Rheological and mechanical properties of tape-casted zirconia-toughened alumina composite thick films reinforced with multiwalled carbon nanotubes

Abstract

This paper reports the effects of adding carbon nanotubes on the mechanical properties of zirconia-toughened alumina thick films prepared by tape casting. Polyvinylpyrrolidone, polyvinyl alcohol, and glycerin were used as dispersant, binder, and plasticizer, respectively. The microstructure and phase content of the samples were studied using scanning electron microscopy and X-ray diffraction methods, respectively. Mechanical properties of thick composite films were investigated by microhardness and nanoindentation methods. It was determined that polyvinylpyrrolidone can be used as a dispersant for carbon nanotube, alumina, and zirconia particles; tape casting can produce thick films with homogeneous phase distribution, and that adding up to 0.01 wt.% carbon nanotube enhanced the zirconia-toughened alumina hardness by more than 30%, and fracture toughness about 40%. Increasing carbon nanotube content over 0.01 wt.% up to 0.1 wt.% increases microhardness and nanohardness but does not affect fracture toughness significantly.