Fabrication and Development of Axial Silicon Nitride Gas Turbine Rotors

Since 1984, GTE Laboratories Inc. has performed research to develop net shape fabrication technology for axial silicon nitride rotors for the Daimler-Benz research gas turbine engine. The initial effort was focused on the fabrication of injection-molded profile disks. Subsequently, efforts were shifted to develop injection molding and slip casting technology for the bladed gasifier rotors. This joint activity has demonstrated that the ceramics technology has improved significantly over the last five years, as is evidenced by a major improvement in properties and performance of silicon nitride components. The evolution of the ceramics fabrication technology at GTE and the role of improved process and NDE methods on components fabricated in recent years are described in this paper.