Mechanical properties and electrical conductivity of TiN–Al2O3 nanocomposites

TiN–Al2O3 nanocomposites with various additions of TiN were prepared by hot pressing of nano TiN–Al2O3 powder that was produced by in-situ nitridation of nano TiO2–Al2O3 powder. TiO2–Al2O3 powder mixtures are prepared by a heterogeneous precipitation method. The effects of nano TiN particles on the mechanical properties and electrical conductivity of TiN–Al2O3 nanocomposites were studied. Experimental results show that the addition of 20 vol.% TiN could increase the bending strength of hot-pressed Al2O3 from 370 to 725 MPa and the fracture toughness from 3.40 to 5.27 MPa m1/2, respectively. The resistivity of nanocomposites decreases with increasing amount of TiN and reaches to a minimum value of 5.5×10−3 Ω cm for the nanocomposite with 25 vol.% TiN.