Powder Metallurgy and Hardness of the Al-10Mg Alloy Reinforced with Carbon Nanotubes

Abstract

In this work, the multi-walled carbon nanotubes (MWCNTs) were purified with an acid treatment and subsequently dispersed using ultrasound and a nonionic surfactant solution of ethoxylated lauric alcohol 7 moles of ethylene oxide (E7E). Then, carbon nanotubes (CNTs) were used as a reinforcement phase (0.4 wt.% and 0.8 wt.%) in the Al-10Mg alloy. The high-energy ball milling was employed for the nanocomposites processing, and the resulting powders consolidate by uniaxial pressure. Measurements of Vickers microhardness, nanohardness, displacement, and Young's modulus were carried out on the compacts. The samples were analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FT-IR), and Raman spectroscopy (RS). Good dispersion of MWCNTs was achieved using 0.5 mg/ml of the E7E surfactant. The CNTs were dispersed in the Al-10Mg matrix using 0.25 h of milling. After powders compaction, the Al-10Mg/0.4MWCNTs nanocomposite presented a microhardness of 190 HV, nanohardness of 3.5 GPa, and Young's modulus 116 GPa.