,
- in which the content of cobalt (Co) in the alloy of the top layer (10) is between 11.0% by weight-14.5% by weight.
The layer system as claimed in one or more of the preceding claims,
- in which the content of chromium (Cr) in the alloy of the top layer (10) is between 14% by weight and 16% by weight.
The layer system as claimed in one or more of the preceding claims,
- in which the content of aluminum (Al) in the alloy of the top layer (10) is between 9% by weight and 13% by weight.
The layer system as claimed in one or more of the preceding claims,
- in which the content of yttrium (Y) in the alloy of the top layer (10) is between 0.1% by weight and 0.7% by weight.
The layer system as claimed in one or more of the preceding claims,
- in which the alloy of the top layer (10) comprises between 4% by weight and 7.5% by weight,
- in particular comprises between 3.0% by weight and 6.0% by weight, tantalum (Ta).
The layer system as claimed in one or more of the preceding claims,
- in which the content of tantalum (Ta) in the alloy of the top layer (10) is between 3.5% by weight and 5.5% by weight,
- in particular is 4.5% by weight.
The layer system as claimed in one or more of the preceding claims,
- in which the content of cobalt (Co) in the alloy of the top layer is between 21% by weight and 25% by weight,
- in particular is between 22% by weight and 23.5% by weight,
- very particularly is 23% by weight.
The layer system as claimed in one or more of the preceding claims,
- in which the content of chromium (Cr) in the alloy of the top layer (10) is between 18% by weight and 22% by weight.
The layer system as claimed in one or more of the preceding claims,
- in which the top layer (10) comprises no yttrium (Y).
The layer system as claimed in one or more of the preceding claims,
- in which the content of aluminum (Al) in the alloy of the top layer (10) is between 8% by weight and 12% by weight.
The layer system as claimed in one or more of the preceding claims,
- in which the content of yttrium (Y) in the alloy of the top layer (10) is between 0.1% by weight and 0.7% by weight.
The layer system as claimed in one or more of the preceding claims,
- in particular a component (120, 130, 155) of a gas turbine (100),
- very particularly in which a substrate (4) of the layer system (120, 130, 155) is nickel-based or cobalt-based,
- in which a ceramic thermal barrier coating (16) is applied to the protective layer (10).
Dependencies are inferred from the claim text.