Cobalt-element-free eutectic medium-entropy alloys with superior mechanical performance and processability

A new composition-design strategy was used to guide the development of Co-free eutectic high-entropy alloy. In the present work, we successfully realized the prediction of the eutectic point of CrFeNiNb x through the energy-dispersive spectrometer data of CoCrFeNiNb x . After that, we systematically investigated the effect of the Nb content on the phase-structure evolution and macro-mechanical properties of the equiatomic CrFeNi alloy. Experimental results show that the removal of Co reduces the eutectic point and decreases the solubility of the Nb element in the face-centered-cubic (FCC) phase. Compared with the Co-bearing eutectic, there are not obvious change of the morphology of the Co-free eutectic, while the interlaminar spacing and volume of the FCC phase increased, which resulting in a decrease in yield strength but a certain degree of improvement in compressive strain.