Research
Massive Transformation - Experiments and Simulations
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A massive phase transformation is a typical example of an interface-controled phase transformation
where the rate of transformation is determined by processes at the interface.
In many iron-based alloys the austenite to ferrite transformation as well
as a phase transformations in the TiAl system is of massive nature.
The goal of this joint project between the Institute for Mechanics and the
Chair for Atomistic Modelling and Design of Materials is to
investigate the process of massive phase transformations.
The role of the Institute of Mechanics is to develop a theory of the massive transformation based on the sharp interface and thick interface models, respectively. The aim of the atomistic modeling part is to determine the necessary thermodynamic functions from ab-initio DFT calculations. To this end, cluster expansions of the binary TiAl and ternay TiAlNb alloys are carried out to determine the effective cluster interactions. These are subsequently used to perform Monte-Carlo simulations resulting in the desired thermodynamic potentials as a function of alloy composition and temperature. |
People: Yuhong Liu, Peter Puschnig, Claudia Ambrosch-Draxl
Collaborations:
Ernst Gamsjaeger, Dieter Fischer (Institute for Mechanics, University of Leoben)
Results:
As a prerequisite for this project we have developed an interface [1] between the
all-electron DFT code Wien2k and the ATAT package capable of performing cluster expansions and
Monte-Carlo simulations.
[1] M. Chakraborty, J. Spitaler, P. Puschnig, C. Ambrosch-Draxl, ATAT@WIEN2k: An interface for cluster expansion based on the linearized augmented planewave method, Computer Physics Communications (2010) (in print).
Funding:
Austrian Science Fund
(FWF)