Effects of microstructure on fretting fatigue crack initiation behavior of Ti-6Al-4V

Fretting fatigue crack initiation behavior was investigated for its dependence on the microstructure of a α/β titanium alloy, which ranged from homogeneous duplex to the fully transformed heterogeneous lamellar texture by increasing the Widmanstatten colony size. When the microstructure changed from homogeneous duplex to the fully transformed heterogeneous lamellar texture, the resistance to fretting fatigue crack initiation decreased. And, this was just the opposite of short and long crack behavior where the resistance to crack growth increases when the microstructure changes from homogeneous duplex to the fully transformed heterogeneous lamellar structure.