Patent ID: 8197950
Filing Date: 2012-06-12
Classification: B32B,C04B,C23C,F01D,Y02T,Y10T

Abstract:
1. A dense vertically cracked thermal barrier coating on an article comprising: a thermally sprayed coating of a high purity yttria stabilized zirconia powder, said powder comprising less than about 0.01 weight percent silicon dioxide (silica), less than about 0.002 weight percent aluminum oxide (alumina), less than about 0.005weight percent calcium oxide, less than about 0.005 weight percent ferric oxide, from about 0 to about 0.002 weight percent magnesium oxide, from about 0 to about 0.005weight 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), less than 0.1 weight percent other oxides, and the balance zirconium oxide (zirconia); wherein said thermal barrier coating having a density greater than 88% of the theoretical density, in the tetragonal crystallographic form; wherein said thermal barrier coating 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 vertical macrocracks substantially homogeneously dispersed throughout the coating, said vertical macrocracks extending in length from half the thickness of the coating to the full thickness of the coating; and wherein said thermal barrier coating has no monoclinic phase after exposure at 1200° C. for 100 hours, as determined by x-ray diffraction methods.