Abstract
We report the mechanical properties and microstructures of multi-walled carbon nanotube (MWCNT)/alumina composites made with MWCNTs that have nanoscale defects on their surfaces from an acid treatment We conducted the fracture surface observations of the composites, in order to evaluate the effects of the acid treatment conditions of MWCNTs on the mechanical properties of the composites and the microstructures such as dispersibility and pullout length of MWCNTs. It was found that the dispersibiity of MWCNTs affected the mechanical properties of the composites. The composites with 0.9 vol.% MWCNTs that were acid-treated for 2 hours showed a higher mechanical properties than those of the composites with identical MWCNTs content that were acid-treated for 0, 0.5, 1, 3 and 4 hours. According to the SEM observations, the pullout length of MWCNTs decreased with increasing of acid treatment time of MWCNTs, and the diameter changed at the tip of some MWCNTs.