The local compositional order at grain boundaries in Ni sub 3 Al

Journal Article · Sat Jun 01 04:00:00 EDT 1991 · Scripta Metallurgica; (United States)

OSTI ID:5654804

Kung, H; Rasmussen, D R; Sass, S L ^[1]

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1. Cornell Univ., Ithaca, NY (United States). Dept. of Materials Science and Engineering

The ordered compound, Ni{sub 3}Al, has received considerable attention during the pst few years due to its potential high temperature applications, because its yield strength increases with increasing temperature up to 600 to 700{degrees}C. The intrinsic brittleness of Ni{sub 3}Al in its polycrystalline form, however, is a major drawback to its use as a structural material. It was found that adding small amounts of boron to a slightly Ni-rich alloy increased its ductility. The boron segregated to the grain boundaries. Ni-enrichment was reported in the vicinity of grain boundaries in boron-doped Ni{sub 3}Al, which lends support to the idea of local disordering at grain boundaries, though similar enrichment was reported in one study in the absence of boron. There was disagreement among the results of the HRTREM studies. The character and composition of the boundaries examined wee frequently not known. In order to understand the role of boron in influencing the mechanical properties of Ni{sub 3}Al, the present paper examines its effect on the local structure of grain boundaries with similar character, in Ni{sub 3}Al with and without boron.

• OSTI ID: 5654804
• Journal Information: Scripta Metallurgica; (United States), Journal Name: Scripta Metallurgica; (United States) Vol. 25:6; 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
360104 -- Metals & Alloys-- Physical Properties
ALLOYS
ALUMINIUM ALLOYS
BORON ADDITIONS
BORON ALLOYS
BRITTLE-DUCTILE TRANSITIONS
CHEMICAL COMPOSITION
CRYSTAL STRUCTURE
GRAIN BOUNDARIES
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
MATERIALS
MECHANICAL PROPERTIES
METALLURGICAL EFFECTS
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL BASE ALLOYS
PHYSICAL PROPERTIES
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
THERMODYNAMIC PROPERTIES
YIELD STRENGTH