Development of Very Lightweight, High Stiffness, TMC Shaft Technology

This proposal is to develop and demonstrate technologies that will enable implementation of aircraft-engine titanium matrix composite (TMC) shafts that are significantly lighter weight and potentially permit engine sub-critical vibratory operation. Current and under-development advanced engines employ long length, nickel-alloy shafts that satisfy rigorous dynamic, torsion, maneuver, temperature and life requirements. A lighter weight TMC shafts will be very beneficial. Ability to operate sub-critical rather than super-critical would be extremely advantageous. Also, gaining experience with such shafts on current engines will provide confidence to proceed with new centerline engine designs that take full advantage of dramatic improvements possible from TMC shafts in applications where nickel-alloy shafts cannot satisfy requirements. This SBIR builds on baseline TMC shaft developments/demonstrations conducted by Woodbine Labs and GE Aviation and extends this technology for payoff on current applications. The use of advanced higher strength, high stiffness, TMC architectures and advanced titanium to nickel-alloy joining offers the potential for lighter weight, sub-critical operating shafts. The proposed program will accomplish system designs, trade studies, conduct critical subelement fabrication/technical experiments and establish feasibility of such shafts. Phase II will build and demonstrate a corrosion resistant significantly lighter weight, high stiffness, nickel-alloy spline ended TMC shaft.