Achieving Inconel 718-level tensile properties at room temperature with 23% less niobium: ICME-enabled design via controlled powder blending of Inconel 718 and stainless steel 316L in additive manufacturing

Mixing commercially available alloy powders in Additive Manufacturing (AM) provides a versatile route for composition exploration, yet tailoring post-heat treatments for such mixtures remains challenging. In this study, we developed an efficient ICME-based high-throughput model framework to screen aging choice as a part of post-heat treatment design for a novel alloy blend between Stainless Steel 316L (SS316L) and Inconel 718 (IN718). The framework centers on a modified yield strength model that explicitly accounts for the non-spherical morphology of γ ′ ′ precipitates and their multi-modal size distributions during multi-step isothermal aging. We applied this approach to a 77 wt% IN718 and 23 wt% SS316L blend (77.IN718), selected for its potential for grain refinement during homogenization. After screening 1944 double-step aging profiles, the simulation identified an optimized treatment (725 °C/8 h + 600 °C/8 h) predicting a yield strength of 1070 MPa, which closely matches the experimental value. Despite a significant reduction in niobium and titanium content relative to standard Inconel 718, the new alloy 77.IN718 achieved performance (1055 MPa yield strength, 1285 MPa ultimate tensile strength, and 19.5% elongation) comparable to bulk IN718 processed by conventional manufacturing at room temperature. This work demonstrates a successful integration of ICME-enabled design and experimental validation, offering a sustainable and efficient pathway for developing high-performance alloys by blending existing commercial feedstocks. The methodology enables alloy development with reduced reliance on critical elements, enhancing supply chain resilience in resource-constrained environments.