Interaction of dislocations with grain boundaries in Ni[sub 3] Al

Journal Article · Thu Oct 01 04:00:00 EDT 1992 · Acta Metallurgica; (United States)

OSTI ID:6987398

Lee, T C; Robertson, I M; Birnbaaum, A K ^[1]

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1. Illinois Univ., Urbana, IL (United States). Dept. of Materials Science and Engineering

In this paper the interaction between slip dislocations and grain boundaries in-hypo-stoichiometric Ni[sub 3]Al, with and without boron, is investigated by using the in situ TEM deformation technique. In both alloys, the slip dislocations were incorporated into the grain boundaries and remained at the point of entry. The difference between the alloys was in the dominant response mode of the grain boundary to the stress concentration associated with the dislocation pileup. In the boron-free material, the stress was relieved primarily by the nucleation and propagation of a crack along the grain boundary. In contrast, in the boron-doped material, relief occurred by the emission of dislocations from the grain boundary. These results are consistent with boron increasing the cohesive energy of the grain boundary. The slip system activated at grain boundaries in the ductile ordered alloy was shown to satisfy the same slip transfer criteria that operate in f.c.c. disordered alloys.

• OSTI ID: 6987398
• Journal Information: Acta Metallurgica; (United States), Journal Name: Acta Metallurgica; (United States) Vol. 10; ISSN 0001-6160; ISSN AMETAR
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
BORON
COUPLING
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DISLOCATIONS
ELECTRON MICROSCOPY
ELEMENTS
GRAIN BOUNDARIES
LINE DEFECTS
MICROSCOPY
MICROSTRUCTURE
NICKEL ALLOYS
SEMIMETALS
SLIP
STOICHIOMETRY
TRANSMISSION ELECTRON MICROSCOPY