Entropy-mediated excellent strength and elastic limit for α-phase Ti-Zr-Al-V alloys

Abstract

High-performance elastic materials are of significance in airplanes and space vehicles. It is usually a trade-off conundrum to achieve high strength and elastic limit (yield strength-to-elastic modulus ratio) simultaneously for engineering materials. In this work, we proposed an entropy-mediated approach to realize the synchronization of high strength and elastic limit for traditional titanium alloys. By the addition of Zr into Ti64 alloy, the entropy-mediated Ti₆₆Zr₂₀V₄Al₁₀ alloy exhibits tensile and yield strength up to ∼1420 MPa and ∼1200 MPa, and elastic limit of 1.3%, respectively, which are increased by 77 %, 77 % and 120 % compared to those of Ti64 alloy. The TEM structure study confirms that the grain boundary, solid solution and dislocation strengthening mechanism are responsible for the high strength. The model of first principles calculation shows that the elasticity is attributed to the high entropy and severe lattice distortion effect.