Temperature dependent deformation mechanisms of Al_0.3CoCrFeNi high-entropy alloy, starting from serrated flow behavior

The deformation mechanisms of Al_0.3CoCrFeNi high-entropy alloy (HEA) is investigated through studying the serrated flow behavior under different conditions. Results show that abnormal variation trends happen in the serration curves during compression, denoting a transition of the deformation mechanism with the temperature increasing. Microstructure characterization reveals this transition is a twining to slip deformation, which is evidenced by nanoscale twins at 600 °C but high density dislocations at 800 °C. This temperature dependent deformation behavior is thought to be related with the dislocation mobility and stacking fault energy (SFE).