Opening the future of lightweight: Research progress in additive manufacturing of TiAl alloys
Yuan-Zheng Wei, Bing-Heng Miao, Shi–Li Shu, Hong‐Yu Yang, Xinmiao Zhong, Bai-Xin Dong, Liang-Yu Chen, Feng Qiu, Qi–Chuan Jiang
Abstract
TiAl alloys are regarded as ideal materials for aero-engine turbine blades, automotive exhaust valves, and high-temperature structural components because of their low density and superior high-temperature properties. However, their widespread industrial application has long been constrained by room-temperature brittleness, narrow hot-working window and susceptibility to hot cracking. In recent years, three primary additive manufacturing (AM) technologies: Laser Powder Bed Fusion (LPBF), Electron Beam Melting (EBM) and Directed Energy Deposition (DED), have provided novel pathways for the precision forming, microstructure control, and performance enhancement of TiAl alloys. This review begins by introducing the principles and characteristics of these three mainstream AM processes (LPBF, EBM, DED) and systematically analyzes the common defect types (hot cracks, porosity, Al evaporation), formation mechanisms, and suppression strategies in TiAl alloys. Subsequently, it reviews the effects of process parameter optimization, alloy composition design, and reinforcement addition on microstructure refinement, phase composition, and mechanical properties. Furthermore, the crucial role of heat treatment in phase transformation control and defect closure is explored. Finally, the challenges faced by AM-fabricated TiAl alloys and their future development directions are discussed, drawing upon existing research findings. This review seeks to present theoretical foundations and technical references for the AM of high-performance TiAl components.