Single-walled carbon nanotube-reinforced composites based on ZrO2 obtained by vacuum pressureless sintering

The results of a study sintered composites based on yttria-stabilized zirconia (ZrO2) reinforced with single-walled carbon nanotubes (SWCNTs) are presented in this paper. Mixing ZrO2 nanopowder SWCNTs was carried out ethanol using an ultrasonic bath and magnetic stirrer. Composite powders 0.1, 0.5 1 wt.% were pressed into compacts at pressure 100 MPa, then they high temperature vacuum furnace for 2 h 1500°C heating rate 300°C / h. Changes the microstructure, phase composition, mechanical properties investigated depending SWCNT content samples. It found that selected sintering mode, density samples (99.2 – 97.5 %) obtained. by scanning electron microscopy undivided, entangled bundles aggregates individual nanotubes, which together formed continuous reinforcing structure, observed microstructure composites. Moreover, led to refinement composites; average grain size 16 % lower than ceramics. X-Ray diffraction only modifications (cubic tetragonal) present ceramics composites, slight decrease coherent scattering domain. Vickers indentation method composite optimal terms properties, since it had highest microhardness (13.6 GPa, 6 higher ceramics) 12 fracture toughness.