Patent ID: 8728967

Claim:
A coating on a substrate made by thermally spraying a high purity yttria or ytterbia stabilized zirconia powder, said powder comprising from about 0 to about 0.01 weight percent silicon dioxide (silica), from about 0 to about 0.002 weight percent aluminum oxide (alumina), from about 0 to about 0.005 weight percent calcium oxide, from about 0 to about 0.005 weight percent ferric oxide, from about 0 to about 0.002 weight percent magnesium oxide, from about 0 to about 0.005 weight percent titanium dioxide, from about 0 to about 2 weight percent hafnium oxide (hafnia), from about 6 to about 25 weight percent yttrium oxide (yttria) or from about 10 to about 36 weight percent ytterbium oxide (ytterbia), from about 0 to 0.1 weight percent other oxides, and the balance zirconium oxide (zirconia); said powder having a particle size of from about 1 to about 150 microns; and said thermally sprayed coating having a tetragonal crystallographic form, with to plurality of vertical macrocracks substantially homogeneously dispersed throughout the coating in which a cross-sectional area of the coating normal to the substrate exposes a plurality of vertical macrocracks extending at least half the coating thickness in length up to the full thickness of the coating and having from about 5 to about 200 vertical macrocracks per linear inch measured in a line parallel to the surface of the substrate and in a plane perpendicular to the surface of the substrate.