Anelastic behavior of precursor-derived amorphous ceramics in the system Si–B–C–N

Abstract

The objective of this paper is to report on the anelastic, i.e., reversible and time-dependent, deformation behavior of precursor-derived amorphous ceramics. Therefore compression experiments under constant and varying stresses up to 250 MPa were performed at a temperature of 1400 °C. In the stress change experiments anelasticity was observed. By comparison of both types of experiments, the anelastic strain rate was determined. It decreased inversely proportional to the time after the stress change and was independent of the preceding duration of the test. Furthermore, deviations from the deformation behavior expected according to the free-volume-model, which were observed in compression creep tests, could be explained by anelastic behavior.