Influence of Manganese Content on Plastic Deformation Mechanisms in Polycrystalline {\alpha}-Ti-Mn Alloys
Titanium alloys are widely used in aerospace, biomedical, and energy applications owing to their high specific strength, corrosion resistance, and biocompatibility. Among them, $\alpha$-titanium alloys with a hexagonal close-packed (hcp) crystal structure exhibit characteristic deformation mechanisms governed by crystallographic slip and defect evolution. In this study, the influence of manganese content on the plastic deformation mechanisms of polycrystalline $\alpha$-Ti-2Mn and $\alpha$-Ti-4Mn (at.%) alloys is investigated using molecular dynamics simulations. Atomistic models were subjected to uniaxial loading at room temperature at a strain rate of 10$^9$ s$^{-1}$. The mechanical response was evaluated through stress-strain behavior, structural evolution, dislocation nucleation and interaction, and analysis of the local deformation field. Plastic deformation in these $\alpha$-Ti-Mn alloys is dominated by dislocation nucleation and their subsequent evolution within the hcp lattice. Increasing Mn content leads to higher stress levels and enhanced resistance to plastic deformation, accompanied by changes in dislocation activity and defect evolution.