Effect of Devitrification on Creep Deformation in Glass‐Containing Ceramics

Many commercial structural ceramics contain glass. This glass is often unstable and devitrifies during creep at elevated temperatures. Two models for this process have been developed, in order to understand how devitrification affects measured creep parameters. They indicate that when creep data are measured after a constant amount of creep strain, the effect of devitrification can be large. Moreover, if devitrification is stress‐state dependent, a different creep rate on the tensile and compressive sides of a bend bar is predicted. This can contribute to the redistribution of stress across a bend bar and complicate the analysis of creep data obtained in bending.