Influence of dispersion/mixture time on mechanical properties of Al-CNTs nanocomposites

摘要

The influence of dispersion/mixture time on microstructural evolution and mechanical properties of aluminum matrix nanocomposites reinforced by carbon nanotubes (Al-CNTs) were investigated in this study. The nanocomposites were produced by conventional powder metallurgy routes. The microstructure was characterized by scanning electron microscopy (SEM), electron backscattered diffraction (EBSD) and high-resolution transmission electron microscopy (HRTEM). Microstructural analysis shows clusters of carbon nanotubes (CNTs) mainly at the grain junctions, but also CNTs well dispersed and embedded in the aluminum matrix. A strong strengthening effect of the CNTs on the aluminum matrix was measured for the nanocomposites produced with 15 min of dispersion/mixture time. For shorter times than 15 min, it is not possible to obtain a dispersion, which can lead to a reinforcement of the aluminum matrix, while longer dispersion/mixture times cause a decrease in mechanical strength due to the damage caused by the increase in the number of defects and junctions of CNTs. (C) 2015 Elsevier Ltd. All rights reserved.