Strength characterization of Yttria/alumina-doped sintered silicon nitride

Abstract

The flexural strength of yttria/alumina-doped sintered silicon nitride (Ford Material—RM 20) was measured as a function of temperature (20 to 1400°C), applied stress and time. Flexural stress rupture testing at 800 and 1000°C indicated that the material can sustain 344 MPa and 276 MPa, respectively, without failure, for a limited time (≤ 100 h). The RM 20 material was susceptible to both oxidation and early stages of creep deformation at temperatures above 1000°C and displayed extensive creep deformation and degradation in strength above 1300°C.