ABRADABLE COATING FOR COMPONENTS IN HIGH-TEMPERATURE MECHANICAL SYSTEMS

An article may include a substrate including a metal or alloy; a bond coat directly on the substrate; an intermediate ceramic layer on the bond coat; and an abradable ceramic layer directly on the intermediate ceramic layer. The intermediate ceramic layer includes a stabilized tetragonal prime phase constitution and defines a first porosity. The abradable ceramic layer includes zirconia or hafnia stabilized in the tetragonal prime phase by a second mixture including between about 5 wt. % and about 10 wt. % ytterbia, between about 0.5 wt. % and about 2.5 wt. % samaria, and between about 1 wt. % and about 4 wt. % of at least one of lutetia, scandia, ceria, neodymia, europia, or gadolinia, and a balance zirconia or hafnia. The abradable ceramic layer defines a second porosity, and the second porosity is higher than the first porosity.