Rotating bending (50 Hz)fatigue tests were performed at room temperature,200 ℃ and 350 ℃,respectively,to evaluate the influence of temperature on the fatigue resistance and fatigue crack growth rates of TC17 alloy.Variation of sample deflection was used to analyze the evolution of crack growth rate at different temperatures.By using scanning electron microscopy,the crack initiation and propagation behavior were examined.The results showed that the portion of fatigue life attributed to crack initiation was more than 90% in the high-cycle regime in this investigation.Not only the crack initiation but also crack propagation was promoted at elevated temperature.
