Synthesis, microstructure and mechanical properties of Yttria Stabilized Zirconia (3YTZP) - Multi-Walled Nanotube (MWNTs) nanocomposite by direct in-situ growth of MWNTs on Zirconia particles

摘要

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 ℃. The flex-ural strength increases from ~260 MPa for samples without CNTs sintered at 1600 ℃ to ~312 MPa for samples with ～4 wt.% CNTs sintered at the same temperature. A corresponding increase in the indentation fracture toughness is also observed for samples with ～4 wt.% CNTs sintered at 1600 ℃ as compared to samples sintered at the same temperature without CNTs.