Orientational dependence of Poisson's ratio in tetragonal γ-TiAl single crystal.

The orientational dependence of Poisson's ratio ν in tetragonal single crystalline γ-TiAl was calculated based on previously measured single crystal elastic constants. Depending on the orientation of the applied stress, ν can be quite isotropic or highly anisotropic when the transverse direction varies. For example, when the stress axis is along the [001] direction, the resulting Poisson's ratio is a constant independent of the transverse direction; when the stress tensile axis is perpendicular to the 1 ¯ 01 crystallographic plane, ν is highly anisotropic, varying from a slightly negative value to more than 0.40. Orientational dependence of Poisson's ratio ν in γ-TiAl single crystal for a [110] tensile direction at T = 298 K . θ is the angle between the [001] crystal axis and the transverse direction. [ABSTRACT FROM AUTHOR]