This Phase I project seeks to develop a low-cost manufacturing technology for gamma titanium aluminide components for aircraft engines. The main goal of Phase I work is to demonstrate the feasibility of investment cast net-shape retaining plates for the PW 7000 first stage high pressure turbine blades. The retaining plate is a rotating component located between the turbine blade root attachment and the disk slot. Its function is to prevent gas leakage. The current bill-of-material is IN 100, a nickel-base superalloy. 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 turbine blade retaining plate can be manufactured by net-shape casting.Modify the selected titanium aluminide alloy to enhance mechanical properties.Develop a manufacturing cost model, based on Technical Cost Modeling methodology, to project the potential manufacturing costs of cast titanium aluminide aerospace components.It is anticipated that replacing IN 100 by cast gamma titanium aluminide will increase the cyclic life of the retaining plate, as a result of reduction in centrifugal loads on the component.Commercial Application: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.
