High specific yield strength TiZrAlNbV high-entropy alloys via coherent nanoprecipitation strengthening

Developing lightweight high-entropy alloys (LHEAs) having considerable strength and ductility is a new perspective in the quest of novel lightweight alloys for potential engineering applications. The paper describes that by tailoring the aging treatment, abundant coherent B2 nanoprecipitates can be induced in body-centered-cubic (BCC) Ti–Zr–Al–Nb–V LHEAs. These nanoprecipitates can strengthen the alloys by around 20% based on the dislocation-shearing mechanism. Moreover, due to the effective inhibition of these precipitates on dislocation propagation, frequent cross-slip events appear, which benefit the deformation delocalization. Finally, based on the B2 precipitation strengthening, a LHEA having specific yield strength as high as ∼202 MPa·m 3 /kg and considerable fracture strain of ∼25% is developed. Our results provide a solution to overcome strength-ductility trade-off for the alloy to be suitable for structural applications.