Microstructural Effects on the Creep Deformation of Alumina/Single-Wall Carbon Nanotubes Composites
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.
Document Type: Research Article
Affiliations: 1: Departamento de Física de la Materia Condensada, Universidad de Sevilla, 41080 Sevilla, Spain 2: Lawrence Berkeley National Laboratory, National Center for Electron Microscopy, Berkeley, California 94720 3: Max-Planck-Institut für Metallforschung, StEM, Heisenbergstraße 3, 70569 Stuttgart, Germany 4: Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210
Publication date: 2010-07-01