US Patent 9714578 Method of depositing abradable coatings under polymer gels

A method of depositing abradable coating on an engine component is provided wherein the engine component is formed of ceramic matrix composite (CMC) and one or more layers, including at least one environmental barrier coating, may be disposed on the outer layer of the CMC. An outermost layer of the structure may further comprise a porous abradable layer that is disposed on the environmental barrier coating and provides a breakable structure which inhibits blade damage. The abradable layer may be gel-cast on the component and sintered or may be direct written by extrusion process and subsequently sintered.