Evolution of tensile strength and ductility of the non-equimolar TiVNbMoCr alloys with maximum entropy under the VEC constraint

Abstract

In this work, a series of non-equimolar TiVNbMoCr alloys were designed according to the maximum entropy principle under the valence electron concentration (VEC) constraint. The effect of the physical parameters on tensile strength and elongation was experimentally investigated and comprehensively discussed. It was found that the lattice constant a and the average grain size d vary with relative changes in the content of each component, and exhibit negative correlations to VEC. Whereas, the self-interstitial formation energy Ei, the atomic radius mismatch δ, the shear modulus mismatch η and the shear modulus G exhibit positive correlations to VEC. These parameters have a significant impact on tensile properties of the alloys. Except for Burgers vector magnitude, the critical physical parameters in the Senkov and Labusch-Maresca-Curtin's strengthening models are positively correlated to the yield strength. The ductility of the solid-solution TiVNbMoCr alloys is related to VEC, a, d and the grain boundary characteristics in strain accommodation, which respectively belong to intrinsic, crystallography structural and microstructural types of parameters.