The effect of grain size on the room-temperature ductility of NiAl

Journal Article · Sat Dec 01 04:00:00 EST 1990 · Scripta Metallurgica; (United States)

DOI:https://doi.org/10.1016/0956-716X(90)90097-Z· OSTI ID:5740371

Nagpal, P; Baker, I ^[1]

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1. Thayer School of Engineering, Dartmouth College, Hanover, NH (US)

This paper reports on limited room temperature ductility ({approximately}2% elongation) first observed in previous work in NiAl at a (nominally) stoichiometric composition; there has been no report of room temperature ductility in NiAl which is not of a near-stoichiometric composition. The material was processed through a casting and hot-extrusion route but no grain size was reported. This produced a similar result for Ni-50.3 at % Al with a grain size between 11 and 16 {mu}m. Since alloys were tested in the as-extruded condition, it was suggested that a deformation substructure and texture were possible reasons for the ductility. Previous work has also reproduced the result for a nominally stoichiometric alloy with a larger grain size (30 {mu}m). It showed that the deformation substructure does not contribute to the ductility since both partially and fully recrystallized alloys exhibited similar ductility. It was noted that the recrystallization texture could influence the tensile ductility, the authors concluded that the observed ductility was due mainly to the low yield strength and that the grain size does not have as significant an effect. Furthermore, the authors suggested that off-stoichiometric NiAl compositions are brittle due to their higher yield strength compared to their stoichiometric composition.

• OSTI ID: 5740371
• Journal Information: Scripta Metallurgica; (United States), Journal Name: Scripta Metallurgica; (United States) Vol. 24:12; 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
CHEMICAL COMPOSITION
CRYSTAL STRUCTURE
DEFORMATION
DUCTILITY
GRAIN SIZE
MECHANICAL PROPERTIES
MICROSTRUCTURE
NICKEL ALLOYS
SIZE
STOICHIOMETRY
TENSILE PROPERTIES