Study on low fatigue damage behavior of TC17 titanium alloy with basket-weave microstructure

Room-temperature low-fatigue tests were conducted on TC17 titanium alloy, and the low-fatigue damage behavior of TC17 titanium alloy with a basket-weave microstructure at room temperature was investigated. The results show that TC17 titanium alloy exhibits different cyclic hardening/softening phenomena at different strain amplitude ( epsilon ta ) levels, which was closely related to the magnitude of strain amplitude, the crack sources of all specimens generated on the surface, and the number of crack sources increases with the increase of strain amplitude level. The competitive relationship between back stress hardening and frictional stress softening caused by changes in different microstructures is the reason for the occurrence of different cyclic hardening/ softening phenomena. The relationship between the holes and secondary cracks near the fracture surface and the basket-weave microstructure was further discussed. The secondary cracks/holes were more likely to initiate in the primary alpha phase where the solid solution strengthening effect was weak. In addition, the interaction between the secondary crack propagation path and the nearby alpha lamellae was studied by the Electron Backscatter Diffraction (EBSD) method.