Influence of Microstructure on Mechanical Response of Silicon Nitride Ceramic Composites in Nano-, Micro- and Macro-volume of Material

The peculiarities of contact-induced deformation in nano-, micro- and macroscopic scale of silicon nitride ceramic composites have been studied by using quasistatic macro- and microindentation techniques, dynamic nanoindentation technique and microstructure investigations. The addition of multiwall carbon nanotubes (MWCNTs) to the ceramic matrix showed the modification of microstructure leading to the modification of mechanical behavior of material: increase of fracture toughness along with the decrease of hardness. The general tendency of hardness increase with decrease of deformation volume was observed for silicon nitride ceramics, as well as, a high fracture resistance in micro- and nano-deformed volumes of material.