| Abstract Scope |
High entropy alloys (HEAs) have demonstrated excellent mechanical properties and damage resistance owing to their unique features of lattice distortion, sluggish diffusion, high-entropy effect and cocktail effect. The great radiation resistance behavior of HEAs derives from the unconventional kinetic evolution of radiation defects from generation to long-term growth. This presentation will introduce a thorough investigation into the irradiation resistance mechanisms of FCC and BCC HEAs. The FCC HEAs, typically composed by Ni, Co, Fe, Cr and Mn, show significantly improved radiation resistance compared to low entropy counterparts. It is found that the evolution of irradiation defects including dislocation loops and voids can be delayed with tuning the alloy compositional complexity. Latest study reveals that unique short-range orders (SROs) structure in HEAs provides a novel strategy to modulate defect annihilation and evolution by tuning chemical and structural heterogeneities. The BCC HEAs, typically composed by refractory elements of Nb, Mo, Hf, Ta and W, are promising for higher temperature application due to their high strength over wide operating temperature ranges. Latest study shows that severe lattice distortion and irregular energy landscape in the NbZrTi alloy result in distinct point defect behaviors. The structural instability of defect clusters and closer mobilities between vacancy and interstitial enhance irradiation tolerance by promoting point defect annihilation and recombination. The exceptional mechanisms of defect evolution in HEAs shed the new light on developing radiation-tolerant materials for advanced fission and fusion reactors. |