Ceramic-Metal Joining for Turbine Applications

A compression bonding method has been developed to join ceramic components to superalloys in turbine engines, e.g., blades-to-disk, vane-to-shaft and hub-to-shaft. The method involves isothermal forging (GATORIZING^®) the metal around the ceramic using a compliant internal layer. The attachment of a Si₃N₄ blade/superalloy disk (hybrid rotor) was characterized based upon the chemical and mechanical compatibility of their interface. The life of the joint was predicted. Finally, the integrity of the hybrid rotor joint was evaluated by spin testing the rotors at 45,000 rpm at a blade temperature of 1505°K (2250°F) for 88 hours.