Effects of microstructure on the mechanical properties of a high-strength Ti20Zr6.5Al4V alloy

Ageing and annealing were selected to process a forged Ti(20)Zr(6.5)Al4V (wt. %) alloy. The microstructure and mechanical properties of the processed alloy samples were investigated by scanning electron microscopy, electron backscatter diffraction, transmission electron microscopy, uniaxial tensile testing and nanoindentation. The analyses showed that the aged alloy consisted of single a- phase, whereas the annealed alloy was composed of dual (alpha+beta) phases. The aged alloy exhibited an ultrahigh tensile strength of 1730 MPa with a low elongation of 2.3%, whereas the annealed alloy showed more balanced strength and ductility (1235 MPa and 10.8%, respectively). The effects of heat treatments on the microstructure and mechanical properties of the alloy were studied. The mechanisms of strengthening as well as the improvement of the ductility of the alloy were also discussed. (C) 2017 Elsevier B. V. All rights reserved.