Low temperature environmental embrittlement in ordered intermetallics
- Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Materials Engineering
- Oak Ridge National Lab., TN (United States)
There are two types of environmental degradation in intermetallics: hydrogen-induced embrittlement occurring at ambient temperatures, and oxygen-induced embrittlement in air at high temperatures. This review is confined to low-temperature embrittlement and discusses metallurgical means of alleviation. Environmentally induced embrittlement is both pernicious and complex. The low ductility and toughness of many ordered alloys, especially aluminides, at room temperature (RT) is now known to arise from an extrinsic effect. Exclusion of moisture or other sources of H from environment causes Ni{sub 3}Al, Ni{sub 3}Si, Fe{sub 3}Al, and FeAl to display high elongations. However, even when H is excluded, other aluminides (NiAl, CoAl, TiAl, Ti{sub 3}Al) exhibit little or no RT ductility. Reasons for this difference is complex; the number of independent slip systems, bonding, and differences in environmental susceptibility are the most obvious factors affecting ductility. Grain size/shape, alloy texture, and impurity content are among the factors influencing environmental embrittlement. Each factor needs to be studied for most intermetallics for possible structural applications.
- Research Organization:
- Oak Ridge National Lab., TN (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 10143599
- Report Number(s):
- CONF-9209328-1; ON: DE93009711
- Resource Relation:
- Conference: Workshop on ordered intermetallics,Honzhou (China),28 Sep - 1 Oct 1992; Other Information: PBD: [1992]
- Country of Publication:
- United States
- Language:
- English
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