Materials Science Forum, Vol.461-464, 265-272, 2004
Low mass bondcoat for robust thermal barrier coatings
Because of their duplex design, Thermal Barrier Coatings (TBCs) have proven their capability to increase the turbine part lifetime of an aero-engine. The ceramic layer acts as a thermal shield for the substrate, and the bondcoat, deposited between the ceramic and the substrate, enhances the adhesion and provide oxidation protection. However, high temperatures, high thermal gradients and thermal shock accelerate TBC damage and reduce reliability. Thermal barrier coatings for application in harsher environments need more thermal and chemical stability in the bondcoat. Novel and innovative bondcoats have been developed for this purpose by exothermal reaction of a multi-layer coating containing platinum and aluminium. The formation of pure composition-controlled intermetallic overlay is therefore possible and comes out with high performance and high stability bondcoat for next generation TBC applications.