Layered ternary Ti2SnC carbides have attracted significant attention because of their advantage as a M2AX phase to bridge the gap between properties of metals and ceramics. In this study, Ti2SnC materials were synthesized by two different methods—an unconventional low-energy ion facility (LEIF) based on Ar+ ion beam sputtering of the Ti, Sn, and C targets and sintering of a compressed mixture consisting of Ti, Sn, and C elemental powders up to 1250 °C. The Ti2SnC nanocrystalline thin films obtained by LEIF were irradiated by Ar+ ions with an energy of 30 keV to the fluence of 1.1015 cm−2 in order to examine their irradiation-induced resistivity. Quantitative structural analysis obtained by Cs-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) confirmed transition from ternary Ti2SnC to binary Ti0.98C carbide due to irradiation-induced β-Sn surface segregation. The nanoindentation of Ti2SnC thin nanocrystalline films and Ti2SnC polycrystalline powders shows that irradiation did not affect significantly their mechanical properties when concerning their hardness (H) and Young’s modulus (E). We highlighted the importance of the HAADF-STEM techniques to track atomic pathways clarifying the behavior of Sn atoms at the proximity of irradiation-induced nanoscale defects in Ti2SnC thin films.