Progress in additive manufacturing of nickel-based superalloys: materials, processing, microstructures, properties and alloy design

Notable advancements have been made in the additive manufacturing (AM) of aerospace materials, driven by the needs for integrated components with intricate geometries and small-lot production of high-value components. Nickel-based superalloys, pivotal materials for high-temperature bearing components in aeroengines, present significant challenges in the fabrication of complex parts due to their great hardness. Huge attention and rapid progress have been garnered in AM processing of nickle-based superalloys, largely owing to its distinct benefits in the freedom of fabrication and reduced manufacturing life-cycle. Despite extensive research into AM in nickel-based superalloys, the corresponding results and conclusions are scattered attributed to the variety of nickel-based superalloys and complex AM processing parameters. Therefore, there is still a pressing need for a comprehensive and deep understanding of the relationship between the AM processing and microstructures and mechanical performance of nickel-based superalloys. This review introduces the processing characteristics of four primary AM technologies utilized for superalloys and summarizes the microstructures and mechanical properties prior to and post-heat treatments. Additionally, this review presents innovative superalloys specifically accommodated to AM processing and offers insights into the material development and performance improvement, aiming to provide a valuable assessment on AM processing of nickel-based superalloys and an effective guidance for the future research.

Graphical abstract