The considerable lack of room temperature ductility and toughness is widely recognized as an important limitation for the commercialization of titanium aluminides in industrial engineering. To meet this target, we optimize a new polycrystalline alloy based on Gamma-titanium aluminide co-alloying with Mo–Cr, Mo–Nb and Mo–Re atom pairs that simultaneously satisfy the physical criteria of workability using the density functional theory within the framework of the generalized gradient approximation. The formation enthalpy calculations showed that the Ti–Ti sites remain the preferential sites of Mo–Cr and Mo–Nb atomic defects, while the Mo–Re elements tend to occupy Ti–Al sites. The elastic properties systematically suggest that TiAl–Mo–Nb system is further resistant to tensile deformation along c-axis and a-axis (b-axis). In addition, the co-alloying Mo–Re atom pair exhibit improved mechanical performance compared to the other systems. These trends are confirmed by analyzing the electronic structure. Using quasi-harmonic approximation, thermodynamic properties were also predicted by including the description of the temperature. The results of co-alloying with molybdenum and rhenium atoms confirm effectively their usability in turbine blades and engine-valves made of Gamma-TiAl alloys.

室温延展性和韧性的严重缺乏被广泛认为是工业工程中铝化钛商业化的重要限制。为了实现这一目标，我们优化了一种基于伽马-铝化钛与 Mo-Cr、Mo-Nb 和 Mo-Re 原子对共合金的新型多晶合金，使用框架内的密度泛函理论同时满足可加工性的物理标准广义梯度近似。生成焓计算表明，Ti-Ti 位点仍然是 Mo-Cr 和 Mo-Nb 原子缺陷的优先​​位点，而 Mo-Re 元素倾向于占据 Ti-Al 位点。弹性性能系统地表明 TiAl-Mo-Nb 系统进一步抵抗沿c 轴和a 轴（b 轴）。此外，与其他系统相比，共合金 Mo-Re 原子对表现出更好的机械性能。这些趋势通过分析电子结构得到证实。使用准谐波近似，还可以通过包括温度的描述来预测热力学特性。与钼和铼原子共合金的结果有效地证实了它们在由 Gamma-TiAl 合金制成的涡轮叶片和发动机阀门中的可用性。