Fabrication of well-dispersed, multiwalled carbon nanotubes-reinforced aluminum matrix composites

Mechanical alloying was used to disperse multiwall carbon nanotubes (MWCNTs) in an aluminum (Al) matrix. Mixtures consisting of 99% pure Al powder and a mass fraction of 2% MWCNTs were sonicated. Then, horizontal ball milling was used to generate mechanical bonding between the Al particles and the MWCNTs. The structure observed by a field-emission scanning electron microscope revealed an attachment of MWCNTs to the surface of the Al-flakes. FESEM results showed that particle size and morphology varied with milling time. Finally, the composite powders were processed into bulk material by compaction and sintering. The macro-hardness confirmed the improvement in the mechanical properties due to the addition of MWCNTs to the Al matrix.