Phase composition-guided design of nano strengthened high-entropy alloys for enhanced mechanical performance

Nanoprecipitation strengthening has demonstrated significant potential in enhancing the mechanical properties of high-entropy alloys (HEAs). However, the inherent compositional complexity of HEAs poses a critical challenge in designing compositions that enable the controllable formation of coherent nano-precipitates. In this study, we introduce a phase composition tracking strategy for the rational design of nano strengthened HEAs. Applying this strategy, we developed a Co₂₈Cr₃₀Cu₆Mn₁₅Ni₂₁ HEA, where dense coherent spinodal decomposition-induced nano-domains were successfully introduced by aging treatment at 600 °C for 5 h. The microstructure resulted in a remarkable 37 % enhancement in yield strength (from 315 ± 10 MPa to 433 ± 10 MPa) while simultaneously improving ductility (elongation increased from 48 ± 2 % to 53 ± 2 %) in room-temperature tensile tests. Mechanistic analysis indicates that the exceptional strength-ductility synergy stems from the strengthening contribution of coherent spinodal nano-domains. This work establishes a universal paradigm for designing high-performance HEAs with tailored nanoprecipitation strengthening, offering valuable insights into the development of compositionally complex alloys for extreme engineering applications.