Near-surface self-resistance hydrogen effect of eutectic high-entropy alloy AlCoCrFeNi2.1

A series of engineering application studies related to hydrogen damage has been carried out for the eutectic highentropy alloy (HEA) AlCoCrFeNi2.1 with excellent comprehensive properties. This work mainly introduces the element segregation and microstructure evolution phenomenon near the surface phase boundary and around the precipitated phase found in the hydrogen damage experiment of the material. Studies have shown that the evolution of the near-surface phase boundary microstructure of HEAs caused by hydrogen charging has a great influence on the hydrogen trap density inside the alloy. The "self-resistance hydrogen effect" is produced, that is, hydrogen-induced microstructure evolution causes the effect of delayed hydrogen diffusion. In this phenomenon, the synergy between hydrogen atoms and vacancies and dislocations on the alloy surface is crucial.