Advanced Titanium Alloy Ti-6Al-2Sn-2Zr-2Mo-2Cr for Commercial Aerospace Applications

Next generation commercial aircraft and aero-engine requirements are pushing the Ti alloy performance needs beyond the upper limits of the workhorse alloy Ti-6Al-4V (Ti-64), necessitating the use of advanced alloy solutions. This presentation will provide an overview of RTI Ti-6Al-2Sn-2Zr-2Mo-2Cr (Ti-62222) alloy capabilities to address the future commercial aerospace needs. Ti-62222 is a judiciously balanced alpha + beta titanium alloy designed and developed by RMI Titanium in the early 1970s, for damage tolerant aerospace applications that required higher strengths than Ti-64 in section sizes up to 4 inches. A nominal silicon content of 0.15% was added to Ti-62222 formulation to retain strength and improve creep resistance at elevated temperatures. Robust manufacturability of Ti-62222 including melting, chemistry control, thermo-mechanical processing (TMP), heat treatment, and fabricability was established. The alloy has been in production since mid-1990s with significant usage on military aircrafts such as US Air Force fighter F/A-22. The alloy is currently produced in most standard wrought product forms such as billet, plate, and sheet. The alloy version optimized for damage tolerance or strength can be produced via controlled TMP and heat treatment. Potential applications of this alloy include: billet and thick plate for airframe structural parts such as bulkheads, frames, spars, and ribs; sheet and thin plate for skin structures and superplastically formed parts; and forged products for engine components at moderate service temperatures.