A novel strategy for the design of compositionally complex alloys for advanced nuclear applications

The development of compositionally complex alloys (CCAs), including medium- and high-entropy alloys (M/HEAs), which can offer exceptional mechanical properties, thermal stability, and corrosion resistance, has largely been driven by trial-and-error, and designing CCAs for specific properties and commercial applications remains an unresolved challenge. This study introduces a novel approach for designing CCAs with specific properties for target applications. It presents a TiVCrFeZrTa high-entropy master alloy (HEMA), composed primarily of refractory elements, with low neutron capture, minimal transmutation, and reduced gamma activity, targeting nuclear applications. Utilizing a natural-mixing guided design (NMGD) methodology, the process identifies the crystalline structures of the HEMA's phases, allowing for the recreation of solid solution phases while avoiding brittle intermetallic phases. The resultant Ti55Zr30Ta6V5Fe2Cr2 CCA exhibits as-cast ductility allowing 86 % thickness reduction during cold-rolling, high tensile yield strengths up to 1360 MPa and fracture toughness up to 36 MPa m1/2, contingent on thermomechanical treatment. This approach demonstrates how tailored property calculations and NMGD can expedite the identification of CCA compositions, streamlining the development process and reducing reliance on extensive, costly trial-and-error experimentation.