Tailoring microstructures of CoCrFeNiNb_(0.25)hypoeutectic high-entropy alloy by hot deformation

摘要

CoCrFeNiNb_(0.25)hypoeutectic high-entropy alloy(HEA)has shown good mechanical properties.However,due to interdendritic eutectics,it is challenging to further optimize the microstructure through cold rolling and annealing.The current study showed that hot defor-mation effectively tailored the hypoeutectic microstructure.We investigated the hot deformation behavior and microstructure evolution of the dual-phase CoCrFe-NiNb_(0.25) HEA at different temperatures from 800 to 1000℃and different strain rates from 0.01 to 10.00 s^(-1).The systematic investigation showed the deformation activation energy around 500 kJ·mol^(-1).Microstructure with refined grains and uniformly distributed Laves phases can be obtained after 70%compression at 900℃with a strain rate of 0.01 s^(-1).