Polysynthetic Twinned High-Performance TiAl Alloy with Ordered Structures of Functional Units
Received date: 2026-02-09
Revised date: 2026-03-07
Online published: 2026-03-17
Supported by
National Natural Science Foundation of China(92463301);National Natural Science Foundation of China(92163215);National Natural Science Foundation of China(52595663);National Natural Science Foundation of China(52571145);National Natural Science Foundation of China(52433016);Advanced Materials-National Science and Technology Major Project(2025ZD0608600);China Postdoctoral Science Foundation(2025M784312);State Key Laboratory of Light Superalloys(sysjj2025101);State Key Laboratory of Light Superalloys(sysjj2025102);State Key Laboratory of Light Superalloys(sysjj2025201);State Key Laboratory of Light Superalloys(sysjj2025202);State Key Laboratory of Light Superalloys(sysjj2025203)
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.
CHEN Guang , CHEN Fengrui , ZHU Demin , LI Guizhong , LI Luo , SONG Weidong , WANG Zite , XIANG Henggao , CHEN Yang , QI Zhixiang . Polysynthetic Twinned High-Performance TiAl Alloy with Ordered Structures of Functional Units[J]. Acta Metall Sin, 2026 , 62(4) : 541 -549 . DOI: 10.11900/0412.1961.2026.00048
| [1] | Chen G, Peng Y B, Zheng G, et al. Polysynthetic twinned TiAl single crystals for high-temperature applications [J]. Nat. Mater., 2016, 15: 876 |
| [2] | Schütze M. Single-crystal performance boost [J]. Nat. Mater., 2016, 15: 823 |
| [3] | Dimiduk D M. Gamma titanium aluminide alloys—An assessment within the competition of aerospace structural materials [J]. Mater. Sci. Eng., 1999, A263: 281 |
| [4] | Clemens H, Mayer S. Design, processing, microstructure, properties, and applications of advanced intermetallic TiAl alloys [J]. Adv. Eng. Mater., 2013, 15: 191 |
| [5] | Wu X H. Review of alloy and process development of TiAl alloys [J]. Intermetallics, 2006, 14: 1114 |
| [6] | Xu X S, Ding H S, Huang H T, et al. Microstructure and elevated temperature tensile property of Ti-46Al-7Nb-(W,Cr,B) alloy compared with binary and ternary TiAl alloy [J]. Mater. Sci. Eng., 2021, A807: 140902 |
| [7] | Bewlay B P, Nag S, Suzuki A, et al. TiAl alloys in commercial aircraft engines [J]. Mater. High Temp., 2016, 33: 549 |
| [8] | Miki Y, Kitaoka H, Sakuraya T, et al. Mechanism for separating inclusions from molten steel stirred with a rotating electro-magnetic field [J]. ISIJ Int., 1992, 32: 142 |
| [9] | Wallgram W, Schm?lzer T, Cha L M, et al. Technology and mechanical properties of advanced γ-TiAl based alloys [J]. Int. J. Mater. Res., 2009, 100: 1021 |
| [10] | Li B H, Hou Z Q, Qiu L X, et al. Development of research on precision forming of TiAl alloys [J]. Aerosp. Mater. Technol., 2008, 38(5): 4 |
| 李宝辉, 侯正全, 邱立新 等. TiAl合金精密成形技术研究进展 [J]. 宇航材料工艺, 2008, 38(5): 4 | |
| [11] | Semlitsch M, Weber H, Streicher R M, et al. Joint prostheses components of warm-forged and surface treated Ti-6Al-7Nb alloy [J]. Biomed. Tech., 1991, 36: 112 |
| [12] | Ma E, Liu C. Achieving alloys with concurrent high strength and high ductility [J]. Acta Metall. Sin., 2025, 61: 665 |
| 马 恩, 刘 畅. 如何使合金兼具高强度与高塑性 [J]. 金属学报, 2025, 61: 665 | |
| [13] | Chen K X, Li L. Ordered structures with functional units as a paradigm of material design [J]. Adv. Mater., 2019, 31: 1901115 |
| [14] | Peng G Y, Hu L, Qu W B, et al. Structural-functional unit ordering for high-performance electron-correlated materials [J]. Interdiscip. Mater., 2023, 2: 30 |
| [15] | Zheng G, Chen Y, Xiang H G, et al. Coupled nucleation of dual-phase lamellar structure [J]. Inn. Mater., 2023, 1: 100043 |
| [16] | Xiang H G, Chen, Y, Qi Z X, et al. Mechanical behavior of TiAl alloys [J]. Sci. China Technol. Sci., 2023, 66: 2457 |
| [17] | Appel F, Clemens H, Fischer F D. Modeling concepts for intermetallic titanium aluminides [J]. Prog. Mater. Sci., 2016, 81: 55 |
| [18] | Chen Y, Cao Y D, Qi Z X, et al. Increasing high-temperature fatigue resistance of polysynthetic twinned TiAl single crystal by plastic strain delocalization [J]. J. Mater. Sci. Technol., 2021, 93: 53 |
| [19] | Ji Z W, Lu S, Hu Q M, et al. Mapping deformation mechanisms in lamellar titanium aluminide [J]. Acta Mater., 2018, 144: 835 |
| [20] | Yoo M H. Slip, twinning, and fracture in hexagonal close-packed metals [J]. Metall. Trans., 1981, 12A: 409 |
| [21] | Qi Z X, Zhu Q, Wang J, et al. Revealing interface-assisted plastic anisotropy via in situ transmission electron microscopy tension of lamellar TiAl [J]. Sci. China Mater., 2023, 66: 4275 |
| [22] | Lu L, Zhao H Z. Progress in strengthening and toughening mechanisms of heterogeneous nanostructured metals [J]. Acta Metall. Sin., 2022, 58: 1360 |
| 卢 磊, 赵怀智. 异质纳米结构金属强化韧化机理研究进展 [J]. 金属学报, 2022, 58: 1360 | |
| [23] | Zhao S T, Zhang R P, Yu Q, et al. Cryoforged nanotwinned titanium with ultrahigh strength and ductility [J]. Science, 2021, 373: 1363 |
| [24] | Lu L, Chen X, Huang X, et al. Revealing the maximum strength in nanotwinned copper [J]. Science, 2009, 323: 607 |
| [25] | Zhong Y B, Shi P J. Hierarchical lamellar heterostructure design renders metallic materials with ultrahigh strength-ductility combinations [J]. Acta Metall. Sin., 2025, 61: 1593 |
| 钟云波, 时培建. 多级层片异构设计构筑超高强塑性金属材料 [J]. 金属学报, 2025, 61: 1593 | |
| [26] | Liu Y, Li J S, Tang B, et al. Formation mechanism of γ twins in β-solidified γ-TiAl alloys [J]. J. Mater. Sci. Technol., 2022, 105: 164 |
| [27] | He N, Qi Z X, Cheng Y X, et al. Atomic-scale investigation on the interface structure of {2 2 ˉ 01} α2-Ti3Al deformation twins in polysynthetically twinned TiAl single crystals [J]. Intermetallics, 2021, 128: 106995 |
| [28] | Blackburn M J. Some aspects of phase transformations in titanium alloys [A]. The Science, Technology and Application of Titanium [M]. Oxford: Pergamon Press, 1970: 663 |
| [29] | He N, Cheng Y X, Yuan T, et al. Atomic-scale investigation of interface structures in polysynthetically twinned TiAl single crystals [J]. Intermetallics, 2024, 164: 108090 |
| [30] | Chen G, Chen F R, Qi Z X, et al. PST TiAl single crystal and its application prospect [J]. J. Vib. Meas. Diagn., 2019, 39: 915 |
| 陈 光, 陈奉锐, 祁志祥 等. 聚片孪生TiAl单晶及其应用展望 [J]. 振动、测试与诊断, 2019, 39: 915 | |
| [31] | Inui H, Nakamura A, Oh M H, et al. High-resolution electron microscope study of lamellar boundaries in Ti-rich TiAl polysynthetically twinned crystals [J]. Ultramicroscopy, 1991, 39: 268 |
| [32] | Peng Y B, Chen F, Wang M Z, et al. Relationship between mechanical properties and lamellar orientation of PST crystals in Ti-45Al-8Nb alloy [J]. Acta Metall. Sin., 2013, 49: 1457 |
| 彭英博, 陈 锋, 王敏智 等. Ti-45Al-8Nb合金PST晶体片层取向与力学性能的关系 [J]. 金属学报, 2013, 49: 1457 | |
| [33] | Li P, Cao Y D, Chen Y, et al. The α2 to orthorhombic phase transformation facilitated high elastically mediated strain transfer ability in high Nb-TiAl alloys [J]. Mater. Charact., 2023, 201: 112924 |
| [34] | Kong L W, Xing Z B, Chen F R, et al. Regulating phase ratios and mechanical properties of polysynthetic twinned TiAl single crystals via annealing [J]. J. Mater. Sci. Technol., 2025, 212: 223 |
| [35] | Imayev V M, Imayev R M, Salishchev G A. On two stages of brittle-to-ductile transition in TiAl intermetallic [J]. Intermetallics, 2000, 8: 1 |
| [36] | Zhao W, Luzzi D E. Characterizations of lamellar interfaces and segregations in a PST-TiAl intermetallic alloy by an analytical scanning transmission electron microscope [J]. MRS Online Proc. Libr., 2000, 652: 104 |
| [37] | Qiu L F, Wang S P, Zhou X, et al. Phase transformation induced plastic deformation mechanism in α2-Ti3Al [J]. Interdiscip. Mater., 2025, 4: 524 |
| [38] | Yan S T, Qi Z X, Chen Y, et al. Interlamellar boundaries govern cracking [J]. Acta Mater., 2021, 215: 117091 |
| [39] | Yokoshima S, Yamaguchi M. Fracture behavior and toughness of PST crystals of TiAl [J]. Acta Mater., 1996, 44: 873 |
/
| 〈 |
|
〉 |
