The effects of smooth (non-damaged)

damaged and three kinds of polishing repaired notch structure on the vibration fatigue properties of TC17 titanium alloy simulated blades are investigated. The results show that smooth simulated blades exhibit the longest fatigue life and smallest life data dispersion

while the fatigue life of simulated blades with damaged notch are the smallest and the dispersion are the largest. The fatigue life increases when the damaged notch is repaired by polishing

the fatigue life of the blades with repaired notch Ⅰ is the largest

but still less than the life of smooth blades. The fatigue cracks in both smooth and repaired blades initiate at blade roots

while in the damaged blades fatigue crack are found at the notch. The crack sites are consistent with the largest stress sites in FEM results. The fatigue fracture regions of simulated blades are flat

in half ellipse morphology. The crack initiations mostly derive from the surface tiny damage. Fatigue propagation regions are characterized by typical fatigue beaches

present the character that cracked along the interface of α / β lamellar microstructure.