A method for processing a component is provided and includes masking a first portion of the component with a maskant. The maskant includes a slurry having a plurality of particles in a fluid carrier. The plurality of particles comprises at least one of silicon, carbon, one or more rare earth disilicates, monosilicates or oxides, and combinations thereof. The method includes depositing a silicon-based coating on a second portion of the component via a chemical vapor deposition process and removing the maskant and any overlying silicon-based coating from the first portion of the component.

In one example, a method for forming an environmental barrier coating (EBC) and/or abradable coating on a substrate. The method may include depositing a coating on a ceramic or ceramic matrix composite (CMC) substrate to form an as-deposited coating, wherein the coating includes at least one of an environmental barrier coating (EBC) and an abradable coating. The method further comprises heat treating the as-deposited coating at or above a first temperature for a first period of time following the deposition of the as-deposited coating on the substrate, wherein heat treating the as-deposited coating includes heating the as-deposited coating to or above the first temperature at a controlled rate. The heat treatment may be configured to at least one of decrease the open pores and/or microcracks of the heat-treated coating compared to the as-deposited coating or control a grain size of the heat-treated coating.

A method to produce a ceramic matrix composite with controlled surface characteristics includes: applying a scrim ply to a surface of a fiber preform, where the fiber preform includes silicon carbide fibers coated with boron nitride; infiltrating the fiber preform and the scrim ply with a slurry, thereby forming an impregnated ply on an impregnated fiber preform; infiltrating the impregnated fiber preform and the impregnated ply with a melt comprising silicon, and then cooling, thereby forming a ceramic matrix composite having a ceramic surface layer thereon, where the ceramic surface layer has a predetermined thickness and is devoid of boron; machining or grit blasting the ceramic surface layer to form an intermediate layer suitable for coating; and depositing an environmental barrier coating on the intermediate layer. Thus, a ceramic matrix composite coated with the environmental barrier coating is formed with the intermediate layer in between.

A method for forming a vertically cracked thermal barrier coating is disclosed including positioning an article relative to a heat source. The article includes a thermal barrier coating disposed on a first surface of a substrate, and the substrate includes a second surface distal across the substrate from the first surface. Heat is applied locally to at least one discrete portion of the second surface of the substrate. At least one vertical crack in the thermal barrier coating is formed disposed over the at least one discrete portion. An article is disclosed including a substrate and a vertically-cracked thermal barrier coating disposed on the substrate. The vertically cracked thermal barrier coating includes at least one vertical crack in the thermal barrier coating and at least one of a low density of less than 85% of a theoretical density for the thermal barrier coating and a selective crack distribution.

Methods of forming sintered coatings are provided, along with the resulting coatings on a substrate. The sintered coating may comprise a rare earth compound and a sintering aid, with the rare earth compound has the formula: A.sub.1−bB.sub.bZ.sub.1−dD.sub.dMO.sub.6 where A is Al, Ga, In, Sc, Y, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Fe, Cr, Co, Mn, Bi, or a mixture thereof; b is 0 to about 0.5; Z is Hf, Ti, or a mixture thereof; D is Zr, Ce, Ge, Si, or a mixture thereof; d is 0 to about 0.5; and M is Ta, Nb, or a mixture thereof. The coating may be densified at a sintering temperature, such as 1300° C. to 1600° C.

Methods for forming a coating on a surface of a substrate are provided. The method can include: preheating the surface of the substrate; spraying a slurry suspension onto the surface of the substrate to form a coating, wherein the slurry composition comprises a rare earth compound, a sintering agent, and a solvent, wherein the rare earth compound has the formula: A.sub.1-bB.sub.bZ.sub.1-dD.sub.dMO.sub.6 where A is Al, Ga, In, Sc, Y, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Fe, Cr, Co, Mn, Bi, or a mixture thereof; b is 0 to 0.5; Z is Hf, Ti, or a mixture thereof; D is Zr, Ce, Ge, Si, or a mixture thereof; d is 0 to 0.5; and M is Ta, Nb, or a mixture thereof; and thereafter, heat treating the coating to densify the coating from an initial porosity to a sintered porosity.

A part includes a substrate having, adjacent to a surface of the substrate, at least a portion that is made of a material that contains silicon, and an environmental barrier formed on the surface of the substrate, the environmental barrier including a first layer including at least one first rare earth silicate and presenting grains with a mean size less than or equal to 1 μm; and a second layer covering the first layer, the second layer including at least one rare earth silicate and presenting grains with a mean size greater than 1 μm.

An environmental barrier coating, comprising a substrate containing silicon; an environmental barrier layer applied to the substrate; the environmental barrier layer comprising an oxide matrix; an oxidant getter phase interspersed throughout the oxide matrix; and a self-healing phase interspersed throughout the oxide matrix.

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.

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.