An article may include a substrate and a coating system on the substrate. The coating system may include an environmental barrier coating (EBC) layer and a CMAS resistant layer on the EBC layer (e.g., as the top coat of the system). The CMAS layer includes a rare-earth (RE) monosilicate composition including a plurality of RE metal cations, wherein RE monosilicate composition is configured to react with CMAS to form a reaction product including a RE apatite phase with a RE.sub.2O.sub.3.SiO.sub.2 composition, wherein the RE of the RE.sub.2O.sub.3.SiO.sub.2 composition includes at least one of the plurality of RE metal cations of the RE monosilicate.

An article may include a substrate and a coating system on the substrate. The coating system may include an environmental barrier coating (EBC) layer and a CMAS resistant layer on the EBC layer (e.g., as the top coat of the system). The CMAS layer includes a rare-earth (RE) monosilicate composition including a plurality of RE metal cations, wherein RE monosilicate composition is configured to react with CMAS to form a reaction product including a RE apatite phase with a RE.sub.2O.sub.3.SiO.sub.2 composition, wherein the RE of the RE.sub.2O.sub.3.SiO.sub.2 composition includes at least one of the plurality of RE metal cations of the RE monosilicate.

A blade outer air seal has at least one internal surface and a layer atop the at least one internal surface. The layer has: a matrix comprising at least one of hafnium silicate (HfSiO.sub.4) and zirconium silicate (ZrSiO.sub.4), ytterbium disilicate (Yb.sub.2Si.sub.2O.sub.7); and barium magnesium alumino silicate (BMAS) or other alkaline earth aluminosilicate.

A blade outer air seal has at least one internal surface and a layer atop the at least one internal surface. The layer has: a matrix comprising at least one of hafnium silicate (HfSiO.sub.4) and zirconium silicate (ZrSiO.sub.4), ytterbium disilicate (Yb.sub.2Si.sub.2O.sub.7); and barium magnesium alumino silicate (BMAS) or other alkaline earth aluminosilicate.

The invention relates to a part made of silicon-based ceramic material or silicon-based ceramic matrix composite (CMC) material comprising an environmental barrier coating (EBC), said coating (12, 13) comprising a bonding layer (12) deposited on the surface of the ceramic material or ceramic matrix composite (CMC), said bonding layer (12) being topped by one or more layers together forming a multifunctional barrier structure (13), characterised in that the bonding layer (12) has at its interface with the multifunctional structure a polycrystalline silica layer (12) or sub-layer (12b).

The invention relates to a part made of silicon-based ceramic material or silicon-based ceramic matrix composite (CMC) material comprising an environmental barrier coating (EBC), said coating (12, 13) comprising a bonding layer (12) deposited on the surface of the ceramic material or ceramic matrix composite (CMC), said bonding layer (12) being topped by one or more layers together forming a multifunctional barrier structure (13), characterised in that the bonding layer (12) has at its interface with the multifunctional structure a polycrystalline silica layer (12) or sub-layer (12b).

Slurry EBC systems and method for fabricating slurry EBC systems for protecting component substrates and extending the longevity of such components are disclosed. The slurry EBC systems include a bond coat having a temperature capability of up to 1482° C. (2700° F.). Example bond coats include a mullite-based bond coat and a rare earth disilicate-based bond coat.

Slurry EBC systems and method for fabricating slurry EBC systems for protecting component substrates and extending the longevity of such components are disclosed. The slurry EBC systems include a bond coat having a temperature capability of up to 1482° C. (2700° F.). Example bond coats include a mullite-based bond coat and a rare earth disilicate-based bond coat.

An article has a substrate and a layer atop the substrate. The layer has: a matrix comprising at least one of hafnium silicate (HfSiO.sub.4) and ytterbium disilicate (Yb.sub.2Si.sub.2O.sub.7); and barium magnesium alumino silicate (BMAS).

An article has a substrate and a layer atop the substrate. The layer has: a matrix comprising at least one of hafnium silicate (HfSiO.sub.4) and ytterbium disilicate (Yb.sub.2Si.sub.2O.sub.7); and barium magnesium alumino silicate (BMAS).