HIGH-CYCLE AND GIGA-CYCLE FATIGUE PROPERTIES OF TITANIUM ALLOY FOR AERO-ENGINE

The high-cycle and giga-cycle fatigue properties of Ti-6Al-4V for hollow fan blade of aero-engine are investigated. The observations show that the Ti-6Al-4V may have fatigue failure above the 10⁷ cycles. The high-cycle and giga-cycle fatigue data are fitted by three parameter power function life curves. The data obtained by two test methods can be joined smoothly. It is concluded that the effect of frequency on giga-cycle fatigue properties under the test conditions is negligible. The fractograph of specimens is analyzed, which indicates that the giga-cycle specimens might generate internal fractures or surface fractures while there are not defects on the specimen surface, and the high-cycle specimens generate only surface fractures.