Indentation pop-in behavior of CoCrFeNiAl0.3 high-entropy alloy

The pop-in behavior of face-centered cubic (FCC) CoCrFeNiAl0.3 high-entropy alloy (HEA) under different loading rates was investigated by nanoindentation with spherical indenter. Experimental results show the distinct three-stage feature of the first pop-in, namely the elastic stage before pop-in, linear plastic stage and deceleration plastic stage for the pop-in evolution. Rate effect was analysed and critical shear stress required for the first pop-in event is obtained. A rheological model was proposed to characterize the pop-in behavior of CoCrFeNiAl0.3 HEA under different loading rates, and the related model parameters are given.