MODELING OF THE DIFFUSION PROCESS IN A COPPER–ALUMINUM BIMATERIAL

The study is devoted to the numerical modeling of diffusion processes in aluminum-copper bimetals using the finite element method. The focus is on the peculiarities of interdiffusion during the heat treatment of Al–Cu bimetallic materials and on the processes of formation and growth of intermetallic compounds in the Al–Cu system under elevated temperatures. The application of a migration diffusion model made it possible to account for the influence of temperature and stress concentration on the annealing process
and on the interaction of materials and compounds under heating – an aspect unattainable with the standard diffusion model. This approach also enabled the construction of concentration distribution curves for copper and aluminum at different annealing temperatures and durations. A computational algorithm was developed for the formation and growth of intermetallic compounds in the sample, taking into account annealing temperature and the concentration of diffusing elements in accordance with the Al–Cu phase equilibrium diagram. As a result, intermetallic layers forming at the metal–metal interface during interdiffusion of copper and aluminum were obtained, which is consistent with experimental findings. It is shown that the numerical experiment demonstrates good qualitative and quantitative agreement with experimental data on
the thickness of the diffusion layer at the Al–Cu interface, with the simulated phase dimensions matching those observed experimentally within the margin of error.