Additive Manufacturing of Complex gamma-TiAl Components for hypersonic Application

The objective of this proposal is to develop new additive manufacturing process and post treatment procedure for light-weight gamma;-TiAl. The new procedure will address the unique fine microstructure inherent with additively manufactured component. It will be customized to achieve desired microstructure specific to different application and property requirement. gamma;-TiAl has attractive properties for structural applications in hypersonic vehicles. Instead of using the procedures set up for traditional manufacturing methods, this new procedure will increase performance while decrease weight and improve fuel efficiency. To meet the challenges in fabricating AM gamma;-TiAl components, this project will develop new technology based on PIrsquo;s two decadesrsquo; experience on gamma;-TiAl and additive manufacturing. nbsp;ICME approach with thermodynamics model will also be used to guide process optimization. First, additive manufacturing processing parameters will be refined and optimized. Then the additively manufactured coupons will be HIPed and heat treated under guidance of ICME. Microstructure and mechanical properties of as built and post treated AM gamma;-TiAl coupons will be characterized. Developed new procedure will be used to fabricate complex components. Two application are identified in this proposal: inlet diverter flap in NASArsquo;s turbine based combined cycle (TBCC) propulsion systems and low pressure turbine blade in gas turbine engine. Microstructure and mechanical properties of fabricated components will be characterized to validate the success of new procedure. This project will pave a solid foundation for future standardization and certification of application of additively manufactured gamma;-TiAl in hypersonic vehicle and other applications. The methodology developed from this project will also provide guidance in processing development for other additive manufacturing application.