The microstructural changes and possible resultant microcrack initiation behavior in a directionally-solidified Ni-base superalloy, CM247LC, are investigated during creep to verify the creep damage mechanism. The microstructural changes at and near the grain boundaries of CM247LC includes the: dissolution of grain-boundary M23C6 carbides and local increase of carbon content in γ and γ′ phases; transformation of γ′ to γ to form the γ′-free zone; and formation of the Al-rich phase in the γ′-free zone due to Al release from the γ′ phase. The changes in grain boundary microstructures can be favorable sites for fracture initiation.
|Number of pages||5|
|Journal||Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science|
|Publication status||Published - 1997 Jan 1|
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys