Abstract
This paper summarizes the results on recent component characterization efforts carried out to verify the mechanical reliability of NT154 silicon nitride microturbine rotors manufactured by Saint-Gobain. Mechanical properties of biaxial discs machined from airfoil as well as hub region of microturbine rotors were evaluated by a ball-on-ring test technique. Results showed that the mechanical properties of specimens from airfoils with as-processed
surfaces exhibited lower characteristic strength than those machined from the hub region with as-machined surfaces. The differences in mechanical performance and reliability between as-processed components and simple-shaped test coupons appear to arise mainly from differences in strength limiting flaw type and microstructure verified by detailed electron microscopy analysis.