High-throughput discovery of ultrahigh-temperature multi-principal element alloys by combinatorial additive manufacturing.

Developing structural materials with ultrahigh-temperature capabilities is crucial for aerospace and energy applications, yet achieving a balance of strength, heat-softening resistance, and plasticity remains challenging. Here, we report a tungsten-based W-Re-Os alloy with exceptional mechanical properties up to 1400 °C. Utilizing multi-principal element alloy design principles, three refractory metals with melting points above 3000 °C-W, Re, and Os elements are alloyed using combinatorial additive manufacturing. This approach enabled rapid fabrication of ~500 compositions in a single run. High-throughput micro-indentation testing identified W42Re30Os28 as a standout candidate, exhibiting an ultrahigh yield strength of ~1.8 GPa and ~9% compressive plasticity at room temperature, while retaining ~1.4 GPa yield strength with remarkable strain-hardening at 1400 °C, far surpassing other high-temperature alloys reported to date. These properties arise from its dual-phase hypoeutectic microstructure and multiple deformation mechanisms, including basal and non-basal dislocation slip, deformation twinning, and hetero-deformation-induced geometrically necessary dislocations.