Improvement of Vickers hardness measurement on SWNT/Al2O3 composites consolidated by spark plasma sintering

Dense alumina composites with different carbon nanotube content were prepared by colloidal processing and consolidated by Spark Plasma Sintering (SPS). Single-wall carbon nanotubes (SWNTs) were distributed at grain boundaries and also into agglomerates homogeneously dispersed. Carrying out Vickers h...

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Bibliographic Details
Authors: Morales-Rodríguez, A., Gallardo-López, Ángela, Fernández-Serrano, A., Poyato, Rosalía, Muñoz, A., Domínguez-Rodríguez, Alejandro
Format: article
Publication Date:2014
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/102095
Online Access:http://hdl.handle.net/10261/102095
Access Level:Open access
Keyword:Spark plasma sintering
Nanocomposites
Alumina
Carbon nanotubes
Vickers hardness
Description
Summary:Dense alumina composites with different carbon nanotube content were prepared by colloidal processing and consolidated by Spark Plasma Sintering (SPS). Single-wall carbon nanotubes (SWNTs) were distributed at grain boundaries and also into agglomerates homogeneously dispersed. Carrying out Vickers hardness tests on the cross-section surfaces instead of top (or bottom) surfaces has shown a noticeable increase in the reliability of the hardness measurements. This improvement has been mainly attributed to the different morphology of carbon nanotube agglomerates, which however does not seem to affect the Vickers hardness value. Composites with lower SWNT content maintain the Vickers hardness of monolithic alumina, whereas it significantly decreases for the rest of compositions. The decreasing trend with increasing SWNT content has been explained by the presence of higher SWNT quantities at grain boundaries. Based on the results obtained, a method for optimizing Vickers hardness tests performance on SWNT/Al2O3 composites sintered by SPS is proposed. © 2014 Elsevier Ltd.