Abstract

 The enhanced high‐temperature creep resistance in alumina/single‐wall carbon nanotubes (SWNTs) composites has been attributed to the unprecedented grain‐boundary structure of these composites, where the SWNTs bundles segregated at the alumina grain boundaries partially impede grain‐boundary sliding. In this study, the effect of SWNTs distributions at alumina grain boundaries on the creep behavior of alumina/SWNTs composites has been investigated. Microstructures of two different alumina/10 vol% SWNTs composites, one with heterogeneous and the other with homogenous distributions of SWNTs at grain boundaries, have been characterized quantitatively. The steady‐state creep rate (uniaxial compression) in the heterogeneous composite has been found to be over three times higher than that in the homogeneous composite at 1300° and 1350°C (argon atmosphere). It is argued that the less uniform distribution of SWNTs at the alumina grain boundaries in the heterogeneous composite results in less effective obstruction of grain‐boundary sliding, and attendant higher creep rate. This also results in more efficient recovery in that composite.