Effect of Strain Waveform on Low-Cycle Fatigue Life of Ti-6Al-4V Alloy at Elevated Temperature
Seiichi NISHINO, Kazuaki SHIOZAWA and Tomonori OHKUMA
Abstract:The effect of strain waveform on low-cycle fatigue strength of Ti-6Al-4V alloy at elevated temperature was studied. Total strain controlled low-cycle fatigue tests were carried out using a smooth specimen with triangular and tension-hold or compression hold trapezoidal waveforms at 773K in air. From the experimental results, low-cycle fatigue life decreased by introducing a hold period as compared with that using a triangular waveform. The fatigue life of the compression-hold tests decreased as compared with tension-hold tests. The low-cycle fatigue life of Ti-6Al-4V alloy with each strain waveform can be evaluated by considering the effect of mean-stress, oxidation of specimen surface and creep damage. Key Words:Low-cycle fatigue, Ti-6Al-4V, Elevated temperature, Waveform, Mean stress, Creep, Oxidation