Spark-plasma-sintered BaTiO3/Al2O3 nanocomposites

Using spark plasma sintering (SPS), BaTiO3/Al2O3 nanocomposites were successfully consolidated to more than 99% of theoretical density at a sintering temperature as low as 1150 °C in only 3 min. The processing methods for these dense nanocomposites where the retained grain size of alumina matrix was in the nanometer level were developed. The maximum volume content of BaTiO3 in the nanocrystalline matrix for toughening was around 15 vol.%. A significant increase in fracture toughness up to 5.36 MPa1/2 has been achieved in the 7.5 vol.% BaTiO3/Al2O3 nanocomposite. The toughening mechanism might be related to ferroelastic domain switching of ferroelectric phase in these nanocomposites.