The influence of chromium addition on the toughness of {gamma}-Ni/{alpha}-Al{sub 2}O{sub 3} interfaces
- MIT, Cambridge, MA (United States)
- Harvard Univ., Cambridge, MA (United States). Div. of Engineering and Applied Sciences
- Max Planck Inst. fuer Metallforschung, Stuttgart (Germany)
Experimental studies designed to characterize the fracture resistance of interfaces between Al{sub 2}O{sub 3} and either pure Ni or a {gamma}-Ni alloy containing Cr have revealed a profound influence of Cr on the debond toughness. The interface between the pure Ni and Al{sub 2}O{sub 3} is susceptible to stress corrosion caused by moisture, resulting in a fracture energy of the order of 10 J/m{sup 2}. The interface between the alloy and the Al{sub 2}O{sub 3} cannot be fractured, even at strain energy release rates in excess of 100 J/m{sup 2}. An analysis of these interfaces has identified two influences of the alloy addition that might govern its role in eliminating stress corrosion: (i) the Cr getters the C near the interface by forming a Cr-carbide reaction product, and (ii) the alloy dissolves some of the alumina during bonding, exposing virgin material to the alloy at the interface. The factors that lead to carbide formation and alumina dissolution are discussed.
- OSTI ID:
- 540939
- Journal Information:
- Acta Materialia, Vol. 45, Issue 9; Other Information: PBD: Sep 1997
- Country of Publication:
- United States
- Language:
- English
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