A coated article, a process of coating an article, and a process of using an article are disclosed. The coated article includes a substrate, a porous coating material, and a thermal barrier coating material. The porous coating material includes a porosity between about 1 percent and about 20 percent, by volume. The thermal barrier coating material has a thermal conductivity that is lower than a thermal conductivity of the substrate. The porous coating material differs in one or both of composition and microstructure from the thermal barrier coating material. Additionally or alternatively, the porous coating material resists at least one of sintering, densification, and phase destabilization for a predetermined period at a predetermined temperature. The process of coating an article includes applying a coating to form the coated article.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with United States Government support under contract number DE-FC26-05NT42643 awarded by the United States Department of Energy. The United States Government has certain rights in this invention.