Methods for Improving Reliability in Ceramic Turbine Rotors

Evaluation of Carborundum (CBO) injection-molded sintered alpha-silicon carbide (Sic) AGT 100 gasifier turbine rotors by spin testing established a baseline for material strength characteristics. Spin test results of a subsequent group of rotors demonstrated a reduction in average failure speed. Post-test fracture analysis identified surface and near-surface flaws in the back face region to be the typical failure origins. Corrective actions were initiated to address the elimination of the strength-controlling flaws. Initial evaluation of rotors fabricated to these process modifications indicates improvements in overall surface quality and average burst speed.