A new technique for dispersion of carbon nanotube in a metal melt

A major issue in achieving the best potential of carbon nanotube (CNT)-reinforced metal matrix composites is to disperse homogeneously CNTs within the matrix of magnesium-aluminum alloys. In order to address this issue, we have developed a new approach by adding multi-walled CNTs (MWCNTs) into a magnesium-aluminum alloy matrix. This could trigger significant de-bundling of the nanotubes within the molten alloy. Also, we have characterized mechanical properties of the CNT-blended matrix, such as microstructure, matrix/nanotube interface, and dispersion of the nanotubes, by employing optical microscopy, scanning electron microscopy, atomic force microscopy and X-ray diffractometer. This method remarkably facilitated a uniform dispersion of nanotubes within the magnesium alloy matrix as well as a refinement of grain size. No significant reaction was observed between the nanotubes and the metallic matrix. Finally, we observed a maximum tensile strength at 210.3 MPa and an elongation rate of 8.56%, which represents an increase of 30.8% and 124.1%, respectively, over the parental alloy. Together, our study establishes a new approach to disperse carbon nanotubes in a metal matrix, which could be applicable for CNT materials with higher potential. (C) 2010 Elsevier B.V. All rights reserved.