Structure of Mechanically Milled CNT-Reinforced Al-Alloy Nanocomposites

Mechanical milling of aluminum-based two Al-Si-Mg alloys were reinforced with multiwalled carbon nanotubes (CNTs) using a planetary ball mill, forming a nanocomposite structure. The milling took place for different timings of 1, 3, and 5 h to follow the dispersion and distribution of CNTs. The effects of concentration of CNTs (ranging from 0.5 to 2 wt%) and milling periods on the final microstructure of the composites were investigated. The mechanically milled powders were investigated by X-ray diffractometer (XRD), scanning electron microscope (SEM), and particle size analyzer. The crystallite size and the accumulating internal strains increased with milling time, and the smallest grain sizes achieved were about 100 nm. The results showed that milling was able to adequately disperse CNTs in the aluminum alloy matrices at different mechanical milling times and range of CNT concentrations.