Electron beam-physical vapor deposition of a ceramic coating having a composition gradient on a substrate, e.g. a gas turbine blade, involves using a ceramic target rod having lengthwise non-uniform composition

• Main Authors: PORTE ISABELLE, MALIE ANDRE, SAINT RAMOND BERTRAND, CHAPUT CHRISTOPHE, DELAGE CYRILLE
• Format: Patent
• Language: English; French
• Published: 24.10.2003
• Edition: 7
• Subjects: AIR INTAKES FOR JET-PROPULSION PLANTS; ARTIFICIAL STONE; BLASTING; CEMENTS; CERAMICS; 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; COMBUSTION ENGINES; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; CONCRETE; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS; DIFFUSION TREATMENT OF METALLIC MATERIAL; ENGINE PLANTS IN GENERAL; GAS-TURBINE PLANTS; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; LIGHTING; LIME, MAGNESIA; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; METALLURGY; NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAMTURBINES; REFRACTORIES; SLAG; STEAM ENGINES; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TREATMENT OF NATURAL STONE; WEAPONS

Formation of a ceramic coating on a substrate (10) by electron beam-physical vapor deposition (EB-PVD) involves: placing a ceramic target rod (20) having lengthwise non-uniform composition in an EB-PVD chamber (14); introducing the substrate into the chamber (14); and sweeping the upper surface of the rod with an electron beam to melt the target and form of a vapor cloud (24) in the chamber. Formation of a ceramic coating on a substrate (10) by EB-PVD involves: placing a rod-shaped, composite target (20) formed from ceramic powders and having lengthwise non-uniform composition in an EB-PVD chamber; introducing the substrate (10) into the chamber (14); and sweeping the upper surface of the rod (20) with an electron beam to cause melting of the material and the formation of a vapor cloud (24) in the chamber under reduced pressure. The rod (20) has a number of superposed layers of different compositions. The composition within each layer is uniform across the cross-section of the rod (20). Each layer comprises zirconia and at least one oxide selected from oxides of nickel, cobalt. iron, yttrium, hafnium, cerium, lanthanum, tantalum, niobium, scandium, samarium, gadolinium, dysprosium, ytterbium and aluminum. The ceramic coating formed on the substrate (10) by progressive consumption of the rod (20) reflects the variation in the composition of the rod (20). Independent claims are given for: (a) the rod-shaped target; and (b) fabrication of the rod-shaped target. On met en place dans une chambre (14) une cible composite en forme de barreau (20) formé de poudres céramiques et présentant une composition non uniforme en direction longitudinale, et on introduit dans la chambre au moins un substrat (10) sur lequel un revêtement céramique ayant un gradient de composition doit être formé. La face supérieure du barreau est balayée par un faisceau d'électrons afin de provoquer la fusion du matériau du barreau à sa face supérieure et la formation d'un nuage de vapeur dans la chambre sous pression réduite. On utilise un barreau (20) présentant une pluralité de couches superposées de compositions différentes, la composition étant, au sein de chaque couche, uniforme dans toute la section transversale du barreau, de sorte que le revêtement céramique formé sur le substrat par consommation progressive du barreau reflète la variation de composition du barreau.