Effiects of temperature, slip amplitude, contact pressure on fretting fatigue behavior of Ti811 alloys at elevated temperatures

Effiects of the temperature, slip amplitude, and contact pressure on fretting fatigue (FF) behavior of the Ti811 titanium alloy were investigated using a high frequency fatigue machine and a home-made high temperature apparatus. The fretting fatigue failure mechanism was studied by observing the fretting surface morphology features. The results show that the sensitivity to fretting fatigue is high at both 350 and 500 °C. The higher the temperature, the more sensitive to the fretting fatigue failure is. Creep is an important factor that influences the fretting fatigue failure process at elevated temperatures. The fretting fatigue life of the Ti811 alloy does not change in a monotonic way as the slip amplitude and contact pressure increase. This is owing to the fact that the slip amplitude affiects the action of fatigue and wear in the fretting process, and the nominal contact pressure affiects the distribution and concentration of the stress and the amplitude of fretting slip at the contact surface, and thus further influences the crack initiation probability and the driving force for propagation.