Composites Science and Technology vol:70 issue:14 pages:2086-2092
In this research, Yttria Stabilized Zirconia (3YTZP) - carbon nanotube (CNT) composites are fabricated by direct in-situ growth of CNTs on the Zirconia particles, followed by densification via the Spark Plasma Sintering (SPS) technique. Scanning electron microscopy analysis of the 3YTZP-CNT powders shows uniform distribution of CNTs without the formation of agglomerates frequently seen with the traditional ex-situ mixing of CNTs in ceramic compositions. The samples were sintered to nearly 100% theoretical density and with a finer grain size microstructure. High Resolution Transmission Electron Microscopy (HRTEM) and Raman Spectroscopy confirm CNT retention in the sintered nanocomposites up to 1600 degrees C. The flexural strength increases from similar to 260 MPa for samples without CNTs sintered at 1600 degrees C to 312 MPa for samples with similar to 4 wt.% CNTs sintered at the same temperature. A corresponding increase in the indentation fracture toughness is also observed for samples with similar to 4 wt.% CNTs sintered at 1600 degrees C as compared to samples sintered at the same temperature without CNTs. Published by Elsevier Ltd.