Development of an atomic mobility database for disordered and ordered fcc phases in multicomponent Al alloys: focusing on binary systems

An atomic mobility database for binary disordered and ordered fcc phases in multicomponent Al-Cu-Fe-Mg-Mn-Ni-Si-Zn alloys was established based on a critical review of diffusion data in various constituent binary systems via the DICTRA (Diffusion Controlled TRAnsformation) software package. The mobility parameters for self-diffusion in the metastable fcc structure were determined through a semi-empirical method. An effective strategy, which takes the homogeneity range and defect concentration into account, was used to optimize the atomic mobilities of L1(2) phase in the Fe-Ni system. Comprehensive comparisons between various calculated and measured diffusivities show that most of the experimental data can be well reproduced by the presently obtained atomic mobilities. The general agreement between the model-predicted concentration profiles and the experimental ones in the Al-Ni-Si, Al-Mg-Zn and Cu-Mn-Ni-Zn diffusion couples validates the potential application of the present atomic mobility database to predict the concentration profiles in higher order systems. An 8-elemental diffusion couple was also simulated with the present database.