Patent ID: 7255940

Claim:
A thermal barrier coating for an underlying substrate comprising: 1. an inner high fracture toughness layer closest to the underlying substrate, the inner layer having a fraction of porosity of about 0.20 or less, and a thickness in the range of from about 0.5 to about 2 mils, and sufficient to impart impact resistance to the thermal barrier coating, and comprising a zirconia-containing ceramic composition having a c/a ratio of the zirconia lattice in the range of from about 1.011 to about 1.016 and stabilized in the tetragonal phase by a stabilizing amount of a stabilizing metal oxide selected from the group consisting of yttria, calcia, ceria, scandia, magnesia, india, lanthana, gadolinia, neodymia, samaria, dysprosia, erbia, ytterbia, europia, praseodymia, and mixtures thereof, wherein the inner layer comprises from about 0.3 to about 0.5% by weight of a metal oxide selected from the group consisting of lanthana, neodymia, gadolinia, and mixtures thereof; and 2. an outer thermal insulating layer adjacent to and overlying the inner layer and comprising a ceramic thermal baffler coating material.