He-ion irradiation effects on the microstructure stability and size-dependent mechanical behavior of high entropy alloy/Cu nanotwinned nanolaminates

Abstract High entropy alloys (HEAs) have attracted extensive attention due to their excellent properties in harsh environments. In this work, we prepare HEA/Cu (HEA = FeCoCrNi) nanotwinned nanolaminates (NTNLs) with equal individual layer thickness (h) and study the He-ion irradiation effects on their deformation behavior and mechanical properties. With decreasing h the microstructure of HEA/Cu NTNLs transits from the nanolayered structure with nanotwins confined in the isolated layers at large h ≥ 25 nm to the columnar grained single crystal-like structure with nanotwins penetrated across the coherent layer interface(s) at small h