Abstract: An internal coating on an internal passage wall exposed at a passage opening through an article external surface is protected from removal during repair of the article, including removal of at least a portion of an external coating, by a masking assembly disposed about the passage opening. The masking assembly comprises a masking member and a substantially flexible seal, substantially inert to a coating removal medium for the external coating. The masking member is shaped for disposition about the passage opening across a gap between the external surface and the masking member. The substantially flexible seal is disposed across the gap substantially to seal the gap.

Abstract: A method for applying, in a non-oxidizing atmosphere, a diffusion aluminide coating to a metallic surface of an article combines use of a relatively low aluminide coating temperature in the range of about 1650-1800° F. with a relatively high Al activity Al source material including Al of at least about 40 weight %. Such combination results in an as-deposited aluminide coating comprising a diffusion portion bonded between a metallic substrate and a coating outer portion of a thickness of no greater than about 60% of the thickness of the coating outer portion, typically less than about 1 mil.

Abstract: An internal coating on an internal passage wall exposed at a passage opening through an article external surface is protected from removal during repair of the article, including removal of at least a portion of an external coating, by a masking assembly disposed about the passage opening. The masking assembly comprises a masking member and a substantially flexible seal, substantially inert to a coating removal medium for the external coating. The masking member is shaped for disposition about the passage opening across a gap between the external surface and the masking member. The substantially flexible seal is disposed across the gap substantially to seal the gap.

Abstract: An internal coating on an internal passage wall exposed at a passage opening through an article external surface is protected from removal during repair of the article, including removal of at least a portion of an external coating, by a masking assembly disposed about the passage opening. The masking assembly comprises a masking member and a substantially flexible seal, substantially inert to a coating removal medium for the external coating. The masking member is shaped for disposition about the passage opening across a gap between the external surface and the masking member. The substantially flexible seal is disposed across the gap substantially to seal the gap.

Abstract: A method for applying, in a non-oxidizing atmosphere, a diffusion aluminide coating to a metallic surface of an article combines use of a relatively low aluminide coating temperature in the range of about 1650-1800° F. with a relatively high Al activity Al source material including Al of at least about 40 weight %. Such combination results in an as-deposited aluminide coating comprising a diffusion portion bonded between a metallic substrate and a coating outer portion of a thickness of no greater than about 60% of the thickness of the coating outer portion, typically less than about 1 mil.

Abstract: A method is provided for treating cooperating, juxtaposed substantially uncoated alloy substrate surfaces in preparation for brazing, for example an inner wall of the radially outer open end of a turbine engine blading member with the rim of an end plate or tip cap. The method includes treating at least one of the cooperating surfaces with a reducing gas comprising halogen gas for a time and at a temperature, for example 1-6 hours at 1650-1950° F., sufficient to remove any surface debris, for example oxides, and to deplete the alloy substrate surface of the total of elements selected from Al and Ti to a level of less than about 1 weight %. Depletion is to a depth in the surface which avoids intergranular attack of the substrate alloy surface. For example, the depth is no greater than about 0.0015″. Then the cooperating surfaces are brazed together.