Mixed metal oxide ceramic compositions for reduced conductivity thermal barrier coatings

摘要

Ceramic compositions comprising a main ceramic component comprising from 63 to 99 mole % zirconia and from 1 to 37 mole % hafnia. These compositions further comprise at least 4 mole % of a stabilizer 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. These ceramic compositions are useful in preparing thermal barrier coatings having reduced thermal conductivity for the substrate f articles that operate at, or are exposed to, high temperatures, as well as good producibility and impact/erosion resistance. Inclusion of hafnia also maintains the reduced conductivity of the thermal barrier coating after thermal exposure due to better sintering resistance.