Abstract: Environmental barrier coatings (EBCs) are disclosed having a topcoat layer having a primary hafnon phase and a dispersed hafnia phase. The hafnia can be homogeneously dispersed or the layer can exhibit a concentration gradient in which the hafnia concentration increases continuously or stepwise. The hafnon primary phase provides a desirable CTE match with the underlying CMC substrate, while the dispersed hafnia provides desirable corrosion resistance.

Abstract: A method of repairing a coating on an article according to an exemplary embodiment of this disclosure, among other possible things includes defining a work area surrounding a discontinuity in the coating, the coating including undisturbed bond coat and undisturbed top coat; removing coating material within the work area; applying a slurry containing bond coat constituents in a carrier fluid to the work area; curing the slurry to form a repaired bond coat; applying a slurry containing top coat constituents in a carrier fluid to the work area; and curing the slurry to form a repaired top coat. A method of repairing a coating on an article and an article are also disclosed.

Abstract: An article may include a substrate. An article may include a barrier layer on the substrate, the barrier layer including: a bond coat comprising a matrix, diffusive particles disposed in the matrix, and gettering particles disposed in the matrix, and a topcoat comprising a first top coat layer adjacent the bond coat and a second top coat layer disposed on the first top coat layer, the first top coat layer having a lower porosity than the second top coat layer.

Abstract: An article according to an exemplary embodiment of this disclosure, among other possible things includes a substrate and a barrier layer on the substrate. The barrier layer includes a bond coat comprising a matrix, diffusive particles disposed in the matrix, and gettering particles disposed in the matrix; a topcoat; and a porous interlayer disposed between the topcoat and the bond coat. The porous interlayer has a porosity that is greater than a porosity of the topcoat. A slurry composition for applying an interlayer to an article and method of applying a top coat to an article are also disclosed.

Abstract: An article includes a substrate and a bond coat disposed on the substrate. The bond coat includes a matrix, a plurality of gettering particles disposed in the matrix, a plurality of diffusive particles disposed in the matrix, a radiation-absorbing component disposed in the matrix, wherein the radiation-absorbing component is concentrated at an outer surface of the bond coat. An article and a method of protecting an article are also disclosed.

Abstract: A method of repairing a coating on an article according to an exemplary embodiment of this disclosure, among other possible things includes defining a work area surrounding a discontinuity in the coating, the coating including undisturbed bond coat and undisturbed top coat; removing coating material within the work area; applying a slurry containing bond coat constituents in a carrier fluid to the work area; curing the slurry to form a repaired bond coat; applying a slurry containing top coat constituents in a carrier fluid to the work area; and curing the slurry to form a repaired top coat. A method of repairing a coating on an article and an article are also disclosed.

Abstract: A method of applying a top coat to an article according to an exemplary embodiment of this disclosure, among other possible things includes applying a first feedstock comprising particles of oxide-based material having diameters between about 1 and about 80 microns via a thermal spray process to form a first top coat layer on an article having a bond coat and applying a second feedstock comprising particles of oxide-based material having diameters between about 15 and about 60 microns via the thermal spray process to form a second top coat layer on the first top coat layer. An article and a barrier layer for an article are also disclosed.

Abstract: A deposition apparatus comprises: an infeed chamber; a preheat chamber; a deposition chamber; and optionally at least one of a cooldown chamber and an outlet chamber. At least a first of the preheat chamber and the cooldown chamber contains a buffer system for buffering workpieces respectively passing to or from the deposition chamber.

Abstract: A feedstock for spray deposition of a coating includes particles each including a particle core and a coating. The particle core is a gettering particle. The coating includes at least one of diffusive material, precursor diffusive material, matrix material, and precursor matrix material. A method of coating a substrate is also disclosed.

Abstract: An article according to an exemplary embodiment of this disclosure, among other possible things includes a substrate and a barrier layer on the substrate. The barrier layer includes a bond coat comprising a matrix, diffusive particles disposed in the matrix, and gettering particles disposed in the matrix. At least about 10% of the gettering particles are in a crystalline phase. The article also includes a top coat. An article is also disclosed.

Abstract: An adaptive surface texturing method is provided for use with a part formed of ceramic matrix composites (CMCs) to be coated with an environmental barrier coating (EBC). The method includes coating a CMC surface of the part with an initial coating, determining a contour and an undulation pattern of the CMC surface and designing a texturing pattern to follow the contour and the undulation pattern and to be formed in the initial coating based on a thickness of the initial coating and an average particle size of a slurry of the EBC.

Abstract: A component for a gas turbine engine according to an exemplary embodiment of the present disclosure can include a substrate, a thermal barrier coating deposited on at least a portion of the substrate, and an outer layer deposited on at least a portion of the thermal barrier coating. The outer layer can include a material that is reactive with an environmental contaminant that comes into contact with the outer layer to alter a microstructure of the outer layer.

Abstract: A deposition apparatus (20) comprising: a chamber (22); a process gas source (62) coupled to the chamber; a vacuum pump (52) coupled to the chamber; at least two electron guns (26); one or more power supplies (30) coupled to the electron guns; a plurality of crucibles (32,33,34) positioned or positionable in an operative position within a field of view of at least one said electron gun; and a part holder (170) having at least one operative position for holding parts spaced above the crucibles by a standoff height H. The standoff height H is adjustable in a range including at least 22 inches.

Abstract: A method of repairing a nonconforming article includes applying a machinable coating to an article with a nonconformance. The article includes a preform at least partially infiltrated with a matrix material, to form a repaired article. The method also includes machining the machinable coating and completing infiltration of the repaired article with the matrix material. A method of repairing an article is also disclosed.

Abstract: An article includes a barrier layer disposed on a bond coat. The barrier layer includes diffusive particles and gettering particles disposed in a matrix. The article also includes a machinable coating disposed on the barrier layer. A method of applying a coating to an article is also disclosed.

Abstract: A coating-substrate combination includes: a Ni-based superalloy substrate comprising, by weight percent: 2.0-5.1 Cr; 0.9-3.3 Mo; 3.9-9.8 W; 2.2-6.8 Ta; 5.4-6.5 Al; 1.8-12.8 Co; 2.8-5.8 Re; 2.8-7.2 Ru; and a coating comprising, exclusive of Pt group elements, by weight percent: Ni as a largest content; 5.8-9.3 Al; 4.4-25 Cr; 3.0-13.5 Co; up to 6.0 Ta, if any; up to 6.2 W, if any; up to 2.4 Mo, if any; 0.3-0.6 Hf; 0.1-0.4 Si; up to 0.6 Y, if any; up to 0.4 Zr, if any; up to 1.0 Re, if any.

Abstract: An article according to an exemplary embodiment of this disclosure includes a substrate and a bond coat disposed on the substrate. The bond coat includes a matrix. The matrix includes regions of ?-cristobalite. The article also includes a plurality of gettering particles disposed in the matrix, a plurality of diffusive particles disposed in the matrix, and an additive operable to stabilize the regions of ?-cristobalite at ambient temperatures dispersed in the matrix. An article and a method of coating an article are also disclosed.

Abstract: An environmental barrier coating includes a barrier layer which includes a matrix, diffusive particles, and gettering particles; and a calcium-magnesia alumina-silicate (CMAS)-resistant component. The CMAS-resistant component includes hafnium silicate and a rare earth hafnate. An article and a method of fabricating an article are also disclosed.

Abstract: An environmental barrier coating includes a barrier layer which includes a matrix, diffusive particles, and gettering particles; and a calcium-magnesia alumina-silicate (CMAS)-resistant component. The CMAS-resistant component includes hafnium silicate and a rare earth hafnate. An article and a method of fabricating an article are also disclosed.

Abstract: A method of correcting a manufactured article includes applying a machinable coating to a manufactured ceramic matrix composite article with a manufacturing artifact and machining the machinable coating to provide a desired geometry. A method of correcting a manufactured article and a corrected article are also disclosed.