The effect of milling time on the sintering kinetics of Si3N4 based nanocomposites

Multi-walled carbon nanotube (MWCNT) reinforced silicon nitride composites have been prepared by hot isostatic pressing at 20 MPa and gas pressure sintering at 2 MPa. To assure a good dispersion of the MWCNTs a highly efficient attritor milling was employed in the preparation process of the powder mixtures. The morphological and micro-structural evolution of the powder particles during the high-energy milling was monitored. We have found that the milling time has a complex influence on the structure and mechanical properties of the resulting nanocomposites through affecting both the dispersion and degradation of the nanoscale filler as well as the phase transformations of the ceramic host.