Outer airseal insulated rub strip
A blade outer airseal has a body comprising: an inner diameter (ID) surface; an outer diameter (OD) surface; a leading end; and a trailing end. The airseal body has a metallic substrate and a coating system atop the substrate along at least a portion of the inner diameter surface. At least over a first area of the inner diameter surface, the coating system comprises an abradable layer and a thermal barrier layer between the abradable layer and the substrate; and the thermal barrier layer comprises a ceramic and metallic phases within the ceramic.
1. A blade outer airseal having:
a body comprising:
an inner diameter surface;
an outer diameter surface;
a leading end;
a trailing end;
a metallic substrate; and
a coating system atop the substrate along at least a portion of the inner diameter surface,
wherein:
at least over a first area of the inner diameter surface, the coating system comprises an abradable layer and a thermal barrier layer between the abradable layer and the substrate;
over a span of the abradable layer, a relative thickness of the abradable layer to the thermal barrier layer decreases from fore to aft; and
the thermal barrier layer comprises a ceramic and metallic phases within the ceramic.
2. The blade outer airseal of claim 1 wherein:
the abradable layer comprises a metal matrix and a solid lubricant.
3. The blade outer airseal of claim 1 wherein:
the abradable layer comprises a metal phase volumetric content greater than a metal phase volumetric content of the thermal barrier layer.
4. The blade outer airseal of claim 1 wherein:
the abradable layer comprises a metal matrix of a first alloy; and
the thermal barrier layer metallic phases are of the first alloy.
5. The blade outer airseal of claim 1 wherein:
the abradable layer has a lower strength than the thermal barrier layer.
6. The blade outer airseal of claim 1 wherein:
the abradable layer has a greater thickness than the thermal barrier layer.
7. The blade outer airseal of claim 1 wherein:
the thermal barrier layer has a stepwise thickness increase.
8. The blade outer airseal of claim 1 wherein:
the thermal barrier layer has a higher volumetric ceramic content than a does the abradable layer, if any.
9. The blade outer airseal of claim 1 wherein one or more of:
the coating system has a bondcoat between the thermal barrier layer and the substrate;
the substrate is a nickel-based superalloy;
the substrate has a radially outwardly extending flange; and
a combined thickness of the abradable layer and the thermal barrier layer has a fore-to-aft increase of at least 10% over a span at least 10% of the longitudinal span of the coating.
10. A method for manufacturing the blade outer airseal of claim 1 , the method comprising:
thermal spray of the thermal barrier layer and the abradable layer in a single chamber.
11. The method of claim 10 further comprising:
thermal spray of a transition layer.
12. A method for using the blade outer airseal of claim 1 , the method comprising:
installing the blade outer airseal on a turbine engine; and
running the turbine engine so that blade tips rub the abradable coating.
13. A blade outer airseal having:
a body comprising:
an inner diameter surface;
an outer diameter surface;
a leading end;
a trailing end;
a metallic substrate; and
a coating system atop the substrate along at least a portion of the inner diameter surface
wherein:
at least over a first area of the inner diameter surface, the coating system comprises an abradable layer and a thermal barrier layer between the abradable layer and the substrate;
the thermal barrier layer comprises a ceramic and metallic phases within the ceramic; and
the thermal barrier layer extends axially beyond the abradable layer.
14. A blade outer airseal having:
a body comprising:
an inner diameter surface;
an outer diameter surface;
a leading end;
a trailing end;
a metallic substrate; and
a coating system atop the substrate along at least a portion of the inner diameter surface,
wherein:
at least over a first area of the inner diameter surface, the coating system comprises an abradable layer and a thermal barrier layer between the abradable layer and the substrate; and
the thermal barrier layer has a thickness profile rearwardly biased relative to a thickness profile of the abradable layer.
15. The blade outer airseal of claim 14 wherein one or more of:
the thermal barrier coating has a rearwardly increasing thickness profile;
the thermal barrier coating has a progressively rearwardly increasing thickness profile; and
the thermal barrier coating is localized to a rear portion of a span of the abradable coating.
16. The blade outer airseal of claim 14 wherein:
the substrate has a radially outwardly extending flange; and
the bias is along a portion of the substrate aft of the flange.
17. A gas turbine engine compressor section comprising:
a stage of blades having Ni-based substrates;
a blade outer airseal comprising:
an inner diameter surface;
an outer diameter surface facing tips of the blades;
a leading end;
a trailing end;
a metallic substrate; and
a coating system atop the substrate along at least a portion of the inner diameter surface,
wherein:
at least over a first area of the inner diameter surface, the coating system comprises an abradable layer and a thermal barrier layer between the abradable layer and the substrate.
18. The gas turbine engine compressor section of claim 17 wherein:
the substrate has a circumferential channel along the inner diameter face;
the abradable coating is substantially localized to the channel; and
the thermal barrier coating extends beyond the channel.
19. The gas turbine engine compressor section of claim 18 wherein:
the thermal barrier coating extends onto the leading end and the trailing end.
20. A blade outer airseal having:
a body comprising:
an inner diameter surface;
an outer diameter surface;
a leading end;
a trailing end;
a metallic substrate; and
a coating system atop the substrate along at least a portion of the inner diameter surface,
wherein:
at least over a first area of the inner diameter surface, the coating system comprises an abradable layer and a thermal barrier layer between the abradable layer and the substrate;
the thermal barrier layer comprises a ceramic and metallic phases within the ceramic; and
one or more of:
the coating system has a bondcoat between the thermal barrier layer and the substrate;
the substrate is a nickel-based superalloy;
the substrate has a radially outwardly extending flange; and
a combined thickness of the abradable layer and the thermal barrier layer has a fore-to-aft increase of at least 10% over a span at least 10% of the longitudinal span of the coating.