摘要 |
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. |