A new approach to design advanced superalloys for additive manufacturing

A novel approach centered on a high Ta/Al ratio and a significant dependence on the boundary composition addressed the challenges in the manufacturability and material performance of additive-manufactured nickel (Ni)-based superalloys. This approach integrated alloy composition, defect management, and mechanical behavior considerations. This study investigated the impact of this approach on microstructural characterization, solidification behavior, elemental microsegregation, and precipitation, demonstrating its efficacy in crack resistance and performance enhancement. Ultimately, this approach facilitated the successful design of a crack-free Ni-based superalloy, ZGH451-1, featuring a high γ′-phase content. Extensive comparisons of mechanical properties, including tensile and creep tests, against reported AM-ed superalloys and partially heat-treated first-generation Ni-based single-crystal superalloys validated the superior mechanical properties and processability of the newly designed alloy. The rationality and feasibility of this approach for achieving collaborative optimization of properties and formability were demonstrated, paving the way for the design of new high-performance superalloys suitable for additive manufacturing.