Effects of Temperature and Frequency on the HCF Behavior of a Ni-based Superalloy

摘要

The objective of this research was to investigate the effects of temperature and frequency on the high cycle fatigue behavior of a single crystal superalloy using an ultrasonic fatigue system. Fatigue testing up to 109 cycles under fully reversed loading was performed at a temperature of 593 C (1100 F) to determine the ultra-high cycle fatigue behavior of PWA1484 at elevated temperature. Endurance limit results were compared to similar data generated on conventional servohydraulic test systems to determine if there are any frequency effects. Scanning electron microscopy was then used to determine the initiation sites and the failure mechanisms. Initial results indicate little or no frequency effect on the fatigue strength or failure mechanisms of PWA 1484 at 1100 F.