The role of boron in suppressing environmental embrittlement in L1[sub 2]-ordered (Co,Fe)[sub 3]V

Journal Article · Sun Nov 15 00:00:00 EST 1992 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(92)90076-Q· OSTI ID:6974304

Pike, L M ^[1]; Liu, C T ^[2]

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1. Univ. of Wisconsin-Madison, Dept. of Materials Science and Engineering, Madison, WI (United States)
2. Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

Many ordered intermetallics have been shown to exhibit environmental embrittlement when tested in air at room temperature at conventional strain rates. These include Ni[sub 3]Al, Co[sub 3]Ti, Ni[sub 3]Is, Ni[sub 3](Al,Mn), Ni[sub 3](Is,Ti) and (Co,Fe)[sub 3]V with the Ll[sub 2] crystal structure and Fe[sub 3]Al and FeAl with the DO[sub 3] and B2 crystal structures, respectively. This embrittlement is believed to be caused by atomic hydrogen released from the reaction of moisture in the air with a reactive element (e.g., Al, Is, Ti, or V) in intermetallics at newly formed surfaces during deformation. In the case of Ll[sub 2] intermetallics, this environmental embrittlement effect is seen to produce intergranular fracture, indicating that the embrittling hydrogen diffuses mainly along the grain boundaries. The addition of boron has been shown to dramatically increase ductility in several intermetallic alloys. In Ll[sub 2] alloys such as Ni[sub 3]Al and Ni[sub 3]Is, boron completely suppresses this environmental effect. On the other hand, boron has no beneficial effect on environmental embrittlement in Co[sub 3]Ti which also has the Ll[sub 2] crystal structure. In this paper the effect of boron addition to (Co, Fe)[sub 3]V, an environmentally susceptible Ll[sub 2] alloy, is investigated.

• OSTI ID: 6974304
• Journal Information: Scripta Metallurgica et Materialia; (United States), Vol. 27:10; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
74 ATOMIC AND MOLECULAR PHYSICS
COBALT BASE ALLOYS
ATOM TRANSPORT
BORON ADDITIONS
CORROSION RESISTANCE
CRYSTAL STRUCTURE
HYDROGEN
DIFFUSION
IRON BASE ALLOYS
VANADIUM ALLOYS
ALUMINIUM ALLOYS
ENVIRONMENTAL EFFECTS
GRAIN BOUNDARIES
HYDROGEN EMBRITTLEMENT
INTERGRANULAR CORROSION
INTERMETALLIC COMPOUNDS
METALLURGICAL EFFECTS
NICKEL BASE ALLOYS
STOICHIOMETRY
ALLOYS
BORON ALLOYS
CHEMICAL REACTIONS
COBALT ALLOYS
CORROSION
ELEMENTS
EMBRITTLEMENT
IRON ALLOYS
MICROSTRUCTURE
NEUTRAL-PARTICLE TRANSPORT
NICKEL ALLOYS
NONMETALS
RADIATION TRANSPORT
360102* - Metals & Alloys- Structure & Phase Studies
360105 - Metals & Alloys- Corrosion & Erosion
664400 - Experimentally Derived Information on Atomic & Molecular Properties- (1992-)
360103 - Metals & Alloys- Mechanical Properties