Tribological and electrical properties of ceramic matrix composites with carbon nanotubes

Abstract

Tribological behaviur of carbon fibrous phases (nanofibers and nanotubes) containing composites with Si 3N 4, ZrO 2 and Al 2O 3 matrices was studied by pin-on-disk technique in conditions of dry sliding. Coefficients of friction and wear rates were measured, wear damage mechanisms were observed and identified. The resulting tribological behaviur was related to microstructure and mechanical properties of respective materials. Electrical conductivity was measured in wide range of frequencies by two-point method and effect of volume fraction and distribution of CNTs and CNFs on percolation threshold was evaluated. Both coefficient of friction and electrical resistivity decreased with increasing amount of carbon phases, in both cases the nanofibers were more efficient than the nanotubes. The wear resistance in most cases decreased but for Si 3N 4-CNT composite a certain optimum (∼5 wt.% CNT) was found. © 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.