Multi-Doping Effect on Ductility of TiAl₃: A DFT Study

In this study, mechanical behaviors of D0₂₂–TiAl₃ intermetallic compound co-doped by W–M (M = C, Ge, Pb, Si and Sn) were simulated using density functional theory. The calculated bulk modulus, shear modulus, Young’s modulus and Pugh’s ratio all confirm that the introduction of W–M co-dopants effectively increases ductility in D0₂₂–TiAl₃. By detailed thermodynamic and electronic structure analysis, we revealed that W–M co-doped TiAl₃ systems are mechanically and thermodynamically stable. Among all systems, the most ductile is realized by W–C co-doping. In addition, the further electronic structure calculations indicated that such high ductility might originate from the dopant-induced d-band shift and the resulting electron redistribution. We systematically investigated the doped TiAl₃ systems from both mechanical and electronic points of view. This study may shed some lights on designing novel TiAl-based materials with enhanced ductility.