Fatigue crack propagation behavior of Ti40 alloy at different temperatures

This paper presented the fatigue crack propagation behavior of Ti40 alloy at room temperature, 300, 500 and 600°C, and the apparent active energy of Ti40 alloy at 300, 500 and 600°C was calculated when ΔK was 20 MPa·m^1/2. The results indicated the fatigue crack propagation rate increased with temperature raise. All the fit lines of the fatigue crack propagation rate at various temperature intersected at one point when ΔK is 45.5 MPa·m^1/2. The value of apparent activation energy increases at first with the increase of temperature, then decreases, which reaches the maximum at 500°C, indicating that the temperature 500°C is a turning point of the thermodynamics properties in Ti40 alloy.