Nanoscale B2 precipitation and strengthening behavior in Al0.5CoCrFeNi high-entropy alloy

The precipitation hardening high-entropy alloys (HEAs) have attracted extensive research interest for their enhanced strength yet considerable ductility. In this study, the Al0.5CoCrFeNi HEA strengthened by nanoscale B2 phases was obtained after aging at temperature of 800 degrees C - 900 degrees C. The evolution of the B2 precipitation and the mechanical properties of Al0.5CoCrFeNi alloy were investigated after different thermomechanical treatments. The volume fraction and the length-width ratio of the B2 phases in the alloy increase with the increase of the aging time. After aging at 850 degrees C for 16 h, the yield strength of the alloy reaches 514 MPa via Orowan strengthening mechanism of the B2 phases. Additionally, the introduction of pre-deformation before aging promotes the formation of B2 phases, which results in strength enhancement of the alloy via precipitation strengthening and work hardening.

Automated summary

This study investigated the effect of thermomechanical treatments on the mechanical properties of high-entropy alloy Al0.5CoCrFeNi. The results showed that the nanoscale B2 phases formed through aging significantly enhanced the strength of the alloy, and pre-deformation facilitated the formation of B2 phases and further improved the strength of the alloy.