Hostname: page-component-77f85d65b8-zzw9c Total loading time: 0 Render date: 2026-04-21T12:57:56.345Z Has data issue: false hasContentIssue false

Counteracting Effects of Boron and Hydrogen on Ductility In Ni3Al

Published online by Cambridge University Press:  22 February 2011

T. K. Chaki*
Affiliation:
State University of New York, Department of Mechanical and Aerospace Engineering, Buffalo, NY 14260
Get access

Abstract

A minute amount of boron doping in polycrystalline Ni3Al can suppress embrit-tlement due to environmental moisture. However, B is ineffective in suppressing hydrogen embrittlement due to cathodic charging. A mechanism is proposed to explain this seemingly contradictory dichotomy. Grain boundaries in B-free Ni3Al contain crack-like microcavities, to the tips of which atomic hydrogen, generated by the reaction of moisture with Al, can diffuse and cause embrittlement. In B-doped Ni3Al interstitial B atoms interact with Ni atoms and reduce the strength of directional bonding between Ni and Al atoms, such that the atoms can relax easily to close up the microcavities, thereby reducing environmental embrittlement. In the presence of a large amount of hydrogen, introduced by cathodic charging, microcracks can be nucleated in B-doped Ni3Al by hydrogen-enhanced dislocation activity, and then hydrogen embrittlement can proceed by enhanced plasticity at the crack tips.

Information

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable