Effects of thermal exposure on cyclic deformation and fracture behavior of Ti600 titanium alloy

摘要

Effects of thermal exposure on cyclic deformation and fracture behavior of Ti600 alloy were investigated by laser scanning confocal microscope (LSCM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results demonstrated that both the nonthermal exposure (NTE) specimens and the thermal exposure (TE) specimens showed the cyclic softening, within a total strain amplitude range from ±0.45% to ±1.00%. During thermal exposure, since the harder α_2 (Ti_3Al) phase precipitated in the α_p (primary a) phase, the resistance of crack propagation of α_p phase could be increased by the precipitation of α_2 phase. Therefore, the fracture behavior of TE specimens is different with that of NTE specimens. For the NTE and TE specimens, the crack mainly passes through the α_p phase with "cutting" and "bypass", respectively.