D. S. Lee, S. J. Veeck, Howmet Research Corporation, Whitehall, MI; R. Boyer, The Boeing Company, Seattle, WA; B. Briggs, The Boeing Company, Renton, WA

Summary:

Boeing and Howmet have continued joint efforts to evaluate investment cast Ti-5553 alloy (Ti-5Al-5V-5Mo-3Cr) relative to the industry standard, Ti -6Al-4V. In prior studies Ti-5553, a near beta alloy, exhibited superior tensile and fatigue characteristics relative to Ti-6Al-4V and better hardenability than Ti-15-3-3-3. More recent efforts have focused on creep, LCF, FCG and thermal stability behavior of the alloy. The efforts included both detailed microstructural characterization and tensile behavior as a function of alloy composition and heat treatment. The results of these studies will be discussed, and the applicability of Ti-5553 alloy castings for aerospace and airframe structural applications will be reviewed.