Small‐Scale Deformation of Pulsed Electric Current Sintered Silicon Oxycarbide Polymer Derived Ceramics

The deformation behavior of pulsed electric current sintered silicon oxycarbide ceramics produced by the solid‐state thermolysis of polyhydridomethylsiloxane at small‐scale is investigated. The ceramics remained X‐ray amorphous after sintering at 1300 °C in vacuum and a high density of ≈2.35 g cm⁻³ is achieved. The elastic constants of these ceramics are determined using non‐destructive ultrasonic testing method. The elasto‐plastic deformation under contact loading is determined using depth sensing nanoindentation technique. An indentation hardness of ≈11 GPa and reduced elastic modulus of ≈105 GPa is observed. The load–displacement curves display significant elastic recovery with an elastic work ratio of ≈0.71. The evolution of Hertzian cone cracks upon microindentation indicates an anomalous deformation behavior.