Patent ID: 9034479
Filing Date: 2015-05-19
Classification: C04B,C23C,F01D,Y02T,Y10T

Abstract:
1. A coating system on a surface region of a component, the coating system comprising: a bond coat; and inner and outer ceramic layers on the bond coat, the inner ceramic layer overlying the bond coat, the inner ceramic layer consisting of zirconia stabilized by about 6 to about 9 weight percent yttria, the inner ceramic layer having a thickness and a porosity level, the outer ceramic layer overlying and contacting the inner ceramic layer and defining an outermost surface of the coating system, the outer ceramic layer consisting of zirconia stabilized by about 25 to about 75 weight percent yttria and greater than 0.5 to 10 weight percent hafnium oxide and optionally 1 to 10 weight percent tantalum oxide, the outer ceramic layer having a thickness that is less than the thickness of the inner ceramic layer and, having a porosity level that is lower than the porosity level of the inner ceramic layer, and wherein the inner and outer ceramic layers are heat treated in a vacuum to a temperature and for a duration sufficient to relieve stresses therein.