Patent ID: 8021762
Filing Date: 2011-09-20
Classification: B32B,C04B,C23C,F01D,Y02T,Y10T

Abstract:
1. An article coated with a thermal barrier coating comprising zirconia partially stabilized by yttria, and having a density greater than 88% of the theoretical density, in the tetragonal crystallographic form, with a plurality of vertical macrocracks substantially homogeneously dispersed throughout the coating in which a cross-sectional area of the coating normal to the article 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 article and in a plane perpendicular to the surface of the article, said thermal barrier coating comprising a thermally sprayed coating of a high purity yttria stabilized zirconia powder, said high purity yttria stabilized zirconia 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 1.5 to about 2 weight percent hafnium oxide (hafnia), from about 6 to about 25 weight percent yttrium oxide (yttria), from about 0 to 0.1 weight percent other oxides, and the balance zirconium oxide (zirconia); wherein said thermal barrier coating, after exposure at 1200° C. for 100 hours, has no monoclinic phase as determined by x-ray diffraction methods.