TY - JOUR

T1 - Micromechanical modelling of the deformation behaviour of gamma titanium aluminides

AU - Marketz, Wilfried T.

AU - Fischer, Franz-Dieter

AU - Clemens, H.

PY - 1999/8

Y1 - 1999/8

N2 - The mechanical properties of γ-TiAl based alloys are determined by their microstructure. The deformation characteristics of two-phase alloys, consisting of the γ-TiAl phase and a small volume fraction of the α2-Ti3Al phase, are simulated by a 3-dimensional micromechanical model based on the unit cell technique using the finite element method. This model considers crystallographic slip and deformation twinning as the deformation mechanisms in addition to the elastic behaviour. The crystallography and the microstructure are considered within the framework of crystal plasticity. Initially, this micromechanical concept was applied to polysynthetically twinned (PST) single crystals. The results of the simulation reflect the experimentally observed anisotropic plastic behaviour of the lamellar microstructure. It can be shown that the chosen micromechanical model reproduces the deformation mechanisms in a realistic way. Consequently, the concept has been extended to polycrystalline materials. In order to start with a rather simple case, a so-called near-γ microstructure is chosen. Furthermore, it is demonstrated that only a fully three-dimensional modelling allows reasonable predictions.

AB - The mechanical properties of γ-TiAl based alloys are determined by their microstructure. The deformation characteristics of two-phase alloys, consisting of the γ-TiAl phase and a small volume fraction of the α2-Ti3Al phase, are simulated by a 3-dimensional micromechanical model based on the unit cell technique using the finite element method. This model considers crystallographic slip and deformation twinning as the deformation mechanisms in addition to the elastic behaviour. The crystallography and the microstructure are considered within the framework of crystal plasticity. Initially, this micromechanical concept was applied to polysynthetically twinned (PST) single crystals. The results of the simulation reflect the experimentally observed anisotropic plastic behaviour of the lamellar microstructure. It can be shown that the chosen micromechanical model reproduces the deformation mechanisms in a realistic way. Consequently, the concept has been extended to polycrystalline materials. In order to start with a rather simple case, a so-called near-γ microstructure is chosen. Furthermore, it is demonstrated that only a fully three-dimensional modelling allows reasonable predictions.

UR - http://www.scopus.com/inward/record.url?scp=0032593523&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0032593523

VL - 90.1999

SP - 588

EP - 593

JO - Zeitschrift fuer Metallkunde/Materials Research and Advanced Techniques

JF - Zeitschrift fuer Metallkunde/Materials Research and Advanced Techniques

SN - 0044-3093

IS - 8

ER -