This Phase I project seeks to develop an efficient production technology for cast gamma titanium aluminide components for aircraft engines. The main goal of Phase I work is to demonstrate the feasibility of investment cast the Garrett TPE 731 fourth stage low pressure turbine (LPT) blade. The lower coefficient of thermal expansion, lower density (half that of nikel-base superalloy), and excellent oxidation resistance of titanium aluminides are attractive properties for this particular application. The following are the technical objectives for Phase I:- Experimentally demonstrate that the selected LPT blade can be manufactured by net-shape (investment) casting. - Experimentally determine the extent to which titanium aluminides can be recycled without adversely affecting mechanical properties. - Determine the optimum combination of ingot manufacturing processes and casting processes by experimental and parametric variations of an existing manufacturing cost model developed under a previous NASA Phase I contract.It is anticipated that replacing nickel-base superalloys by cast gamma titanium aluminides will increase the cyclic life of rotating components, as a result of reduction in centrifugal loads on the components.
Potential Commercial Applications:If gamma titanium aluminide aircraft engine components can be manufactured in a cost-effective way, it is anticipated that widespread replacement of steel and nickel-based superalloys will occur for compressor and low pressure turbine components, combustor swirlers, transition duct hangers, and nozzle tile liners.
