Effects of atomic radius mismatch and Burgers vector magnitude on tensile properties of the Ti50-ZrVNbCr medium-entropy alloys.

In this study, four Ti50-ZrVNbCr alloys were designed and prepared with the same valence electron concentration (VEC) value, and effects of atomic radius mismatch and Burgers vector magnitude on tensile properties were experimentally investigated. The results showed that multiple slip systems were activated in the alloys. With the increment of atomic radius mismatch and Burgers vector magnitude, the relative activity of {110}<111> slip mode decreased, and the relative activities of {112}<111> and {123}<111> slip modes increased. Atomic radius mismatch dominated the yield strength of the alloys by solid-solution strengthening. The reduction of lattice constant can lead to the increment of dislocation density that favors for increasing ductility. As lattice constant increased, dislocations gradually condensed in some slip-bands that could form shear bands, resulting in a localization of deformation and a stress concentration, which could easily lead to cracks on grain boundaries. • Four Ti50-ZrVNbCr alloys were prepared with a constant VEC value; • Roles of atomic radius mismatch and Burgers vector were addressed; • The relative activities of slip modes vary with radius mismatch and latticeconstant; • Burgers vector magnitude played a dominant role in strengthening these alloys; • Lattice constant dominated the ductility. [ABSTRACT FROM AUTHOR]