Material Instabilities - Theory and Application,
(Eds. R.C.Barta, H.M.Zbib), pp. 357-368, 1994
O.I. Minchev¹, F.G. Rammerstorfer² and F.D. Fischer³
¹Institute of Mechanics,
Bulgarian Academy of Sciences, Sofia, Bulgaria
²Institute of Lightweight Structures and Aerospace Engineering,
TU Wien, Vienna, Austria
³Institute of Mechanics,
University of Mining and Metallurgy, Leoben, Austria
The advanced two-phase TiAl-alloys based on gamma-TiAl and
alpha2-Ti3Al generally exhibit, in an as cast state, a nearly
fully lamellar microstructure,
consisting of lamellar grains of alternating layers of ordered gamma and
alpha2 platelets with a specific orientation relationship.
This microstructure plays an important role in the deformation and
fracture behaivor of titanium aluminides.
In respectg with their practical application the microstructure must be
changed by a deformation process from a lamellar to a globular one.
The aim of this investigation is to provide knowledge on how to achieve
the desired microstructure during the primary forming process.
This can therefore give valuable information for further alloy design towards
improved mechanical properties.