Mixing Entropy Threshold for Entropy-Tailored Materials

To determine the effect of mixing entropy on multicomponent alloys and to find the mixing entropy threshold for entropy-tailored materials, including high-entropy alloys and medium-entropy alloys, the microstructure and mechanical properties of 23 Ti-Zr-Nb-V alloys were investigated. The Laves phase content of Ti-Zr-Nb-V alloys was obtained using image recognition technology . According to the component threshold for Laves phases and HCP phase disappearance, V(Nb)-Zr(Ti) pseudo-binary phase diagrams, which can predict the phases of ternary Ti-Zr-V and Zr-Nb-V alloys, were established. By comparing the Laves phase content in Ti-Zr-Nb-V alloys obtained from experimental statistics, pseudo-binary phase diagrams and thermodynamic calculations, the Δ S mix threshold for entropy-tailored materials was 1.10~1.21R. The dependence of the yield strength and fracture strain of the Ti-Zr-Nb-V alloys further reveals that the mechanical properties of entropy-tailored alloys are essentially controlled.