Materials Research Engineer, NASA LeRC, Cleveland, OH
Resident Research Associate, Cleveland State University, Cleveland, OH
Pages: 15 Published: Jan 1994
The creep behavior of a hot-pressed silicon nitride was determined in flexure in air at 1200 and 1300°C by monitoring the creep deflection, the specimen curvature and the position of the neutral axis. The resulting data was used to evaluate the steady-state creep rate from the conventional elastic solution, curvature-moment relations and a model accounting for neutral axis shift. Fractography and measurements of specimen compliance before and after testing indicated bulk cracking and a loss of stiffness. The validity of flexural data to determine creep life parameters was considered.
silicon nitride, creep, tension, compression, bending, flexure, neutral axis, cracking, stiffness
Paper ID: STP12776S