Article with surface structures for CMAS resistance
AssigneeROLLS-ROYCE plc
InventorsTaylor K. Blair, Ted J. Freeman, Aaron Sippel
Life of this patent
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Abstract
In some examples, article used as a component for a turbine engine that operates in a high temperature environment. The article may include: a ceramic or ceramic matrix composite (CMC) substrate; and a coating on the ceramic or the CMC substrate, wherein the coating defines an outer surface of the article. The coating includes a plurality of surface features defining channels on the outer surface of the article. The channels are configured to modify a flow of molten Calcia-Magnesia-Alumina Silicate (CMAS) over the outer surface of the coating in a gas flow over the outer surface of the article to reduce accumulation of the molten CMAS on the outer surface of the article.
Claims20
An article comprising:
- a ceramic or ceramic matrix composite (CMC) substrate;
- and
- a coating on the ceramic or the CMC substrate, wherein the coating defines an outer surface of the article, wherein the coating includes a first portion which does not include surface features and a second portion adjacent to the first portion, the second portion defining a plurality of surface features, the plurality of surface features defining channels on the outer surface of the article, wherein the channels are configured to modify a flow of molten Calcia-Magnesia-Alumina Silicate (CMAS) over the outer surface of the coating in a gas flow over the outer surface of the article to reduce accumulation of the molten CMAS on the outer surface of the article, wherein:
- the plurality of surface features includes one or more protrusions protruding out of a surface plane of the coating, wherein the surface plane of the coating is defined by the first portion of the coating, and wherein the one or more protrusions define the channels on the outer surface of the article,
- respective channels on the outer surface of the coating are defined by neighboring individual protrusions of the one or more protrusions, and
- the respective channels have a ramped surface between the neighboring individual protrusions, wherein the ramped surface is a planar surface and defines a first point and a second point on the planar surface, wherein the first point and the second point are at different distances away from the surface plane of the coating along a line substantially parallel to the gas flow over the outer surface of the article, wherein the ramped surface defines an elevation change in a Z-direction relative to the surface plane of the coating such that the respective channels are recessed into or protrude out of the surface plane of the coating.
A method comprising forming a coating on a ceramic or ceramic matrix composite (CMC) substrate on an outer surface of an article, wherein the coating includes a a first portion which does not include surface features and a second portion adjacent to the first portion, the second portion defining a plurality of surface features, the plurality of surface features defining channels on the outer surface of the article, wherein the channels are configured to modify a flow of molten Calcia-Magnesia-Alumina Silicate (CMAS) over the outer surface of the coating in a gas flow over the outer surface of the article to reduce accumulation of the molten CMAS on the outer surface of the article, wherein:
- the plurality of surface features includes one or more protrusions protruding out of a surface plane of the coating, wherein the surface plane of the coating is defined by the first portion of the coating, and wherein the one or more protrusions define the channels on the outer surface of the article,
- respective channels on the outer surface of the coating are defined by neighboring individual protrusions of the one or more protrusions, and
- the respective channels have a ramped surface between the neighboring individual protrusions, wherein the ramped surface is a planar surface and defines a first point and a second point on the planar surface, wherein the first point and the second point are at different distances away from the surface plane of the coating along a line substantially parallel to the gas flow over the outer surface of the article, wherein the ramped surface defines an elevation change in a Z-direction relative to the surface plane of the coating such that the respective channels are recessed into or protrude out of the surface plane of the coating.
Dependencies are inferred from the claim text.