The electronic structures and properties of ten TiAl/Ti₂AlNb heterogeneous interfaces with three Ti₂AlNb phases (B2, D0₁₉, O) and different terminations/boundaries were comprehensively studied via first-principles calculations. Their interfacial bonding features, strength and relative stability are quantitatively and qualitatively revealed by the equilibrium energy, Fermi energy, interfacial energy (γ_int), electron localization function and bonding charge density (Δρ), respectively. Accordingly, it was revealed by the partial and total electron density of states that the decreasing tendency of the bond strength in the order of Ti-Nb > Ti-Al > Nb-Al at the interfaces was attributed to the electrons hybridization of Ti-d states, Nb-d states and Al-p states. Since the γ_int decreased in the order of TiAl/B2 > TiAl/O > TiAl/D0₁₉, the TiAl/D0₁₉ interfaces with the lowest energy was regarded as the most stable phase boundaries and was further validated by the electron back-scattered diffraction analysis. It is found that the D0₁₉ phase is dominated at the interface boundaries while the B2 serves as a transition phase distributed on its both sides. On the contrary, the metastable O phase can form in the bulk Ti₂AlNb but not at the interface due to their largest distortion when precipitating at the phase boundary. This work provides an insight into the atomic and electronic basis for the bonding and strengthening mechanisms of TiAl/Ti₂AlNb heterogeneous interfaces.

通过第一性原理计算，全面研究了十个具有三个Ti ₂ AlNb相（B2，D0 ₁₉，O）和不同末端/边界的TiAl / Ti ₂ AlNb异质界面的电子结构和性能。他们的界面结合特性，强度和相对稳定性由平衡能量，费米能量，界面能量（被定量和定性地显示γ _INT），电子定位功能和粘结电荷密度（Δ ρ）， 分别。因此，通过部分和全部电子密度表明，界面处的结合强度按Ti-Nb> Ti-Al> Nb-Al的顺序降低的趋势归因于Ti-d的电子杂化。态，Nb-d态和Al-p态。由于γ _INT中的顺序减小的TiAl / B2>的TiAl / O>的TiAl / D0 ₁₉，TiAl金属/ D0 _19个接口具有最低能量被视为最稳定的相界和由电子背散射被进一步验证衍射分析。发现D0 ₁₉B2在界面两侧占主导地位，而B2则是分布在其两侧的过渡阶段。相反，由于在相边界处析出的最大变形，亚稳O相可以在块体Ti ₂ AlNb中形成，但不能在界面处形成。这项工作为TiAl / Ti ₂ AlNb异质界面的键合和增强机制提供了原子和电子基础的见识。