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R. Radis, E. Kozeschnik:
"Numerical Simulations of the Precipitation Kinetics of gamma' in UDIMET 720 Li using the Thermo-Kinetic Software MatCalc";
Talk: Modeling Seminar UBC, University of British Columbia, Vancouver, Kanada; 2010-03-31.

The thermo-kinetic software MatCalc is presented, which is based on a model describing the evolution of the radii and chemical composition of individual precipitates of different phases in multi-component systems. In connection with classical nucleation theory (CNT), the model is able to describe the evolution of the precipitate structure in the classical stages of nucleation, growth and coarsening as well as interaction of precipitates of different phases, of different chemical composition and of different sizes via diffusion in the matrix and along grain boundaries. In the present work, the software is employed for the calculation of the evolution of the precipitate distribution of gamma´ precipitates during continuous cooling of the nickel-base superalloy UDIMET 720 Li from the solution-annealed state. Depending on cooling rate, monomodal, bimodal and even multimodal size distributions are observed. The calculated results are confirmed by experimental investigations, obtained from scanning electron microscopy and energy-filtered transmission electron microscopy analysis. The theoretical background for occurrence of multimodal size distributions during continuous cooling is discussed.

precipitation kinetics, modeling, gamma prime, UDIMET 720 Li