Metallic Bond Coat with Enhanced TBC Spallation Resistance

Abstract

An article (20) has a metallic substrate (22) and a coating (28) atop the substrate. The coating has an at least local composition by weight percent of: Ni as a largest by weight content; 14.00 to 18.00 Cr; 20.00 to 24.00 Co; 11.00 to 13.50 Al; 0.40 to 0.80 Y; 0.10 to 0.40 Hf; 0.30 to 0.70 Si; to 0.02 C, if any; to 0.01 S, if any; to 0.01 P, if any; to 0.40 Fe, if any; to 0.10 Mo, if any; 0.05 to 0.90 Ta; to 0.40 W, if any; to 0.60 Zr, if any; and to 1.0 other, if any, total. In weight percent, one or more of: Zr+W+Ta+Fe is 0.50 to 1.30; Zr+W is 0. 40 to 0.90; and Zr+W+Ta is 0.40 to 1.10.

Description

METALLIC BOND COAT WITH ENHANCED TBC SPALLATION RESISTANCECROSS-REFERENCE TO RELATED APPLICATION

[0001] Benefit is claimed of U.S. Patent Application No. 63 / 673910, filed July 22, 2024, and entitled "Metallic Bond Coat with Enhanced TBC Spallation Resistance", the disclosure of which is incorporated by reference herein in its entirety as if set forth at length.BACKGROUND

[0002] The disclosure relates to gas turbine engines. More particularly, the disclosure relates to MCrAlY bondcoats for ceramic barrier coating systems.

[0003] Gas turbine engines (used in propulsion and power applications and broadly inclusive of turbojets, turboprops, turbofans, turboshafts, industrial gas turbines, and the like) have gaspath components exposed to extreme heat and thermal gradients during various phases of engine operation. Thermal-mechanical stresses and resulting fatigue contribute to component failure. Significant efforts are made to cool such components and provide thermal barrier coatings to improve durability.

[0004] Example thermal barrier coating systems include systems with a metallic bondcoat atop a substrate and a ceramic thermal barrier coating atop the bondcoat. An example system includes an MCrAlY (e.g., NiCoCrAlY) bondcoat as the first layer (e.g., low pressure plasma sprayed (LPPS)) and yttria- stabilized zirconia (YSZ) (or gadolinium zirconate (GdZ or GZO)) thermal barrier coating (TBC) (e.g., air plasma sprayed (APS), suspension plasma sprayed (SPS) or electron beam physical vapor deposited (EB-PVD)) as the second layer. Prior to and while the thermal barrier coat layer is being deposited, a thermally grown oxide (TGO) layer (e.g., alumina) may form atop the bondcoat layer. As time-at-temperature and the number of cycles increase during subsequent service exposure, this TGO interface layer grows in thickness. An example YSZ is 7 weight percent yttria- stabilized zirconia (7YSZ).

[0005] Example TBCs are applied to thicknesses of 1-40 mils (0.025-1.0 mm) and can contribute to a temperature reduction of up to 300° F (167° C) at the base metal. This temperature reduction translates into improved part durability, or higher turbine operating temperatures and improved turbine efficiency.SUMMARY

[0006] One aspect of the disclosure involves an article having a metallic substrate and a coating atop the substrate. The coating has an at least local composition by weight percent of: Ni as a largest by weight content; 14.00 to 18.00 Cr; 20.00 to 24.00 Co; 11.00 to 13.50 Al;0.40 to 1.0 Y; 0.10 to 0.40 Hf; 0.30 to 0.70 Si; to 0.02 C, if any; to 0.01 S, if any; to 0.01 P, if any; to 0.40 Fe, if any; to 0.10 Mo, if any; 0.05 to 0.90 Ta; to 0.40 W, if any; to 0.60 Zr, if any; and to 1.0 other, if any, total. In weight percent, one or more of: Zr+W+Ta+Fe is 0.50 to 1.30; Zr+W is 0. 40 to 0.90; and Zr+W+Ta is 0.40 to 1.10.

[0007] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, in weight percent said other is no more than 0.50 total.

[0008] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, in weight percent said other is no more than 0.20 other elements individually.

[0009] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, said other is limited to impurities.

[0010] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, in said at least local composition in weight percent, one or more of: Zr+W+Ta+Fe is 0.50 to 1.20; Zr+W is 0. 40 to 0.80; and Zr+W+Ta is 0.40 to 0.95.

[0011] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, in said at least local composition in weight percent, one or more of: Zr+W+Ta+Fe is 0.85 to 1.20; Zr+W is 0.55 to 0.80; and Zr+W+Ta is 0.55 to 0.95.

[0012] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, in said at least local composition in weight percent Zr+W+Ta+Fe is 0.50 to 1.20.

[0013] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, in said at least local composition in weight percent Zr+W is 0. 40 to 0.80.

[0014] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, in said at least local composition in weight percent Zr+W+Ta is 0.40 to 0.95.

[0015] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, in said at least local composition in weight percent: Zr+W+Ta+Fe is 0.50 to 1.20; Zr+W is 0. 40 to 0.80; and Zr+W+Ta is 0.40 to 0.95.

[0016] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, the at least local composition comprises in weight percent: 0.10 to 0.25 Fe; 0.05 to 0.10 Mo; 0.10 to 0.20 Ta; 0.15 to 0.35 W, if any; 0.15 to 0.40 Zr, if any; and to 0.50 other, if any, total.

[0017] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, the at least local composition comprises in weight percent 0.90 to 1.0 Y, optionally 0.92 to 1.0 Y.

[0018] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, the at least local composition comprises in weight percent: to 0.20 each other, individually.

[0019] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, the article further comprises a ceramic coating atop the coating.

[0020] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, the substrate is a nickel-based alloy and the coating is on an airfoil region of the substrate.

[0021] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, a method for manufacturing the article comprises: applying the coating via cathodic arc deposition; and applying a ceramic coating atop the coating.

[0022] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, the ceramic coating is applied by physical vapor deposition.

[0023] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, a method for using the article comprises: installing the article in a gas turbine engine; and running the engine to heat the article.

[0024] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively the running exposes the article to combustion gas.

[0025] A further aspect of the disclosure involves a method for coating an article, the method comprising: applying a bondcoat layer to a metallic substrate of the article; and applying a ceramic coating atop the bondcoat layer. After the applying of the bondcoat layer, the bondcoat layer or a sublayer thereof has an at least local composition by weight percent of: Ni as a largest by weight content; 14.00 to 18.00 Cr; 20.00 to 24.00 Co; 11.00 to 13.50 Al; 0.40 to 1.0 Y; 0.10 to 0.40 Hf; 0.30 to 0.70 Si; to 0.02 C, if any; to 0.01 S, if any; to 0.01 P, if any; to 0.40 Fe, if any; to 0.10 Mo, if any; 0.05 to 0.90 Ta; to 0.40 W, if any; to 0.60 Zr, if any; and to 0.50 other, if any, total and, weight percent, one or more of: Zr+W+Ta+Fe is 0.50 to 1.30; Zr+W is 0. 40 to 0.90; and Zr+W+Ta is 0.40 to 1.10.

[0026] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively: the applying the bondcoat layer is via cathodic arc deposition; and the applying the ceramic coating is via PVD.

[0027] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, the local composition is an average across a region of at least 50% of the thickness of the bondcoat layer and / or at least 20.0 micrometers and across a continuous planform area of at least 100 mm2.

[0028] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively: the article is a blade; and the applying the bondcoat layer and the ceramic coating is to an airfoil thereof.

[0029] A further aspect of the disclosure involves a coating or a sublayer thereof having an at least local composition by weight percent of: Ni as a largest by weight content; 14.00 to 18.00 Cr; 20.00 to 24.00 Co; 11.00 to 13.50 Al; 0.40 to 1.0 Y; 0.10 to 0.40 Hf; 0.30 to 0.70 Si; to 0.02 C, if any; to 0.01 S, if any; to 0.01 P, if any; to 0.40 Fe, if any; to 0.10 Mo, if any; 0.05 to 0.90 Ta; to 0.40 W, if any; to 0.60 Zr, if any; and to 0.50 other, if any, total and, weight percent, one or more of: Zr+W+Ta+Fe is 0.50 to 1.30; Zr+W is 0. 40 to 0.90; and Zr+W+Ta is 0.40 to 1.10.

[0030] In a further embodiment of any of the foregoing embodiments, additionally and / or alternatively, said at least local composition is an average over a continuous volume defined by a depthwise region of at least 20.0 micrometers and across a continuous planform area of at least 100 mm2.

[0031] The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG. 1 is a schematic sectional view of a coating system on a substrate.

[0033] FIG. 2 is a view of a blade as such a coated substrate.

[0034] Like reference numbers and designations in the various drawings indicate like elements.DETAILED DESCRIPTION

[0035] FIG. 1 shows a coated article 20 exposed to the gaspath 40 of a gas turbine engine. The article comprises a substrate 22 having a surface 24. Example substrates are metallic (e.g. nickel-based superalloy, cobalt-based superalloy, or the like, typically a casting). Alternative substrates are monolithic ceramics, ceramic matrix composites (CMC) (e.g., SiC — SiC), and the like. The coated article further includes a thermal barrier coating and / or environmental barrier coating system (coating system) 26 atop the substrate. Broadly, example articles are hot section components of gas turbine engines and the coating system 26 may be along gaspath-facing surfaces of such components. Example components are blades (FIG. 2)(with the airfoil 52 pressure side 54 and suction side 56 surfaces and platform 60 outer diameter (OD) surface 62 being key), vanes (with the airfoil pressure side and suction side surfaces, inner diameter (ID) shroud OD surface, and OD shroud ID surface being key), bulkheads, combustor panels, struts, and the like. Further variations involve abradable coatings on the inner diameter surface of blade outer airseals (BOAS) where a porosity increase may improve abradability.

[0036] The coating system 26 includes an MCrAlY bondcoat 28 (namely a NiCoCrAlY discussed below). The distribution and application technique of the bondcoat may be dependent on the particular substrate and use and may reflect any of numerous prior art or yet-developed distributions and methods. The example bondcoat layer is applied by cathodic arc (cat-arc or arc-PVD) deposition.

[0037] The coating system 26 further includes a ceramic coating such as a thermal barrier coating (TBC) 32 at least over some portion of the bondcoated substrate surface (e.g. there may be other portions with or without bondcoat and lacking the ceramic). The example TBC is a single layer system. The example single layer is a yttria- stabilized zirconia (e.g., 7YSZ). Example ceramic application technique is physical vapor deposition (PVD) such as electron beam physical vapor deposition (EB-PVD). Alternatives include thermal spray.

[0038] An alternative two-layer TBC may have a first layer (base layer) atop the bondcoat 28 and a second layer atop an outer surface of the base layer and extending to an outer surface. Other variations are possible.

[0039] FIG. 1 shows an example bondcoat thickness TB and a larger example ceramic thickness Tc. Example TB is 25 to 75 micrometers (more narrowly, 35 micrometers to 55 micrometers) and example Tc is 100 to 400 micrometers (more narrowly 150 micrometers to 250 micrometers).

[0040] The present NiCoCrAlY bondcoat is further discussed in the context of an example coated article as a blade. The example has at at least one location, layering formed by the application of the NiCoCrAlY bondcoat directly to the substrate and a ceramic barrier coating layer directly to the NiCoCrAlY (e.g., no further bondcoat layer applied). Similarly, the example has only a single ceramic barrier coating layer. Nevertheless, other articles (e.g., vanes, combustor panels, and the like), other bondcoat layerings (e.g., an additional NiCoCrAlY layer application before or after described layer application and / or a pre- or post-aluminiding), and other barrier coatings (e.g., including multi-layer and multi-technique) may be involved.

[0041] As noted above, a specific example involves cathodic arc deposition of theNiCoCrAlY bondcoat and electron beam physical vapor deposition (EB-PVD) of a yttria- stabilized zirconia (e.g., 7YSZ) barrier coating.

[0042] Table I shows weight percent compositions for several examples and a prior art (PA) example. The identified relative performance is measured as the change in ceramic coating spallation relative to PAI as a baseline. Specifically, using a cyclic air furnace (e.g., to 2050°F (1121°C)) on a test coupon of a Ni-based superalloy and a low conductivity ceramic (e.g., US patent 6,177,200) or 7YSZ one can measure time to a particular threshold amount of spallation by visual inspection.Table I* Measured composition t Prophetic nm Composition not measured because limited sample size was unable to support specialized analysis

[0043] Table II shows weight percent compositions for several published ranges.Table II

[0044] Table III shows weight percent compositions for several compositional ranges.Table III

[0045] In Table III, the “Other” entry may represent an aggregate of all other elements not listed. For further alternative limitations on “Other”, an additional or alternative limitation of up to 0.050 of each other element or 0.020 of each other element may be used. In further embodiments, said “Other” may be limited to commercial or inevitable impurities. For further narrowing variations / limitations on the Table III ranges one or more of:• Zr+W+Ta+Fe is 0.50-1.30, with alternative lower limits of 0.70 or 0.85 and alternative upper limits of 1.25, 1.20, 1.15, 1.10, 1.05, or 1.00 in any combination;• Zr+W is 0. 40-0.90, with alternative lower limits of 0.50 or 0.55 and alternative upper limits of 0.80, 0.75 or 0.70 or 0.65 in any combination; and• Zr+W+Ta is between 0.40-1.10, with alternative lower limits of 0.50 or 0.55 or 0.60 and alternative upper limits of 0.95, 0.90, 0.80, 0.75 or 0.70 in any combination.

[0046] Also, in Table III, further variations on any of the ranges may occur by substituting the yttrium content of the other ranges. In particular, the higher yttrium ranges with lower limits greater than 0.40 may be substituted into the ranges that have levels starting at 0.40. Similarly, alternative ranges may be created by adopting the conventional prior art range of 0.40-0.80.

[0047] In various implementations, such a bondcoat may reduce the frequency of coater maintenance relative to similar NiCoCrAlY bond coats (e.g., including commercial implementations of the Table II bondcoats) in that the chemistry allows for a more uniform application during the coating process which forms a more dense MCrAlY coating. The coating that forms on the chamber walls and shields is also more dense. The associated reduction in surface area reduces the amount of moisture adsorbed during loading and unloading and facilitates quicker pump downs to low pressure and more coating cycles before the coater needs to be cleaned.

[0048] The bondcoat composition as described is essentially an as-applied composition rather than a source material composition. Differential attrition of species from the source material (e.g., a thermal spray powder or a PVD ingot or an arc or sputtering target) may cause departures in composition between the source material and the material reaching the substrate. Additionally, there will typically be at least local diffusion with the substrate the bondcoat material is applied to (or with an underlayer such as a lower MCrAlY layer in a two-layer bondcoat). Additionally, there may be diffusion or chemical reaction with a layer applied atop the subject MCrAlY (such as a second MCrAlY layer, an aluminization, or a ceramic barrier coating layer).

[0049] Accordingly, to discount the diffusion and / or reaction zones, the MCrAlY composition may be measured in a depthwise region (having a thickness TREF in FIG. 1) spaced from the substrate and potentially also from the outer surface of the subject MCrAlY layer. This may be averaged over a relevant surface / planform area of the article.

[0050] For example, one could cut a part, mount and polish the exposed cross-section (from substrate to surface), identify a depthwise TREF region area that encompasses an example 80% of the thickness of the coating MCrAlY (more broadly, at least 30% or at least 50%), place the coating in an electron microprobe (EPMA) and conduct wavelength- dispersive spectroscopy (WDS) to determine the chemistry of the coating. This may apply to the inspection of an actual coated part (e.g., blade) or a test coupon. Multiple such crosssections may be taken over a given planform area of the article. Example TREF may alternatively be at least 20 micrometers or at least 30 micrometers or at least 40 micrometers (e.g., 20 micrometers to 50 micrometers or 20 micrometers to 40 micrometers).

[0051] In a test scenario, one could alternatively apply the coating to a test substrate (such as a copper foil or coupon), remove the substrate by dissolving it using chemicals, digest the remaining coating in acid and use inductively coupled plasma (ICP) to determine the chemistry. This latter process may be used to calibrate source material for a given coater to produce a desired as-applied coating composition.

[0052] Selection of feedstock composition to yield the desired as-applied composition may be an iterative process such as starting with applying feedstock of the desired final as-applied composition, running a test, and, based on the results of the test, adjusting the feedstock composition based on measured as-applied composition. The differential attrition may be influenced by factors such as the general type of deposition apparatus, the particular model of apparatus, and the operating parameters. There may be sufficient knowledge of relevant attrition so as to allow direct selection of appropriate source material without need for iterative refinement.

[0053] The coating and layer thickness, composition, and properties may be measured at a single location or across an area of the article as noted above. Such area may be a total or continuous area (e.g., truly continuous or continuous ignoring cooling hole outlets). With an area, that TREF thickness and composition may be at all locations or an average (mean, median, or mode). A representative area is at least 1.0 square centimeters.

[0054] Or, a representative area may be a fraction or percentage of a relevant area. For example, the relevant area may be the gaspath-facing surface of a component for a thermal barrier coating or the inner diameter face of a blade outer air seal for an abradable coatingsystem. For a TBC on a blade (e.g., having attachment root (e.g., firtree or dovetail), airfoil, and optional intervening platform), the relevant area includes pressure and suction side surfaces of the airfoil and the gaspath-facing facing outer diameter surface of the platform. For a non-cantilever vane, it would include such airfoil surfaces, and platform (inner diameter (ID) shroud) and outer diameter (OD) shroud gaspath-facing surfaces (OD and ID respectively). A cantilever vane would typically lack the ID shroud. A combustor panel may be formed as a generally frustoconical segment for an annular combustor where the relevant area would be the ID face of an OD panel or the OD face of an ID panel. Example combustor panel substrates would include threaded mounting studs protruding from the surface opposite the gas path- facing surface. A representative such fraction or percentage is at least 10% or at least 50% or at least 90%.

[0055] The use of “first”, “second”, and the like in the following claims is for differentiation within the claim only and does not necessarily indicate relative or absolute importance or temporal order. Similarly, the identification in a claim of one element as “first” (or the like) does not preclude such “first” element from identifying an element that is referred to as “second” (or the like) in another claim or in the description.

[0056] One or more embodiments have been described. Nevertheless, it will be understood that various modifications may be made. For example, when applied to an existing baseline configuration, details of such baseline may influence details of particular implementations. Accordingly, other embodiments are within the scope of the following claims.

Claims

CLAIMSWhat is claimed is:

1. An article (20) comprising: a metallic substrate (22); and a coating (28) atop the substrate having an at least local composition by weight percent of:Ni as a largest by weight content;14.00 to 18.00 Cr;20.00 to 24.00 Co;11.00 to 13.50 Al;0.40 to 1.0 Y;0.10 to 0.40 Hf;0.30 to 0.70 Si; to 0.02 C, if any; to 0.01 S, if any; to 0.01 P, if any; to 0.40 Fe, if any; to 0.10 Mo, if any;0.05 to 0.90 Ta; to 0.40 W, if any; to 0.60 Zr, if any; and to 1.0 other, if any, total, and wherein in weight percent, one or more of:Zr+W+Ta+Fe is 0.50 to 1.30;Zr+W is 0. 40 to 0.90; andZr+W+Ta is 0.40 to 1.10.

2. The article of claim 1 wherein in weight percent: said other is no more than 0.50 total.

3. The article of claim 1 wherein in weight percent: said other is no more than 0.20 other elements individually.

4. The article of any of claim 1 to claim 3 wherein in said at least local composition in weight percent, one or more of:Zr+W+Ta+Fe is 0.50 to 1.20;Zr+W is 0. 40 to 0.80; andZr+W+Ta is 0.40 to 0.95.

5. The article of any of claim 1 to claim 3 wherein in said at least local composition in weight percent, one or more of:Zr+W+Ta+Fe is 0.85 to 1.20;Zr+W is 0.55 to 0.80; andZr+W+Ta is 0.55 to 0.95.

6. The article of any of claim 1 to claim 3 wherein in said at least local composition in weight percent:Zr+W+Ta+Fe is 0.50 to 1.20.

7. The article of any of claim 1 to claim 3 wherein in said at least local composition in weight percent:Zr+W is 0. 40 to 0.80.

8. The article of any of claim 1 to claim 3 wherein in said at least local composition in weight percent:Zr+W+Ta is 0.40 to 0.95.

9. The article of any of claim 1 to claim 3 wherein in said at least local composition in weight percent:Zr+W+Ta+Fe is 0.50 to 1.20;Zr+W is 0. 40 to 0.80; andZr+W+Ta is 0.40 to 0.95.

10. The article of any of claim 1 to claim 3 wherein said at least local composition comprises in weight percent:0.10 to 0.25 Fe;0.05 to 0.10 Mo;0.10 to 0.20 Ta;0.15 to 0.35 W, if any;0.15 to 0.40 Zr, if any; and to 0.50 other, if any, total11. The article of any of claim 1 to claim 3 wherein the coating at least local composition comprises in weight percent:0.90 to 1.0 Y.

12. The article of any of claim 1 to claim 3 wherein the coating at least local composition comprises in weight percent:0.92 to 1.0 Y.

13. The article of claim 12 wherein the coating at least local composition comprises in weight percent: to 0.20 each other, individually.

14. The article of any of claim 1 to claim 3 further comprising: a ceramic coating (32) atop the coating.

15. The article of any of claim 1 to claim 3 wherein: the substrate is a nickel-based alloy; and the coating is on an airfoil region of the substrate.

16. A method for manufacturing the article of any of claim 1 to claim 3, the method comprising: applying the coating (28) via cathodic arc deposition; and applying a ceramic coating (32) atop the coating.

17. The method of claim 16 wherein: the ceramic coating is applied by physical vapor deposition.

18. A method for using the article of any of claim 1 to claim 3, the method comprising: installing the article in a gas turbine engine; andrunning the engine to heat the article.

19. The method of claim 18 wherein: the running exposes the article to combustion gas.

20. A method for coating an article (20), the method comprising: applying a bondcoat layer (28) to a metallic substrate (22) of the article; and applying a ceramic coating (32) atop the bondcoat layer, wherein: after the applying of the bondcoat layer, the bondcoat layer or a sublayer thereof has an at least local composition by weight percent of:Ni as a largest by weight content;14.00 to 18.00 Cr;20.00 to 24.00 Co;11.00 to 13.50 Al;0.40 to 1.0Y;0.10 to 0.40 Hf;0.30 to 0.70 Si; to 0.02 C, if any; to 0.01 S, if any; to 0.01 P, if any; to 0.40 Fe, if any; to 0.10 Mo, if any;0.05 to 0.90 Ta; to 0.40 W, if any; to 0.60 Zr, if any; and to 0.50 other, if any, total and wherein in weight percent, one or more of:Zr+W+Ta+Fe is 0.50 to 1.30;Zr+W is 0. 40 to 0.90; andZr+W+Ta is 0.40 to 1.10.

21. The method of claim 20 wherein: the applying the bondcoat layer is via cathodic arc deposition; andthe applying the ceramic coating is via PVD.

22. The method of claim 21 wherein: the local composition is an average across a region of at least 50% of the thickness of the bondcoat layer and / or at least 20.0 micrometers and across a continuous planform area of at least 100 mm2.

23. The method of claim 20 wherein: the local composition is an average across a region of at least 50% of the thickness of the bondcoat layer and / or at least 20.0 micrometers and across a continuous planform area of at least 100 mm2.

24. The method of claim 20 wherein: the article is a blade; and the applying the bondcoat layer and the ceramic coating is to an airfoil thereof.

25. The method of claim 20 wherein in weight percent: said other is no more than 0.50 total.

26. The method of claim 20 wherein in weight percent: said other is no more than 0.20 other elements individually.

27. The method of any of claim 20 to claim 26 wherein in weight percent in said at least local composition, one or more of:Zr+W+Ta+Fe is 0.50 to 1.20;Zr+W is 0. 40 to 0.80; andZr+W+Ta is 0.40 to 0.95.

28. The method of any of claim 20 to claim 26 wherein in weight percent in said at least local composition, one or more of:Zr+W+Ta+Fe is 0.85 to 1.20;Zr+W is 0.55 to 0.80; andZr+W+Ta is 0.55 to 0.95.

29. The method of any of claim 20 to claim 26 wherein in weight percent in said at least local composition:Zr+W+Ta+Fe is 0.50 to 1.20.

30. The method of any of claim 20 to claim 26 wherein in weight percent in said at least local composition:Zr+W is 0. 40 to 0.80.

31. The method of any of claim 20 to claim 26 wherein in weight percent in said at least local composition:Zr+W+Ta is 0.40 to 0.95.

32. The method of any of claim 20 to claim 26 wherein in weight percent in said at least local composition:Zr+W+Ta+Fe is 0.50 to 1.20;Zr+W is 0. 40 to 0.80; andZr+W+Ta is 0.40 to 0.95.

33. The method of any of claim 20 to claim 26 wherein said at least local composition comprises in weight percent:0.10 to 0.25 Fe;0.05 to 0.10 Mo;0.10 to 0.20 Ta;0.15 to 0.35 W, if any;0.15 to 0.40 Zr, if any; and to 0.50 other, if any, total34. The method of any of claim 20 to claim 26 wherein said at least local composition comprises in weight percent:0.90 to 1.0 Y.

35. The method of any of claim 20 to claim 26 wherein said at least local composition comprises in weight percent:0.92 to 1.0 Y.

36. The method of any of claim 20 to claim 26 wherein said at least local composition comprises in weight percent: to 0.20 each other, individually.

37. The method of any of claim 20 to claim 26 further comprising: applying a ceramic coating (32) atop the coating.

38. The method of any of claim 20 to claim 26 wherein: the substrate is a nickel-based alloy; and the coating is on an airfoil region of the substrate.

39. A coating (26) or sublayer (28) thereof having an at least local composition by weight percent of:Ni as a largest by weight content;14.00 to 18.00 Cr;20.00 to 24.00 Co;11.00 to 13.50 Al;0.40 to 1.0Y;0.10 to 0.40 Hf;0.30 to 0.70 Si; to 0.02 C, if any; to 0.01 S, if any; to 0.01 P, if any; to 0.40 Fe, if any; to 0.10 Mo, if any;0.05 to 0.90 Ta; to 0.40 W, if any; to 0.60 Zr, if any; and to 0.50 other, if any, total and wherein in weight percent, one or more of:Zr+W+Ta+Fe is 0.50 to 1.30;Zr+W is 0. 40 to 0.90; andZr+W+Ta is 0.40 to 1.10.

40. The coating or sublayer thereof of claim 39 wherein said at least local composition is an average over a continuous volume defined by a depthwise region of at least 20.0 micrometers and across a continuous planform area of at least 100 mm2.

41. The coating or sublayer thereof of claim 39 wherein in weight percent: said other is no more than 0.50 total.

42. The coating or sublayer thereof of claim 39 wherein in weight percent: said other is no more than 0.20 other elements individually.

43. The coating or sublayer thereof of any of claim 39 to claim 42 wherein in weight percent in said at least local composition, one or more of:Zr+W+Ta+Fe is 0.50 to 1.20;Zr+W is 0. 40 to 0.80; andZr+W+Ta is 0.40 to 0.95.

44. The coating or sublayer thereof of any of claim 39 to claim 42 wherein in weight percent in said at least local composition, one or more of:Zr+W+Ta+Fe is 0.85 to 1.20;Zr+W is 0.55 to 0.80; andZr+W+Ta is 0.55 to 0.95.

45. The coating or sublayer thereof of any of claim 39 to claim 42 wherein in weight percent in said at least local composition:Zr+W+Ta+Fe is 0.50 to 1.20.

46. The coating or sublayer thereof of any of claim 39 to claim 42 wherein in weight percent in said at least local composition:Zr+W is 0. 40 to 0.80.

47. The coating or sublayer thereof of any of claim 39 to claim 42 wherein in weight percent in said at least local composition:Zr+W+Ta is 0.40 to 0.95.

48. The coating or sublayer thereof of any of claim 39 to claim 42 wherein in weight percent in said at least local composition:Zr+W+Ta+Fe is 0.50 to 1.20;Zr+W is 0. 40 to 0.80; andZr+W+Ta is 0.40 to 0.95.

49. The coating or sublayer thereof of any of claim 39 to claim 42 wherein said at least local composition comprises in weight percent:0.10 to 0.25 Fe;0.05 to 0.10 Mo;0.10 to 0.20 Ta;0.15 to 0.35 W, if any;0.15 to 0.40 Zr, if any; and to 0.50 other, if any, total50. The coating or sublayer thereof of any of claim 39 to claim 42 wherein said at least local composition comprises in weight percent:0.90 to 1.0 Y.

51. The coating or sublayer thereof of any of claim 39 to claim 42 said at least local composition comprises in weight percent:0.92 to 1.0 Y.

52. The coating or sublayer thereof of any of claim 39 to claim 42 wherein said at least local composition comprises in weight percent: to 0.20 each other, individually.

53. The coating or sublayer thereof of any of claim 39 to claim 42 wherein: a ceramic coating (32) atop the coating or sublayer.

54. The coating or sublayer thereof of any of claim 39 to claim 42 wherein: the coating is on a substrate; the substrate is a nickel-based alloy; andthe coating is on an airfoil region of the substrate.

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