发展具有变革性的TiAl合金是航空发动机叶片等热端部件的重点方向，对航空航天高端装备轻量化具有重大意义。针对传统TiAl合金室温脆性大和长时承温能力低两大世界难题，本团队基于“功能基元序构”材料设计新范式，通过精确调控软相γ-TiAl、硬相α₂-Ti₃Al及纳米孪晶等功能基元本征特性和序构参数，显著提升了聚片孪生(polysynthetic twinned，PST) TiAl合金的强塑性和承温能力。发现了界面类型、片层取向、片层厚度及相比例等序构参数对合金力学性能的决定性作用，澄清了γ相孪生诱导强塑性、α₂相层错提高疲劳强度、α₂相变增韧及γ/α₂共格界面提高断裂韧性等强韧化物理机制，为探索功能基元序构的高性能TiAl合金探明了方向。最后，展望了TiAl合金功能基元序构的发展方向。

Transformative TiAl alloys are in high demand for hot-end components such as aeroengine blades and for lightweighting advanced aerospace equipment. However, traditional TiAl alloys are brittle at room temperature and exhibit low long-term capability at high temperatures. To overcome these limitations, our team has proposed a new material-design paradigm based on “ordered structures of functional units.” By precisely regulating the intrinsic characteristics and ordered structures of the soft γ-TiAl phase, the hard α₂-Ti₃Al phase, and nano-twins, we considerably enhance the strength, plasticity, and high-temperature capability of polysynthetic twinned TiAl alloys. We also demonstrate the decisive roles of ordered-structure parameters, such as interface type, lamellar orientation, lamellar thickness, and phase proportion, on the mechanical properties of the alloy. The physical strengthening and toughening mechanisms include twinning-induced strengthening and plasticity in the γ phase, fatigue-strength-enhancing stacking faults in the α₂ phase, toughening via transformation of the α₂ phase, and γ/α₂ coherent interfaces, which improve fracture toughness. These insights illuminate promising directions for the development of TiAl alloys with ordered functional unit structures.