2012 Volume 98 Issue 9 Pages 491-496
The effect of impurity elements on the mechanical properties of Ti-6Al-4V alloy is presented in this paper. Impurity levels of oxygen and iron were varied between 0.1 and 0.7%. Tensile and proof strength increased and elongation, cross-sectional area reduction, and Charpy impact strength decreased as the oxygen content increased. Furthermore, it was found that Japanese Industrial Standards requirements were maintained up to impurity levels of 0.3% O and 0.7% Fe by mass. Finally, the fatigue strength and seizure characteristics of Ti-6Al-4V fabricated from off-grade sponge titanium as the raw material was clarified by a series of experiments. The results showed that mechanical properties of Fe-bearing Ti-6Al-4V alloy are comparable to those of conventional Ti-6Al-4V alloy.