Environmental embrittlement and grain-boundary fracture in Ni sub 3 Si

Journal Article · Thu Aug 01 00:00:00 EDT 1991 · Scripta Metallurgica; (United States)

OSTI ID:5429457

Liu, C T; Oliver, W C ^[1]

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1. Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

Recent studies have demonstrated that many ordered intermetallic alloys exhibit environmental embrittlement when tested in air at ambient temperatures. The embrittlement involves the reaction of reactive elements in ordered intermetallics (such as Al and Si) with moisture in air, resulting in the generation of atomic hydrogen that diffuses into the alloys and causes brittle crack propagation and low ductility. In the case of Bcc-based ordered intermetallic alloys, such as iron aluminides (FeAl and Fe{sub 3}Al) the moisture-induced hydrogen causes brittle cleavage fracture and ductility reduction from 18% to 2 {approximately} 4% at room temperature. In the case of fcc-based ordered intermetallics, the embrittlement occurs mainly along grain boundaries and causes brittle intergranular fracture and reduced ductility of Co{sub 3}Ti, Ni{sub 3}(Al,Mn), (Co,Fe){sub 3}(Si,Ti) alloys. In this paper, the study of environmental effects is extended to include the binary nickel silicide, Ni{sub 3}Si(22.5 at. % Si).

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5429457
• Journal Information: Scripta Metallurgica; (United States), Vol. 25:8; ISSN 0036-9748
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
08 HYDROGEN
NICKEL BASE ALLOYS
CRACK PROPAGATION
GRAIN BOUNDARIES
HYDROGEN EMBRITTLEMENT
INTERGRANULAR CORROSION
SILICON ALLOYS
ALUMINIUM BASE ALLOYS
AMBIENT TEMPERATURE
BINARY ALLOY SYSTEMS
CASTING
DUCTILITY
ENVIRONMENTAL EFFECTS
FABRICATION
HOT PRESSING
INTERMETALLIC COMPOUNDS
IRON BASE ALLOYS
MELTING
PHASE TRANSFORMATIONS
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
CHEMICAL REACTIONS
CORROSION
CRYSTAL STRUCTURE
EMBRITTLEMENT
IRON ALLOYS
MATERIALS WORKING
MECHANICAL PROPERTIES
MICROSTRUCTURE
NICKEL ALLOYS
PRESSING
TENSILE PROPERTIES
360103* - Metals & Alloys- Mechanical Properties
360102 - Metals & Alloys- Structure & Phase Studies
360105 - Metals & Alloys- Corrosion & Erosion
080800 - Hydrogen- Properties & Composition