High-temperature deformation of amorphous Si–C–N and Si–B–C–N ceramics derived from polymers

Abstract This work focuses on the high-temperature deformation of amorphous Si–(B)–C–N ceramics fabricated from polymers. Compression creep tests were performed at temperatures of 1350–1500 °C with stresses ranging from 5 to 300 MPa. A continuous decrease in the deformation rate with time is found. Overall, the total deformation rate can be decomposed into free shrinkage, anelastic deformation and viscous deformation. Although the viscosity depends on the annealing treatment, it is independent of the loading history. The linear rise in the viscosity and the decrease in the shrinkage rate are thought to be related to defect annihilation during annealing.