Overcoming the strength-ductility trade-off in refractory medium-entropy alloys via controlled B2 ordering

Herein, we showed that controlled additions of Al, which provided a certain degree B2 ordering, resulted in ∼ 37%-enhancement both yield strength and uniform elongation Alx(NbTiZr)100-x (x = 0; 2.5; 5; 7.5 at.%) refractory medium-entropy alloys. The improvement properties stemmed from the solid solution short-range order strengthening, as well alteration character dislocation glide. ordering caused formation multiple bands activation cross-slip, improved macroscopic stability plastic flow extended strengthening stage, thereby postponing necking.