Alumina-based composites reinforced with single-walled carbon nanotubes

Abstract

Monolithic Al[2]O[3] ceramics and Al[2]O[3] - 3 vol% single-walled carbon nanotubes (SWCNTs) composites were prepared by spark plasma sintering. The influence of SWCNTs and sintering temperature on sintering behavior and mechanical properties were investigated. Nanotubes were relatively homogeneously distributed in the composite powder, although some agglomerates/bundles existed. It was found that SWCNTs addition retards slightly the sinterability of alumina by nanotubes hindering of particle rearrangement. The average microhardness of the composites was lower than that of Al[2]O[3] ceramics, but there were also high microhardness values of composites (20.41 GPa). The reduction in microhardness is explained in this paper. The average values of the fracture toughness (4.94 MPa·m{1/2}) from the composite sintered at 1500 °C were approximately 6 % and 12 % higher than those from the Al[2]O[3] ceramics sintered at 1500 °C and 1600 °C, respectively. In addition, the analysis of the phase composition and the parameters of the crystal structure of the samples were made.