A method for fabricating multi-layer ceramic broadband radome includes thermal-spraying layers of coating materials on the radome. The assembled structure exhibits tuned RF transparency response depending on the thickness and the dielectric constant of the deposited layers. Sub-micron thick ceramic layers, which are essential for broadband performance and hard to produce due to their fragile nature, can be deposited on big and complex objects by a fast and automated process.

A method for fabricating multi-layer ceramic broadband radome includes thermal-spraying layers of coating materials on the radome. The assembled structure exhibits tuned RF transparency response depending on the thickness and the dielectric constant of the deposited layers. Sub-micron thick ceramic layers, which are essential for broadband performance and hard to produce due to their fragile nature, can be deposited on big and complex objects by a fast and automated process.

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.

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.

A method for coating a substrate includes spraying a combination of powders. The combination of powders includes: Hf.sub.0.5Si.sub.0.5O.sub.2; Zr.sub.0.5Si.sub.0.5O.sub.2; and, optionally, at least one of HfO.sub.2 and ZrO.sub.2. A molar ratio of said Hf.sub.0.5Si.sub.0.5O.sub.2 and HfO.sub.2 combined to said Zr.sub.0.5Si.sub.0.5O.sub.2 and ZrO.sub.2 combined is from 2:1 to 4:1. A molar ratio of said Hf.sub.0.5Si.sub.0.5O.sub.2 to said HfO.sub.2 is at least 1:3.

A method for coating a substrate includes spraying a combination of powders. The combination of powders includes: Hf.sub.0.5Si.sub.0.5O.sub.2; Zr.sub.0.5Si.sub.0.5O.sub.2; and, optionally, at least one of HfO.sub.2 and ZrO.sub.2. A molar ratio of said Hf.sub.0.5Si.sub.0.5O.sub.2 and HfO.sub.2 combined to said Zr.sub.0.5Si.sub.0.5O.sub.2 and ZrO.sub.2 combined is from 2:1 to 4:1. A molar ratio of said Hf.sub.0.5Si.sub.0.5O.sub.2 to said HfO.sub.2 is at least 1:3.

A ceramic material which contains yttrium oxide as stabilizers and at least one of the materials erbium oxide or ytterbium oxide provides a phase having sintering stability for a ceramic material for ceramic layers and a ceramic layer system which maintain the mechanical and thermal properties for a long time even when used at high temperatures.

A ceramic material which contains yttrium oxide as stabilizers and at least one of the materials erbium oxide or ytterbium oxide provides a phase having sintering stability for a ceramic material for ceramic layers and a ceramic layer system which maintain the mechanical and thermal properties for a long time even when used at high temperatures.