A powder composition is described for use in the preparation of an environmental barrier coating or an abradable coatings. The particles of the powder composition possess an internal porosity and are prepared by spray drying feed particles to form agglomerated particles. The agglomerated particle may further contain dislocator material and/or pore forming material.

A powder composition is described for use in the preparation of an environmental barrier coating or an abradable coatings. The particles of the powder composition possess an internal porosity and are prepared by spray drying feed particles to form agglomerated particles. The agglomerated particle may further contain dislocator material and/or pore forming material.

A method and device are described for plasma spraying of multiple powders. A first powder is introduced into a plasma jet at a first distance from the nozzle of a plasma spray torch. A second powder is introduced into the plasma jet at a second distance from the nozzle of the plasma spray torch. The second distance is greater than the first distance so that the second powder is introduced into the plasma jet at a different point than which the first powder enters the plasma jet. The method and device can be used to simultaneously plasma spray different powders that have, for example, different compositions and/or different particle morphology.

A method and device are described for plasma spraying of multiple powders. A first powder is introduced into a plasma jet at a first distance from the nozzle of a plasma spray torch. A second powder is introduced into the plasma jet at a second distance from the nozzle of the plasma spray torch. The second distance is greater than the first distance so that the second powder is introduced into the plasma jet at a different point than which the first powder enters the plasma jet. The method and device can be used to simultaneously plasma spray different powders that have, for example, different compositions and/or different particle morphology.

A blade outer air seal includes a center web having a radially inner face and a radially outer face, at least one mounting arm extending from the radially outer face, and a coating disposed on the radially inner face. The coating includes an environmental barrier coating layer and an abradable layer disposed on the environmental barrier layer. The abradable layer has a Mohs hardness of 3.5 to 7.5 and the porosity of the abradable layer is chosen in view of the Mohs hardness, which significantly improves the durability of the abradable layer. A gas turbine engine and a method of protecting a blade outer air seal are also disclosed.

A blade outer air seal includes a center web having a radially inner face and a radially outer face, at least one mounting arm extending from the radially outer face, and a coating disposed on the radially inner face. The coating includes an environmental barrier coating layer and an abradable layer disposed on the environmental barrier layer. The abradable layer has a Mohs hardness of 3.5 to 7.5 and the porosity of the abradable layer is chosen in view of the Mohs hardness, which significantly improves the durability of the abradable layer. A gas turbine engine and a method of protecting a blade outer air seal are also disclosed.