Active learning for the accelerated discovery of complex concentrated NiCoCr alloys in additive manufacturing

Many conventional alloys are poorly suited to laser-based additive manufacturing (also known as 3D printing) because of complex laser-material interactions and thermal histories. Identifying new printable alloys out of vast compositional spaces is a daunting task, particularly for complex concentrated alloys of three or more elements. Here, we integrate active learning with additive manufacturing to accelerate the discovery of NiCoCr complex concentrated alloys via a high-throughput highway. We identify six new printable alloys that are up to ~40% harder than the popular equiatomic NiCoCr at room temperature. Among them, two new alloys exhibit complementary advantages: Ni 12 Co 62 Cr 26 retains ~50% higher hardness than NiCoCr at 600 °C, whereas Ni 36 Co 14 Cr 50 reduces oxidation mass gain by 85% at 1000 °C compared with conventional superalloys. Our study demonstrates that optimum performance can reside far from equiatomic proportions and can be uncovered with substantially fewer experiments when exploration is guided by application-specific objectives. The modular workflow provides a general route to rapidly discover new printable, alloys for targeted demanding service conditions.