Regresar

Mechanical and electrical characterization of Cu-2wt.% SWCNT nanocomposites synthesized by in situ reduction

Abstract:

Copper-2wt.% single walled carbon nanotubes (SWCNT) nano composites have been synthesized by a chemical method of dissociation of copper nitrate containing CNTs, followed by reduction under a H 2 atmosphere. Bulk nano-composite pellets were obtained by a pre-compactation under a uniaxial pressure of 60MPa followed by isostatic pressure of 150MPa and sintering under Ar atmosphere. Both X-ray diffraction and transmission electron microscopy (TEM) were used as characterization tools. The former confirmed the presence of pure metallic copper with carbon; and the later allowed for the observation of a good dispersion, and also for a proper adherence between Cu particles onto CNT. Powder copper particles were observed to be in the 50-300nm range, while the bulk Cu-CNT grain size was observed to be in the 150nm-3μm range. The composite Cu-CNT presented less resistivity at low temperature (2×10 -6Ωcm at 83K) compared with copper. Hardness measured by nanoindentation exhibited higher values for the composite than for copper (1.7GPa vs. 1.2GPa). © 2012 Elsevier B.V.