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. Small-scale deformation behavior of pulsed electric current sintered silicon oxycarbide ceramics 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. 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. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.