Research progress on powder bed fusion additive manufacturing of TiAl-based alloy
Abstract
TiAl-based alloys represent a novel class of lightweight, high-temperature structural materials that exhibit exceptional properties, including low densities, high specific strength, and remarkable thermal resistance. These properties make them exceedingly promising for supplanting nickel-based superalloy in the production of pivotal components for aerospace, marine, and automotive engines. Regrettably, like most intermetallic compounds, TiAl-based alloys are subject to certain shortcomings, such as room-temperature brittleness, deformation difficulties, and susceptibility to cracking, which present challenges for shaping these materials into intricate forms using traditional processing methods. In this regard, additive manufacturing (AM), with its high processing freedom and energy, has emerged as a revolutionary technology for the fabrication of complex structural components of TiAl-based alloys. However, AM TiAl-based alloys are still plagued by issues such as cracking, porosity, and uneven microstructure. Therefore, various post-processing techniques were employed to tune the microstructure, and thus enhance the performance of AM TiAl-based alloys. This paper reviews the research progress of AM TiAl-based alloys, summarizing the effects of process parameters, alloying, heat treatment, and surface treatment on the microstructure and mechanical properties of these alloys. Additionally, it discusses the challenges and prospects for the future development of AM TiAl-based alloys.
