Baseline Characterization of Ti-6242 Sheet for Low-Temperature SPF Applications

“Ti-6Al-2Sn-4Zr-2Mo Sheet is widely used in aerospace structures requiring creep resistance at elevated temperatures. Many components are manufactured using superplastic forming (SPF) at temperatures as high as 1700F (927C). In recent years, significant effort has been devoted to developing Ti-6Al-4V sheet with “low-temperature” SPF capability in the 1400-1500F range, and for which the benefits have been described in recent conferences. Engine components and heat shields (currently manufactured from Ti-6Al-4V sheet) requiring increased elevated temperature resistance are being converted to Ti-6242. Consequently, airframe manufacturers and tier 1 suppliers have expressed an interest in Ti-6242 sheet exhibiting “low-temperature” SPF behavior at 1550F or lower. As with Ti-6Al-4V, lowering the SPF temperature will provide for improved die life, less alpha case, the need for chemical milling, and thus reducing associated environmental concerns. The purpose of this present work is to define baseline data for 1550F-1700F SPF behavior of Ti-6242 sheet produced per AMS 4919, and to identify opportunities for future investigation.”