抄録
Superplastic formability of Ti–4.5Al–3V–2Fe–2Mo (mass%) alloy and its mechanical properties after superplastic forming were investigated. The sheets of 0.8 mm thick were formed at strain rate of 2 × 10−4 to 1 × 10−3 s−1 into rectangular pans at temperatures ranging from 750 to 800°C. These superplastic forming temperatures for the alloy were lower by over 100°C than those for Ti–6Al–4V. Excellent superplastic formability was obtained in wide ranges of the above conditions. Due to mainly the lowered forming temperatures, grain growth during superplastic forming was limited, and subsequently drop in tensile strengths of the formed parts was marginal. Aeronautical structural components of this alloy was successfully formed by the established low-temperature superplastic forming process.
