Abstract: Additive manufacturing (AM) technology has demonstrated significant potential in the green, lightweight, and functional development of metal materials, offering greater freedom and flexibility in the manufacturing process. However, the microstructural heterogeneity and mechanical property anisotropy of nickel-based superalloys along the build direction, stemming from thermal cycling, limit their widespread application in the aerospace industry. The proposed hybrid manufacturing process introduces external energy fields (thermal, ultrasonic, magnetic fields) into the forming processes, offering an innovative pathway to overcome the limitations of AM superalloys. This paper systematically discusses the influence of energy fields on the AM process of nickel-based superalloys, focusing on key issues such as cracking, porosity, microstructural heterogeneity, and mechanical property. Various energy fields modulate the melt pool dynamics and solidification process through distinct mechanisms. However, there remain several unresolved challenges and controversies regarding their mechanisms, particularly concerning the microstructural evolution under the synergistic effects of multiple energy fields. To address this issue, current studies predominantly focus on experimental validation, with a lack of unified theoretical models and numerical simulations, which limits the further development of energy field optimization strategies. Accordingly, the roles and advantages of various energy fields in AM of nickel-based superalloys are summarized. And engineering challenges are highlighted, such as multi-field synergistic control strategies, quantitative prediction models for microstructure-property, and energy field optimization methods for practical applications. Finally, the future trends of energy field-assisted AM for high-performance superalloys are discussed, with an outlook on its potential applications in re-manufacturing technologies and integrated equipment.

Key words: Additive manufacturing, External energy fields, Multi-energy field coupling, Superalloys, Heterogeneity