Microstructure and properties of carbon nanotube/zirconia composite

摘要

Sintering and hot pressing have been used for preparation of monolithic ZrO_2 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 ZrO_2 consists of a submicron-sized grains. The matrix of the ZrO_2-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 MPam~(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.