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

摘要

The invention refers to a process for the formation of a thermal barrier coating on a substrate, comprising the steps of:
a) applying a bond coat on the substrate;b) subjecting the bond coat to a low activity aluminizing process, thus obtaining, above the bond coat, a temporary intermediate diffusion layer;c) applying, on the temporary intermediate diffusion layer, aluminum powder in suspension with a solvent or aqueous base, said aluminum powder having size distribution from 15 to 150 μm;d) performing a thermal treatment in a vacuum at a pressure from 10−3 to 10−5 bars, at a temperature from 800° C. to 1050° C. and with an active phase having duration in the range of 60 minutes to 4 hours, thus obtaining above the bond coat an enriched intermediate diffusion layer; ande) applying a definitive barrier layer on said enriched intermediate diffusion layer.

主权项

1. A method for forming a thermal barrier coating (102) on a substrate (101), comprising the steps of:
a) applying a bond coat (103) on said substrate (101); b) subjecting said bond coat (103) to a low activity aluminizing process, thus obtaining a temporary intermediate diffusion layer on said bond coat (103); characterized in that it comprises the steps of c) applying on said temporary intermediate diffusion layer obtained from said phase b) aluminium powder in suspension with a solvent or aqueous base, said aluminium powder having a size distribution from 15 to 150 μm; d) carrying out a vacuum heat 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 e) applying a definitive barrier layer (104) on said enriched intermediate diffusion layer (105).