Title: Strengthening mechanisms in carbon nanotube-reinforced aluminum composites CARBON
Authors: Jong Gil Park, Dong Hoon Keum and Young Hee Lee
Abstract: Although carbon nanotubes (CNTs) are reinforced into aluminum alloys to enhance mechanical properties, the underlying strengthening mechanism has not been clarified yet. Here, we focus on elucidating the multiple strengthening mechanisms of load transfer and generation of dislocation by thermal mismatch and Orowan looping system to explain the enhanced mechanical properties in the CNT-reinforced Al. The sample preparation process involves mechanically pulverized Al in paraffin oil mixed with dispersed CNTs in dichloroethane, which was further sintered and melt-blended to get solid type sample. Formation of covalent bonds (Al4C3¬) between Al and CNT walls was confirmed by X-ray diffraction, Raman spectroscopy, and transmission electron microscope measurements. The yield strength and tensile strength were improved by 60 % and 23 %, respectively with an addition of 0.2 wt% CNTs. These enhancements are well corroborated with the predicted values from the multiple strengthening mechanisms; load transfer, thermal mismatch, and Orowan looping system.