Low Cycle Fatigue Behavior of ZTC4 (Ti-6Al-4V) Titanium Alloy at Room Temperature

Low cycle fatigue (LCF) behavior of ZTC4 titanium alloy has been investigated under fully reversed total strain-controlled mode. The cyclic stress-strain and strain-life data were analyzed to determine the individual strain fatigue parameters of Manson-Coffin model by double logarithm linear regression processing. The results showed that the ZTC4 titanium alloy exhibited an initial slight cyclic hardening, followed by cyclic softening at the total strain amplitude of 0.4%-0.5%, then cyclic softening at a total strain amplitude of 0.6%-0.8%. The fatigue cracks initiated at the surface of the samples. The fatigue crack propagation regions were composed of fatigue striations. The fatigue fracture surface of specimens revealed the fracture characteristics of dimple.