Roller Working Effect on Fatigue Strength of Ti-6Al-4V Alloy
The fatigue strength have been investigated about the plastic deformed specimens by roller working in Ti-6Al-4V alloy with a notch by 4 kinds of plastic deformation ratio. The plastic deformation values (Δ t) are employed 0.05, 0.1, 0.25 and 0.4 mm on notched specimens of Ti-6Al-4V alloy by roller-working. The hardness test, fatigue test and SEM observation was carried out on non-roller worked specimens and roller-worked specimens at room temperature. Based on the results of these tests, Though the hardness number of roller worked materials are higher than those of non-deformed Ti-6Al-4V alloy, the fatigue limit of roller worked materials becomes deteriorated in spite of roller working. Fatigue fracture had occurred in the non- deformed area where tensile residual stress exists. From the results of the SEM observation, stepped defect could be notch effect for reducing the fatigue strength of Ti-6Al-4V alloy.
Kikuo Kishimoto, Masanori Kikuchi, Tetsuo Shoji and Masumi Saka
S.Y. Son et al., "Roller Working Effect on Fatigue Strength of Ti-6Al-4V Alloy", Key Engineering Materials, Vols. 261-263, pp. 1269-1274, 2004