Creep behavior and tensile properties of Mo- and Fe-added orthorhombic Ti–22Al–11Nb–2Mo–1Fe alloy

A compositionally modified Ti–22Al–11Nb–2Mo–1Fe alloy was created by adding the quaternary β-phase stabilizing elements Mo and Fe in substitution for a portion of Nb in Ti2AlNb-based alloy. The steady-state creep rate, 1% creep-strain lifetime and transient creep behavior of Ti–22Al–11Nb–2Mo–1Fe were improved in comparison with that of Ti–22Al–27Nb. The additions of Mo and Fe enhanced the activation energy of self-diffusion in the Ti2AlNb-based alloy. The Ti–22Al–11Nb–2Mo–1Fe alloy also exhibited high 0.2% yield strength and ultimate tensile strength at high temperatures.