Abstract
The objective of this research was to investigate the high cycle fatigue behavior of a titanium alloy using an ultrasonic fatigue system. Fatigue testing up to one billion cycles under fully reversed loading conditions was performed to determine the ultra-high cycle fatigue behavior of Ti-6Al-4V. Endurance limit results were compared to similar data generated on conventional servohydraulic test systems and electromagnetic shaker systems to determine if there are any frequency effects. In addition, specimens were tested with and without cooling air to determine the effects of temperature on the fatigue behavior. Results indicate that the fatigue strength determined from ultrasonic testing was consistent with conventional testing. However, preliminary results indicate that cooling air may increase the fatigue limit stress at very long lives.