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

► A new high-strength refractory alloy, Ta20Nb20Hf20Zr20Ti20. ► The alloy has a BCC crystal structure. The lattice parameter a = 340.4 pm. ► The alloy density and Vickers microhardness are 9.94 g/cm 3 and 3826 MPa. ► The compression yield stress σ 0.2 = 929 MPa and ductility ɛ > 50%. ► The alloy shows considerable strain hardening and homogeneous deformation. ► A model of solid-solution strengthening is proposed to explain the behavior. A new refractory alloy, Ta 20Nb 20Hf 20Zr 20Ti 20, 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 a = 340.4 pm. The alloy density and Vickers microhardness are ρ = 9.94 g/cm 3 and H v = 3826 MPa. The alloy has high compression yield strength ( σ 0.2 = 929 MPa) and ductility ( ɛ > 50%). The alloy shows considerable strain hardening and homogeneous deformation. A simple model of solid-solution strengthening is proposed to explain the behavior.