Abstract: A method of locally repairing parts coated with a thermal barrier including a ceramic outer layer and a metal underlayer of alumina-forming alloy for protecting the substrate against oxidation and for bonding with the ceramic outer layer, includes: defining the zone for repair with a mechanical mask adapted to the shape of the part and the zone for repair; scouring the zone for repair so as to remove the ceramic, the alumina layer, and the damaged portions of the underlayer; supplying materials for repairing the underlayer to the repair zone by subjecting the partially-scoured part to metal deposition by use of an electrical current; and subjecting the part to a heat treatment in order to enable the added metals to diffuse into the remaining underlayer in the repair zone for repair and to enable a surface film of alumina to form. After the underlayer has been reconstituted, the zone for repair is again defined by a mechanical mask and a new ceramic layer is deposited thereon.

Abstract: The invention provides a method of locally repairing parts coated in a thermal barrier constituted by a ceramic outer layer (5) and a metal underlayer (3) of alumina-forming alloy for protecting the substrate (1) against oxidation and for bonding with the ceramic outer layer (5), characterized by the following steps: a) defining the zone (6) for repair with a mechanical mask (8) adapted to the shape of the part (1) and the zone (6) for repair; b) scouring the zone (6) for repair so as to remove from said zone the ceramic, the alumina layer (3b), and the damaged portions of the underlayer (3); c) supplying materials for repairing the underlayer (3) to said zone (6) by subjecting the partially-scoured part to metal deposition by means of electrical current; and d) subjecting the part to heat treatment in order to enable the added metals to diffuse into the remaining underlayer in the zone (6) for repair and to enable a surface film (3b) of alumina to form.

Abstract: A method of improving the oxidation and corrosion resistance of a superalloy article comprises providing a superalloy substrate having a sulphur content which is less than 0.8 ppm by weight, and depositing on the substrate a protective antioxidation coating having a sulphur content also less than 0.8 ppm by weight. A heat barrier layer may also be provided by depositing on the protective anti-oxidation coating a ceramic coating of columnar structure.

Abstract: A method of improving the oxidation and corrosion resistance of a superalloy article comprises providing a superalloy substrate having a sulphur content which is less than 0.8 ppm by weight, and depositing on the substrate a protective antioxidation coating having a sulphur content also less than 0.8 ppm by weight. A heat barrier layer may also be provided by depositing on the protective anti-oxidation coating a ceramic coating of columnar structure.

Abstract: A thermal barrier coating for a superalloy part used, in particular, in turbomachines comprises a ceramic coating and a sub-layer interposed between the superalloy substrate and the ceramic coating, the sub-layer being composed of a nickel and/or cobalt aluminide containing at least one platinum-like metal and at least one metal for promoting the formation of a layer of oxide constituted by the alpha-allotropic variety of alumina.