Effects of Microstructure on Low Cycle Fatigue Property of TC18 Titanium Alloy Under Stress-controlled Condition

The effect of lamellar and bi-modal microstructures on low cycle fatigue life under different stress swing of TC18 titanium alloy was studied.The results show that fatigue life is not sensitive to the change of microstructure of TC18 titanium alloy.Fatigue lives of bi-modal and lamellar microstructures are very similar under the same stress swing.The low cycle fatigue life N of TC18 titanium alloy is determined by stress swing.The relationship between σmax and N is logarithmic and the correlative coefficient is larger than 0.99.