Powder-Based Additive Manufacturing of Ti₂AlNb Alloys: A Review of Processes, Microstructure and Mechanical Properties

ABSTRACT: Ti₂AlNb alloy, a new generation of low-density titanium aluminide intermetallic compound, possesses excellent high-temperature strength, creep resistance, and moderate density, making it a promising candidate for high-temperature aerospace structural components. Powder-based additive manufacturing technology provides an effective approach for fabricating high-performance Ti₂AlNb components, featuring high design freedom, efficient forming, and a controllable microstructure. This paper systematically reviews the research progress of powder-based additive manufacturing of Ti₂AlNb alloys, focusing on three mainstream powder-based processes, including Selective Laser Melting (SLM), Selective Electron Beam Melting (SEBM), and Direct Laser Deposition (DLD). The regulation effect of the extreme non-equilibrium thermal cycle during powder-based additive manufacturing on the alloy microstructure is analyzed, and the correlation between process parameters and mechanical properties of components is summarized. Meanwhile, the key challenges in this field are identified, such as the difficulty in completely eliminating typical forming defects, insufficient precision of microstructure regulation, and a lack of theoretical guidance for process optimization. Finally, combined with technological development trends, future research directions are prospected from the aspects of defect control, microstructure, and mechanical property regulation, as well as engineering application.