Thermal barrier coating protected by infiltrated alumina and method for preparing same

• Main Authors: ACKERMAN JOHN FREDERICK, BOUTWELL BRETT ALLEN, NAGARAJ BANGALORE ASWATHA
• Format: Patent
• Language: English
• Published: 02.09.2004
• Edition: 7
• Subjects: BLASTING; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; ENGINE PLANTS IN GENERAL; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; METALLURGY; NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAMTURBINES; STEAM ENGINES; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; WEAPONS

A thermal barrier coating for an underlying metal substrate of articles that operate at, or are exposed to, high temperatures, as well as being exposed to environmental contaminant compositions. This coating includes a porous outer layer having an exposed surface and comprising a non-alumina ceramic thermal barrier coating material, as well as alumina infiltrated within the porous outer layer in an amount sufficient to protect the coating at least partially against environmental contaminants that become deposited on the exposed surface. This coating can be used to provide a thermally protected article having a metal substrate and optionally a bond coat layer adjacent to and overlaying the metal substrate. The thermal barrier coating can be infiltrated with the alumina by treating the porous outer layer with a liquid composition comprising an alumina precursor and then converting the infiltrated alumina precursor to alumina.