Norton Advanced Ceramics (NAC) has performed ceramic turbine blade fabrication development as part of several DOD and DOE-sponsored programs including: (1) The Experimental Turbine Engine Concept (ETEC); (2) The Advanced Turbine Technology Applications Project (ATTAP); (3) The Ceramic Turbine Engine Development Project (CTEDP); and (4) The Ceramic Stationary Gas Turbine (CSGT). NAC has developed two HIPed silicon nitide materials for fabricating turbine blades within these programs — One is designated NT154; and the second is designated NT164. Under the ETEC program with AlliedSignal Engines, NT154 blades were fabricated and delivered for proof and engine testing. Blade fabrication development efforts were augmented by NAC’s work under the ATTAP, which was directed at developing manufacturing technologies for rotors, stators, scrolls, vanes, and other components. Under the ATTAP, complex-shape forming was emphasized utilizing pressure slip-casting. NAC has employed pressure slip casting developed under the ATTAP to fabricate ceramic turbine blades and other gas-turbine components for various advanced heat-engine efforts. NT154 nozzles have been delivered to AlliedSignal Engines under internally sponsored and DOD-sponsored programs. NT154 diffusers, nozzles, and monorotors have been delivered to Sundstrand Power Systems. Under the CTEDP and CSGT programs, continued efforts on turbine blade fabrication development are anticipated for 1995 and beyond. Work under the CTEDP program with AlliedSignal Engines is focused on cost reduction through process simplification and scale-up. Under the CSGT program, NAC is participating with Solar Turbines Incorporated to deliver prototype quantities of NT164 silicon nitride blades using a controlled fabrication process. NAC is utilizing its prior experience in fabricating similar blade geometries under the ETEC, ATTAP, and CTEDP programs in the CSGT effort.
Open-Porous Silicon Nitride-Based Ceramics in Tubular Geometry Obtained by Slip-Casting and Gelcasting
