Microstructure and properties of carbon nanotube/zirconia composite

Sintering and hot pressing have been used for preparation of monolithic ZrO2 and zirconia-carbon nanotube (CNT) composite. The effect of the processing route and the CNT's addition on the microstructure, fracture/mechanical and electrical properties of the zirconia has been investigated at room temperature. The microstructure of the sintered and hot-pressed monolithic ZrO2 consists of a submicron-sized grains. The matrix of the ZrO2-CNT composite consists of a grains with even smaller size (approximately 140 nm) with relatively well dispersed carbon nanotubes. The hardness and the indentation toughness of the sintered monolithic zirconia are 1297 kg/mm(2) and 8.01 MPa m(0.5) and of the hot-pressed monolithic zirconia 1397 kg/mm(2) and 6.24 MPa m(0.5), respectively. The addition of the CNT's decreased the hardness and indentation toughness to 830 kg/mm(2) and 5.6 MPa m(0.5) however the electrical resistivity decreased significantly in comparison to the monolithic zirconia to the value of 0.1 Omega cm. (c) 2007 Elsevier Ltd. All rights reserved.