2013 Volume 7 Issue 3 Pages 394-402
Multi-walled carbon nanotube (MWCNT)/alumina composites with different amounts of MWCNTs were prepared by a simple mechanical mixing method followed by a pressureless sintering. The effects of microstructures including grain size, MWCNT location, fracture patterns of the matrix and dispersibility of MWCNTs on the mechanical properties of the resultant composites were investigated. It was demonstrated from microstructural observations and fracture tests of the composites that grain size, MWCNT location and fracture patterns had no significant impact on the mechanical properties of the composites prepared under the processing conditions used in this research. In contrast, the state of MWCNT dispersion within the composites was shown to be one of the important factors affecting the strength and toughness enhancement in our composites. The dispersibility of MWCNTs decreased monotonically as a function of MWCNT volume fraction. The degradation in the mechanical properties observed for the composites with a higher amount of MWCNTs was shown to be associated with the dispersibility of MWCNTs, and a MWCNT agglomerate was anticipated to act as imperfections and led to a reduction of mechanical properties.
