Zr35Ti35Nb20V5Al5 refractory high entropy alloy designed for low-density, high specific strength and ductility

Abstract

Refractory high entropy alloys have gained significant interest over the past decade as promising candidates for high-strength applications, particularly at high temperatures. However, achieving ductility and workability at room temperature remains a challenge for large-scale manufacturing and applications. This study explores the design and characterisation of a novel RHEA with low density, high ductility, and high strength at room temperature. High-throughput screening and experimental validation identified a non-equiatomic composition, Zr₃₅Ti₃₅Nb₂₀V₅Al₅ (at%), which exhibits a room-temperature yield strength of 1030 MPa, 11% tensile strain to failure, and a low density of 6 g/cm³. The alloy's grain size was refined to <20 μm through rolling and recrystallisation, bypassing traditional high-temperature homogenisation while avoiding microsegregation. The tailored Zr₃₅Ti₃₅Nb₂₀V₅Al₅ RHEA demonstrates a new design approach and processing route, opening applications in next-generation nuclear and aerospace technologies.