Molecular dynamics simulation of interdiffusion between nanocrystalline titanium and aluminum

Molecular dynamics simulation was used to study interdiffusion between titanium with a nanocrystalline structure and aluminum. Particular attention was given to the influence of grain size in titanium on the intensity of component diffusion at different temperatures. For comparison, single-crystal and amorphous titanium cases were also considered. It was shown that grain size in titanium significantly affects the intensity of interdiffusion between titanium and aluminum. The aluminum structure influences mutual dissolution intensity to a lesser degree. As the average grain size in titanium decreases, the grain boundary density near the interphase boundary increases accordingly, with these boundaries serving as accelerated diffusion pathways. It should be noted that the influence of grain size on the intensity of mutual component dissolution is most pronounced for very small grain sizes, that is, in the case of nanocrystalline structure. Based on the results obtained in this work and data from our previous studies, we believe that the primary factors reducing the activation energy of the synthesis reaction in the Ti-Al system after mechanical treatment of the initial mixture are two: the release of energy accumulated in defects formed by intensive deformation, and the high grain boundary density in titanium, which leads to accelerated interdiffusion.

1. Ministry of Science and Higher Education of the Russian Federation - FZMM-2026-0005