METHOD FOR PROVIDING A THERMAL BARRIER COATING AND SUBSTRATE HAVING SUCH COATING

摘要

Method for providing a thermal barrier coating and substrate. The thermal barrier coating is provided on a thermally grown oxide which is grown on a metallic bond coating provided on said substrate. Adhesion between the bond coating and thermally grown oxide coating is improved by providing projections at the interface of yttria-alumina garnet compounds. Service life at relatively high temperature of the thermally grown oxide coating is improved by having alumina grain with relatively large size. These are obtained by pre-annealing the bond coating in an inert gas atmosphere followed by controlled preoxidation.