Investigation of deformation behavior and microstructure evolution of a Ti-6Al-4V-0.5Ni-0.5Nb-0.05Ru alloy

Abstract

(1) The dynamic deformation behavior and microstructure evolution of a new Ti-6Al-4V-0.5Ni-0.5Nb-0.05Ru alloy was studied in this paper. The constitutive model of the tested alloy was calculated, and a series of processing maps considering strain were constructed. The results revealed that the thermal activation energy of the tested alloy was 531.856 kJ/mol, which was lower than that of the Ti-6Al-4V-0.1Ru alloy. (2) The constitution model between peak-state flow behavior and TMP parameters can be expressed as ε̇=9.177×1021sinh0.0109×σp3.9086exp−531.856RT. The optimal thermomechanical process (TMP) parameter of the tested alloy was calculated to be in a temperature range of 940–1000 °C and a 0–1 s−1 strain rate, while the unstable region was in a temperature range of 930–990 °C and a 0.01–0.6 s−1 strain rate. Due to the rotation and deformation coordination of the large amount of equiaxed α phase and dynamic recrystallization α phase, the dynamic softening mechanism was a typical continuous dynamic recrystallization (CDRX) in the α + β phase region, and the dynamic recovery of the tested alloy occurred mainly in the β phase region.