Environmental Effects in Advanced Intermetallics
This paper provides a comprehensive review of environmental embrittlement in iron and nickel aluminizes. The embrittlement involves the interaction of these intermetallics with moisture in air and generation of atomic hydrogen, resulting in hydrogen-induced embrittlement at ambient temperatures. Environmental embrittlement promotes brittle grain-boundary fracture in Ni{sub 3}Al alloys but brittle cleavage fracture in Fe{sub 3}Al-FeAl alloys. The embrittlement strongly depends on strain rate, with tensile-ductility increase with increasing strain rate. It has been demonstrated that environmental embrittlement can be alleviated by alloying additions, surface modifications, and control of grain size and shape. Boron tends to segregate strongly to grain boundaries and is most effective in suppressing environmental embrittlement in Ni{sub 3}Al alloys. The mechanistic understanding of alloy effects and environmental embrittlement has led to the development of nickel and iron aluminide alloys with improved properties for structural use at elevated temperatures in hostile environments.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research (ER) (US)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 2982
- Report Number(s):
- ORNL/CP-102188; KC 02 01 05 0; KC 02 01 05 0; TRN: AH200112%%434
- Resource Relation:
- Conference: International Symposium on Environment-Conscious Innovative Materials Processing with Advanced Energy Sources, Kyoto (JP), 11/24/1998--11/27/1998; Other Information: PBD: 24 Nov 1998
- Country of Publication:
- United States
- Language:
- English
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