Method of globally repairing a part covered with a thermal barrier

• Main Authors: FOURNES JEAN-PAUL, OBERLANDER GUILLAME ROGER PIERRE, MALIE ANDRE HUBERT LOUIS, RICHIN CATHERINE MARIE-HELENE, MANESSE DENIS GEORGES, BOUCARD BRUNO GILLES FRANCOIS
• Format: Patent
• Language: English
• Published: 09.12.2004
• Edition: 7
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; CLEANING OR DEGREASING OF METALLIC MATERIAL BY CHEMICALMETHODS OTHER THAN ELECTROLYSIS; CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TOTRANSPORTATION; 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; COMBINED OPERATIONS; DIFFUSION TREATMENT OF METALLIC MATERIAL; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; METALLURGY; OTHER WORKING OF METAL; PERFORMING OPERATIONS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TRANSPORTING; UNIVERSAL MACHINE TOOLS

The invention relates to a method of overall repair for a part (1) coated in a thermal barrier constituted by a ceramic outer layer (5) and a metal underlayer (3) of alumina-forming alloy, the method being characterized by the following steps: a) subjecting the metal part (1) for repair to thermochemical treatment under fluorine-containing halogen gas for a length of time that is sufficient to eliminate the aluminum contained in the underlayer (3) and any oxides and sulfur compounds that might be present at the surface of the part (1) and in cracks (6), thereby causing the ceramic layer (5) to be removed and causing the part (1) to be passivated; b) restoring mechanical integrity to the part (1) by methods of repairing any cracks (6) by adding material; c) enriching the surface of the part in aluminum, if necessary; and d) depositing a new layer (5) of ceramic. The invention is particularly applicable to the blades of the high pressure turbine of a turbomachine.