Preparation and properties of dual-matrix carbon nanotube-reinforced aluminum composites

Recent studies on Aluminum-Carbon Nanotube (Al/CNT) composites reported improved strength with the addition of small amounts of CNTs. Most studies reported low ductility which is limiting the potential of such materials. In the current study, a novel Al/CNT microstructural design was introduced to improve ductility while maintaining adequate strength. Al/CNT composites were prepared as: Single Matrix (SM) and Dual Matrix (DM) structures. The SM composites were synthesized by dispersing CNTs in aluminum powders. The DM composites were produced by embedding pre-processed SM Al/CNT powders into a secondary matrix of soft aluminum. Two overall CNT compositions, 1 wt.% and 2.5 wt.%, were synthesized. The DM approach was found to lead to enhancements of up to 14.8% in ductility compared to SM composites of the same CNT content. Nanoindentation hardness and modulus of DM composites were found to be comparable to their SM counterparts. (C) 2017 Elsevier Ltd. All rights reserved.