Superalloy article cleaning and repair method
AssigneeGeneral Electric Company
InventorsDonald L. Keller, David L. Resor
Life of this patent
Estimating the term…
Abstract
A narrow crevice in a Ni-base superalloy article is repaired by first removal of a complex oxide of at least one metal selected from Al and Ti, by treatment of the oxide in the crevice with gaseous active fluoride ions in a non-oxidizing atmosphere at a temperature at which the oxide will react with the fluoride ions under the conditions around the oxide. The crevice is then repaired in a subsequent step such as by filling with metal or pressure bonding.
Claims6
A method for repairing a narrow crevice in the surface of a Ni-base superalloy article, the crevice having an opening at the surface in the range of about 0.001 - 0.1 inch and including a complex oxide which includes at least one metal selected from the group consisting of A1 and Ti, comprising the steps of:
- providing a non-oxidizing atmosphere about the oxide;
- contacting the oxide with gaseous active fluoride ions while heating the oxide at a temperature no greater than about 2000.degree. F. and at which the oxide will react with the fluoride ions to convert the oxide to a gaseous fluoride, without substantially affecting detrimentally the structure and mechanical properties of the article;
- applying a powdered repair alloy which melts and flows at a temperature less than that which will affect detrimentally mechanical properties of the article on the article surface over the crevice;
- providing a vacuum about the article;
- and then
- heating the article and repair alloy at a temperature less than that which will affect detrimentally the mechanical properties of the article for a time sufficient to melt the bonding alloy and to flow the repair alloy into the crevice to fill the crevice and to diffuse the repair alloy with walls of the crevice.
A method for repairing a narrow crevice in the surface of a Ni-base superalloy article, the crevice having an opening at the surface in the range of about 0.001 - 0.1 inch and including a complex oxide which includes at least one metal selected from the group consisting of Al and Ti, comprising the steps of:
- providing a non-oxidizing atmosphere about the oxide;
- contacting the oxide with gaseous active fluoride ions while heating the oxide at a temperature no greater than about 2000.degree. F. and at which the oxide will react with the fluoride ions to convert the oxide to a gaseous fluoride, without substantially affecting detrimentally the structure and mechanical properties of the article;
- providing at the article surface over the crevice a pressure barrier which will prohibit fluid flow into the crevice;
- and then
- diffusion bonding walls of the crevice by the hot isostatic pressing method.
Dependencies are inferred from the claim text.