Mechanical and electrical properties of carbon nanotube/Cu nanocomposites by molecular-level mixing and controlled oxidation process.

A molecular-level mixing and controlled oxidation process is proposed as a novel fabrication technique for the production of CNT/Cu nanocomposite powders. The fabricated CNT/Cu2O nanocomposite powders showed microstructures with homogeneous dispersion of implanted CNTs in a Cu2O matrix. The CNT/Cu2O nanocomposite powders were reduced to CNT/Cu nanocomposite powders with H2 gas and then the as-prepared CNT/Cu nanocomposite powders were spark plasma sintered to fabricate CNT/Cu nanocomposites. The mechanical properties of the Cu and the CNT/Cu nanocomposites were characterized by tensile testing before and after hot compression. Before hot compression, the CNT/Cu nanocomposites were brittle, but after hot compression both yield strength and elongation were increased, while the yield strength of the Cu was decreased after hot compression. Hot compression enhanced the ductility and strength of the CNT/Cu nanocomposites due to alignment of Cu grains and CNTs. Electrical conductivity was also enhanced due to a reduced scattering of electrons because of the alignment of the CNTs and Cu grains as well as the annealing effects of the Cu matrix.