Stacking fault strengthening in CoCrFeMnNi high-entropy alloy

The effects of stacking faults (SFs) on the mechanical properties of high-entropy alloys (HEAs) may not be ignored because of the lower or even negative SF energy. Here, we investigated the SF strengthening of CoCrFeMnNi and clarified its potential mechanism. It showed experimentally that the CoCrFeMnNi with more SFs had higher strength and hardness than that with fewer SFs, revealing significant SF strengthening. To gain an insight into such effects, we performed simulations for the mechanical responses of CoCrFeMnNi samples with different plane defects at the atomic scale. The results showed that the strengths of the CoCrFeMnNi samples containing SFs or twin boundaries were higher than that of single crystal ones. Overall, our results suggested that the effects of SFs on the mechanical properties of FCC HEAs could not be ignored, and the atomistic insights into the strengthening mechanism of HEAs we provided would be beneficial to improve the mechanical properties of FCC HEAs.