Microstructure and room temperature properties of a high-entropy TaNbHfZrTi alloy

A new refractory alloy, Ta20Nb20Hf20Zr20Ti20, produced by vacuum arc-melting followed by hot isostatic pressing (HIPing) at T = 1473 K and P = 207 MPa for 3 h has predominantly a single-phase body-centered cubic (BCC) structure with the lattice parameter alpha = 340.4 pm. The alloy density and Vickers microhardness are rho = 9.94 g/cm(3) and H-v = 3826 MPa. The alloy has high compression yield strength (sigma(0.2) = 929 MPa) and ductility (epsilon > 50%). The alloy shows considerable strain hardening and homogeneous deformation. A simple model of solid- solution strengthening is proposed to explain the behavior. (C) 2011 Elsevier B.V. All rights reserved.