The role of ordered domains and slip mode of [alpha][sub 2] phase in the plastic behavior of TiAl crystals containing oriented lamellae

Journal Article · Thu Apr 01 04:00:00 EST 1993 · Acta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-7151(93)90163-M· OSTI ID:6268660

Umakoshi, Y; Nakano, T ^[1]

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1. Osaka Univ. (Japan). Dept. of Materials Science and Engineering

TiAl crystals containing a single set of lamellae composed of the [alpha][sub 2] and [gamma] phases were grown using the floating zone method. The lamellar spacing was controlled in the range between 0.37 and 1.8 [mu]m. The plastic behavior of these crystals depends strongly on the deformation mode of [alpha][sub 2] phase, the domain size and the lamellar spacing. When the stress is applied parallel to the lamellar planes, shear deformation occurs across the lamellae and the (10[bar 1]0) prismatic slip is activated in the [alpha][sub 2] phase. For specimens with the loading axis perpendicular to the lamellar planes, the (11[bar 2]1) pyramidal slip occurs with application of high stress. The mode of deformation in the [alpha][sub 2] phase is responsible for a large anisotropy of plastic behavior of TiAl containing lamellae. The lamellar spacing and the domain size affect the yield stress similar to the effect caused by grain size. The lamellar boundaries between thin [alpha][sub 2] plates and [gamma] phase provided more effective strengthening than the domain boundaries.

• OSTI ID: 6268660
• Journal Information: Acta Metallurgica et Materialia; (United States), Journal Name: Acta Metallurgica et Materialia; (United States) Vol. 41:4; ISSN 0956-7151; ISSN AMATEB
• 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
ANISOTROPY
CRYSTAL STRUCTURE
DEFORMATION
GRAIN BOUNDARIES
GRAIN SIZE
INTERMETALLIC COMPOUNDS
LAMELLAE
MECHANICAL PROPERTIES
MICROSTRUCTURE
PHASE STUDIES
PLASTICITY
SIZE
SLIP
STRESSES
TITANIUM ALLOYS