Method for forming an improved thermal barrier coating (TBC), thermal-barrier-coated article and method for the repair thereof

A method for repairing an article (100) comprising a substrate (101) coated with a thermal barrier coating comprising a bond coat (103);

• characterized in that it comprises the steps of:
• i) subjecting said bond coat (103) to a low activity aluminizing process, thus obtaining a temporary intermediate diffusion layer on said bond coat (103);
• j) applying, on said temporary intermediate diffusion layer, aluminium powder in suspension with a solvent or aqueous base, said aluminium powder having a size distribution from 15 to 150 μm;
• k) carrying out a thermal vacuum treatment on the substrate, bond coat and temporary intermediate diffusion layer as a whole, at a pressure from 10−3 to 10−5 bar, at a temperature from 800° C. to 1050° C. and with an active phase in the range of 60 min-4 h, thus obtaining an enriched intermediate diffusion layer (105) on said bond coat (103);
• and
• l) applying a definitive barrier layer (104) on said enriched intermediate diffusion layer (105).

A method for repairing an article (100) comprising a substrate (101) coated with a thermal barrier coating comprising a bond coat (103) and a temporary intermediate diffusion layer arranged on said bond coat;

• characterized in that it comprises the steps of:
• j) applying, on said temporary intermediate diffusion layer, aluminium powder in suspension with a solvent or aqueous base, said aluminium powder having a size distribution from 15 to 150 μm;
• k) carrying out a thermal vacuum treatment on the substrate, bond coat and temporary intermediate diffusion layer as a whole, at a pressure from 10-3 to 10-5 bar, at a temperature from 800° C. to 1050° C. and with an active phase in the range of 60 min-4 h, thus obtaining an enriched intermediate diffusion layer (105) on said bond coat (103);
• and
• l) applying a definitive barrier layer (104) on said enriched intermediate diffusion layer (105).