General Electric Company

Other

General Electric Aviation Service Operation Pte. Ltd.

Keng N Chen

Genfa Hu

Kwok Heng Yow

Shih Tung Ngiam

Nigel Brian Thomas Langley

A gas turbine blade which has previously been in service is protected by cleaning the gas turbine blade, and then first depositing a platinum first layer on the airfoil and the platform of the gas turbine blade. Thereafter, a platinum second layer is deposited over the platform but not the airfoil. A platinum-aluminide protective coating is formed by depositing an aluminum-containing layer overlying both the platform and the airfoil and interdiffusing the platinum and the aluminum.

Method for selective surface protection of a gas turbine blade which has previously been in service

A method for controlled removal of a portion of a diffusion coating from the outer surface of a nickel-containing superalloy article. A diffusion coating typically includes a diffusion layer between an outer aluminide layer and the nickel-containing substrate. The method includes contacting the coated superalloy article in a preselected chemical stripping solution for a preselected period of time sufficient to remove only the outer aluminide layer, without substantially affecting the diffusion layer underlying the outer aluminide layer. After neutralizing the stripping solution, the article can be inspected and repaired as needed. The aluminide outer layer can then be restored in a conventional manner.

Method for renewing diffusion coatings on superalloy substrates

An improved coating and method for applying the coating to minimize the consumption of substrate material during high temperature service by formation of an intermediate metal aluminide layer. A layer of Ni or Co or combinations of Ni and Co are added to the substrate material as an overlay by a process such as electroplating or electroless plating. A diffusion aluminide is then formed at the surface by exposing the plated substrate to a source of aluminum at an elevated temperature.

Coating and method for minimizing consumption of base material during high temperature service

An improved process for applying aluminide coatings to superalloy components used in gas turbine applications resulting in a more uniform coating with less hazardous waste by-products. The process involves the steps of placing the superalloy components into a retort with an aluminum-containing source, evacuating air from the retort and introducing an inert gas, heating the retort to a preselected temperature, while maintaining the preselected temperature purging the inert gas from the retort by introducing hydrogen gas, while maintaining the preselected temperature, pulsing, by reducing the retort pressure to a preselected pressure below atmospheric pressure, followed by introducing a halide-containing gas to react with the aluminum-containing source to create an aluminum-rich vapor that deposits aluminum on the components, then reintroducing hydrogen gas into the retort to purge the gases within the retort; and cooling the retort.

Pulsed-vapor phase aluminide process for high temperature oxidation-resistant coating applications

A method for identifying and repairing indications open to the surface of a turbine component, such as cracks or other tight crevices that may develop during turbine engine operation. The process includes cleaning the component of debris, dirt or other foreign material that may otherwise mask the presence of the indications. This is followed by applying a fluorescent penetrant to the surface of the component. Without removing the penetrant, the article is visually inspected under normal lighting conditions and repair alloy is applied as needed to areas requiring repair. Next, the article is inspected under an ultraviolet light, at which time very tight indications not otherwise detectable by the unaided eye are identified as areas requiring repair and repair alloy is applied to these additional areas, by an automatic and/or manual process. Without removing the penetrant, the article is then heated to an elevated temperature sufficient to liquify at least a portion of the repair alloy to accomplish the repair.

Growing community of inventors

Singapore, Singapore

Keng N Chen