Résumé
Dense and homogeneous multi-walled carbon nanotube/metal composites are prepared by powder metallurgy [1,2]. The distribution of the nano-reinforcements in the matrix is studied by scanning electron microscopy and Raman spectroscopy, and the mechanical properties of the composites are determined by means of static tensile tests and Vickers micro-hardness measurements. We show that a homogeneous dispersion of the nanotubes at the micron scale is required in order to improve the mechanical properties of the metal matrix composite [1]. This can be achieved using ball-milling through the mechanisms of plastic deformation and cold-welding. Accordingly, we report significant improvements to the mechanical properties of composites prepared with a high-performance aluminium alloy AA5083 matrix. From the evolution of the composite Young’s modulus and yield strength as a function of carbon nanotube concentration, we get an estimate of the nanotubes Young’s modulus and aspect ratio [2]. We compare the results for single-walled and multi-walled carbon nanotubes, and discuss how to optimise the mechanical properties of carbon nanotube-reinforced aluminium alloy composites. 1. J. Stein et al, Carbon 50 (2012) 2264-22722. J. Stein et al, to be published