A Study of the Deformation Behavior of Lamellar γ-TiAl by Numeric Modeling

In this paper the deformation behavior of a fully lamellar microstructure, which is usually present in cast γ-TiAl based alloys, is studied by numerical modeling. After large compressive deformation at elevated temperatures the lamellar colonies are often bent or buckled depending on their orientation, which is representative for a deformation instability characterized by a large wave length. Such a deformation behavior is triggered by both, structural defects of the lamellae and their somewhat irregular arrangement. In addition, a shear band-type deformation mode occurs according to an instability mode exhibiting a short wave length. These two deformation modes interact in a rather subtle way, which leads to a very inhomogeneous deformation pattern.