Research progress of laser powder bed fusion of Ti2AlNb-based alloys: Microstructure, defects and properties

Ti2AlNb-based intermetallic alloys have emerged as promising candidates for aeroengine components due to their exceptional strength-to-weight ratio and superior high-temperature performance. Laser powder bed fusion (LPBF) has garnered considerable attention in the development of Ti2AlNb-based alloys because it enables the fabrication of complex structural parts with intricate geometries. However, LPBF-fabricated Ti2AlNb alloys still encounter significant challenges, including difficulties in microstructure control, the presence of various defects, and inadequate high-temperature ductility, which severely restrict their practical applications. This paper offers a comprehensive review of recent advancements in LPBF-built Ti2AlNb alloys and explores the interrelationships among microstructure, defects, and properties. First, we summarize the fundamental structure and properties of Ti2AlNb-based alloys. Next, we provide an in-depth examination of LPBF process characteristics and powder preparation methods. Subsequently, we describe the unique microstructural features of LPBF-built Ti2AlNb alloys and discuss the formation mechanisms of defects such as porosity and cracking, along with corresponding mitigation strategies. We also summarize effective methods for enhancing mechanical properties. Finally, we propose future development directions, including the design of new alloy compositions, crack control, optimization of heat treatment processes, and performance evaluation of practical engineering components.