Development of CoCrNi-based alloys: Insights into elemental doping and additive manufacturing

Abstract

CoCrNi-based medium-entropy alloys (MEAs) exhibit exceptional mechanical properties, making them promising candidates for advanced applications. Currently, most of the studies focus on CoCrNi-based alloys prepared by traditional techniques, where a combination of casting and thermo-mechanical treatment is employed to achieve a synergy of strength and ductility. However, this approach is complex and unsuitable for fabricating components with complex geometries. In contrast, laser additive manufacturing (LAM) has gained considerable attention as an innovative method to fabricate MEAs, offering a near-net-shape fabrication approach with precise microstructural control. Currently, comprehensive reviews on CoCrNi-based alloys are still limited, with few addressing the impact of LAM on these alloys. In this paper, we review the effect of elemental doping on CoCrNi-based alloys, focusing on strengthening mechanisms, recrystallization behavior, and stacking fault energy (SFE). Additionally, this review highlights the influence of LAM on CoCrNi-based alloys and compares the mechanical properties of alloys produced via traditional processing routes and LAM. Finally, the future outlook for optimizing LAM-processed (LAMed) CoCrNi-based alloys is discussed, offering insights into future research and development directions.