Grain boundary segregation of carbon and boron in Ni sub 3 Al + B/C

Journal Article · Sun Apr 01 04:00:00 EDT 1990 · Scripta Metallurgica; (United States)

OSTI ID:5740389

Brenner, S S; Ming-Jian, H ^[1]

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1. Dept. of Materials Science and Engineering, Univ. of Pittsburgh, Pittsburgh, PA (US)

The addition of boron greatly increases the ductility of Ni-rich, polycrystalline Ni{sub 3}Al. This remarkable effect is clearly due to the segregation of the boron to the grain boundaries although other, as yet unknown, requirements must be met since the segregation of boron to Al-rich Ni{sub 3}Al does not produce a comparable effect. It might be thought that carbon would have the same effect as boron on the ductility of Ni{sub 3}Al since the size, electronic structure and the interstitial nature of the two atoms are similar. However, this is not the case. The authors of this paper used the field-ion microscope atom probe (FIM/AP) to measure the concentration of carbon at grain boundaries in Ni-rich Ni{sub 3}Al to obtain a more accurate measure of the degree of enrichment compared to that of boron. This information may help to explain the lack of ductilization by carbon. The alloy the authors' studied was supplied by Oak Ridge National Laboratory and nominally only contained carbon as a dopant. However, atom probe analysis of the material indicated that it also contained a small but significant amount of boron. This gave the authors the opportunity to compare the relative enrichment of the two dopants at the same boundary.

• OSTI ID: 5740389
• Journal Information: Scripta Metallurgica; (United States), Journal Name: Scripta Metallurgica; (United States) Vol. 24:4; ISSN 0036-9748; ISSN SCRMB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
AUGER ELECTRON SPECTROSCOPY
BORON ADDITIONS
BORON ALLOYS
CARBON ADDITIONS
CRYSTAL STRUCTURE
CRYSTALS
DOPED MATERIALS
DUCTILITY
ELECTRON SPECTROSCOPY
ELECTRONIC STRUCTURE
GRAIN BOUNDARIES
MATERIALS
MECHANICAL PROPERTIES
METALLURGICAL EFFECTS
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL BASE ALLOYS
POLYCRYSTALS
PROBES
SPECTROSCOPY
TENSILE PROPERTIES