Fabrication process and mechanical properties of CNT/Al nanocomposite

Abstract

Carbon nanotubes (CNTs) have attracted much attention during past decade because of their unique mechanical, chemical, and electrical properties. Thus CNTs open a new area with high driving force to develop multi-functional nanocomposites. However, the research efforts in this field have mostly dealt with CNT/polymer nanocomposites, which exhibit a tremendous strengthening effect for the composites. So far, few researchers have studied CNT/metal composites because of the difficulties in homogeneously distributing CNTs in a metal matrix by traditional methods. Since recently CNT/Co and CNT/Cu composite have been developed in our group by molecular-level mixing process, many researchers encouraged to the use of CNTs as reinforcement for metal matrices. Nevertheless, no breakthrough has been made on a CNT/Al composite so far. Limited research accomplished because of the obstacles associated with the interfacial bonds between CNTs and Al powders, and the lack of a suitable synthesis technique to get homogenous molecular-level mixing between CNTs and aluminum. In this study, CNT/Al nanocomposite was fabricated by using molecular level mixed CNT/Cu nanocomposite powders. Molecular level mixed CNT/Cu nanocomposite powders have morphology of CNTs are homogeneously dispersed and surface of CNTs are well coated with copper. Therefore, this could be beneficial to disperse in aluminum matrix and to prevent the formation of aluminum carbide due to minimize interface between aluminum and carbon nanotube. For homogeneous dispersion of CNT, powder metallurgy process and spray coating process were performed to fabricate CNT/Al nanocomposites. The CNT/Al nanocomposite was fabricated by using molecular level mixed CNT/Cu nanocomposite powders. CNT/Cu nanocomposite powders were fabricated by using functionalization of CNTs and molecular level mixing process. The former makes CNTs dispersed in a solvent and provides the attaching site between CNT and copper nanoparticles. Th...