Place: 12th International Conference on Aluminium Alloys, Yokohama, Japan
Helena Zapolsky, University of Rouen, Rouen, France
W. Lefebvre, Université et INSA de Rouen, Saint-Etienne du Rouvray, France
The coarsening kinetics of L12 (ϒ’) precipitates in ternary Al-Ti-Zr alloys is studied by using the three-dimensional phase-field simulations. Our focus is on the influence of misfit in the system and the difference of diffusion coefficients for different sort of atoms on the transformation path kinetics from disordered f.c.c. matrix to two phase equilibrium state with ϒ’ precipitates and f.c.c. disordered matrix. The simulation results demonstrate that the Al3Zr particles precipitate firstly following by a precipitation of Ti atoms. In this case, Ti atoms diffuse inside of precipitates and form homogeneous L12 particles. The coarsening kinetics in Al-Zr-Ti alloys is discussed in comparison with kinetics in Al-Zr-Sc system. Our simulations results are in good agreement with our experimental TEM images and 3D atom probe analyses.