Ductility and fracture toughness issues related to implementation of NiAl for gas turbine applications

Progress made in improving properties of NiAl alloys to compete with single crystal Ni-base superalloys is described. NiAl turbine airfoils with complex design features were fabricated by a combination of casting and machining processes. Such airfoils were successfully component and engine tested. Key issues related to poor ductility and fracture toughness limiting the application of intermetallics are discussed. Progress made in resolving some of the issues is discussed. Some of the production implementation issues are also discussed.