Experimental study of diffusion coefficients and assessment of atomic mobilities in FCC Al-Cu-V alloys

With the increasing demand for high-temperature aluminum (Al) alloys, there is a need for fundamental kinetic information to guide their design and development. This study investigates the diffusion behavior of the FCC Al-Cu-V system and assesses the atomic mobility parameters. Diffusion couples were assembled and annealed at 530, 555, and 580 degrees C for 1500 h to facilitate solute diffusion. The concentration profiles of Cu and V were measured using electron probe microanalysis (EPMA), and the diffusion coefficients were extracted using the Forward Simulation Analysis (FSA) method. The atomic mobility parameters for the Al-Cu-V system were assessed using the diffusion models in the DICTRA software program and verified by validation experiments involving annealing at temperatures of 535 and 565 degrees C for 1500 h. The activation energies for the diffusion of Cu and V were calculated and analyzed. The results reveal that adding Cu increased the diffusivity of V, while adding V decreased the diffusivity of Cu within the Al-Cu-V system. These findings of the kinetics of the FCC Al-Cu-V system would be beneficial for alloy design and processing optimization.