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; and e) applying a definitive barrier layer on said enriched intermediate diffusion layer.