Additive manufacturing and characterization of microstructure evolution of Inconel 718 superalloy produced by vat photopolymerization

Vat photopolymerization is a potential method to prepare metal parts. This research reports the first manufacturing of nickel-based superalloy Inconel 718 components by vat photopolymerization. The photocurable pastes with a high-volume loading of metal powder of 55 % were prepared, and it has the advantages of excellent stability and fluidity at a constant shear rate, which is suitable for fabricating green body. Inconel 718 complex green parts with high precision were successfully printed by vat photopolymerization. Subsequently, the green body was debinded to remove resin and sintered at different temperatures to obtain metal parts and retain their specific characteristics. The microstructure evolution of the printed parts during sintering was studied comprehensively, and the sintering mechanism was discussed in detail. The microstructure and phase compositions were characterized by SEM, EDX, and XRD, respectively. The results indicate that oxides were formed in the sintered parts, hindering further densification of Inconel 718 metal components. Nickel-based superalloy with complex structures was obtained using vat photopolymerization technology.