Abstract: Methods are provided for forming a thermal barrier coating having a non-linear compositional gradient and/or a non-linear porosity gradient, along with coated components formed therefrom. The method includes spraying a deposition mixture of a first composition and a second composition via a solution precursor plasma spray apparatus onto a surface of a substrate; while spraying the deposition mixture, adjusting at least one deposition parameter such that the thermal barrier coating is formed with the non-linear gradient.

Abstract: A coating method is provided. The coating method includes applying, via electrophoretic deposition or slurry deposition, an overcoat composition on an outer surface of a thermal barrier coating system on a substrate. The overcoat composition includes a coating material comprising a plurality of particles having a particle size of less than 1000 nm. The method includes sintering the overcoat composition in the presence of one or more sintering aids to form an overcoat layer having a surface roughness of less than 1 micrometer.

Abstract: A composition comprising an yttria-rare earth-doped zirconium oxide is provided that has a tetragonal structure and a formula: YaLnbCexZr1-a-b-xO2-? where Ln is a mixture of rare earth elements; 0.01?a?0.051; 0.01?b?0.051 such that Y and each rare earth element is included in the composition in substantially equal molar amounts; 0.05?(a+b)?0.07; 0?x?0.051; and 0???0.05. Methods of forming a coating that includes this composition, along with the resulting coated components, are also provided.

Abstract: A composition is provided of a rare earth-doped zirconium oxide having a tetragonal structure and having a formula: YaLnbTaxNbzZr1-a-b-x-zO2-? where Ln is a rare earth element or a mixture of rare earth elements; 0?a?0.06; 0.06?b?0.12; 0?x?0.1; 0?z?0.1; 0.08?(x+z)?0.1; 0.16?(a+b+x+z)?0.22; and 0.01???0.05. Methods of forming a coating with this composition, along with the coated components, are also provided.

Abstract: Coated components, along with methods of their formation, are provided. The coated component may include a substrate having a surface and a thermal barrier coating on the surface of the substrate. The thermal barrier coating includes a plurality of elongated surface-connected voids therein, and wherein the thermal barrier coating comprises a plurality of nonspherical particles within a thermal barrier material.