Kinetics of water vapor reactions with intergranular fracture surfaces of Ni{sub 3}Al with and without boron

Journal Article · Fri Nov 15 04:00:00 EST 1996 · Scripta Materialia

DOI:https://doi.org/10.1016/1359-6462(96)00279-5· OSTI ID:415375

Lee, K H; Lukowski, J T; White, C L ^[1]

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1. Michigan Technological Univ., Houghton, MI (United States)

In recent years, there has appeared some convincing evidence that the brittleness normally observed in Ni{sub 3}Al polycrystals at ambient temperature and pressure is at least partially due to an environmental effect associated with trace levels of moisture present in many testing environments. In a previous study, the authors found that undoped Ni{sub 3}Al is susceptible to environmental embrittlement in either moist Ar or Ar + 5%H{sub 2} gas, indicating similar embrittling effect of both environments. In contrast to this, boron-doped Ni{sub 3}Al is not very susceptible to moisture-induced embrittlement whereas it is susceptible to gaseous hydrogen-induced intergranular embrittlement. In both H{sub 2}O and H{sub 2} environments, crack tip processes leading to embrittlement may involve gas phase transport to the crack tip, adsorption of the gaseous species (associative and dissociative), absorption and diffusion of atomic hydrogen. Once atomic hydrogen is produced at the surface, its absorption and diffusion should be the same regardless of whether it originates as environmental H{sub 2}O or as H{sub 2}.

• OSTI ID: 415375
• Journal Information: Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 10 Vol. 35; ISSN 1359-6462; ISSN SCMAF7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
BORON
BORON ADDITIONS
CRACKS
DIFFUSION
EMBRITTLEMENT
FRACTURE PROPERTIES
GRAIN BOUNDARIES
HYDROGEN
INTERMETALLIC COMPOUNDS
INTERSTITIALS
METALLURGICAL EFFECTS
NICKEL ALLOYS
SOLUTES
WATER