High cycle fatigue (HCF) properties for high temperature titanium alloys without and with different content of rare earth element Y have been tested at ambient temperature at a frequency of 100Hz or so and a load ratio R of 0.1, and the effect of Y on fatigue fracture behavior was also analyzed. The results indicated that the HCF strength for the alloys increases with the increment of rare earth element content, and the strength of the two alloys with Y are lower than that of the alloy without Y. Compared with the alloy without Y, the strength for the two alloys with Y decreases 11.2% and 17.4%, respectively. The particle size for rare earth oxide dispersely precipitated from the matrix alloy varies from several hundred nanometer to several micrometer. The crack initiations for the alloys are related to the fracture of rare earth oxide particles.
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