STUDY ON THE HIGH CYCLE FATIGUE PROPERTY OF Ti-600 ALLOY AT AMBIENT TEMPERATURE

High cycle fatigue (HCF) property of one kind of near alpha titanium alloy named after Ti-600 was investigated at a frequency of 120~130Hz and with a load ratio R of 0.1. The HCF strength for the alloy at ambient temperature was found to be 475MPa. The observed high HCF strength was attributed to its overlapping plate like α+β phase microstructure. At the same stress of 600MPa, the distance between two fatigue stripes for the sample fractured at 8.61×10⁵ cycles was wider than that of the sample failured at 1.78×10⁶ cycles, which indicated that their propagation resistance for fatigue cracks was smaller.