Low temperature environmental embrittlement in ordered intermetallics

Conference · Wed Jan 01 00:00:00 EST 1992

OSTI ID:6672266

Stoloff, N S ^[1]; Liu, C T ^[2]

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1. Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Materials Engineering
2. 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; USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6672266
• Report Number(s): CONF-9209328-1; ON: DE93009711
• Resource Relation: Conference: Workshop on ordered intermetallics, Honzhou (China), 28 Sep - 1 Oct 1992
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HYDROGEN EMBRITTLEMENT
KINETICS
REVIEWS
INTERMETALLIC COMPOUNDS
ALUMINIUM ALLOYS
COBALT ALLOYS
FRACTURE PROPERTIES
GRAIN SIZE
IRON ALLOYS
MICROSTRUCTURE
SILICON ALLOYS
TEMPERATURE RANGE 0273-0400 K
TITANIUM ALLOYS
ALLOYS
CRYSTAL STRUCTURE
DOCUMENT TYPES
EMBRITTLEMENT
MECHANICAL PROPERTIES
SIZE
TEMPERATURE RANGE
360103* - Metals & Alloys- Mechanical Properties
360105 - Metals & Alloys- Corrosion & Erosion