Micromechanical modeling of the deformation behavior of polysynthetically twinned (PST) TiAl crystals
- Univ. for Mining and Metallurgy Leoben (Austria)
The deformation behavior of polysynthetically twinned (PST) crystals of TiAl with a nearly stoichiometric composition depends on the angle {theta} between the lamellar boundaries and the load axis. This anisotropic behavior is simulated by using a micromechanical model based on the unit cell technique applying the finite element method and crystal plasticity for the two lamellar phases {gamma}-TiAl and {alpha}{sub 2}-Ti{sub 3}Al. As a deformation mode at room temperature ordinary slip along {l_angle}1{bar 1}0[square bracket] is taken into account in the {gamma} phase as well as pyramidal and prismatic slip in the hexagonal {alpha}{sub 2} phase. Stress-strain curves are calculated for an orientation angle {theta} varying from 0{degree} {<=} {theta} {<=} 90{degree}, and their yield stresses are compared with experiments. Additionally a first attempt is described to consider the second major deformation mechanism of {gamma}-TiAl, namely deformation twinning, in the modeling.
- OSTI ID:
- 225098
- Report Number(s):
- CONF-950201--; ISBN 0-87339-304-X
- Country of Publication:
- United States
- Language:
- English
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