Room temperature strain rate sensitivity in precursor derived HfO2/Si-C-N(O) ceramic nanocomposites

Investigation on the room temperature strain rate sensitivity using depth sensing nanoindentation is carried out on precursor derived HfO2/Si-C-N(O) ceramic nanocomposite sintered using pulsed electric current sintering. Using constant load method the strain rate sensitivity values are estimated. Lower strain rate sensitivity of ∼ 3.7 × 10−3 is observed and the limited strain rate sensitivity of these ceramic nanocomposites is explained in terms of cluster model. It is concluded that presence of amorphous Si-C-N(O) clusters are responsible for the limited flowability in these ceramics.