Strain rate effect on moisture and hydrogen-induced environmental embrittlement of Ni{sub 3}Al with an without boron

Journal Article · Sat Jul 01 04:00:00 EDT 1995 · Scripta Metallurgica et Materialia

DOI:https://doi.org/10.1016/0956-716X(95)00111-8· OSTI ID:99240

Lee, K H; White, C L ^[1]

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1. Michigan Technological Univ., Houghton, MI (United States). Dept. of Metallurgical and Materials Engineering

At slow strain rates, boron-free Ni{sub 3}Al was embrittled in both most Ar and mixture of Ar + 5% H{sub 2}. In contrast to this, boron-doped Ni{sub 3}Al was not embrittled in moist Ar, but susceptible to embrittlement in mixture of Ar + 5% H{sub 2}. These results indicate that while the addition of boron virtually eliminates embrittlement of Ni{sub 3}Al due to water vapor, it does not eliminate embrittlement due to gaseous hydrogen. This different behavior of the boron-doped Ni{sub 3}Al tends to suggest that the beneficial role of boron segregation in suppressing moisture-induced embrittlement may be associated with its effect on the interaction between water vapor and the intergranular crack surface, rather than on hydrogen transport along grain boundaries. The environmental component of the embrittlement was greatly diminished at higher strain rates. The increased tensile ductilities of boron-doped Ni{sub 3}Al as compared to those of boron-free Ni{sub 3}Al at the higher strain rates then can be interpreted to be due to an intrinsically beneficial boron effect. This suggests that the role of boron in ductilizing Ni{sub 3}Al is at least two-fold: (1) it acts partly to limit the embrittling effects of water vapor and (2) it strengthens the boundaries sufficiently to eliminate intergranular failure, but the latter effect seems to be large.

• OSTI ID: 99240
• Journal Information: Scripta Metallurgica et Materialia, Journal Name: Scripta Metallurgica et Materialia Journal Issue: 1 Vol. 33; ISSN 0956-716X; ISSN SCRMEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
ARGON
BORON ADDITIONS
CRACKS
DUCTILITY
EMBRITTLEMENT
GRAIN BOUNDARIES
HYDROGEN
INTERMETALLIC COMPOUNDS
MOISTURE
NICKEL ALLOYS
OXYGEN
SEGREGATION
STRAIN RATE
TENSILE PROPERTIES