Room-temperature mechanical behavior of FeAl: Effects of stoichiometry, environment, and boron addition
- Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.
- Auburn Univ., AL (United States). Materials Engineering Program
The intrinsic ductility of FeAl (in ultrahigh vacuum) decreases with increasing Al content, from around 16% in Fe-37Al to zero in Fe-48Al. The sharpest decline occurs around the composition where the fracture mode changes from transgranular to intergranular. Boron shifts this ductile-brittle transition to higher Al levels by segregating to the grain boundaries and suppressing grain-boundary fracture. However, its effectiveness decreases with increasing Al concentration, even though the amount of B segregating to the grain boundaries remains the same, independent of alloy stoichiometry. Consequently, even the B-doped alloys become brittle and fracture intergranularly as the stoichiometric composition is approached. Low-pressure hydrogen embrittles FeAl, although not as severely as atmospheric moisture. Environmental embrittlement is most noticeable in Fe-rich FeAl; with increasing Al concentration, the grain boundaries become intrinsically weak, and brittle fracture persists even after environmental effects are eliminated.
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 302356
- Journal Information:
- Acta Materialia, Journal Name: Acta Materialia Journal Issue: 17 Vol. 46; ISSN 1359-6454; ISSN ACMAFD
- Country of Publication:
- United States
- Language:
- English
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