Dense vertically cracked thermal barrier coatings

Abstract

This invention relates to dense, vertically cracked thermal barrier coatings made from high purity yttria or ytterbia stabilized zirconia powders. The high purity yttria or ytterbia stabilized zirconia powder consisting essentially of less than about 0.01 weight percent silicon dioxide (silica), less than about 0.002 weight percent aluminum oxide (alumina), less than about 0.005 weight percent calcium oxide, less than about 0.005 weight percent ferric oxide, less than about 0 to about 0.002 weight percent magnesium oxide, less than 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), less than 0.1 weight percent other impurity oxides, and the balance zirconium oxide (zirconia) and the balance zirconium oxide (zirconia). The thermal barrier coatings are intended to be used in cyclic thermal environments such as for gas turbine blades, vanes and seal surfaces exposed in the hot section of gas turbine engines.